WO2006130588A1 - Bicyclic 6-alkylidene-penems as class-d beta-lactamases inhibitors - Google Patents

Bicyclic 6-alkylidene-penems as class-d beta-lactamases inhibitors Download PDF

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Publication number
WO2006130588A1
WO2006130588A1 PCT/US2006/020891 US2006020891W WO2006130588A1 WO 2006130588 A1 WO2006130588 A1 WO 2006130588A1 US 2006020891 W US2006020891 W US 2006020891W WO 2006130588 A1 WO2006130588 A1 WO 2006130588A1
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optionally substituted
alkyl
added
solution
heteroaryl
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PCT/US2006/020891
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French (fr)
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Tarek Suhayl Mansour
Aranapakam Mudumbai Venkatesan
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Wyeth
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Priority to CA002609428A priority Critical patent/CA2609428A1/en
Priority to BRPI0610957-8A priority patent/BRPI0610957A2/en
Priority to JP2008514772A priority patent/JP2008545747A/en
Priority to MX2007015172A priority patent/MX2007015172A/en
Priority to EP06771575A priority patent/EP1885357A1/en
Priority to AU2006252604A priority patent/AU2006252604A1/en
Publication of WO2006130588A1 publication Critical patent/WO2006130588A1/en
Priority to IL187694A priority patent/IL187694A0/en
Priority to NO20076076A priority patent/NO20076076L/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
    • A61K31/425—Thiazoles
    • A61K31/429—Thiazoles condensed with heterocyclic ring systems
    • A61K31/43—Compounds containing 4-thia-1-azabicyclo [3.2.0] heptane ring systems, i.e. compounds containing a ring system of the formula, e.g. penicillins, penems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
    • A61K31/42—Oxazoles
    • A61K31/424—Oxazoles condensed with heterocyclic ring systems, e.g. clavulanic acid
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/41—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having five-membered rings with two or more ring hetero atoms, at least one of which being nitrogen, e.g. tetrazole
    • A61K31/425—Thiazoles
    • A61K31/429—Thiazoles condensed with heterocyclic ring systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A61P31/04—Antibacterial agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/30—Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change

Definitions

  • This invention relates to certain bicyclic 6-alkylidene penems which act as a inhibitor of class-D enzymes.
  • ⁇ -Lactamases hydrolyze ⁇ -lactam antibiotics, and as such serve as the primary cause of bacterial resistance.
  • the compounds of the present invention when combined with ⁇ -lactam antibiotics will provide an effective treatment against life threatening bacterial infections.
  • Class D ⁇ -lactamases are the smallest (27 kDa) amongst the active-site- serine ⁇ -lactamases. These enzymes lack overall amino acid sequence ( ⁇ 20% amino acid identity) with the more prevalent and better-understood ⁇ -lactamases of classes A and C ( Naas, T. and Nordmann, P. Curr. Pharm. Design, 1999, 5,865). To date, almost 30 class D enzymes are known. Class D ⁇ -lactamases are also called oxacillinases because of their ability to hydrolyze oxacillin and cloxacillin two to four times faster than classical penicillins such as penicillin G (Ledent, P., Raquet,X, Joris, B.
  • OXA-1 from Escherichia coli is found to be monomeric in solution and in the crystal, (Sun, T 1 Nukuga, M, Mayama, K, Braswell, E.H., Knox. J.R. Protein Sci., 2003, 12,82.).
  • Sun, T 1 Nukuga, M, Mayama, K, Braswell, E.H., Knox. J.R. Protein Sci., 2003, 12,82. As a result of point mutations and plasmid transfer, natural OXA variants (e.g.
  • OXA-15, OXA-18, OXA-19 have arisen with an expanded substrate spectrum that includes imipenem and third-generation cephalosporins such as cefotaxime, ceftriaxone, and aztreonam while new variants such as OXA-11 and OXA-14 to OXA-20, show an extended-spectrum profile (ESBLs). These aspects make them important clinically (Buynak, J, Curr. Med. Chem., 2004, 11, 1951).
  • Penicillins, cephalosporins, and carbapenems are the most frequently and widely used ⁇ -lactam antibiotics in the clinic.
  • the development of resistance to ⁇ -lactam antibiotics by different pathogens has had a damaging effect on maintaining the effective treatment of bacterial infections.
  • Coleman, K. Expert Opin. Invest. Drugs 1995, 4, 693; Sutherland, R. Infection 1995, 23 191 ; Bush, K, Cur. Pharm. Design 1999, 5, 839 The most significant known mechanism related to the development of bacterial resistance to the ⁇ -lactam antibiotics is the production of class-A, class-B, class-C and class-D ⁇ -lactamases.
  • Class-A enzymes preferentially hydrolyze penicillins
  • class-B hydrolyze all B-lactams including carbapenems
  • class-C lactamases have a substrate profile favoring cephalosporin hydrolysis
  • substrate preference for class D ⁇ -lactamases include oxacillin.
  • ⁇ -lactamase inhibitors such as clavulanic acid, sulbactam and tazobactam are all effective against class-A producing pathogens.
  • Clavulanic acid is clinically used in combination with amoxicillin and ticarcillin; similarly sulbactam with ampicillin and tazobactam with piperacillin.
  • these compounds are ineffective against class C producing organisms.
  • the mechanism of inactivation of class-A ⁇ -lactamases (such as PCI and TEM-1) has been elucidated. (Bush, K.; Antimicrob. Agents Chemother.
  • 6-methylidene penems bearing a bicyclic heterocycle as class-A, class-B and class-C ⁇ -lactamse inhibitors have been disclosed in US 2004-0077622 A1 , which is hereby incorporated by reference thereto.
  • 6-methylidene penems bearing a tricyclic heterocycle as class-A, class-B, and class-C ⁇ -lactamase inhibitors have been disclosed in US 2004-00043978A1.
  • the present invention relates to novel, low molecular weight broad spectrum ⁇ -lactam compounds, and in particular to a class of bicyclic heteroaryl substituted 6- alkylidene penems which have ⁇ -lactamase inhibitory activity that when used in combination with a ⁇ -lactam antibiotic enhance the activity against class-D producing organisms and thereby enhance the antibacterial properties.
  • the compounds are therefore useful in the treatment of antibacterial infections in humans or animals, either alone or in combination with other antibiotics.
  • the compounds may be prepared in accordance with US 2004-0077622A1 which is hereby incorporated by reference thereto.
  • a and B denotes hydrogen and the other an optionally substituted fused bicyclic heteroaryl group.
  • the expression 'fused bicyclic heteroaryl group' is used in the specification and claims to mean:
  • the fused bicyclic heteroaryl group contains one to six heteroatoms selected from the group O, S, N and N-R 1 ;
  • the fused bicyclic heteroaryl group is bonded to the remainder of the molecule through a carbon atom in the aromatic ring as shown in the formula I;
  • the aromatic ring of the fused bicyclic heteroaryl group contains five or six ring atoms (including bridgehead atoms) selected from CR 2 , N, O, S or N-R 1 .
  • the aromatic ring of the fused bicyclic heteroaryl group contains 0 to 3 heteroatoms selected from the group O, S, N and N-R 1 ;
  • X is O or S, preferably S;
  • R 5 is H 1 an in vivo hydrolyzable ester such as C1 -C6 alkyl, C5 - C6 cycloalkyl, CHR 3 OCOCI -C6 or salts such as Na, K, Ca; preferably R 5 is H or a salt;
  • R 1 is H, optionally substituted -C1-C6 alkyl, optionally substituted -aryl, optionally substituted -heteroaryl or mono or bicyclic saturated heterocycles, optionally substituted -C3-C7 cycloalkyl, optionally substituted -C3-C6 alkenyl, optionally substituted -C3-C6 alkynyl with the proviso that both the double bond and the triple bond should not be present at the carbon atom which is directly linked to N; optionally substituted -C1-C6 per fluoro alkyl, -S(O) P optionally substituted alkyl or aryl where p is 2, optionally substituted -
  • R 2 is hydrogen, optionally substituted C1-C6 alkyl, optionally substituted C2-
  • R 2 groups are H, optionally substituted alkyl, optionally substituted alkoxy, optionally substituted heteroaryl, halogen, CN, hydroxy, optionally substituted heterocycle, -CONR 6 R 7 , COOR 6 , optionally substituted aryl, S(O) q -alkyl, and S(O) q -aryl.
  • R 3 is hydrogen, C1-C6 alkyl, C5 - C6 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl; preferred R 3 groups are H or C1-C6 alkyl;
  • R 6 and R 7 groups are H, C1-C6 alkyl, arylalkyl, heteroarylalkyl or R 6 and R 7 together forming a 3-7 membered saturated ring system optionally having one or two heteroatoms.
  • alkyl means both straight and branched chain alkyl moieties of 1-12 carbons, preferably of 1-6 carbon atoms.
  • alkenyl means both straight and branched alkenyl moieties of 2-8 carbon atoms containing at least one double bond, and no triple bond, preferably the alkenyl moiety has 1 or two double bonds.
  • alkenyl moieties may exist in the E or Z conformations; the compounds of this invention include both conformations.
  • heteroatoms such as O, S or N-R 1 should not be present on the carbon that is bonded to a double bond;
  • alkynyl includes both straight chain and branched alkynyl moieties containing 2-6 carbon atoms containing at least one triple bond, preferably the alkynyl moiety has one or two triple bonds.
  • hetero atoms such as O, S or N-R 1 should not be present on the carbon that is bonded to a double or triple bond;
  • cycloalkyl refers to a alicyclic hydrocarbon group having 3-7 carbon atoms.
  • perfluoroalkyl is used herein to refer to both straight- and branched- chain saturated aliphatic hydrocarbon groups having at least one carbon atom and two or more fluorine atoms. Examples include CF 3 , CH 2 CF 3 , CF 2 CF 3 and CH(CF 3 ) 2 .
  • halogen is defined as Cl, Br, F, and I.
  • alkyl, alkenyl, alkynyl, or cycloalkyl is "optionally substituted", one or two of the following are possible substituents: nitro, -aryl, -heteroaryl, alkoxycarbonyl-, -alkoxy, -alkoxy-alkyl, alkyl-O-C2-C4alkyl-O-, -cyano, -halogen, -hydroxy, -N-R 6 R 7 , - COOH, -COO-alkyl, -trifluoromethyl, -trifluoromethoxy, arylalkyl, alkylaryl, R 6 R 7 N-alkyl-, HO-C1-C6-alkyl-, alkoxyalkyl-, alkyl-S-, -SO 2 N-R 6 R 7 , r SO 2 NHR 6, - CO 2 H, CONR 6 R 7 , aryl-O-, heteroaryl-O-, -S
  • Aryl is defined as an aromatic hydrocarbon moiety selected from the group: phenyl, ⁇ -naphthyl, ⁇ -naphthyl, biphenyl, anthryl, tetrahydronaphthyl, fluorenyl, indanyl, biphenylenyl, acenaphthenyl, groups.
  • the preferred aryl groups are phenyl and biphenyl.
  • Heteroaryl is defined as a aromatic heterocyclic ring system (monocyclic or bicyclic) where the heteroaryl moieties are selected from: (1) furan, thiophene, indole, azaindole, oxazole, thiazole, isoxazole, isothiazole, imidazole, N-methylimidazole, pyridine, pyrimidine, pyrazine, pyrrole, N-methylpyrrole, pyrazole, N- methylpyrazole, 1 ,3,4-oxadiazole, 1 ,2,4-triazole, 1-methyl-1 ,2,4-triazole, 1 H-tetrazole, 1-methyltetrazole, benzoxazole, benzothiazole, benzofuran, benzisoxazole, benzimidazole, N-methylbenzimidazole, azabenzimidazole, indazole, quinazoline, quinoline, and iso
  • Preferred heteroaryl groups are furan, oxazole, thiazole, isoxazole, isothiazole, imidazole, N-methylimidazole, pyridine, pyrimidine, pyrazine, pyrrole, N- methylpyrrole, pyrazole, N-methylpyrazole, 1 ,3,4-oxadiazole, 1 ,2,4-triazole, 1- methyl-1 ,2,4-triazole, 1 H-tetrazole, 1-methyltetrazole, quinoline, isoquinoline, and naphthyridine.
  • Arylalkyl is defined as Aryl-C1-C6alkyl— ;
  • Arylalkyl moieties include benzyl, 1- phenylethyl, 2-phenylethyl, 3-phenylpropyl, 2-phenylpropyl and the like.
  • the term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or aryl moiety as defined above.
  • Alkylaryl is defined as C1-C6alkyl-aryk
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the aryl or alkyl moiety as defined above.
  • Heteroaryl-C1-C6- alkyl is defined as a heteroaryl substituted alkyl moiety wherein the alkyl chain is 1-6 carbon atoms (straight or branched).
  • Alkyl heteroaryl moieties include Heteroaryl-(CH 2 ) 1-6 -- and the like.
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or heteroaryl moiety as defined above;
  • C1-C6 alkylheteroaryl is defined an alkyl chairrof 1-6 carbon atoms (straight or branched) attached to a heteroaryl moiety, which is bonded to the rest of the molecule.
  • CI-Ce-alkyl-Heteroaryl- The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or heteroaryl moiety as defined above;
  • Saturated or partially saturated heterocycles groups are defined as heterocyclic rings selected from the moieties; aziridinyl, azetidinyl, 1 ,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, dihydrobenzimidazolyl, dihydrobenzofuranyl, dihydrobenzothienyl, dihydrobenzoxazolyl, dihydrofuranyl, dihydroimidazolyl, dihydroindolyl, dihydroisooxazolyl, dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl, dihydropyrrazinyl, dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, dihydroquinolinyl, di
  • Preferred saturated or partially saturated heterocycles are aziridinyl, azetidinyl, 1 ,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, dihydroimidazolyl, and dihydroisooxazolyl.
  • C1-C6 alkyl mono or bicyclic saturated or partially saturated heterocycles is defined as an alkyl group (straight or branched) of C1-C6 attached to a heterocycles (which is defined before) through a carbon atom or a nitrogen atom and the other end of the alkyl chain attached to the rest of the molecule.
  • the terms 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyi or heterocyclic portion of the molecule, as defined before;
  • Arylalkyloxyalkyl is defined as Aryl-C1-C6alkyl-O-C1-C6alkyl—
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl and/or aryl portions as defined before;
  • Alkyloxyalkyl is defined as C1-C6 alkyl-O-C1-C6alkyl— .
  • the term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before;
  • Aryloxyalkyl is defined as Aryl-O-C1-C6 alkyl—.
  • the term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl or aryl moiety as defined before;
  • Heteroarylalkyloxyalkyl is defined as Heteroaryl-C1-C6alkyl-O-C1-C6alkyl—
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl or heteroaryl moiety as defined before;
  • Aryloxyaryl is defined as Aryl-O-Aryl— .
  • the term Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present on the aryl moiety as defined before;
  • Aryloxyheteroaryl is defined as Aryl-0-Heteroaryl- or -Aryl-O-Heteroaryl; In this definition either the aryl moiety or the heteroaryl moiety can be attached to the remaining portion of the molecule;
  • Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present on the aryl moiety or on the heteroaryl moiety as defined before;
  • Alkyl aryloxyaryl is defined as Aryl-O-Aryl-C1-C6alkyl — ;
  • Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present at the aryl moiety as defined before;
  • Alkylaryloxyheteroaryl is defined as Heteroaryl-O-Aryl-C1-C6alkyl ⁇ ;
  • Optionally substituted refers to unsubstituted or substituted with 1 or 2 substituents present on the aryl moiety or on the hetroaryl moiety as defined before;
  • Alkylaryloxyalkylamine is defined as R 6 R 7 N-CI -C ⁇ alkyl-O-Aryl-CIC ⁇ alkyl— ;
  • the terms 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl or aryl moiety as defined before; R 6 and R 7 as defined before;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl portion of the alkoxy moiety as defined before;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the aryl moiety as defined before;
  • the term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
  • Alkoxy is defined as C1-C6a!kyl-O ⁇ ;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before;
  • Aryloxy is defined as Aryl-O--;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the aryl moiety as defined before;
  • Heteroaryloxy is defined as Heteroaryl-0--;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
  • Alkenyloxy is defined as C3-C6 alkene-O--; Example allyl-O--, bute-2-ene-0 like moieties;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkene moiety as defined before, with the proviso that no hetero atom such as O, S or N-R 1 is present on the carbon atom, which is attached to a double bond;
  • Alkynyloxy is defined as C3-C6alkyne-O ⁇ ;
  • optionally substituted refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyne moiety as defined before, with the proviso that no hetero atom such as O, S or N-R 1 is present on a carbon atom which is attached to a double or triple bond;
  • Alkylaminoalkoxy is defined as R 6 R 7 N-CI -C6-alkyl-O-C1-C6-alkyl— , where the terminal alkyl group attached to the oxygen is connected to the rest of the molecule;
  • R 6 and R 7 are defined above;
  • the term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before;
  • Alkylenedioxy is defined as -0-CH 2 -O- or -O— (CH 2 ) 2 — O— ;
  • Aryloxyalkylamine is defined as R 6 R 7 N-CI -C ⁇ -alkyl-O-Aryl-, where the aryl is attached to the rest of the molecule;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl or aryl moiety as defined before;
  • Arylalkenyl is defined as Aryl-C2-C8alkene-, with the proviso that no hetero atom such as O, S or N-R 1 is present on the carbon atom, which is attached to a double bond;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkene or aryl moiety as defined before;
  • Heteroaryloxyalkyl is defined as Heteroaryl-O-C1-C6alkyl— ;
  • the term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
  • Heteroaryloxyaryl is defined as Heteroaryl-0-aryl— , where the aryl moiety is attached to the rest of the molecule;
  • Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety or the aryl moiety as defined before;
  • Alkoxy, alkoxyalkyl, alkoxyalkyloxy and alkylthioalkyloxy are moieties wherein the alkyl chain is 1-6 carbon atoms (straight or branched).
  • Aryloxy, heteroaryloxy, arylthio and heteroarylthio are moieties wherein the aryl and heteroaryl groups are as herein before defined.
  • Arylalkyloxy, heteroarylalkyloxy, arylalkylthio and heteroarylalkylthio are moieties wherein the aryl and heteroaryl groups are as herein before defined and wherein the alkyl chain is 1-6 carbons (straight or branched).
  • Aryloxyalkyl, heteroaryloxyalkyl, aryloxyalkyloxy and heteroaryloxyalkyloxy are substituents wherein the alkyl radical is 1-6 carbon atoms.
  • the terms monoalkylamino and dialkylamino refer to moieties with one or two alkyl groups wherein the alkyl chain is 1-6 carbons and the groups may be the same or different.
  • the terms monoalkylaminoalkyl and dialkylaminoalkyl refer to monoalkylamino and dialkylamino moieties with one or two alkyl groups (the same or different) bonded to the nitrogen atom which is attached to an alkyl group of 1-3 carbon atoms. Examples of fused bicyclic heteroaryl groups are optionally substituted ring systems such as one of the following:
  • arylalkyl such as benzyl
  • alkoxyarylalkyl such as 4-methoxy benzyl
  • C1-C6alkyl such as methyl
  • heteroarylalkyl such as pyridin-3-ylmethyl
  • arylalkylCO- such as phenylacetyl
  • heteroarylCO- such as pyridin-3-ylcarbonyl
  • alkylCO- such as acetyl
  • 4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazine optionally substituted, .e.g. by alkoxyalkylCO- such as 2-methoxyacetyl; or by alkyloxyalkylCO- such as methoxyacetyl.
  • Z1 , Z2 and Z3 are independently CR 2 , N, O, S or N-R 1 and one of Z1 -Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • one of Z's is CR 2 the other two Zs can be either two N or one N and O, S, N-R 1 in any combinations with out disrupting the aromaticity;
  • two Z,s CR 2 the other Z can be optionally selected from one N, O, S or N-R 1 in any combination with out disrupting the aromaticity;
  • Z1 , Z2 and Z3 are independently CR 2 , N, O, S or N-R 1 and one of Z1 -Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • the other two Z's can be independently CR 2 , N, O, S or N-R 1 in any combinations with out disrupting the aromaticity;
  • Y 1 and Y 2 N or C; with the proviso that when the aromatic heterocycle is imidazole, the saturated ring may not contain a S adjacent to the bridgehead carbon.
  • Z1 , Z2, Z3 and Z4 are independently CR 2 or N and one of Z1
  • -Z4 is carbon and is bonded to the remainder of the molecule.
  • Y 1 and Y 2 are independently C or N.
  • Z1 is N, S, N-R 1 or O and one of Z2 or Z3 is CR 2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • Z3 is N, S, N-R 1 or O and one of Z2 or Z1 is CR 2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule as shown in formula I. 4.
  • Z2 is N, S, N-R 1 or O and one of Z1 or Z3 is CR 2 and the other of
  • Z1 or Z3 is carbon bonded to the remainder of the molecule as shown in formula
  • ⁇ Z1 is N, N-R 1 , O or S and Z3 is N, O or S and Z2 is a carbon bonded to the penem portion of the molecule as shown in formula I.
  • Z1 is N, S, N-R 1 or O and Z2 or Z3 is CR 2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule; W 1 , W 2 and W 3 are independently CR 4 R 4 .
  • Z3 is N, S, N-R 1 or O and one of Z2 or Z1 is CR 2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule; W 1 , W 2 , and W 3 are independently CR 4 R 4 .
  • Z2 is N, S, N-R 1 or O and one of Z1 or Z3 is CR 2 and the other of Z1 or Z3 is carbon and is bonded to the remainder of the molecule; W 1 , W 2 , and
  • W 3 are independently CR 4 R 4 .
  • Z1 is N, N-R 1 , O or S and Z2 is N, O or S; Z3 is a carbon bonded to the penem portion of the molecule; W 1 , W 2 , W 3 are independently CR 4 R 4 .
  • ⁇ Z3 is N, N-R 1 , O or S;
  • Z2 is N, O or S;
  • Z1 is a carbon bonded to the penem portion of the molecule;
  • W 1 , W 2 , W 3 are independently CR 4 R 4 .
  • Z1 is N, N-R 1 , O or S ;
  • Z3 is N 1 O or S;
  • Z2 is a carbon bonded to the penem portion of the molecule;
  • W 1 , W 2 , W 3 are independently CR4R4.
  • Z3 is N, N-R 1 , O or S;
  • Z1 is N, O or S;
  • Z2 is a carbon bonded to the penem portion of the molecule;
  • W 1 , W 2 , W 3 are independently CR4R4.
  • Z1 and Z3 are N; Y1 is N ; Y2 is C and Z2 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • Z2 and Z3 are N; Y1 is N; Y2 is C and Z1 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • Z1 is N
  • Y1 is N
  • Y2 is C
  • one of Z 2 or Z 3 is CR 2
  • the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I.
  • Z1 is N
  • Y1 is C
  • Y2 is N
  • one of Z 2 or Z 3 is CR 2 and the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I
  • W 1 and W 3 are independently CR4R4
  • t 1-3
  • another W 2 is CR4R4.
  • Z3 is N
  • Y1 is N
  • Y2 is C
  • Z1 and Z2 are N; Y1 is N; Y2 is C; and Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
  • Z3 is N; Y1 is N; Y2 is C; Z1 is CR 2 and Z2 is the carbon atom bonded to the remainder of the molecule.
  • Z1 and Z2 are N; Y1 is N; Y2 is C; Z3 is carbon and is bonded to the remainder of the molecule; W 1 and W 3 are independently CR4R4; W 2 is N-
  • Z1 and Z2 are independently CR 2 ; Y1 is C; Y2 is N; Z3 is carbon and is bonded to the remainder of the molecule; W 1 and W 3 are independently
  • Z3 and Z2 are independently CR 2 ; Y1 is C; Y2 is N; Z1 is carbon and is bonded to the remainder of the molecule; W 1 and W 3 are independently
  • W 1 , W 2 and W 3 are independently CR4R4, S, SO, SO 2 , O, or N-R 1 .
  • W 1 , W 2 and W 3 are independently CR4R4, S, SO, SO2, O, or N-R 1 .
  • formula IX In formula IX.
  • the compounds according to the present invention have ⁇ -lactamase inhibitory and antibacterial properties and are useful for the treatment of infections in humans and animals. It should be noted that the compounds of the present invention, when used in combination with ⁇ -lactam antibiotics will result in the increased antibacterial activity (synergistic effect) against class-D producing organisms.
  • ⁇ -Lactam antibiotics include penicillin antibiotics such as piperacillin, amoxycillin, ticarcillin, benzylpenicillins, ampicillin, sulbenicillin, other known penicillins, cephalosporins such as cefatrizine, cephaloridine, cephalothin, cefazolin, cephalexin, cephradine, other known cephalosporins, aztreonam and latamoxef (Moxalactam), and carbapenems such as meropenem and imipenem. Most preferably compounds of this present invention are used with piperacillin or amoxicillin which has a broad spectrum of activity against Gram positive and Gram negative pathogens.
  • the compounds of the present invention may be provided prior to, simultaneously with, or subsequent to a ⁇ -lactam antibiotic ("co-administration").
  • co-administration it is intended to include administering the compound directly or in vivo, e.g. pro-drugs.
  • the ratio of the amount of the compound to the amount of the ⁇ -lactam antibiotic may vary in a wide range.
  • the ratio of ⁇ -lactam antibiotic to ⁇ - lactamase inhibitor may vary from 1:1 to 100:1.
  • the ratio of the ⁇ -lactam antibiotic to ⁇ -lactamase inhibitor is less than 10:1.
  • composition of the present invention may be in a form suitable for oral (PO), intravenous (IV) or topical administration.
  • the compositions of the invention may be in a form of tablets, capsules, creams, syrups, suspension, sterile solutions suitable for injection or infusion.
  • the compounds of the present invention are co-administered with piperacillin intravenously or amoxicillin intravenously or orally.
  • a compound's structural formula includes any tautomers, any stereoisomers (except where stereochemistry is clearly noted) and any crystalline forms.
  • This invention also provides a process for preparing a compound of formula I which comprises subjecting to reductive elimination a compound of fomula II:
  • A' is A or B as defined above, X is O or S, P is an ester leaving group, e.g., acetate, mesylate, triflate or tosylate, and R is a protecting group, followed if necessary by removal of the protecting group, to give a compound of formula I wherein R 5 is hydrogen; and if desired converting to a pharmaceutically acceptable salt or to an ester wherein R 5 is C1 -C6 alkyl, C5 - C6 cycloalkyl, or CHR 3 OCOCI -C ⁇ alkyl.
  • compounds of the general formula I can be prepared by a novel, mild and a facile way, by condensing an appropriately substituted aldehyde 4 with a 6-bromo-penem derivative of structure 1.. (Scheme 1) in the presence of anhydrous MgBr 2 or MgBr 2 : etherate and a base such as triethylamine or DBU or DMAP, preferably at -2O 0 C to -40 0 C.
  • the intermediate aldol product 5 can be functionalized with acid chlorides or anhydrides to an acetate, triflate or a tosylate 6.
  • Compound 6 can be smoothly converted to the desired product by a reductive elimination process using a metal such as activated zinc and phosphate buffer at 20 0 C to 35 0 C at a pH of 6.5 to 8.0.
  • a metal such as activated zinc and phosphate buffer at 20 0 C to 35 0 C at a pH of 6.5 to 8.0.
  • the protecting group on the carboxylate oxygen is a para-nitrobenzyl substitiuent then the reductive elimination and deprotection can be achieved by a single step.
  • the protecting group is other than a para-nitrobenzyl substituent, a two step procedure can be followed depending up on the nature of the protecting group.
  • the product can be isolated as a free acid or as an alkali metal salt. The above mentioned two step procedure can be carried out in one step by carrying out the entire process without isolating the intermediate 6.
  • compound 6 can be hydrogenated at 40 psi pressure in the presence of Pd/C (10%) in THF and 6.5 phosphate buffer to yield the final product.
  • aldol condensation reaction is very versatile and it can be applied to any bromopenem derivative, where the carboxy group is protected other than 4-nitrobenzyl moiety.
  • Example of other protecting group include benzyl, para-methoxy benzyl derivative, benzyhydrol , trityl, alkyl and allyl derivatives.
  • the protecting group is other than 4-nitrobenzyl group, a separate deprotection step need to be carried out after the reductive elimination procerdure.
  • the chemistry involved in the deprotection step is well known to people who are skilled in that art.
  • the required aldehydes 4 for the above mentioned transformations can be prepared from their respective alcohol derivatives by MnO 2 oxidation or by Swern oxidation. In some cases the required aldehyde functionality can be introduced directly in the heterocyclic moiety by a Vilsmier Haack reaction using DMF/POCI 3 .
  • the aldehydes required for the present investigation may be prepared as depicted in Schemes 2 to 5. The N-(tert-butoxycarbonyl)- (ie) t-Boc protected -4-piperidone is treated with DMF/POCI 3 to yield 4-chloro -3 -formyl derivative. (Scheme 2).
  • This reaction can be conducted on tetrahydro-4H-pyran-4-one and the corresponding tetrahydro-4H-thiopyran-4-one derivative to give the corresponding oxygen and the sulfur derivatives.
  • This reaction can also be conducted on five to eight membered cyclic ketones derivatives.
  • the chloro formyl intermediate can be reacted with 2- mercapto ethyl acetate to give the thieno derivative.
  • the ester can be converted to alcohol, which can be converted to the starting aldehyde functionality.
  • Scheme 3 illustrates the preparation of the imidazolo- tetrahydro pyridine derivative and imidazolo pyrazine derivative.
  • Aldehydes required for examples 24-32 and 34, 35 were prepared by the route indicated schemes 8 to 18.
  • Step 2 5-benzyl-4.5.6.7-tetrahvdrothienor3.2-c1pyridin-2-vnmethanol: To stirred suspension of LAH (2.0 gms) a solution of ethyl 5-benzoyl-4,5,6,7- tetrahydrothieno[3,2-c]pyridine-2-carboxylate (6.0 g, 19 mmol) in THF was added slowly at 0° C. After addition reaction mixture was stirred for 30 minutes and quenched with saturated NH 4 CI. It was diluted with CHCI 3 and filtered. The fitrate was washed with saturated brine solution and dried over anhydrous MgSO 4 . It was filtered and taken to next step with out purifications. Yield: 4.5 g 91%. Yellow liquid. Step 3: 2-Formyl (5-benzyl-4,5,6,7-tetrahvdrothienor3,2-c1pyridine:
  • Step 4j 4-Nitrob ⁇ nzv-6-rfacetyloxy)(5-benzyl-4.5.6.7- tetrahvdrothienor3,2-cipyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- azabicyclore. ⁇ .OIhept ⁇ -ene- ⁇ -carboxylate: 2-Formyl (5-benzyl-4,5,6,7-tetrahydrothieno[3,2-c]pyridine (565 mg, 2.2 mmol) and the dry THF solution (20 ml.) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (772 mg, 2.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr 2 : 0(Et) 2 (390 mg,
  • Step-5 (5R,6Z)-6-rf5-ben2yl-4.5.6,7-tetrahvdrothienor3.2-c1pyridin-2- v ⁇ methylene1-7-oxo ⁇ -thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid:
  • Step 1 lmidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester: Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2-aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 0 C and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et 2 O to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution.
  • Step 5 (5R, 6RS)-6-[(/?S)-Acetoxy(7-methyl-5,6,7,8- tetrahydroimidazo[1 ,2-a]pyrazin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (diastereo mixture ⁇ :
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was stirred for 4.5 h at -20 0 C and treated with acetic anhydride (1.36 mL) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 17 h at 0 0 C.
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine.
  • the organic layer was dried (MgSO 4 ) and filtered.
  • the filtrate was concentrated under reduced pressure.
  • the residue was applied to silica gel column chromatography, then the column was eluted with CHCI 3 - acetone (9/1 ⁇ 2/1).
  • the titled compound was obtained as two diastereo mixture. Red oil, Yield: 1.13 g.
  • Step 6 (5R),(62)-6-(7-Methyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazin-2- ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
  • the reaction mixture was filtered through a pad of Celite, cooled to 3 0 C, and 1 M NaOH was added to adjust pH to 7.5.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was concentrated under high vacuum at 35 0 C.
  • the concentrate was applied to Diaion HP-21 (20 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H 2 O - MeCN(1/0 ⁇ 95/5). The combined fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid.
  • 2-Ketopiperazine may be prepared according to procedures in US 2004- 0077622A1 Step 1 : 4-p-Nitrobenzyloxycarbonyl-2-ketopiperazine
  • Step 2j S-Methoxy- ⁇ -p-nitrobenzyloxycarbonyl-i.2.3.6- tetrahvdropyrazine:
  • Trimethyloxonium tetrafluoroborate (97%, 3.7 g) was added to the dry dichloromethane (120 mL) solution of 4-p-nitrobenzyloxycarbonyl-2-ketopiperazine (6.7 g) at room temperature and stirred for 17 hours.
  • the reaction mixture was treated with saturated sodium hydrogen carbonate aqueous solution, and the organic layer was separated.
  • the aqueous layer was extracted with ethyl acetate (3 x 100 mL), then the combined organic layer was washed with saturated sodium hydrogen carbonate aqueous solution and brine.
  • the organic layer was dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduce pressure and the title compound was obtained as a pale brown solid.
  • Step 4 7-p-Nitrobenzyloxycarbonyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrazine-2-carbaldehyde (9) and 7-p-nitrobenzyloxycarbonyl-5,6,7,8 tetrahydroimidazo[1,2-a]pyrazine-3-carbaldehyde:
  • Step 5 (5R)-6-[Acetoxy-(7-p-nitrobenzyloxycarbonyl-5,6,7,8- tetrahydroimidazo[1 ,2-a]pyrazin-2-yl)-methyl]-6-bromo-7-oxo-4-thia- 1azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester:
  • Step 6 (5R), (62)-7-Oxo-6-(5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazin-2- ylmethylene)-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
  • the reaction solution was filterd through a pad of Celite and the pad was washed with water (150 mL) and n- butanol (150 mL). The aqueous layer was separated and then the organic layer was extracted with water (2 x 50 mL). The combined aqueous layer was concentrated to 61 g and applied to Diaion HP-21 resin (80 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution. The combined fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid.
  • Step 1 5-tert-butyl 2-ethyI 6,7-dihydrothieno[3,2-c]pyridine-2,5(4H)- dicarboxyiate:
  • Step 3 tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)- carboxylate: tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate was prepared according to the procedure outlined in Example 1, (Step 3). Starting from tert-butyi 2-(hydroxymethyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate (1.0 g).
  • Step 4 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine: 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine was prepared starting from tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate (1.0 g 3.7 mmol) was dissolved in CH 2 CI 2 (20 ml), MeOH (90% 20 ml) and 1N. HCI in dioxane (10 ml). The reaction mixture was stirred at room temperature for 48 hrs. At the end reaction mixture was concentrated to dryness and taken to next step without purification. Yield: 750 mg (HCI salt, Quantitative); M+H 168.
  • Step 5 2-Formyl [5-(4-methoxybenzyl)-4,5,6,7-tetrahydrothieno][3,2- c]pyridine: To a stirred solution of 2-(formyl)-6 I 7-dihydrothieno[3,2-c]-5(4H)-pyridine (1.4 g, 5.2 mmol) in DMF ( 20 ml) , 4-methoxybenzyl chloride (0.94 g, 6.2 mmol) and N 1 N- diisopropylethylamine (10 ml, excess) was added at room temperature. The reaction mixture was stirred for 24 hrs and quenched with water.
  • Step 6 4-Nitrobenzy-6-[(acetyloxy)[5(4-methoxybenzyl)-4,5,6,7- tetrahydrothieno[3,2-c]pyridin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylate:
  • Step-7 (5R,6Z)-6- ⁇ [5-(4-methoxybenzyJ)-4,5,6,7-tetrahydrothieno[3,2- c]pyridin-2-yl)]methylene ⁇ -7oxo-4-thia-1-azabIcyclo[3.2.0]hept-2-ene-2- carboxylic acid:
  • the reaction mixture was vigorously stirred for 2 h at room temperature.
  • the reaction mixture was filtered, cooled to 3 0 C, and 0.1 M NaOH was added to adjust pH to 8.5.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was concentrated under high vacuum at 35 0 C to give yellow precipitate.
  • the product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 18%; as yellow crystals; mp. 127°C; (M+H) 441 .
  • 5-Methylthio-3,6-dihydro-2H-[1 ,4]thiazine hydroiodide may be prepared by the method as outlined in US 2004-0077622A1. Step 2: 3-lminothiomorpholin hydrochloride
  • Step 3 5,6-Dihydro-8H-imidazo[2,1-c][1,4]thiazine-2-carbardehyde and 5,6-Dihydro-8H-imidazo[2,1 -c][1 ,4]thiazine-3-carbardehyde
  • Step 4 (5R), (6Z)-6-(5,6-dihydro-8H-imidazo[2,1-c][1,4]thiazin-2- ylmethyIene)-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
  • Citric acid aqueous solution (240 mL) is added to the reaction mixture and the aqueous layer is extracted with ethyl acetate (3 x 100 mL). The combined organic layer is washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO 4 ) and filtered. The filtrate is concentrated under reduced pressure.
  • Freshly activated Zn dust (2.2 g) is added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 17 ml_). The reaction vessel is covered with foil to exclude light. The reaction mixture is vigorously stirred for 2 h at room temperature.
  • reaction solution is filterd through a pad of Celite and the pad is washed with water (40 mL) and n-butanol (30 mL).
  • the aqueous layer is separated and then the organic layer is extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 10 mL).
  • the combined aqueous layer is concentrated to 23 g, 1 mol/L NaOH is added to adjust pH to 7.25 and applied to Diaion HP-21 resin (30 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column is eluted with water and then 10% acetonitrile aqueous solution.
  • reaction mixture was cooled to room temperature, washed with 50% K2CO3, dried over anhydrous K2CO3, filtered, and evaporated under reduced pressure.
  • the residue was applied with silicagel column chromatography, eluted with CHCI3-acetone (2:1), and 6,7-Dihydro-5H-pyrrolo[1 ,2- a]imidazole-2-carbaldehyde (41%, 1.51g) was obtained as a pale yellow solid.
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was stirred for 3 h at -20 0 C and treated with acetic anhydride (1.89 mL) and DMAP (370 mg) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 14.5 h at 0 0 C.
  • the mixture was diluted with ethyl acetate and washed with 1 M citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine.
  • the organic layer was dried (MgSO 4 ) and filtered.
  • the pad was washed with ethyl acetate.
  • the filtrate was concentrated under reduced pressure.
  • the residue was dissolved in THF (166 mL) and acetonitrile (77 mL).
  • Freshly activated Zn dust (23.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 243 mL).
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was vigorously stirred for 2 h at room temperature.
  • the reaction mixture was filtered, cooled to 3 0 C, and 1 M NaOH was added to adjust pH to 8.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated. 1 M NaOH was added to the aqueous layer again to adjust pH to 8.
  • the resultant mixture was concentrated under high vacuum at 35 0 C.
  • the concentrate was applied to Diaion HP-21 (20 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography.
  • STEP 1 MORPHOLIN-3-ONE Morpholin-3-one was prepared in the method of USP 5,349,045.
  • Step 6 5R). /6Z ⁇ -6-(5.6-Dihvdro-8H-imidazor2.1-ci ⁇ .41oxazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was stirred for 4 h at -20 0 C and treated with 4-dimethylamino pyridine (100 mg) and acetic anhydride (1.5 mL) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 18 h at 0 0 C.
  • 10% Citric acid aqueous solution (1 L) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 500 mL).
  • the combined organic layer was washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO 4 ) and filtered.
  • Freshly activated Zn dust (14 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 72 mL) to the THF (72 mL) solution of (5f?)-6-[acetoxy- ( ⁇ . ⁇ -dihydro- ⁇ H-imidazop.i-cHi ⁇ loxazin ⁇ -yOmethyll-e-bromo ⁇ -oxo ⁇ -thia-i- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester.
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was vigorously stirred for 2.5 h at room temperature.
  • the reaction solution was filtered through a pad of Celite and the pad was washed with water (170 mL) and n-butanol (170 mL).
  • the aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL).
  • the combined aqueous layer was concentrated to 90 g, 1mo!/L NaOH was added to adjust pH to 7.5 and applied to Diaion HP-21 resin (120 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution.
  • the combined active fractions was concentrated under high vacuum at 35°C and lyophilized to give the title as a yellow amorphous solid (756 mg, 29.1%).
  • Step 1 5.6-Dihvdro-4H-pyrrolori,2-foipyrazole-2-carboxyHc acid ethyl ester
  • the titled compound was prepared in the same way of Ranganathan and co-workers (Indian J. Chem. 1991, 30 B, 169-175).
  • Step 2 (5,6-Dihvdro-4H-pyrrolori,2-frTpyrazol-2-yl)methanol MeOH (2.73 mL) was added to the THF (180 mL) solution of LiBH 4 (1.63 g) under a nitrogen atmosphere at room temperature, and then 5,6-dihydro-4H- pyrrolo[1 ,2-fc]pyrazole-2-carboxylic acid ethyl ester (8.11 g) was added to the suspension and stirred for 2 h at 40 0 C. The mixture was quenched with 1 mol/L HCI at pH 1 and stirred for 1 h at room temperature.
  • Step 3 5,6-Dihvdro-4H-pyrrolof1,2-toipyrazole-2-carbaldehyde MnO 2 (activated) (24.4 g) was added to the CHCI 3 (350 mL) solution of (5,6- dihydro-4H-pyrrolo[1 ,2-/)]pyrazol-2-yl)methanol (4.87 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was reduced under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 1/2). The title compound was obtained as yellow oil (4.35 g, 91 %).
  • Step 4 (5/?). ( 6Zi-6-(5.6-Dihvdro-4H-pyrrolo ⁇ .2-frlPyrazol-2-ylmethylene)- 7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt 5,6-Dihydro-4H-pyrrolo[1,2-jb]pyrazole-2-carbaldehyde (1.36 g) was added to the dry acetonitrile (148 mL) solution of anhydrous MgBr 2 (5.52 g) under a nitrogen atmosphere at room temperature.
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine.
  • the organic layer was dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduced pressure.
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was vigorously stirred for 1.5 h at room temperature.
  • the reaction mixture was filtered through a pad of Celite.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was cooled to 3 0 C and 1 M NaOH was added to adjust pH to 8.0.
  • the mixture was concentrated under high vacuum at 35 0 C.
  • the concentrate was applied to Diaion HP-21 (79 mL,
  • Trifluoroacetic anhydride (1.93 g) was added to the THF (92 ml_) solution of crude (2RS)-1-nitrosopiperidine-2-carboxylic acid under a nitrogen atmosphere at 0 0 C and stirred for 5 h at 0 0 C and for 2 h at room temperature. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 0/1). The titled compound was obtained as colorless crystals (1.10 g, 33%).
  • 1 H NMR (CDCI 3 ) ⁇ 1.93 - 1.99 (m, 2H), 2.08 - 2.15 (m, 2H), 2.65 (t,
  • Step 2 4.5.6,7-Tetrahvdropyrazolof1.5-a1pyridine-2-carboxylic acid ethylester:
  • the titled compound was obtained as yellow oil (871 mg, 65%), and 4,5,6,7-tetrahydropyrazoIo[1 ,5-a]pyridine-3-carboxyiic acid ethyl ester was obtained as yellow oil (345 mg, 26%).
  • Step 4 4.5.6.7-Tetrahvdropyrazolo ⁇ .S-alpyridine ⁇ -carbaldehvde
  • Step 5 f5/?)(6Z)-7-Oxo-6-f4.5.6,7-tetrahvdropyrazolori ,5-a1pyridin-2- ylmethylene)-4-thia-1 -azabicvclorS ⁇ .Olhept- ⁇ -ene- ⁇ -carboxylic acid, sodium salt 4,5,6,7-Tetrahydropyrazolo[1 ,5-a]pyridine-2-carbaldehyde (483 mg) was added to the dry acetonitrile (48 mL) solution of anhydrous MgBr 2 (1.81 g) under a nitrogen atmosphere at room temperature.
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine.
  • the organic layer was dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduced pressure.
  • the titled compound was prepared in the same way of S.Rajappa and
  • Step 2 5-Amino-1-methyl-3.6-dihvdro-1H-pyrazin-2-one
  • a mixture of 5-methoxy-1-methyl-3,6-dihydro-1 H-pyrazin-2-one (2.3 g) and ammonium chloride (936 mg) in dry ethanol (32 ml_) was stirred at room temperature for 1 h and then refluxed for 2 h.
  • the reaction mixture was cooled to room temperature and evaporated under reduced pressure.
  • the residue was triturated with chloroform at room temperature for 30 min.
  • the precipitate was filtered off and dried in vacuo.
  • the 5-amino-1-methyl-3,6-dihydro-1H-pyrazin-2-one hydrochloride was obtained as a pale brown powder (1.7 g, 66%).
  • Step 4 (5R 6RS)- 6- rAcetoxy-(7-methyl-6-oxo-5,6J,8-tetrahydro- imidazori,2-alpyrazin-2-vO-methyll-6-bromo-7-oxo-4-thia-1-aza- bicyclor3.2.01hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester 7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo [1 ,2-a]pyrazine-2-carbaldehyde
  • the reaction mixture was stirred for 3 h at -20 0 C and treated with 4-dimethylaminopyridine (44 mg) and acetic anhydride (0.35 mL) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 20 h at 0 0 C.
  • the mixture was diluted with ethyl acetate and H 2 O. After separating organic layer, the aqueous layer was extracted with ethyl acetate. The organic layers were combined and washed with 5% citric acid aqueous solution and brine. The organic layer was dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then eluted with chloroform. The title compound was obtained as diastereo mixture (yellow amorphous solid ; 410 mg, 38%).
  • Step 5 l5RU6Z)-6-l 7-Methyl-6-oxo-5.6.7.8-tetrahvdro-imidazo ⁇ .2- aiPyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclor3.2.01hept-2-ene-2-carboxylic acid sodium salt and (5ffl,f6E)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahvdro-imidazo ⁇ .2- aipyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid sodium salt
  • the reaction mixture was vigorously stirred for 2 h at room temperature.
  • the reaction solution was mixed with ethyl acetate and filtered through a pad of Celite.
  • the pad was washed with water and the aqueous layer was separated.
  • the aqueous layer was cooled to 3 0 C and 1 M NaOH was added to adjust pH to 8.0.
  • the mixture was concentrated under high vacuum at 35 0 C and lyophilized.
  • Each solution was concentrated under high vacuum at 35 0 C.
  • Each concentrate was applied to Diaion HP-21 (60 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with water and then with 5% acetonitrile-water.
  • the titled compound was prepared in the same way of Shiraiwa and co-workers (Biosci. Biotechnol. Biochem. 1998, 62, 2382-2387).
  • Step 2j 3-Oxo-3a.4.6,7-tetrahvdro-3H-2-oxa-5-thia-1-aza-7a- azonioindenide
  • Trifluoroacetic anhydride (7.07 g) was added to the THF (169 mL) solution of crude (3R)-4-nitrosothiomorpholine-3-carboxylic acid under a nitrogen atmosphere at 0 0 C and stirred for 3 h at 0 0 C and for 17 h at room temperature. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 0/1). The titled compound was obtained as pale brown crystals (3.41 g, 64%).
  • Step 3 e.y-Dihvdro ⁇ H-pyrazolor ⁇ .i-ci ⁇ ithiazine ⁇ -carboxylic acid ethyl ester
  • Ethyl propiolate (2.33 g) was added to the o-xylene (72 ml_) solution of 3-oxo- 3a,4,6,7-tetrahydro-3/-/-2-oxa-5-thia-1-aza-7a-azonioindenide (3.41 g) under a nitrogen atmosphere and refluxed for 15 h.
  • the solution was concentrated under a reduced pressure.
  • the residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (2/1 - 1/1).
  • the titled compound was obtained as yellow oil (3.13 g, 68%), and the other unwanted regio isomer 6,7- dihydro-4/-/-pyrazolo[5,1-c][1 ,4]thiazine-3-carboxylic acid ethyl ester was obtained as yellow oil (556 mg, 12%).
  • Step 4 (6.7-Dihvdro-4H-pyrazolor5.1 -clH .41thiazin-2-v0methanol
  • Step 5 6.7-Dihvdro-4H-pyrazolor5.1-ci ⁇ ,41thiazine-2-carbaldehvde MnO 2 (activated) (11.46 g) was added to the CHCI 3 (135 mL) solution of (6,7- dihydro-4H-pyrazolo[5,1-c][1,4]thiazin-2-yl)methanol (2.31 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n- hexane - AcOEt (1/1). The titled compound was obtained as pale yellow crystals (1.78 g, 78%).
  • Step 1 3-Oxo-3a, 4-dihvdro-3H, 6H-2-oxa-5-thia-1-aza-6a-azonio-3a- pentalenide
  • Trifluoroacetic anhydride (5.0 mL) was added to the THF (350 mL) solution of crude N-nitrosothioproline under a nitrogen atmosphere at 0 0 C and stirred for 5 h at 0 0 C. The solution was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1 : 1). The titled compound was obtained as a pale brown solid (4.0 g, 15.1%).
  • Step 2 4H-5-Thia-1.6a-diazapentalen-2-carboxylic acid ethylester
  • the titled compound was obtained as a yellow solid (2.7 g, 49.3%), and 4H-5-thia-1 ,6a-diazapentalen-3-carboxylic acid ethylester was obtained as pale yellow crystals (1.2 g, 21.7%).
  • LiBH 4 (cont. 90%) (459 mg) was added to the ether (126 ml_) solution of AH- 5-thia-1,6a-diazapentalen-2-carboxylic acid ethylester (2.5 g) and MeOH (0.77 ml_) under a nitrogen atmosphere at room temperature, then refluxed for 1.5 h. The mixture was quenched with 1 mol/L HCI (25 ml_) and stirred for 1 h at room temperature. The mixture was neutralized by saturated sodium hydrogen carbonate solution and separated. The aqueous layer was extracted with dichloromethane (10 x 25 mL). The organic layer was dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with AcOEt. The titled compound was obtained as a pale yellow solid (1.7 g, 87.9%).
  • the dry dichloromethane (8 mL) solution of dimethylsulfoxide (2.2 mL) was added dropwise to the dry dichloromethane (110 mL) solution of oxalyl chloride (2.0 mL) at -78°C.
  • the reaction mixture was stirred for 15 min at the same temperature.
  • the dry dichloromethane (40 mL) solution of (4H-5-thia-1 ,6a-diazapentalen-2- yl)methanol, (1.7 g) was added dropwise to the reaction mixture at -78°C, and stirring was continued for an additional 15 min.
  • the reaction mixture was allowed to warm to -45°C and stirred for 1 h.
  • Triethylamine (11.3 mL) was added dropwise and the reaction mixture was allowed to warm to 0 0 C. After 20min, saturated ammonium chloride solution (50 mL) and water (100 mL) were added and separated. The aqueous layer was extracted with AcOEt (3 x 150 mL). The combined organic layers were washed with water (200 mL) and brine (200 mL), dried (MgSO 4 ) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with hexane - AcOEt (1 : 1). The titled compound was obtained as a yellow solid (1.7 g, quant.).
  • the reaction mixture was stirred for 3 h at -20 0 C and treated with 4-dimethylamino pyridine (138 mg) and acetic anhydride (2.1 mL) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 15 h at 0 0 C.
  • the 1mol/L Citric acid aqueous solution 1000 mL was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 400 mL).
  • the combined organic layers were washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO 4 ) and filtered.
  • Freshly activated Zn dust (19.3 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 100 mL) to the THF (100 mL) solution of crude (5R)-6- [acetoxy-(4H-5-thia-1 ,6a-diazapentalen-2-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo [3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester.
  • the reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2.5 h at room temperature.
  • reaction solution was filtered through a pad of Celite and the pad was washed with water (200 mL) and n-butanol (200 mL).
  • the aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL).
  • the combined aqueous layers were concentrated to 90 g, 1 mol/L NaOH was added to adjust pH to 8.0 and applied to Diaion HP-21 resin (180 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 15% acetonitrile aqueous solution.
  • the thiazolidine-4-thione was obtained as a pale yellow powder (10.7 g, 65%).
  • Methyl iodide 28.4 g was added to the boiling solution of thiazolidine-4- thione (9.5 g) in chloroform (400 mL), and the reaction mixture was refluxed for 1.5 h.
  • an additional methyl iodide 56.8 g was added in 5 portions at 30-60 min intervals. After refluxing for additional 1 h, the reaction mixture was cooled to room temperature. Then 10% potassium carbonate aqueous solution (200 mL) was added and stirred for 15min at room temperature. After separating organic layer, the aqueous layer was extracted with CHCI 3 (100 mL x 3). Organic layers were combined, dried (MgSO 4 ) and filtered.
  • the concentrate was applied to Diaion HP-21 (321 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H 2 O - MeCN (1/0 - 9/1). The combined fractions were concentrated under high vacuum at 35 0 C and lyophilized to give the title compound as a yellow amorphous solid (1.1 g, 51%, pH 7.5).
  • Step 3 1 -(2-fflert-butyl(dimethyl)silylloxy>ethvn-1 H-pyrazole-3,5- dicarbaldehvde
  • Step 4 4-oxo-6,7-dihydro-4H-pvrazolof5.1 -el M .41oxazine-2-carbaldehvde
  • 1-(2- ⁇ [tert-butyl(dimethyl)silyl]oxy ⁇ ethyl)-1H-pyrazole-3,5- dicarbaldehyde (1.02 g, 6.07 mmol) in THF (30 ml) was added 6.68 ml of a 1.0 M solution of tetrabutylammonium fluoride in THF at 0 0 C. After stirring for 1 hr, the mixture was treated with 10 ml of saturated ammonium chloride solution and extracted with ethyl acetate.
  • Step 5 4-nitrobenzyl f5R)-6-r(acetyloxy)(4-oxo-6J-dihydro-4H-pyrazolor5,1- cU1,41oxazin-2-yl)methvn-6-bromo-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene- 2-carboxylate
  • the compound was dissolved in DCM (200ml) and was added 6.0 gram of ethyl 2-6,7-Dihydro-4H-thieno[3,2- c]thiopyran-2-carbaldehyde-acetate and 10 ml TEA. The mixture was refluxed for 18 hrs. Then it was washed with water and dried over magnesium sulfate. It was then filtered, concentrated and flash chromatographed with 20 ethyl acetate in hexane. The collected material was dissolved in 100ml THF and LAH (150ml, 0.5M in THF) was injected and left at 23oC for 10 minutes. Then it was refluxed for 18 hrs.
  • LAH 150ml, 0.5M in THF
  • STEP 1 PREPARATION OF ej-DIHYDRO ⁇ H-THIENOre.Z-CITHIOPYRAN- ⁇ - CARBALDEHYDE
  • Step 2 Preparation of 6- ⁇ 6.7-Dihvdro-4H-thienor3.2-cUhiopyran-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid 6,7-Dihydro-4H-thieno[3,2-c]thiopyran-2-carbaldehyde (320mg, 1.72mmol) was dissolved in 17ml acetonitrile and magnesium bromide etherate (450 mg, 1.74mmol) was then added under N2 atmosphere. The mixture was stirred at 23oC for half an hour.
  • Step 1 Preparation of (5-Methyl-4,5,6,7-tetrahvdro-thienor3,2-cipyridin-2-yl)- methanol 6,7-Dihydro-4H-thieno[3,2-c]pyridine-2,5-dicarboxylic acid diethyl ester (46 gram, 163mmol) was dissolved in 200ml THF. The solution was injected LAH (1M, THF) 300ml at 23oC. Then it was stirred at 23oC for 18 hrs. The reaction was quenched with 10ml water and dried directly over sodium sulfate. Filter and concentrate yielded 29.3 gram (160mmol, 98%) crude product.
  • Step 2 Preparation of 5-Methyl-4.5.6,7-tetrahvdro-thienor3.2-cTpyridine-2- carbaldehvde DMSO (1.7ml, 24mmol) in 5ml CH 2 CI 2 was cooled to -50-60OC. Oxalyl chloride (1ml, 11mmol) in 20ml DCM was then added within 5 minutes at 50oC.
  • Step 3 Preparation of 6-(5-Methyl-4,5,6.7-tetrahvdro-thienof3,2-c1pyridin-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid
  • Triethylamine (2ml) was then injected and the mixture stirred at -20oC for 3 hrs.
  • acetic anhydride (0.66ml) was injected and the mixture was stirred at OoC for 48 hrs.
  • the reaction media was then diluted with 500ml ethyl acetate and washed with 50 ml 5% citric acid, 50 ml saturated sodium bicarbonate, and 50ml brine. Another 300ml ethyl acetate was used to wash each aqueous solution. The combined organic layers were then dried over sodium sulfate. Filter, concentrate, and flash column chromatograph using 20% ethyl acetate in hexane gave 1.56 gram (64% yield) product.
  • Triethylamine (4ml) was then injected and the mixture stirred at -20oC for 4 hrs.
  • acetic anhydride (1ml) was injected and the mixture was stirred at OoC for 20 hrs.
  • the reaction media was then diluted with 500ml ethyl acetate and washed with 100ml 5% citric acid, 100 ml saturated sodium bicarbonate, and 100ml brine.
  • Step 3j (5K 1 6flS)-6-KftS)-Acetoxy(7-benzyl-5.6.7.8- tetrahvdroimidazori.2-alpyrazin-2-yl)methv ⁇ -6-bromo-7-oxo-4-thia-1- azabicvclor3.2.01hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (diastereo mixture)
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was stirred for 5 h at -20 0 C and treated with acetic anhydride (0.11 mL) and DMAP (7 mg) in one portion.
  • the reaction mixture was warmed to 0 0 C and stirred for 15 h at 0 0 C.
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine.
  • the organic layer was dried (MgSO 4 ) and filtered.
  • the filtrate was concentrated under reduced pressure.
  • the residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (3/1 ⁇ 1/1).
  • the titled compound was obtained as two diastereo mixture (80/20, purple amorphous solid, 233 mg, 61%).
  • Step 4 (5ffl,(6Z)-6-(7-Benzyl-5.6.7.8-tetrahvdroimidazof1.2-a1pyrazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid. sodium salt
  • the concentrate was applied to Diaion HP-21 (79 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H 2 O - MeCN(1/0 ⁇ 4/1). The combined fractions were concentrated under high vacuum at 35 0 C and lyophilized to give the title compound as a yellow amorphous solid (390 mg, 49%, pH 7.7).
  • Step 1 2-Formyl r5-(pyridin-3-ylmethylM.5.6.7-tetrahvdrothienoU3.2- ci pyridine: To a stirred solution of 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine
  • Step 2 4-Nitrobenzv-6-r(acetyloxyU5(pyridin-3-ylmethvn-4.5.6.7- tetrahvdrothienor3,2-cipyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- aza p icvclore. ⁇ .Olhept- ⁇ -ene- ⁇ -carboxylate:
  • Step-3 (5R.6Z)-6-(r5-(pyridin-3-ylmethyl)-4,5,6.7-tetrahvdrothienor3,2- cipyridin- ⁇ -vOlmethyleneWoxo- ⁇ hia-i-azabicvclore ⁇ .Oihept- ⁇ -ene- ⁇ - carboxylic acid:
  • the reaction mixture was filtered, cooled to 3 0 C, and 0.1 M NaOH was added to adjust pH to 8.5.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was concentrated under high vacuum at 35 0 C to give yellow precipitate.
  • the product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 12%; as yellow crystals; mp. 134-136 0 C; (M+H) 412 .
  • Step 1 2-Formyl f5-( pyridin-3-ylcarbonv ⁇ -4.5, ⁇ ,7-tetrahvdrothienolf3.2- clpyridine:
  • Step 2 4-Nitrobenzv-6-r(acetyloxy)f5(pyridin-3-ylcarbonyl)-4.5.6.7- tetrahvdrothtenore ⁇ -cipyridin- ⁇ -vOcarbonv ⁇ -S-bromo ⁇ -oxo ⁇ -thia-i- azabicvclore. ⁇ . ⁇ ihept ⁇ -ene ⁇ -carboxylate:
  • Step-3 (5R.6Z)-6-fr5-(pyridin-3-ylcarbonyl)-4,5. ⁇ .7-tetrahvdrothienor3.2- cipyridin- ⁇ -vOimethylenel ⁇ oxo ⁇ -thia-i-azabicvclo ⁇ .Oihept ⁇ -ene-a- carboxylic acid sodium salt:
  • the reaction mixture was filtered, cooled to 3 0 C, and 0.1 M NaOH was added to adjust pH to 8.5.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was concentrated under high vacuum at 35 0 C to give yellow precipitate.
  • the product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 12%; as yellow crystals; mp. 195 0 C; (M+H) 426.
  • Step 1 2-Formyl r5-fphenylacetvn-4,5,6.7-tetrahvdrothienoir3.2- cipyridine: To a stirred solution of 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine
  • Step 2 4-Nitrobenzy-6-r(acetvioxy)r5(phenylacetyl)-4.5.6.7- tetrahvdrothienor3,2-c1pyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- azabicyclorS ⁇ .OIhept- ⁇ -ene ⁇ -carboxylate:
  • Step-3 (5R.6Z)-6-fr5-(phenylacetyl)-4.5.6.7-tetrahvdrothienor3.2- cipyridin- ⁇ -vDimethyleney ⁇ oxo ⁇ -thia-i-azabicvclors. ⁇ .OIhept ⁇ -ene- ⁇ - carboxylic acid:
  • Step 1 5.5-Dioxo-4,5.6.7-tetrahvdro-5 ⁇ 6 -pyrazolor5,1 -cIM ,41th iazine-2- carbaldehyde m-Chloroperbenzoic acid (cont. 69%) (6.36 g) was added to the
  • Step 2 (5R 6/?S)-6-r(/?S)-Acetoxy-f5.5-dioxo-4.5.6.7-tetrahvdro-5 ⁇ 6 -pyrazolor5.1- ci ⁇ ithiazin- ⁇ -v ⁇ -methvn- ⁇ -bromo ⁇ -oxo ⁇ -thia-i-azabicvclorS. ⁇ .Olhept- ⁇ -ene- 2-carboxylic acid 4-nitrobenzyl ester
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate and brine.
  • the organic layer was dried (MgSO 4 ), followed by concentration under reduced pressure.
  • Step 3 (5ffl.(6Z)-6-(5.5-Dioxo-4,5,6,7-tetrahvdro-5 ⁇ ⁇ -pyrazolor5.1 - ciri,41thia2in-2-ylmethylene)-7-oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2- carboxylic acid, sodium salt (5R, 6RS)-6-[(RS)-Acetoxy-(5,5-dioxo-4,5,6,7-tetrahydro-5D 6 -pyrazolo[5,1-
  • the filtrate was added H 2 O (27 mL) and washed with ethyl acetate (27 mL) and the aqueous layer was cooled to 3 0 C and 1 M HCI was added to adjust pH to 2.5.
  • the mixture was stirred for 1 d at the same temperature and added H 2 O (55 mL), then stirred for 4 d at the same temperature.
  • the mixture was stirred for 10 h at room temperature.
  • the resultant mixture was cooled to 3 0 C and 1 M NaOH was added to adjust pH to 8.
  • the mixture was concentrated under high vacuum at 35 0 C.
  • the concentrate was treated to Diaion HP-21 (80 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography.
  • the suspension was filtered and the filtered material was diluted with EtOH - H 2 O (7 : 3, 550 mL) and refluxed for 10 min.
  • the reaction mixture was filtered to obtain the colorless crystals.
  • the recrystallization from the filtrate was carried out 3 times to obtain additional crystals.
  • the combined crystals were dried under reduced pressure to obtain the titled compound (26.25 g, 77%) as colorless crystals.
  • Step 2 5-(4-Nitrobenzyloxycarbonyl)-3-oxo-3a.4,6.7-tetrahvdro-3H-2- oxa-1,5-diaza-7a-azoniainden-3a-ifte
  • the H 2 O (300 mL) solution of NaNO 2 (cont. 98.5 %) (6.66 g) was added to the acetic acid (864 mL) solution of piperazine-1 ,3-dicarboxylic acid 1-(4- nitrobenzyl) ester (26.72 g) under a nitrogen atmosphere at 0 0 C for 0.5 h and stirred for 1 h.
  • the H 2 O (132 mL) solution of NaNO 2 (cont. 98.5 %) (2.41 g) was added to the solution at 0 0 C for 0.5 h and stirred for 1 h.
  • the solution was concentrated under reduced pressure and H 2 O (500 mL) was added to the residue.
  • the THF (10 mL) solution of trifluoroacetic anhydride (24.0 g) was added to the THF (371 mL) solution of crude 4-nitrosopiperazine-1 ,3-dicarboxylic acid 1-(4-nitrobenzyl) ester under a nitrogen atmosphere at 0 0 C for 15 min. The solution was stirred for 1.5 h at 0 0 C and for 1h at room temperature.
  • the THF (5 mL) solution of trifluoroacetic anhydride (8.0 g) was added to the solution for 5 min and stirred for 20 h at room temperature. To the solution was added trifluoroacetic anhydride (8.0 g) for 5 min and the solution was stirred for 4h.
  • Step 3 6.7-Dihvdro-4/-/-pyrazolof1,5-a1pyrazine-2.5-dicarboxylic acid 2- ethyl ester 5-(4-nitrobenzyl) ester
  • LiBH 4 (640 mg) and MeOH (1.2mL) was added to the THF (267 ml.) solution of 6,7-dihydro-4/-/-pyrazolo[1,5-a]pyrazine-2,5-dicarboxylic acid 2-ethyl ester 5-(4- nitrobenzyl) ester (10 g) under a nitrogen atmosphere at room temperature and stirred for 3 h at 40 0 C. Additional LiBH 4 (523 mg) and MeOH (1.0 mL) was added to the solution and stirred for 1 h at 40 0 C and 1 h at 50 0 C.
  • Step 6 2- ⁇ (ffS)-Acetoxy-r(5R 6/?S)-6-bromo-2-(4-nitrobenzyloxycarbonv ⁇ -7- oxo ⁇ -thia-i-azabicvclorS. ⁇ .OIhept- ⁇ -en-G-vn-methyll-ej-dihvdro ⁇ f/- pyrazoloH,5-a1pyrazine-5-carboxylic acid 4-nitrobenzyl ester
  • the mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine.
  • the organic layer was dried (MgSO 4 ), followed by concentration under reduced pressure.
  • the residue was purified with silica-gel column chromatography three times (n-hexane - AcOEt (1/1 to 2/3), CHCI 3 - acetone (29/1 to 19/1) and CHCI 3 - acetone (29/1)).
  • the titled compound was obtained as yellow amorphous (diastereo-mixture (64 : 36), 3.30 g, 53%).
  • Step 7 f5ffl.(6Z>-7-Oxo-6-f4.5.6.7-tetrahvdropyrazolo ⁇ .5-aipyrazin-2- ylmethylenei-4-thia-1 -aza-bicvcf or3.2.01hept-2-ene-2-carboxylic acid, sodium sa
  • the reaction mixture was vigorously stirred for 1.5 h at room temperature.
  • the insoluble material was filtered off and was washed with H 2 O (63 ml_).
  • the filtrate was washed with ethyl acetate (63 ml.) and the aqueous layer was cooled to 3 0 C and 1 M HCI was added to adjust pH to 2.5.
  • the mixture was stirred for 4 h at the same temperature and added H 2 O (63 mL) and 1 M HCI to adjust pH to 2.5, then stirred for 17 h at the same temperature.
  • To the mixture was added 1 M NaOH to adjust pH to 8.
  • the mixture was concentrated under high vacuum at 35 0 C.
  • the concentrate was treated to Diaion HP-21 (124 mL, Mitsubishi Kasei Co.
  • Step 4 5.5-Dimethy
  • LiAIH 4 0.85 g, 22.3 mmol
  • Step 3 S. ⁇ -Dihydro ⁇ H-cvclopentarbifuran- ⁇ -carbaldehyde Activated MnO 2 (9.3 g) was added to the CHCI 3 (135 mL) solution of (5,6- dihydro-4H-cyclopenta[£>]furan-2-yl)methanol (1.86 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (9/1 - 7/1). The titled compound was obtained as yellow crystals (1.51 g, 77%).
  • Step 4 (5R. 6/?S)-6-r(RS)-Acetoxy(5.6-dihvdro-4H-cvclopentarb1furan-2- yl)methv ⁇ -6-bromo-7-oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester
  • Step 5 (5R)AGZ)- 6-(5.6-Dihvdro-4H-cvclopentarfo1furan-2-ylmethylene)- 7-oxo-4-thia-1-azabicvclor3.2.0lhept-2-ene-2-carboxylic acid, sodium salt
  • the reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0 C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0 C. The concentrate was applied to Diaion HP-21 (181 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H 2 O - MeCN (1/0 - 85/15). The combined fractions were concentrated under high vacuum at 35 0 C and lyophilized to give the titled crude product (288mg).
  • Step 1 DL-Tetrahvdro-1.3-thiazine-4-carboxylic acid hydrochloride
  • DL-Tetrahydro-1,3-thiazine-4-carboxylic acid hydrochloride was prepared according to the method of Lewis (J. Med. Chem., 21, 1070 (1978)).
  • Step 2 4.5-Dihvdro-3aH.7H-2-oxa-3-oxo-6-thia-1 -aza-7a-azonioinden
  • a suspension of DL-tetrahydro-1 ,3-thiazine-4-carboxylic acid hydrochloride (48.6 g, 0.26 mol) in 666 ml_ of AcOH was added to the solution of 27.4 g (0.40 mol) of NaNO 2 in 333 mL of water over 16 min at room temperature and stirred for 3 h.
  • the solution was concentrated under reduced pressure.
  • Acetone 300 mL was added to the residue and the precipitate was filtered off.
  • the filtrate was concentrated under reduced pressure to dryness and crude 3- nitroso[1 ,3]thiazinane-4-carboxylic acid was obtained as brown amorphous solid.
  • Step 5 (5RU6Zl-6-(4.5-Dihvdro-6-thia-1.7a-diazainden-2-ylmethylene)-7- oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
  • reaction mixture was warmed to 0 0 C and stirred for 15 h at 0 0 C.
  • Ethyl acetate (280 mL) and 1mol/L citric acid aqueous solution (140 mL) was added to the reaction mixture and separated.
  • the organic layer was washed with saturated sodium hydrogen carbonate and brine, dried (MgSO 4 ) and filtered.
  • Freshly activated Zn dust (21.4 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 112 mL) to the THF (76 mL) and acetonitrile (36 mL) solution of crude (5f?)-6-[acetoxy-(4,5-dihydro- 6-thia-1 ,7a-diazainden-2-yI)methyl]-6- bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester.
  • the reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature.
  • the reaction solution was cooled at 0 0 C, and then the pH was adjusted to 8.0.
  • Ethyl acetate (56 mL) was added to the mixture and filtered through a pad of Celite. The pad was washed with water (150 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 30 mL). The combined aqueous layers were cooled at 0 0 C, and then the pH was adjusted to 8.0.
  • the mixture was concentrated to 236 g, and then applied to Diaion HP-21 resin (480 mL, Mitsubishi Kasei Co. Ltd.) column chromatography.
  • the column was eluted with water (960 mL) and then acetonitrile aqueous solution (5%; 960 mL, 10%; 960 mL, 20%; 960 mL).
  • acetonitrile aqueous solution 5%; 960 mL, 10%; 960 mL, 20%; 960 mL.
  • the combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the titled compound as a yellow amorphous solid (1.28 g, 40.5 %, pH 7.45).
  • Trimethyloxonium tetrafluoroborate (97%, 11.9 g, 78 mmol) was added to the dry dichloromethane (156 ml_) solution of 5,5-dimethyl-2-piperidone
  • Step 4 6,6-Dimethyl-5.6,7.8-tetrahvdroimidazoH .2-alPyridine-2- carbaldehvde &
  • Step 5 (5f?).(6Z)-6-(6.6-Dimethyl-5.6.7,8-tetrahvdroimidazof1 ,2-aipyrizin- 2- ylmethylene)-7-oxo-4-thia-1 -azabicvclor3.2.0 ' lhept-2-ene-2-carboxylic acid. sodium salt
  • Freshly activated Zn dust (53.6 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 282 mL) to the THF (192 mL) and acetonitrile (90 mL) solution of (5fi)-6-[acetoxy-(6,6-dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridin-2- yl)methyl]-6-bromo-7-oxo-4-thia- 1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p- nitrobenzyl ester.
  • the reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature.
  • the reaction mixture was cooled at 0 0 C, and then the pH was adjusted to 7.6.
  • Ethyl acetate 140 mL was added to the reaction mixture, and then the mixture was filtered through a pad of Celite and the pad was washed with water (200 mL).
  • the aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL).
  • the pH of the combined aqueous layer was adjusted to 8.1 and the mixture was concentrated to 584 g. 1 mol/L NaOH was added to adjust pH to 8.2 and applied to Diaion HP-21 resin (420 mL, Mitsubishi Kasei Co. Ltd.) column chromatography.
  • the solid obtained above chromatography was dissolved in THF (11 mL). Freshly activated Zn dust (1.4 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 11 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction solution was filterd through a pad of Celite and the pad was washed with water (26 mL) and n-butanol (26 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 5 mL).
  • the combined aqueous layer was concentrated to 18 g, 1 mol/L NaOH was added to adjust pH to 7.3 and applied to Diaion HP-21 resin (20 ml_, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution. The combined active fractions was concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid (81 mg).
  • Step 1 Preparation of 3-Oxo-3a, 4-dihvdro-3H. 6H-2-oxa-4-thia-1-aza-6a- azonio-3a-pentalenide
  • the solution was concentrated under reduced pressure.
  • the residue was applied to a silica-gel column chromatography, and then the column was eluted with ⁇ -hexane - ethyl acetate (1 : 1).
  • the titled compound was obtained as a pale brown crystal (19.2 g, 44.5 %).
  • Step 2 Preparation of 2.3-Dihvdropyrazolor5.1-frlthiazol-6-carboxylic acid ethyl ester and 2.3- dihydropyrazolor5,1-b1thiazol-7-carboxylic acid ethyl ester
  • Ethyl propiolate (20.3 ml, 0.20 mol) was added to an o-xylene (600 ml) solution of 3-oxo-3a, 4-dihydro-3H, 6H-2-oxa-4-thia-1-aza-6a-azonio-3a- pentalenide (19.2 g, 0.13 mol) under a nitrogen atmosphere and refluxed for 21 hours.
  • the solution was cooled to room temperature and concentrated under reduced pressure.
  • the residue was applied to a silica gel column chromatography, and then the column was eluted with n-hexane - ethyl acetate (2 :21 to 1 : 1 ).
  • Step 3 2.3-Dihvdropyrazolor5.1-fo1thiazol-6-carbaldehvde and 2.3- dihydro- pyrazolof5.1 -bithiazol-7-carbaldehvde
  • the column was eluted with water (1 bed volume) and then 5 % (2 bed volume), 10 % (2 bed volume) and 20 % acetonitrile aqueous solution.
  • the combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a orange amorphous solid (2.09 g, 39.2 %, pH 7.10).
  • Step 1 Preparation of ethyl2,3-dihvdropyrazolor5,1-biri.3loxazole-6- carboxylate: To the stirred suspension of ethyl 5-hydroxy-1 H-pyrazole-3-carboxylate (10.34 g, 0.66 mol) and 36.62 g of potassium carbonate in 500 ml of acetonitrile was added 13.68 g of 1 ,2-dibromoethane, and refluxed for 16 hours. The reaction mixture was allowed to cool to room temperature, then filtered, the solid was washed with acetonitrile. The filtrate was concentrated to an oil. The residue was dissolved in ethyl acetate and extracted with water.
  • Step 2 Preparation of 2.3-dihvdropyrazolor5.1-biri.3loxazole-6-methanol: To the stirred solution of ethyl2,3-dihydropyrazolo[5,1-b][1,3]oxazole-6- carboxylate
  • Step 3 Preparation of 2.3-dihvdropyrazolor5,1-b1H,31oxazole-6-carbaldehvde: To the stirred solution of 2,3-dihydropyrazolo[5,1-b][1 ,3]oxazole-6-methanol
  • Step 4 4-Nitrobenzv (5R)-6-r(acetyloxyH2.3-dihvdropyrazolor5.1- bi H ,31oxazol-6-yl) -)methyll-6-bromo-7-oxo-4-thia-1 -azabicvclor3.2.01hept-2- ene-2-carboxylate: 2,3-dihydropyrazolo[5,1-b][1,3]oxazole-6-carbaldehyde (607 mg, 4.3 mmol) and the dry THF solution (20 mL) of (5R 1 6S)-6-bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept- 2-ene-2-carboxylic acid 4-nitro-benzyl ester (1.54 g, 4.6 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr 2 : 0(Et) 2 (2.21 g
  • Step 1 5-acetyl-4.5.6 J-tetrahvdrothienore. ⁇ -clpyridine- ⁇ -carbaldehvde: To a cold (0° C) suspension of 1.5 g.(7.4 mmol) of 4,5,6,7-tetrahydrothieno[3,2- c]pyridine-2-carbaldehyde hydrochloride in 50 mL methylene chloride, under N 2 atm., dry conditions, was added dropwise under stirring 2.6 mL (2.5 eqs) of triethylamine. RM stirred for 30 min at 0° C.
  • Step 2 Preparation of 4-nitrobenzyl(5R ⁇ -6-F(acetyloxy)(5-acetyl-4.5,6.7- tetrahvdrotienor3.2-cl pyridin-2-yl)methv ⁇ -6-bromo-7-oxo-4-thia-1- azabicvclore. ⁇ .O.Ihept- ⁇ -ene- ⁇ carboxylate ⁇ -acetyM. ⁇ . ⁇ J-tetrahydrothienotS ⁇ -clpyridine ⁇ -carbaldehyde (540 mg, 2.57 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (950 mg, 2.5 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr 2
  • Step 3 ( 5R.6Z)-6-r ( 5-acetyl-4.5.6.7-tetrahvdrothienor3.2-clpyridin-2- v ⁇ methvlenei-oxo ⁇ -thia-i-azabicvclora. ⁇ .O.Ihept ⁇ -ene ⁇ -p.arhnwIic acid (E+2 Isomers mixture.Sodium salt)
  • Step 2 6.7-Dihvdro-4H- ⁇ .2.31oxadiazolor4.3-ci ⁇ .41oxazin-8-ium-3-olate
  • THF 250 ml
  • Step 4 6.7-Dihvdro-4H-pyrazolor5,1-ci ⁇ .41oxazin-2-ylmethanol
  • ethyl 6,7-dihydro-4H-pyrazolo[5,1-c][1 ,4]oxazine-2-carboxylate (1.57 g, 8.0 mmol) in methylene chloride (30 ml)
  • the mixture was warmed to room temperature for 2 hr.
  • Step 5 6.7-Dihvdro-4H-pyrazolof5,1-ciri .41oxazine-2-carbaldehyde
  • Step 7 (5/?. ⁇ Z)- ⁇ -(6.7-dihvdro-4H-pyrazolor5.1 -ciH .41oxazin-2-ylmethylene ⁇ -7- oxo-4-thia-1 -azabicvclore. ⁇ .OIhept- ⁇ -ene- ⁇ -carboxylic acid
  • Step 1 Preparation of ethyl 6,7-dihvdro-5H-pyrazolor5,1-biri,31oxazine- 2-carboxvlate: To the stirred suspension of ethyl ⁇ -hydroxy-I H-pyrazole-S-carboxylate (10.34 g, 0.66 mol) and 36.62 g of potassium carbonate in 500 ml of acetonitrile was added 14.7 g of 1 ,3-dibromopropane, and refluxed for 16 hours. The reaction mixture was allowed to cool to room temperature, then filtered, the solid was washed with acetonitrile. The filtrate was concentrated to an oil.
  • Step 2 Preparation of 2.3-dihvdro-5H-pyrazolor5,1-bi ⁇ .31oxazin-2-yl- methanol:
  • Step 3 Preparation of 6,7-dihvdro-5H-pyrazolor5,1-blH,31oxazine-2- carbaldehvde: To the stirred solution of 2,3-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-2-yl-methanol
  • Step 4 4-Nitrobenzv(5R)-6-r(acetyloxyH6,7-dihvdro-5H-pyrazolor5,1 - 2-carboxylate:
  • the reaction mixture was filtered, cooled to 3 0 C, and 0.1 M NaOH was added to adjust pH to 8.5.
  • the filtrate was washed with ethyl acetate and the aqueous layer was separated.
  • the aqueous layer was concentrated under high vacuum at 35 0 C to give yellow precipitate.
  • the product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% acetonitrile: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried.
  • the reaction mixture was refluxed for 4 days.
  • the mixture was quenched with small amount of saturated potassium carbonate solution, dried (MgSO 4 ) and filtered.
  • the filtrate was concentrated under reduced pressure.
  • the residue was applied to silica- gel column chromatography, then the column was eluted with 10% methanol in chloroform.
  • the titled compound was obtained as a white solid (1.49 g, 89 %).
  • the reaction mixture was refluxed for 1 hour. After refluxing, the mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was dried in vacuo and the crude 5-(4,5-dihydrothiazol-2-yl)-4,5,6,7- tetrahydropyrazolo[1,5-a]pyrazine-2-carbaldehyde was obtained as a colorless solid.
  • the crude aldehyde thus obtained(2.56 g) was added to a dry acetonitrile (200 ml) solution of MgBr 2 (7.36 g) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 minutes.
  • the reaction vessel was covered with foil to exclude light.
  • the reaction mixture was vigorously stirred for 2 hours at 30 to 35 0 C.
  • the reaction mixture was cooled at 0 0 C, and then the pH was adjusted to 7.6.
  • Ethyl acetate was added to the reaction mixture and filtered through a pad of Celite. The pad was washed with water and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0 C.
  • the concentrate was applied to Diaion HP-21 (170 ml, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with water and then with 5% to 15% acetonitrile aqueous solution. The combined active fractions was concentrated under high vacuum at 35 0 C and lyophilized to give the titled compound as a crude yellow amorphous solid (1.60 g).
  • the titled compound was prepared from 0.669 grams of methyl 2-formyl-4,7- dihydrofuro[2,3-c]pyridine-6(5H)-carboxylate and 1.155 grams of 4-nitrobenzyl (5R)- 6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate yielded 1.65 grams of product (84%), which was used directly for the next step. MS: 652.2(M+H)
  • Microtiter plates containing 50 ⁇ L per well of two- fold serial dilutions of piperacillin combined with a constant amount (4ug/ml) of a B- lactamase inhibitor were inoculated with 50 ⁇ L of inoculum to yield the appropriate density (10 5 CFU/mL) in 100 ⁇ L final volume.
  • the plates were incubated for 18 - 22 hours at 35 0 C in ambient air.
  • the minimal inhibitory concentration (MIC 50 ) for all isolates was defined as the lowest concentration of antimicrobial agent that completely inhibits the growth of the organism as detected by the unaided eye.
  • MIC 50 data obtained by the above said procedure are enlisted in Table 1.
  • a control piperacillin has an MIC 50 value of >64 ⁇ g/mL.
  • Both OXA-10 and PSE-2 are class D ⁇ -lactamases. (Bush, K. Jacoby, G.A., Medeiros, A.A. Antimicrob. Agents

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Abstract

ABSTRACT This invention relates to certain bicyclic 6-alkylidene penems which act as a inhibitor of class-D enzymes. β-Lactamases hydrolyze β-lactam antibiotics, and as such serve as the primary cause of bacterial resistance. The compounds of the present invention when combined with β-lactam antibiotics will provide an effective treatment against life threatening bacterial infections. In accordance with the present invention there are provided compounds of general formula I or a pharmaceutically acceptable salt or in vivo hydrolyzable ester R5 thereof: Formula (I) wherein: One of A and B denotes hydrogen and the other an optionally substituted fused bicyclic heteroaryl group; and X=O or S.

Description

BICYCLIC 6-ALKYLIDENE- PENEMS AS CLASS-D BETA- LACTAMASES INHIBITORS
This invention relates to certain bicyclic 6-alkylidene penems which act as a inhibitor of class-D enzymes. β-Lactamases hydrolyze β-lactam antibiotics, and as such serve as the primary cause of bacterial resistance. The compounds of the present invention when combined with β-lactam antibiotics will provide an effective treatment against life threatening bacterial infections.
BACKGROUND OF THE INVENTION
Class D β-lactamases are the smallest (27 kDa) amongst the active-site- serine β-lactamases. These enzymes lack overall amino acid sequence (<20% amino acid identity) with the more prevalent and better-understood β-lactamases of classes A and C ( Naas, T. and Nordmann, P. Curr. Pharm. Design, 1999, 5,865). To date, almost 30 class D enzymes are known. Class D β-lactamases are also called oxacillinases because of their ability to hydrolyze oxacillin and cloxacillin two to four times faster than classical penicillins such as penicillin G (Ledent, P., Raquet,X, Joris, B. VanBeemen, J, Frere, J. M. Biochem. J.1993,292,555). They are designated OXA-1 , OXA-2, etc., and fall into at least five subgroups on the basis of phylogeny analysis ( Barlow, M, Hall, B.G. J. MoI. Evol. 2002, 55,314.).OXA-1 is the most common of the class D enzymes and is found in up to 10% of Escherichia coli isolates, in Pseudomonas aeruginosa and in epidemic strains of salmonellae (Medeiros, A.A. Brit. Med. J. 1984,40,18. The genes for most of these enzymes are borne either as chromosomal or plasmid-mediated, which facilitate their dissemination among various organisms. The current knowledge about the catalytic mechanism of the class D β-lactamases is rather limited (Golemi.D, Maveyraud.L, Vakulenko.S, Tranier.S, Ishiwata, A, Kotra, L.P.,Samana, J-P., Mobashery, S. J. Am. Chem. Soc. 2000,122, 6132). Class D enzymes are dimeric, however, OXA-1 from Escherichia coli is found to be monomeric in solution and in the crystal, (Sun, T1 Nukuga, M, Mayama, K, Braswell, E.H., Knox. J.R. Protein Sci., 2003, 12,82.). As a result of point mutations and plasmid transfer, natural OXA variants (e.g. OXA-15, OXA-18, OXA-19) have arisen with an expanded substrate spectrum that includes imipenem and third-generation cephalosporins such as cefotaxime, ceftriaxone, and aztreonam while new variants such as OXA-11 and OXA-14 to OXA-20, show an extended-spectrum profile (ESBLs). These aspects make them important clinically (Buynak, J, Curr. Med. Chem., 2004, 11, 1951).
Penicillins, cephalosporins, and carbapenems are the most frequently and widely used β-lactam antibiotics in the clinic. However, the development of resistance to β-lactam antibiotics by different pathogens has had a damaging effect on maintaining the effective treatment of bacterial infections. (Coleman, K. Expert Opin. Invest. Drugs 1995, 4, 693; Sutherland, R. Infection 1995, 23 191 ; Bush, K, Cur. Pharm. Design 1999, 5, 839) The most significant known mechanism related to the development of bacterial resistance to the β-lactam antibiotics is the production of class-A, class-B, class-C and class-D β-lactamases. These enzymes degrade the β-lactam antibiotics, resulting in the loss of antibacterial activity. Class-A enzymes preferentially hydrolyze penicillins, class-B hydrolyze all B-lactams including carbapenems, class-C lactamases have a substrate profile favoring cephalosporin hydrolysis, whereas substrate preference for class D β-lactamases include oxacillin. (Bush, K.; Jacoby, G.A.; Medeiros, A.A. Antimicrob. Agents Chemother. 1995, 39, 1211). To date over 250 different β-lactamases have been reported ( Payne, D.J,: Du, W and Bateson, J. H. Exp. Opin. Invest. Drugs 2000, 247.) and there is a need for a new generation of broad spectrum β-lactamase inhibitors. Bacterial resistance to these antibiotics could be greatly reduced by administering the β-lactam antibiotic in combination with a compound which inhibits these enzymes.
The commercially available β-lactamase inhibitors such as clavulanic acid, sulbactam and tazobactam are all effective against class-A producing pathogens. Clavulanic acid is clinically used in combination with amoxicillin and ticarcillin; similarly sulbactam with ampicillin and tazobactam with piperacillin. However, these compounds are ineffective against class C producing organisms. The mechanism of inactivation of class-A β-lactamases (such as PCI and TEM-1) has been elucidated. (Bush, K.; Antimicrob. Agents Chemother. 1993, 37, 851 ; Yang, Y.; Janota, K.; Tabei, K.; Huang, N.; Seigal, M.M.; Lin, Y.I.; Rasmussen, BA and Shlaes, D.M. J. Biol. Chem. 2000, 35, 26674-26682). To date there are no reported inhibitors of class D enzymes in clinical use.
Recently certain 6-methylidene penems bearing a bicyclic heterocycle as class-A, class-B and class-C β~-lactamse inhibitors have been disclosed in US 2004-0077622 A1 , which is hereby incorporated by reference thereto. In addition a number of 6- methylidene penems bearing a tricyclic heterocycle as class-A, class-B, and class-C β-lactamase inhibitors have been disclosed in US 2004-00043978A1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to novel, low molecular weight broad spectrum β-lactam compounds, and in particular to a class of bicyclic heteroaryl substituted 6- alkylidene penems which have β-lactamase inhibitory activity that when used in combination with a β-lactam antibiotic enhance the activity against class-D producing organisms and thereby enhance the antibacterial properties. The compounds are therefore useful in the treatment of antibacterial infections in humans or animals, either alone or in combination with other antibiotics. The compounds may be prepared in accordance with US 2004-0077622A1 which is hereby incorporated by reference thereto.
In accordance with the present invention there are provided compounds of general formula I or a pharmaceutically acceptable salt or in vivo hydrolyzable ester R5 thereof:
Figure imgf000005_0001
I and preferred compounds of the formula:
Figure imgf000005_0002
wherein:
One of A and B denotes hydrogen and the other an optionally substituted fused bicyclic heteroaryl group. The expression 'fused bicyclic heteroaryl group' is used in the specification and claims to mean:
A group comprising two fused rings in which one has aromatic character [i.e. Huckel's rule (4n+2)] and the other ring is non-aromatic;
The fused bicyclic heteroaryl group contains one to six heteroatoms selected from the group O, S, N and N-R1;
The fused bicyclic heteroaryl group is bonded to the remainder of the molecule through a carbon atom in the aromatic ring as shown in the formula I; The aromatic ring of the fused bicyclic heteroaryl group contains five or six ring atoms (including bridgehead atoms) selected from CR2 , N, O, S or N-R1. The aromatic ring of the fused bicyclic heteroaryl group contains 0 to 3 heteroatoms selected from the group O, S, N and N-R1;
The non-aromatic ring of the fused bicyclic heteroaryl group contains five to eight ring atoms (including bridgehead atoms) selected from CR4R4, N, N-R1, O, S(O)n where n= 0-2. The non-aromatic ring of the fused bicyclic heteroaryl group contains O to 4 heteroatoms selected from N, N-R1, O or S(O)n where n = O to 2 . X is O or S, preferably S;
R5 is H1 an in vivo hydrolyzable ester such as C1 -C6 alkyl, C5 - C6 cycloalkyl, CHR3OCOCI -C6 or salts such as Na, K, Ca; preferably R5 is H or a salt; R1 is H, optionally substituted -C1-C6 alkyl, optionally substituted -aryl, optionally substituted -heteroaryl or mono or bicyclic saturated heterocycles, optionally substituted -C3-C7 cycloalkyl, optionally substituted -C3-C6 alkenyl, optionally substituted -C3-C6 alkynyl with the proviso that both the double bond and the triple bond should not be present at the carbon atom which is directly linked to N; optionally substituted -C1-C6 per fluoro alkyl, -S(O)P optionally substituted alkyl or aryl where p is 2, optionally substituted -C=Oheteroaryl, optionally substituted - C=Oaryl, optionally substituted -C=O (C1-C6) alkyl, optionally substituted -C=O (C3- C6) cycloalkyl, optionally substituted -C=O mono or bicyclic saturated heterocycles, optionally substituted C1-C6 alkyl aryl, optionally substituted C1-C6 alkyl heteroaryl, optionally substituted aryl-C1-C6 alkyl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, -CONR6R7, -SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted -alkyl-O-alkyl-aryl, optionally substituted -alkyl-O-alkyl-heteroaryl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, optionally substituted C1-C6alkyl aryloxyaryl, optionally substituted C1-C6 alkyl aryloxyheteroaryl, optionally substituted alkyl aryloxy alkylamines, optionally substituted alkoxy carbonyl, optionally substituted aryloxy carbonyl, optionally substituted heteroaryloxy carbonyl. Preferred R1 groups are H, optionally substituted alkyl, optionally substituted aryl, -C=O(CI -C6)alkyl, C3- C6alkenyl, C3-C6alkynyl, optionally substituted cycloalkyl, S02alkyl, S02aryl, optionally substituted heterocycles, -CONR6R7, and optionally substituted heteroaryl.
R2 is hydrogen, optionally substituted C1-C6 alkyl, optionally substituted C2-
C6 alkenyl having 1 to 2 double bonds, optionally substituted C2-C6 alkynyl having 1 to 2 triple bonds, halogen, cyano, N-R6R7, optionally substituted C1-C6 alkoxy, hydroxy; optionally substituted aryl, optionally substituted heteroaryl, COOR6, optionally substituted alkyl aryloxy alkylamines, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted C3-C6 alkenyloxy, optionally substituted C3 -C6 alkynyloxy, C1-C6 alkylamino-C1-C6 alkoxy, alkylene dioxy, optionally substituted aryloxy-C1-C6 alkyl amine, C1-C6 perfluoro alkyl, S(0)q- optionally substituted C1-C6 akyl, S(0)q- optionally substituted aryl where q is O, 1 or 2, CONR6R7, guanidino or cyclic guanidino, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted C1-C6 alkylheteroaryl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, optionally substituted heteroaryloxyaryl, optionally substituted C1-C6alkyl aryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl , optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted alkyiaryloxyalkylamines. Preferred R2 groups are H, optionally substituted alkyl, optionally substituted alkoxy, optionally substituted heteroaryl, halogen, CN, hydroxy, optionally substituted heterocycle, -CONR6R7, COOR6, optionally substituted aryl, S(O)q-alkyl, and S(O)q-aryl. R3 is hydrogen, C1-C6 alkyl, C5 - C6 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl; preferred R3 groups are H or C1-C6 alkyl;
R4 is H, optionally substituted C1-C6 alkyl, one of R4 is OH, C1-C6 alkoxy, - S-C1-C6 alkyl, COOR6, -NR6R7, -CONR6R7 ; or R4R4 may together be =0 or R4R4 together with the carbon to which they are attached may form a spiro system of five to eight members with or without the presence of heteroatoms selected N, O, S=(O)n (where n =0 to 2), N-R1; preferred R4 groups are H, C1-C6 alkyl, NR6R7 or R4R4 together with the carbon to which they are attached may form a spiro system of five to eight members with or without the presence of heteroatoms, eg one or two of oxygen, nitrogen and sulfur;
R6 and R7 are independently H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C1-C6 alkyl aryl, optionally substituted arylalkyl, optionally substituted heteroarylalkyl, optionally substituted C1-C6 alkyl heteroaryl, R6 and R7 can be together to form a 3-7 membered saturated ring system optionally having one or two heteroatoms such as N-R1, O, S=(O)n n = 0-2. Preferred R6 and R7 groups are H, C1-C6 alkyl, arylalkyl, heteroarylalkyl or R6 and R7 together forming a 3-7 membered saturated ring system optionally having one or two heteroatoms. Chemical Definitions
The term alkyl means both straight and branched chain alkyl moieties of 1-12 carbons, preferably of 1-6 carbon atoms.
The term alkenyl means both straight and branched alkenyl moieties of 2-8 carbon atoms containing at least one double bond, and no triple bond, preferably the alkenyl moiety has 1 or two double bonds. Such alkenyl moieties may exist in the E or Z conformations; the compounds of this invention include both conformations. In the case of alkenyl, heteroatoms such as O, S or N-R1 should not be present on the carbon that is bonded to a double bond;
The term alkynyl includes both straight chain and branched alkynyl moieties containing 2-6 carbon atoms containing at least one triple bond, preferably the alkynyl moiety has one or two triple bonds. In the case of alkynyl, hetero atoms such as O, S or N-R1 should not be present on the carbon that is bonded to a double or triple bond;
The term cycloalkyl refers to a alicyclic hydrocarbon group having 3-7 carbon atoms.
The term perfluoroalkyl is used herein to refer to both straight- and branched- chain saturated aliphatic hydrocarbon groups having at least one carbon atom and two or more fluorine atoms. Examples include CF3, CH2CF3, CF2CF3 and CH(CF3)2.
The term halogen is defined as Cl, Br, F, and I.
If alkyl, alkenyl, alkynyl, or cycloalkyl is "optionally substituted", one or two of the following are possible substituents: nitro, -aryl, -heteroaryl, alkoxycarbonyl-, -alkoxy, -alkoxy-alkyl, alkyl-O-C2-C4alkyl-O-, -cyano, -halogen, -hydroxy, -N-R6R7, - COOH, -COO-alkyl, -trifluoromethyl, -trifluoromethoxy, arylalkyl, alkylaryl, R6R7N-alkyl-, HO-C1-C6-alkyl-, alkoxyalkyl-, alkyl-S-, -SO2N-R6R7, rSO2NHR6, - CO2H, CONR6R7, aryl-O-, heteroaryl-O-, -S(O)s-aryl (where s = 0 -2), -alkyl-O-alkyl- NR6R7, -alkyl-aryl-O-alkylN-R6R7, C1-C6alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy- alkyl-O-, R6R7N-alkyl-, and -S(O)s-heteroaryl (where s = 0 -2); Preferred substitutents for alkyl, alkenyl, alkynyl, and cycloalkyl include: halogen, nitro, aryl, heteroaryl, -COOH, -COO-alkyl, alkoxycarbonyl-, alkoxy, -alkoxy-alkyl, -cyano, hydroxy, and -N-R6R7.
Aryl is defined as an aromatic hydrocarbon moiety selected from the group: phenyl, α-naphthyl, β-naphthyl, biphenyl, anthryl, tetrahydronaphthyl, fluorenyl, indanyl, biphenylenyl, acenaphthenyl, groups. The preferred aryl groups are phenyl and biphenyl.
Heteroaryl is defined as a aromatic heterocyclic ring system (monocyclic or bicyclic) where the heteroaryl moieties are selected from: (1) furan, thiophene, indole, azaindole, oxazole, thiazole, isoxazole, isothiazole, imidazole, N-methylimidazole, pyridine, pyrimidine, pyrazine, pyrrole, N-methylpyrrole, pyrazole, N- methylpyrazole, 1 ,3,4-oxadiazole, 1 ,2,4-triazole, 1-methyl-1 ,2,4-triazole, 1 H-tetrazole, 1-methyltetrazole, benzoxazole, benzothiazole, benzofuran, benzisoxazole, benzimidazole, N-methylbenzimidazole, azabenzimidazole, indazole, quinazoline, quinoline, and isoquinoline; (2) a bicyclic aromatic heterocycle where a phenyl, pyridine, pyrimidine or pyridizine ring is: (a) fused to a 6-membered aromatic (unsaturated) heterocyclic ring having one nitrogen atom; (b) fused to a 5 or 6- membered aromatic (unsaturated) heterocyclic ring having two nitrogen atoms; (c) fused to a 5-membered aromatic (unsaturated) heterocyclic ring having one nitrogen atom together with either one oxygen or one sulfur atom; or (d) fused to a 5- membered aromatic (unsaturated) heterocyclic ring having one heteroatom selected from O, N or S. Preferred heteroaryl groups are furan, oxazole, thiazole, isoxazole, isothiazole, imidazole, N-methylimidazole, pyridine, pyrimidine, pyrazine, pyrrole, N- methylpyrrole, pyrazole, N-methylpyrazole, 1 ,3,4-oxadiazole, 1 ,2,4-triazole, 1- methyl-1 ,2,4-triazole, 1 H-tetrazole, 1-methyltetrazole, quinoline, isoquinoline, and naphthyridine.
If aryl or heteroaryl is Optionally substituted', one or two of the following are possible substituents: nitro, -aryl, -heteroaryl, alkoxycarbonyl-, -alkoxy, -alkoxy-alkyl, alkyl-O-C2-C4alkyl-O-, -cyano, -halogen, -hydroxy, -N-R6R7, -trifluoromethyl, - trifluoromethoxy, arylalkyl, alkylaryl, R6R7N-alkyl-, HO-C1-C6-alkyl-, alkoxyalkyl-, alkyl-S-, -SO2N-R6R7, -SO2NHR6, -CO2H1 CONR6R7, aryl-O-, heteroaryl-O-, -S(O)5- aryl (where s = 0 -2), -alkyl-O-alkyl-NR6R7, -alkyl-aryl-O-alkylN-R6R7, C1-C6alkyl, aikenyl, alkynyl, cycloalkyl, alkoxy-alkyl-O-, R6R7N-alkyl-, and -S(O)s-heteroaryl (where s = O -2); Preferred substituents for aryl and heteroaryl include: alkyl, halogen, -N-R6R7, trifluoromethyl, -trifluoromethoxy, arylalkyl, and alkylaryl.
Arylalkyl is defined as Aryl-C1-C6alkyl— ; Arylalkyl moieties include benzyl, 1- phenylethyl, 2-phenylethyl, 3-phenylpropyl, 2-phenylpropyl and the like. The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or aryl moiety as defined above.
Alkylaryl is defined as C1-C6alkyl-aryk The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the aryl or alkyl moiety as defined above.
Heteroaryl-C1-C6- alkyl is defined as a heteroaryl substituted alkyl moiety wherein the alkyl chain is 1-6 carbon atoms (straight or branched). Alkyl heteroaryl moieties include Heteroaryl-(CH2)1-6-- and the like. The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or heteroaryl moiety as defined above;
C1-C6 alkylheteroaryl is defined an alkyl chairrof 1-6 carbon atoms (straight or branched) attached to a heteroaryl moiety, which is bonded to the rest of the molecule. Ex. CI-Ce-alkyl-Heteroaryl-. The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents on the alkyl or heteroaryl moiety as defined above;
Saturated or partially saturated heterocycles groups are defined as heterocyclic rings selected from the moieties; aziridinyl, azetidinyl, 1 ,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, dihydrobenzimidazolyl, dihydrobenzofuranyl, dihydrobenzothienyl, dihydrobenzoxazolyl, dihydrofuranyl, dihydroimidazolyl, dihydroindolyl, dihydroisooxazolyl, dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl, dihydropyrrazinyl, dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, dihydroquinolinyl, dihydrotetrazolyl, dihydrothiadiazolyl, dihydrothiazolyl, dihydrothienyl, dihydrotriazolyl, dihydroazetidinyl, dihydro-1 ,4- dioxanyl, tetrahydrofuranyl, tetrahydrothienyl, tetrahydroquinolinyl, and tetrahydroisoquinolinyl. Preferred saturated or partially saturated heterocycles are aziridinyl, azetidinyl, 1 ,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, dihydroimidazolyl, and dihydroisooxazolyl.
C1-C6 alkyl mono or bicyclic saturated or partially saturated heterocycles is defined as an alkyl group (straight or branched) of C1-C6 attached to a heterocycles (which is defined before) through a carbon atom or a nitrogen atom and the other end of the alkyl chain attached to the rest of the molecule. The terms 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyi or heterocyclic portion of the molecule, as defined before;
Arylalkyloxyalkyl is defined as Aryl-C1-C6alkyl-O-C1-C6alkyl— The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl and/or aryl portions as defined before;
Alkyloxyalkyl is defined as C1-C6 alkyl-O-C1-C6alkyl— . The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before;
Aryloxyalkyl is defined as Aryl-O-C1-C6 alkyl—. The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl or aryl moiety as defined before;
Heteroarylalkyloxyalkyl is defined as Heteroaryl-C1-C6alkyl-O-C1-C6alkyl— The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl or heteroaryl moiety as defined before; Aryloxyaryl is defined as Aryl-O-Aryl— .. The term Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present on the aryl moiety as defined before;
Aryloxyheteroaryl is defined as Aryl-0-Heteroaryl- or -Aryl-O-Heteroaryl; In this definition either the aryl moiety or the heteroaryl moiety can be attached to the remaining portion of the molecule; The term Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present on the aryl moiety or on the heteroaryl moiety as defined before;
Alkyl aryloxyaryl is defined as Aryl-O-Aryl-C1-C6alkyl — ; The term Optionally substituted' refers to unsubstituted or substituted withi or 2 substituents present at the aryl moiety as defined before;
Alkylaryloxyheteroaryl is defined as Heteroaryl-O-Aryl-C1-C6alkyl~; The term
Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the aryl moiety or on the hetroaryl moiety as defined before;
Alkylaryloxyalkylamine is defined as R6R7N-CI -Cδalkyl-O-Aryl-CICΘalkyl— ; The terms 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl or aryl moiety as defined before; R6 and R7 as defined before;
Alkoxycarbonyl is defined as C1-C6alkyl-O-C=O-; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkyl portion of the alkoxy moiety as defined before;
Aryloxycarbonyl is defined as Aryl-O-C=O--; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the aryl moiety as defined before; Heteroaryloxy carbonyl is defined as Heteroaryl-O-C=O--; The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
Alkoxy is defined as C1-C6a!kyl-O~; The terms Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before;
Aryloxy is defined as Aryl-O--; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the aryl moiety as defined before;
Heteroaryloxy is defined as Heteroaryl-0--; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
Alkenyloxy is defined as C3-C6 alkene-O--; Example allyl-O--, bute-2-ene-0 like moieties; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkene moiety as defined before, with the proviso that no hetero atom such as O, S or N-R1 is present on the carbon atom, which is attached to a double bond;
Alkynyloxy is defined as C3-C6alkyne-O~; Example CH triple bond C-CH2-O-
, like moieties; The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyne moiety as defined before, with the proviso that no hetero atom such as O, S or N-R1 is present on a carbon atom which is attached to a double or triple bond;
Alkylaminoalkoxy is defined as R6R7N-CI -C6-alkyl-O-C1-C6-alkyl— , where the terminal alkyl group attached to the oxygen is connected to the rest of the molecule; The terms R6 and R7 are defined above; The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl moiety as defined before; Alkylenedioxy is defined as -0-CH2-O- or -O— (CH2)2— O— ;
Aryloxyalkylamine is defined as R6R7N-CI -Cβ-alkyl-O-Aryl-, where the aryl is attached to the rest of the molecule; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the alkyl or aryl moiety as defined before;
Arylalkenyl is defined as Aryl-C2-C8alkene-, with the proviso that no hetero atom such as O, S or N-R1 is present on the carbon atom, which is attached to a double bond; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present on the alkene or aryl moiety as defined before;
Heteroaryloxyalkyl is defined as Heteroaryl-O-C1-C6alkyl— ; The term 'optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety as defined before;
Heteroaryloxyaryl is defined as Heteroaryl-0-aryl— , where the aryl moiety is attached to the rest of the molecule; The term Optionally substituted' refers to unsubstituted or substituted with 1 or 2 substituents present at the heteroaryl moiety or the aryl moiety as defined before;
Alkoxy, alkoxyalkyl, alkoxyalkyloxy and alkylthioalkyloxy are moieties wherein the alkyl chain is 1-6 carbon atoms (straight or branched). Aryloxy, heteroaryloxy, arylthio and heteroarylthio are moieties wherein the aryl and heteroaryl groups are as herein before defined. Arylalkyloxy, heteroarylalkyloxy, arylalkylthio and heteroarylalkylthio are moieties wherein the aryl and heteroaryl groups are as herein before defined and wherein the alkyl chain is 1-6 carbons (straight or branched). Aryloxyalkyl, heteroaryloxyalkyl, aryloxyalkyloxy and heteroaryloxyalkyloxy are substituents wherein the alkyl radical is 1-6 carbon atoms. The terms monoalkylamino and dialkylamino refer to moieties with one or two alkyl groups wherein the alkyl chain is 1-6 carbons and the groups may be the same or different. The terms monoalkylaminoalkyl and dialkylaminoalkyl refer to monoalkylamino and dialkylamino moieties with one or two alkyl groups (the same or different) bonded to the nitrogen atom which is attached to an alkyl group of 1-3 carbon atoms. Examples of fused bicyclic heteroaryl groups are optionally substituted ring systems such as one of the following:
4,5,6,7-tetrahydrothieno[3,2-c]pyridine, optionally substituted by e.g., arylalkyl such as benzyl; by alkoxyarylalkyl such as 4-methoxy benzyl; by C1-C6alkyl such as methyl; by heteroarylalkyl such as pyridin-3-ylmethyl; by arylalkylCO- such as phenylacetyl; or heteroarylCO- such as pyridin-3-ylcarbonyl; e.g. by alkylCO- such as acetyl;
5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine, optionally substituted e.g., by C1-C6alkyl such as methyl;
5,6-dihydro-8H-imidazo[2,1-c][1,4]thiazine;
6,7-Dihydro-5H-pyrrolo[1 ,2-a]imidazole
5,6-Dihydro-8/-/-imidazo[2,1 -c][1 ,4]oxazine
5,6-Dihydro-4H-pyrrolo[1 ,2-ϋ]pyrazole 4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyridine
6-OXO-5.6, 7,8-tetrahydro-imidazo[1,2-a]pyrazine, optionally substituted e.g., by C1- C6alkyl such as methyl;
6,7-Dihydro-4H-pyrazolo[5,1-c][1 ,4]thiazine;
4H-5-thia-1 ,6a-diazapentalene; 7H-lmidazo[1 ,2-c]thiazole;
4-oxo-6,7-dihydro-4H-pyrazolo[5, 1 -c][1 ,4]oxazine;
6,7-Dihydro-4H-thieno[3,2-c]pyran;
6,7-Dihydro-4H-thieno[3,2-c]thiopyran;
6,7-dihydro-4H-thieno[3,2-c]pyridine, optionally substituted by C2-C7alkoxycarbonyl;
6,7,8,9-tetrahydro-5H-imidazo[1,2-a]azepine;
5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine, optionally substituted by arylalkyl such as benzyl;
S.δ-Dioxo^.S.βJ-tetrahydro-Sλ^pyrazolofδ, 1 -c][1 ,4]thiazine; 4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazine; 5,6-Dihydro-4/-/-cyclopenta[£)]furan; 4,5-Dihydro-6-thia-1 ,7a-diazaindene; 5,6-Dihydro-8-fy-imidazo[2,1-c][1 ,4]thiazine; 4H-5-thia-1 ,6a-diazapentalene; 2,3-Dihydropyrazolo[5,1-jb]thiazole; 2,3-Dihydropyrazolo[5, 1 -ό]oxazole; 6,7-dihydro-4/-/-pyrazolo[5,1-c][1,4]oxazine; 6,7-5H-Dihydropyrazolo[5,1-/j]oxazine; and
4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazine optionally substituted, .e.g. by alkoxyalkylCO- such as 2-methoxyacetyl; or by alkyloxyalkylCO- such as methoxyacetyl.
Examples of bicyclic heteroarylgroup:
Figure imgf000016_0001
I1A I1B I1C
In formula 1^\ Z1 , Z2 and Z3 are independently CR2, N, O, S or N-R1 and one of Z1 -Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I. When one of Z's is CR2 the other two Zs can be either two N or one N and O, S, N-R1 in any combinations with out disrupting the aromaticity; when two Z,s = CR2 the other Z can be optionally selected from one N, O, S or N-R1 in any combination with out disrupting the aromaticity;
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, N-R1, C=O; with the proviso that no S-S or O-O or S-O bond formation can occur to form the saturated ring system; t= 1 to 4.
In formula 1J3 Z1 , Z2 and Z3 are independently CR2, N, O, S or N-R1 and one of Z1 -Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
When one of Z's = CR2 , then the other two Z's can be independently CR2, N, O, S or N-R1 in any combinations with out disrupting the aromaticity;
When two Z's =N, then the other carbon in the ring is bonded to the penem portion of the molecule as shown in formula I. W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, N-R1, t= 1 tO 4;
Y1 and Y2 = N or C; with the proviso that when the aromatic heterocycle is imidazole, the saturated ring may not contain a S adjacent to the bridgehead carbon.
In formula ^C Z1 , Z2, Z3 and Z4 are independently CR2 or N and one of Z1
-Z4 is carbon and is bonded to the remainder of the molecule.
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1; with the proviso that no S-S or O-O or S-O bond formation can occur to form the saturated ring system; t= 1 to 4. Y1 and Y2 are independently C or N.
The more preferred embodiment of the formula 1-A: 1. t= 1 to 3.
2. In formula 1-A Z1 is N, S, N-R1 or O and one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
3. In formula 1-A Z3 is N, S, N-R1 or O and one of Z2 or Z1 is CR2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule as shown in formula I. 4. In formula 1-A Z2 is N, S, N-R1 or O and one of Z1 or Z3 is CR2 and the other of
Z1 or Z3 is carbon bonded to the remainder of the molecule as shown in formula
I 5. In formula 1-A Z1 is N, N-R1, O or S and Z2 is N, O or S and Z3 is a carbon bonded to the penem portion of the molecule as shown in formula I. 6. In formula I1A Z3 is N, N-R1, O or S and Z2 is N, O or S and Z1 is a carbon bonded to the penem portion of the molecule as shown in formula I.
7. In formula ±Λ Z1 is N, N-R1, O or S and Z3 is N, O or S and Z2 is a carbon bonded to the penem portion of the molecule as shown in formula I.
8. In formula 1-A Z1 is N, S, N-R1 or O and Z2 or Z3 is CR2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule; W1, W2 and W3 are independently CR4R4. 9. In formula 1-A Z3 is N, S, N-R1 or O and one of Z2 or Z1 is CR2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule; W1, W2, and W3 are independently CR4R4.
10. In formula 1-A. Z2 is N, S, N-R1 or O and one of Z1 or Z3 is CR2 and the other of Z1 or Z3 is carbon and is bonded to the remainder of the molecule; W1, W2, and
W3 are independently CR4R4.
11. In formula J^A Z1 is N, N-R1, O or S and Z2 is N, O or S; Z3 is a carbon bonded to the penem portion of the molecule; W1, W2, W3 are independently CR4R4.
12. In formula ±Λ Z3 is N, N-R1, O or S; Z2 is N, O or S; Z1 is a carbon bonded to the penem portion of the molecule; W1, W2, W3 are independently CR4R4.
13. In formula 1ΛV Z1 is N, N-R1, O or S ; Z3 is N1 O or S; Z2 is a carbon bonded to the penem portion of the molecule; W1, W2, W3 are independently CR4R4.
14. In formula tΛ\ Z3 is N, N-R1, O or S; Z1 is N, O or S; Z2 is a carbon bonded to the penem portion of the molecule; W1, W2, W3 are independently CR4R4.
15. In formula 1-A Z1 is N, S, N-R-, or O; one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule, t = 1 - 3; one W2 is N-R1, O or S(O)n n = 0-2 and another W2 is CR4R4.
16. In formula 1-A Z3 is N, S, N-R1 or O; one of Z2 or Z1 is CR2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule, t = 1 - 3; one W2 is N-R11 O Or S(O)H n = 0-2 and another W2 =CR4R4.
17. In formula ±Λ_ Z2 is N, S, N-R1 or O; one of Z1 or Z3 is CR2 and the other of Z1 or Z3 is carbon and is bonded to the remainder of the molecule; t = 1 - 3; one W2 is N-R1, O or S(O)n n = 0-2 and another W2 is CR4R4.
18. In formula 1-A when Z1 = N, N-R1, O or S and Z2 = N, O or S and Z3 = a carbon bonded to the penem portion of the molecule where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4. 19. In formula 1^A Z3 = N, N-R1, O or S and Z2 = N, O or S and Z1 = a carbon bonded to the penem portion of the molecule where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4.
20. In formula 1^A when Z1 = N1 N-R1, O or S and Z3 = N, O or S and Z2 = a carbon bonded to the penem portion of the molecule where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4.
21. In formula 1^. Z1 =N, S, N-R1 or O and Z2 or Z3 = CR2 and the other of Z2 or Z3 is carbon and is bonded to the remainder of the molecule; then W1 and W3 = CH2 or both hydrogens on the methylene linkage can be substituted to form a spiro system with or without the presence of hetero atoms selected from O, S=(O)n (n= 0 to 2), N-R1 to form five to eight membered cyclic system; t = 1 - 3; one W2 = N- R1 , O or S(O)n n = 0-2 and other W2 = CR4R4.
22. In formula 1-A Z3 =N, S, N-R1 or O and Z2 or Z1 = CR2 and the other of Z2 or Z1 is carbon and is bonded to the remainder of the molecule; then W1 and W3 = CR4R4; where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4.
23. In formula I2A. Z2 =N, S, N-R1 or O and Z1 or Z3 = CR2 and the other of Z1 or Z3 is carbon and is bonded to the remainder of the molecule; then W1 and W3 = CR4R4, where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4.
24. In formula I1A when Z1 = N1 N-R1, O or S and Z2 = N1 O or S then Z3 = a carbon bonded to the penem portion of the molecule; then W1 and W3 = CR4R4, where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4.
25. In formula I^ Z3 = N1 N-R1, O or S and Z2 = N1 O or S then Z1 = a carbon bonded to the penem portion of the molecule; then W1 and W3 = CR4R4, where t = 1 - 3 then one W2 = N-R1, O or S(O)n n = 0-2 and other W2 = CR4R4. 26. In formula I1A when Z1 = N, N-R1, O or S and Z3 = N, O or S then Z2 = a carbon bonded to the penem portion of the molecule; then W1 and W3 =CR4R4 ; t = 1 - 3; one W2 is N-R1, O or S(O)n n = 0-2 and another W2 is CR4R4.
27. In formula I1A Z3 is N, N-R1, O or S; Z1 is N, O or S; Z2 is a carbon bonded to the remainder of the molecule; W1 and W3 are independently CR4R4 ; t = 1 - 3; one W2 is N-R1, O or S(O)n n = 0-2 and another W2 is CR4R4.
The more preferred embodiments of the formula 1-B:
28. In formula I1B t=3.
29. In formula 1-B Z1 and Z3 are N; Y1 is N ; Y2 is C and Z2 is carbon and is bonded to the remainder of the molecule as shown in formula I.
30. In formula 1-B Z2 and Z3 are N; Y1 is N; Y2 is C and Z1 is carbon and is bonded to the remainder of the molecule as shown in formula I.
31. In formula IJB. Z1 is N, Y1 is N, Y2 is C, one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I.
32. In formula U5 Z1 is N, Y1 is C, Y2 is N, one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I.
33. In formula I1B Z1 is N, Y1 is N, Y2 is C, one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I, W-, and W3 are independently CR4R4; t = 1-3; one W2 is N-R1, O, S=(O)n (n = 0-2), and another W2 is CR4R4.
34. In formula 1J| Z1 is N, Y1 is C, Y2 is N, one of Z2 or Z3 is CR2 and the other of Z2 or Z3 is a carbon and is bonded to the remainder of the molecule as shown in formula I; W1 and W3 are independently CR4R4; t = 1-3; one W2 is N-R1, O, S=(O)n (n = 0-2), and another W2 is CR4R4. 35. In formula I1B. Z3 is N; Y1 is N; Y2 is C; one of Z1 or Z2 is CR2 and the other of Z1 or Z2 is carbon and is bonded to the remainder of the molecule as shown in formula I. 36. In formula I1B. Z2 is N; Y1 is N; Y2 is C; one of Z1 or Z3 is CR2 and the other of Z1 or Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
37. In formula 1-B Z1 and Z2 are N; Y1 is N; Y2 is C; and Z3 is carbon and is bonded to the remainder of the molecule as shown in formula I.
38. In formula I1B- Z1 , Z2 and Z3 are independently CR2; Y1 is C; Y2 is N; except one of Z1-Z3 is carbon and is bonded to the remainder of the molecule as shown in formula ].
39. In formula 1^B_ Z1 and Z3 are N; Y1 is N; Y2 is C; Z2 is carbon and is bonded to the remainder of the molecule as shown in formula I; and t = 1-3.
40. In formula 1-B Z2 and Z3 are N ; Y1 is N; Y2 is C; and Z1 is carbon and is bonded to the remainder of the molecule; and t = 1-3;
41. In formula 1-B Z2 and Z3 are N , Y1 is C and Y2 =N and Z1 is carbon and is bonded to the remainder of the molecule and t = 1-3; 42. In formula 1-B Z2 and Z3 are N , Y1 is N; Y2 is C; Z1 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CH2 or both hydrogens on the methylene linkage can be substituted to form a spiro system with or without the presence of hetero atoms selected from O, S(O)n n= 0-2, N-R1 to form five to eight membered cyclic system; t = 1-3 and W2 is CH2, N-R1, O, S(O)n where n = 0 -2.
43. In formula 1-B Z3 is N; Y1 is N; Y2 is C; Z1 is CR2 and Z2 is the carbon atom bonded to the remainder of the molecule.
44. In formula I1B- Z3 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z2 is the carbon atom bonded to the remainder of the molecule; W1, W2 and W3 are independently CR4R4; t = 1 to 3.
45. In formula I1B- Z3 is N; Y1 is N; Y2 is C; Z1 is CR2; Z2 is the carbon atom bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; and one of W2 is N-R1, O or S(O)n , and another W2 is CR4R4; t = 1-3.
46. In formula U|_ Z3 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z2 is the carbon atom bonded to the remainder of the molecule; W1 and W2 are independently CR4R4;
W3 is N-R1, O or S(O)n ; and t = 2. 47. In formula I1B- Z3 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z2 is the carbon atom bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; W2 is N-R1, O or S(O)n ; and t = 1.
48. In formula 1J5_ Z2 is N; Y1 is N; Y2 is C; Z3 is CR2; Z1 is the carbon bonded to the remainder of the molecule; Wi and W2 is CH2 or both hydrogens on the methylene linkage can be substituted to form a spiro system with or without the presence of hetero atoms selected from O, S(O)n n= 0-2, N-R1 to form five to eight membered cyclic system; W3 is N-R1, O or S(O)n ; and t = 3.
49. In formula 1-B Z2 is N; Y1 is N; Y2 is C, Z3 is CR2 ; Z1 is the carbon bonded to the remainder of the molecule; W1 and W3 are independently CH2 or both hydrogens on the methylene linkage can be substituted to form a spiro system with or without the presence of hetero atoms selected from O, S(O)n n= 0-2, N-R1 to form five to eight membered cyclic system; and one W2 is N-R1, O or S(O)n and another W2 is CR4R4; and t=2. 50. In formula 1-B Z2 is N; Y1 is N; Y2 is C; Z3 is CR2 ; Z1 is the carbon bonded to the remainder of the molecule; W1 and W3 are independently CH2 or both hydrogens on the methylene linkage can be substituted to form a spiro system with or without the presence of hetero atoms selected from O, S(O)n n= 0-2, N-R1 to form five to eight membered cyclic system; W2 is N-R1, O or S(O)n ; and t = 1. 51. In formula I1B. Z2 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z3 is the carbon bonded to the remainder of the molecule; W-, and W3 are independently CR4R4; one of W2 is N-R1, O or S(O)n and another W2 is CR4R4; and t = 3.
52. In formula ;M3_ Z2 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z3 is the carbon bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; one W2 is N-R1, O or S(O)n, and another W2 is CR4R4; and t = 2.
53. In formula 1J5. Z2 is N; Y1 is N; Y2 is C; Z1 is CR2 ; Z3 is the carbon bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; W2 is N- R1, O or S(O)n ; and t = 1.
54. In formula 1J3_ Z1 and Z2 are N; Y1 is N; Y2 is C; Z3 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4 ; one of W2 is N-R1, O or S(O)n and another W2 is CR4R4; and t = 3. 55. In formula 1-B Z1 and Z2 are N; Y1 is N; Y2 is C; Z3 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; one of W2 is N-R11 O Or S(O)n and another W2 is CR4R4; and t = 2.
56. In formula 1-B Z1 and Z2 are N; Y1 is N; Y2 is C; Z3 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; W2 is N-
R1, O or S(O)n ; and t = 1
57. In formula I1B. Z1 and Z2 are independently CR2 ; Y1 is C; Y2 is N; Z3 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; one Of W2 is N-R1, O or S(O)n ; another W2 is CR4R4; and t = 3 . 58. In formula I1B. Z1 and Z2 are independently CR2; Y1 is C and Y2 is N and Z3 is carbon and is bonded to the remainder of the molecule; Wi and W3 are independently CR4R4; and one W2 is N-R1, O or S(O)n and the other W2 is CR4R4; and t = 2.
59. In formula 1-B Z1 and Z2 are independently CR2; Y1 is C; Y2 is N; Z3 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently
CR4R4; W2 is N-R1, O or S(O)n ; and t = 1.
60. In formula 1-B Z1 and Z3 are independently CR2; Y1 is C; Y2 is N; Z2 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; one W2 is N-R1, O or S(O)n ; another W2 is CR4R4; and t = 3. 61. In formula IJJ. Z1 and Z3 are independently CR2; Y1 is C; Y2 is N; Z2 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; and one W2 is N-R1, O or S(O)n and the other W2 is CR4R4; and t = 2.
62. In formula 1-B Z1 and Z3 are independently CR2 ; Y1 is C; Y2 is N; Z2 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; W2 is N-R1, O or S(O)n ; and t = 1.
63. In formula I1B, Z3 and Z2 are independently CR2 ; Y1 is C; Y2 is N; Z1 is carbon and is bonded to the remainder of the molecule; W1 and W2 are independently CR4R4; one W2 is N-R1, O or S(O)n; another W2 is CR4R4; and t = 3.
64. In formula 1-B Z3 and Z2 are independently CR2 ; Y1 is C; Y2 is N; Z1 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently
CR4R4; one W2 is N-R1, O or S(O)n; the other W2 is CR4R4; and t = 2. 65. In formula 1-B Z3 and Z2 are independently CR2 ; Y1 is C; Y2 is N; Z1 is carbon and is bonded to the remainder of the molecule; W1 and W3 are independently CR4R4; W2 is N-R1, O or S(O)n ; and t = 1.
66. In formula I1B. Z3 is N; Y1 is N; Y2 is C; one of Z1 and Z2 is CR2 and the other is C; W1 is CR4R4; W2 is CR4R4; W3 is CH2, N-R1 or O; and t= 1.
67. In formula 1-B Z3 is N; Y1 is N; Y2 is C; one of Z1 and Z2 is CR2 and the other is C; W1 is CR4R4 ; W2 is C=O; W3 is N-R1; and t= 1.
68. In formula 1^B_ Z3 is N; Y1 is N; Y2 is C; one of Z1 and Z2 is CR2 and the other is C; W1 is N-R1 ; W2 is C=O; W3 is CR4R4; and t= 1. 69. In formula IJL Z3 is N; Y1 is N; Y2 is C; one of Z1 and Z2 is CR2 and the other is C; W1 is C=O; W2 is N-R1 ; W3 is CH2; and t= 1.
The more preferred embodiments of the formula I^ are:
70. In formula ^C Z1 , Z2, Z3 and Z4 are independently CR2 ;one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C; t = 1 to 3; and
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
71. In formula 1j£ Z1, Z2, Z3 and Z4 are independently CR2 and one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 = C or N; t = 1 to 3; W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 72. In formula I1C Z1, Z2, Z3 and Z4 are independently CR2; Y1 and Y2 are N; t = 1 to 3; W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
73. In formula ±G Z1 is N and Z2, Z3 and Z4 are independently CR2 ; Y1 and Y2 are C; t = 1 to 3; W1, W2 and W3 are independently CR4R4, S, SO, SO2, O1 or N-R1.
74. In formula I1C Z1 is N and Z2, Z3 and Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C; Y2 is N; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
75. In formula t£ Z2 = N and Z1 , Z3 and Z4 are independently CR2 ; one of Z1- Z4 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 76. In formula I1C Z2 is N and Z1 , Z3 and Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C; Y2 is N; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 77. In formula IX Z3 is N; Z1, Z2 and Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Yi and Y2 are C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-RL
78. In formula IX Z3 is N and Z1, Z2 and Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C and Y2 is N; t
= 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
79. In formula IX Z4 is N and Z1 , Z2 and Z3 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 80. In formula IX Z4 is N and Z1 , Z2 and Z3 are independently CR2; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is N; Y2 is C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S1 SO1 SO2, O, or N-R1.
81. In formula IX. Z1 is N and Z2, Z3 and Z4 are independently CR2; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O1 or N-R1.
82. In formula 1X Z1 and Z2 are N and Z3 or Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C; Y2 is N; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 83. In formula IX. Z1 and Z3 are N and Z2 or Z4 are independently CR2 ; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C; Y2 is N; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O1 or N-R1.
84. In formula IX Z1 and Z4 are N and Z2 or Z3 are independently CR2; one of Z1-Z4 is carbon and is bonded to the remainder of the molecule; Y1 is N; Y2 is C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-
85. In formula IX Z1, Z2, Z3 are N and Z4 is carbon and is bonded to the remainder of the molecule; Y1 is C; Y2 is N; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S1 SO, SO2, O, or N-R1.
86. In formula IX. Z1, Z3 and Z4 are N and Z2 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C; t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1. 87. In formula ^NC Z1 , Z2 and Z4 are N . and Z3 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C and t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
88. In formula ^C Z2, Z3, Z4 are N and Z1 is carbon and is bonded to the remainder of the molecule; Y1 and Y2 are C and t = 1 to 3; and W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1.
The compounds according to the present invention have β-lactamase inhibitory and antibacterial properties and are useful for the treatment of infections in humans and animals. It should be noted that the compounds of the present invention, when used in combination with β-lactam antibiotics will result in the increased antibacterial activity (synergistic effect) against class-D producing organisms. β-Lactam antibiotics include penicillin antibiotics such as piperacillin, amoxycillin, ticarcillin, benzylpenicillins, ampicillin, sulbenicillin, other known penicillins, cephalosporins such as cefatrizine, cephaloridine, cephalothin, cefazolin, cephalexin, cephradine, other known cephalosporins, aztreonam and latamoxef (Moxalactam), and carbapenems such as meropenem and imipenem. Most preferably compounds of this present invention are used with piperacillin or amoxicillin which has a broad spectrum of activity against Gram positive and Gram negative pathogens.
The compounds of the present invention may be provided prior to, simultaneously with, or subsequent to a β-lactam antibiotic ("co-administration"). By "provided", it is intended to include administering the compound directly or in vivo, e.g. pro-drugs. When the compounds of the present invention are co-administered with a β-lactam antibiotic, the ratio of the amount of the compound to the amount of the β-lactam antibiotic may vary in a wide range. The ratio of β-lactam antibiotic to β- lactamase inhibitor may vary from 1:1 to 100:1. Preferably the ratio of the β-lactam antibiotic to β-lactamase inhibitor is less than 10:1. The composition of the present invention may be in a form suitable for oral (PO), intravenous (IV) or topical administration. The compositions of the invention may be in a form of tablets, capsules, creams, syrups, suspension, sterile solutions suitable for injection or infusion. Preferably, the compounds of the present invention are co-administered with piperacillin intravenously or amoxicillin intravenously or orally.
A compound's structural formula includes any tautomers, any stereoisomers (except where stereochemistry is clearly noted) and any crystalline forms.
General Synthetic Scheme(s) for Preparation of Compounds
This invention also provides a process for preparing a compound of formula I which comprises subjecting to reductive elimination a compound of fomula II:
Figure imgf000027_0001
wherein A' is A or B as defined above, X is O or S, P is an ester leaving group, e.g., acetate, mesylate, triflate or tosylate, and R is a protecting group, followed if necessary by removal of the protecting group, to give a compound of formula I wherein R5 is hydrogen; and if desired converting to a pharmaceutically acceptable salt or to an ester wherein R5 is C1 -C6 alkyl, C5 - C6 cycloalkyl, or CHR3OCOCI -Cβalkyl. Conveniently compounds of the general formula I can be prepared by a novel, mild and a facile way, by condensing an appropriately substituted aldehyde 4 with a 6-bromo-penem derivative of structure 1.. (Scheme 1) in the presence of anhydrous MgBr2 or MgBr2: etherate and a base such as triethylamine or DBU or DMAP, preferably at -2O0C to -400C. The intermediate aldol product 5 can be functionalized with acid chlorides or anhydrides to an acetate, triflate or a tosylate 6. Compound 6 can be smoothly converted to the desired product by a reductive elimination process using a metal such as activated zinc and phosphate buffer at 200C to 350C at a pH of 6.5 to 8.0. If the protecting group on the carboxylate oxygen is a para-nitrobenzyl substitiuent then the reductive elimination and deprotection can be achieved by a single step. However, if the protecting group is other than a para-nitrobenzyl substituent, a two step procedure can be followed depending up on the nature of the protecting group. The product can be isolated as a free acid or as an alkali metal salt. The above mentioned two step procedure can be carried out in one step by carrying out the entire process without isolating the intermediate 6. This is a very general, relatively simple and efficient procedure in terms of yield and economic feasibility. This procedure can be adopted to large scale synthesis and is amenable to a variety of aldehydes. Alternatively, compound 6 can be hydrogenated at 40 psi pressure in the presence of Pd/C (10%) in THF and 6.5 phosphate buffer to yield the final product.
The above mentioned aldol condensation reaction is very versatile and it can be applied to any bromopenem derivative, where the carboxy group is protected other than 4-nitrobenzyl moiety. Example of other protecting group include benzyl, para-methoxy benzyl derivative, benzyhydrol , trityl, alkyl and allyl derivatives. However, when the protecting group is other than 4-nitrobenzyl group, a separate deprotection step need to be carried out after the reductive elimination procerdure. The chemistry involved in the deprotection step is well known to people who are skilled in that art.
The required aldehydes 4 for the above mentioned transformations can be prepared from their respective alcohol derivatives by MnO2 oxidation or by Swern oxidation. In some cases the required aldehyde functionality can be introduced directly in the heterocyclic moiety by a Vilsmier Haack reaction using DMF/POCI3. The aldehydes required for the present investigation may be prepared as depicted in Schemes 2 to 5. The N-(tert-butoxycarbonyl)- (ie) t-Boc protected -4-piperidone is treated with DMF/POCI3 to yield 4-chloro -3 -formyl derivative. (Scheme 2). This reaction can be conducted on tetrahydro-4H-pyran-4-one and the corresponding tetrahydro-4H-thiopyran-4-one derivative to give the corresponding oxygen and the sulfur derivatives. This reaction can also be conducted on five to eight membered cyclic ketones derivatives. The chloro formyl intermediate can be reacted with 2- mercapto ethyl acetate to give the thieno derivative. The ester can be converted to alcohol, which can be converted to the starting aldehyde functionality. Scheme 3 illustrates the preparation of the imidazolo- tetrahydro pyridine derivative and imidazolo pyrazine derivative. 2- aminopyridine or 2-aminopyrazine can be reacted with ethyl bromopyruvate in boiling ethanol to give the cyclized derivative (Scheme 3). Reduction of one ring can be achieved. by hydrogenating it over Pd/C under 40 psi pressure in a par apparatus. Subsequently the ester group can be reduced to alcohol and converted to the aldehyde. In the case of X = N the intermediate amino ester can be derivatized using an appropriate R1Q (where Q is a leaving group or a condensing group). In the case of Scheme 3, where R1 = H can be synthesized by the procedure outlined in Scheme 4.
Scheme 4
Figure imgf000029_0001
Additional aldehydes may be synthesized as outlined in Schemes 5-7.
Scheme 5
Figure imgf000030_0001
2) Et3N (1.0 eq) CHCI3, reflux/ 2.5 Hrs
Aldehydes required for examples 24-32 and 34, 35 were prepared by the route indicated schemes 8 to 18.
The following examples further illustrate the invention; they are not to be construed as limiting the invention. It will be readily apparent to one of ordinary skill in the art that additional embodiments can be made that are still within the spirit and scope of the invention.
Example 1
Preparation of (5R.6Z)-6-rf5-benzyl-4.5.6.7-tetrahvdrothienor3.2- cipyridin-Σ-vOmethylenei^oxo-^thia-i-azabicvclore^.Oihept-Z-ene-Z- carboxylic acid
Stepi: 5-benzoyl-4,5,6.7-tetrahvdrothienor3.2-c1pyridine-2- carboxylate:
To a stirred dry DMF (7.3 g, 100 mmol), POCI3 (12.25 g, 80 mmol) was slowly added between O0C to 5° C. After the addition the solidified mass was dissolved in CH2CI2 (20 ml) and stirred at room temperature for 2 hrs. Again the temperature was cooled to O0C and 1-benzoyl-4-piperidone in CH2CI2 was added slowly. After the addition the reaction mixture was stirred at room temperature for 2 hrs and poured over crushed ice and sodium acetate. It was stirred for 30 minutes at room temperature. Extracted with CH2CI2; washed well with water; dired over anhydrous MgSO4 and concentrated. The crude product was dissolved in CH2CI2 and ethylmercaptoacetae ( 9.6 g, 80 mmol) / Et3N (10.1 g, 100 mmol) was added slowly at room temperature. The reaction mixture was refluxed for 2 hrs and quenched with water. CH2CI2 layer was washed well with water; dried over anhydrous MgSO4; filtered and concentrated. The product was purified by SiO2 column chromatography by eluting it with 50% ethylacetae; hexane. Yellow oil; Yield: 6.4 gms (25%); M+H 316.
Step: 2 (5-benzyl-4.5.6.7-tetrahvdrothienor3.2-c1pyridin-2-vnmethanol: To stirred suspension of LAH (2.0 gms) a solution of ethyl 5-benzoyl-4,5,6,7- tetrahydrothieno[3,2-c]pyridine-2-carboxylate (6.0 g, 19 mmol) in THF was added slowly at 0° C. After addition reaction mixture was stirred for 30 minutes and quenched with saturated NH4CI. It was diluted with CHCI3 and filtered. The fitrate was washed with saturated brine solution and dried over anhydrous MgSO4. It was filtered and taken to next step with out purifications. Yield: 4.5 g 91%. Yellow liquid. Step 3: 2-Formyl (5-benzyl-4,5,6,7-tetrahvdrothienor3,2-c1pyridine:
To a stirred solution of (5-benzyl-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-2- yl)methanol (4.0 g, 15.4 mmol) in CH2CI2 (300 ml) active MnO2 (20 g, excess) was added and stirred at room temperature for 18 hrs. At the end, the reaction mixture was filtered through celite and washed with CHCI3. Reaction mixture was washed well with water; dried and concentrated. The product was found to be pure and taken to next step without purifications. Yield: 3.0 g (76%); (M+H: 257).
Step 4j 4-Nitrobθnzv-6-rfacetyloxy)(5-benzyl-4.5.6.7- tetrahvdrothienor3,2-cipyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- azabicyclore.Σ.OIheptø-ene-Σ-carboxylate: 2-Formyl (5-benzyl-4,5,6,7-tetrahydrothieno[3,2-c]pyridine (565 mg, 2.2 mmol) and the dry THF solution (20 ml.) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (772 mg, 2.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (390 mg, 1.5 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 °C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1:1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 550 mg, 40%; M+H 687.
Step-5: (5R,6Z)-6-rf5-ben2yl-4.5.6,7-tetrahvdrothienor3.2-c1pyridin-2- vπmethylene1-7-oxo^-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid:
4-Nitrobenzy-6-[(acetyloxy)(5-benzyl-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-2- yl)methyl]-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate( 450 mg, 0.65 mmol) was dissolved in THF (20 ml_) and acetonitrile (10 ml_). Freshly activated Zn dust (5.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 28 ml_). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 hours at room temperature. The reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 "C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 18%; as yellow crystals; mp. 1980C; (M+H) 411 . 1H NMR (DMSO-d6)δ d 2.7 (m, 2H), 2.8 (bm, 2H), 3.4 (m, 2H), 3.8 (s, 2H), 6.3
(s, 1H), 6.5 (s, 1H)1 7.1(s, 1H), 7.28(s, 1H), 7.4 (s, 5H).
EXAMPLE 2
Preparation of (5RU6Z)-6-(7-Methyl-5.6,7,8-tetrahvdroimidazori .2- alpyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclor3.2.01hept-2-ene-2- carboxylic acid, sodium salt
Step 1 : lmidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester: Ethyl bromopyruvate (62.9 g) was added to the DME (258 mL) solution of 2-aminopyrazine (24.8 g) at room temperature and stirred for 2.5 h. The reaction mixture was cooled to 0 0C and stirred for 30 min to afford a pale brown precipitate. The precipitate was filtered and washed with Et2O to give pale brown crystals. The suspension of the precipitate (66.1 g) in EtOH (1.29 L) was heated at reflux temperature to turn to clear solution. After refluxing for 2h, the reaction mixture was concentrated under reduced pressure, then mixed with CHCI3 and saturated NaHCO3aq. The mixture was filtered through a pad of Celite and the separated organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - MeOH (99/1 ~ 97/3), and collected fractions were concentrated under reduced pressure followed by recrystallization from CHCI3 - Et2O. The titled compound was obtained as pale pink crystals. Yield: 10.9 g, 22%).
1H NMR(CDCI3)δ d 1.46(t, 3H, J = 7.2 Hz), 4.49(q, 2H, J = 7.2 Hz), 7.96(d, 1 H, J = 4.7 Hz), 8.08(dd, 1 H, J = 1.2, 4.7 Hz), 8.26(s, 1 H), 9.21 (d, 1 H, J = 1.2 Hz).
Step 2: 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine-2-carboxylic acid ethyl ester,
Hydrochloride: 0.46 M HCI - EtOH (169 mL) and 10% Pd-C (50% wet) (1.37 g) were added to the EtOH (546 mL) solution of imidazo[1 ,2-a]pyrazine-2-carboxylic acid ethyl ester (13.7 g). The mixture was hydrogenated under H2 at 40 psi at room temperature for 15 h. The reaction mixture was filtered and Pd-C was washed with EtOH. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - MeOH (9/1 ~ 2/1). The titled compound was obtained as brown crystals Yield: 10.4 g, 63%.
1H NMR(CDCI3)δ d 1.38(t, 3H, J = 7.1 Hz), 3.90(t, 2H, J = 5.7 Hz), 4.40(q, 2H, J = 7.1 Hz), 4.59(t, 2H, J = 5.7 Hz)1 4.80(s, 2H), 8.20(s, 1H). Step 3: 7-Methyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine-2-carboxylic acid ethyl_ester:
Et3N (3.44 mL), 37% HCHO aq. (2.02 mL) and NaBH3CN (1.78 g) were added successively to the MeOH (75 mL) solution of 5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrazine-2-carboxylic acid ethyl ester, hydrochloride (5.2 g) at room temperature and stirred for 3.5 h under a nitrogen atmosphere. The mixture was diluted with CH2CI2 and washed with 50% K2CO3 aq. The organic layer was dried (K2CO3) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - acetone (1/1 ~ 1/2). The titled compound was obtained as orange oil. Yield: 2.68 g, 57%).
1H NMR(CDCI3)δ d 1.37(t, 3H1 J = 7.1 Hz), 2.50(s, 3H), 2.85(t, 2H, J = 5.5 Hz), 3.69(s, 2H), 4.06(t, 2H, J = 5.5 Hz), 4.36(t, 2H, J = 7.1 Hz), 7.52(s, 1H). Step 4: 7-Methyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine-2- carbaldehyde:
1.01 M solution of DIBAL in toluene (13.6 mL) was added to the dry CH2CI2 (86 mL) solution of 7-methyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine-2- carboxylic acid ethyl ester (1.8 g) under a nitrogen atmosphere at -78 0C and stirred for 2 h. The mixture was quenched with 1 M HCI. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with 50% K2CO3 aq. and the aqueous layer was extracted with CH2CI2 three times. The combined organic layer was dried (K2CO3) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - MeOH (19/1 ~ 9/1). The titled compound 5 was obtained as colorless crystals. Yield: 591 mg, 42%).
1H NMR(CDCI3)δ d 2.51 (s, 3H)1 2.87(t, 2H, J = 5.5 Hz), 3.70(s, 2H), 4.10(t, 2H, J = 5.5 Hz), 7.53(s, 1H), 9.82(d, 1 H, J = 1.4 Hz).
Step 5: (5R, 6RS)-6-[(/?S)-Acetoxy(7-methyl-5,6,7,8- tetrahydroimidazo[1 ,2-a]pyrazin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (diastereo mixture}:
7-Methyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine-2-carbaldehyde (1.19 g) was added to the dry acetonitrile (97 mL) solution of anhydrous MgBr2 (4.05 g) under a nitrogen atmosphere at room temperature. The dry THF solution (97 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1 -aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (3.32 g) was added to the mixture, cooled to -20 0C, and Et3N (3.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 4.5 h at -20 0C and treated with acetic anhydride (1.36 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 17 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - acetone (9/1 ~ 2/1). The titled compound was obtained as two diastereo mixture. Red oil, Yield: 1.13 g.
1H NMR(CDCI3)δ d 1.20(s, 0.81x3H), 2.24(s, 0.19x3H), 2.48(s, 3H), 2.80 ~ 2.84(m, 2H), 3.57 - 3.67(m, 2H), 3.97 ~ 4.02(m, 2H), 5.27(d, 1 H, J = 13.6 Hz), 5.42(d, 0.19x1 H, J = 13.6 Hz), 5.45(d, 0.81x1 H, J = 13.6 Hz), 6.07(s, 0.19x1 H), 6.30(s. 0.81 x2H), 6.79(s, 0.19x1 H), 6.80(s, 0.19x1 H), 7.02(s, 0.81x1 H), 7.44(s, 0.19X1H), 7.47(s, 0.81x1H), 7.60(d, 0.19x2H, J = 8.2 Hz), 7.62(d, 0.81x2H, J = 8.6 Hz)1 8.22 ~ 8.26(m, 2H). Step 6: (5R),(62)-6-(7-Methyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazin-2- ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
(5R, 6RS)-6-[(RS)-Acetoxy(7-methyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazin- 2- yl)methyl]-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyI ester (1.11 g) was dissolved in THF (32 mL) and acetonitrile (32 mL). Freshly activated Zn dust (4.46 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 48 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered through a pad of Celite, cooled to 3 0C, and 1 M NaOH was added to adjust pH to 7.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (20 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN(1/0 ~ 95/5). The combined fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid. Yield: 417 mg, 65%: mp 200 0C (dec); 1H NMR(D2O)δ d 2.32(s, 3H)1 2.79 ~ 2.81 (m, 2H), 3.54(s, 2H), 3.95(t, 2H, J = 5.6 Hz), 6.39(s, 1H), 6.85(s, 1H), 6.87(s, 1 H), 7.26(s, 1H).
EXAMPLE 3
Preparation of (5ffl. (62>7-Oxo-6-(5,6J.8-tetrahvdroimidazori,2- aTpyrazin-2-ylmethylene)-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt 2-Ketopiperazine
2-Ketopiperazine may be prepared according to procedures in US 2004- 0077622A1 Step 1 : 4-p-Nitrobenzyloxycarbonyl-2-ketopiperazine
The 48.7% solution of p-nitrobenzyloxycarbonyl chloride in 1 ,4-Dioxane (10.7 mL) was added to the dichloromethane (110 mL) solution of 2-Ketopiperazine (2.21 g) and diisopropylethylamine (4.6 mL) at O0C and stirred for 0.5 h at 0 0C. Water (300 mL) was added to the reaction mixture, and extracted with dichloromethane (3 x 100 mL). The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduce pressure. The residue was applied to silica gel column chromatography, eluted with CHCI3 - methanol (30 : 1 ), and the title compound was obtained as white solid (7.1 g, quant.).
1H NMR (d, CDCI3)δ 3.42-3.45 (m, 2H), 3.74 (t, 2H, J = 5.4 Hz), 4.19 (s, 2H), 5.26 (s, 2H)1 6.39 (brs, 1 H), 7.52 (d, 2H, J = 8.6 Hz), 8.24 (d, 2H, J = 8.6 Hz).
Step 2j S-Methoxy-^-p-nitrobenzyloxycarbonyl-i.2.3.6- tetrahvdropyrazine:
Trimethyloxonium tetrafluoroborate (97%, 3.7 g) was added to the dry dichloromethane (120 mL) solution of 4-p-nitrobenzyloxycarbonyl-2-ketopiperazine (6.7 g) at room temperature and stirred for 17 hours. The reaction mixture was treated with saturated sodium hydrogen carbonate aqueous solution, and the organic layer was separated. The aqueous layer was extracted with ethyl acetate (3 x 100 mL), then the combined organic layer was washed with saturated sodium hydrogen carbonate aqueous solution and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduce pressure and the title compound was obtained as a pale brown solid. Yield; 5.7 g, 80.6. 1H NMR (d, CDCI3)δ 3.48 (m, 2H), 3.57 (m, 2H), 3.70 (s, 3H), 3.97 (s, 2H)1 5.26 (s, 2H), 7.52 (d, 2H, J = 8.7 Hz), 8.23 (d, 2H, J = 8.7 Hz). Step 3: 2-lmino-4-p-nitrobenzyloxycarbonyl piperazine: The mixture of δ-methoxy^-p-nitrobenzyloxycarbonyl-i , 2,3,6- tetrahydropyrazine (5.7 g) and ammonium chloride (1.6 g) in dry ethanol (100 mL) was heated to reflux for 4 hours. The reaction mixture was then concentrated under reduced pressure. Dichloromethane (100 mL) was added to the residue and extracted with water (3 x 50 mL) then the combined aqueous layer was washed with dichloromethane. The aqueous layer was neutralized with 10% potassium carbonate aqueous solution and then extracted with dichloromethane (8 x 50 mL). The combined organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and the title compound was obtained as a white solid. Yield: 4.9 g, 91.2%.
1H NMR (d, CDCI3)δ 3.49 (brs, 4H), 3.98 (brs, 2H), 5.26 (s, 2H), 7,52 (d, 2H, J = 8.6 Hz), 8.23 (d, 2H, J = 8.6 Hz).
Step 4: 7-p-Nitrobenzyloxycarbonyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrazine-2-carbaldehyde (9) and 7-p-nitrobenzyloxycarbonyl-5,6,7,8 tetrahydroimidazo[1,2-a]pyrazine-3-carbaldehyde:
The mixture of 2-bromo-3-hydroxypropenal (2.8 g), p-toluenesulfonic acid monohydrate (33 mg) and 2-propanol (3.5 mL) in cyclohexane (28 mL) was azeotroped until the vaper temperature rose to 800C. The reaction mixture was concentrated under reduce pressure. The residue was dissolved in dry acetonitrile
(30 mL). The dry acetonitrile (310 mL) solution of 2-imino-4-p-nitrobenzyloxycarbonyl piperazine (4.7 g) was added at room temperature. The reaction mixture was stirred at room temperature for 3 h, and then the reaction solution was removed in vacuo.
The residue was dissolved in ethyl acetate (170 mL) and triethylamin (2.4 mL) was added, then the reaction mixture was heated to reflux for 1.5 h. The reaction mixture was cooled to room temperature, and then water (170 mL) was added to the reaction mixture and separated. The aqueous layer was extracted with dichloromethane (2 x 100 mL). The combined organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduce pressure. The residue was applied to silica gel column chromatography, eluted with CHCI3 - methanol (50 : 1), and the title compound was obtained as a brown solid, (Yield: 2.9 g, 51.6%) and its regio isomer (orange amorphous solid, Yield; 0.8 g, 14.9%) were obtained.
1H NMR (d, CDCI3) 3.99 (t, 2H, J = 5.4 Hz), 4.14 (t, 2H, J = 5.4 Hz), 4.85 (S, 2H), 5.29 (s, 2H)1 7.54 (d, 2H, J = 8.6 Hz), 7.57 (s, 1 H), 8.24 (d, 2H, J = 8.6 Hz), 9.85 (s, 1H).
Regio isomer 1H NMR (d, CDCI3)δ 3.95 (t, 2H, J = 5.4 Hz), 4.44 (t, 2H, J = 5.4 Hz), 4.87 (s, 2H), 5.29 (s, 2H), 7.54 (d, 2H, J = 8.7 Hz), 7.78 (s, 1H)1 8.24 (d, 2H, J = 8.7 Hz), 9.71 (s, 1 H).
Step 5: (5R)-6-[Acetoxy-(7-p-nitrobenzyloxycarbonyl-5,6,7,8- tetrahydroimidazo[1 ,2-a]pyrazin-2-yl)-methyl]-6-bromo-7-oxo-4-thia- 1azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester:
The dry acetonitrile (25 ml_) solution of 7-p-nitrobenzyloxycarbonyl-5,6,7,8- tetrahydroimidazo[1 ,2-a]pyrazine-2-carbaldehyde (1.6 g) was added to the dry acetonitrile (55 mL) solution of MgBr2 (2.2 g) under an nitrogen atmosphere at room temperature then the mixture was stirred for 10 min. The dry THF (80 mL) solution of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4- nitro-benzyl ester (1.8 g) was added, the mixture was cooled to -20 0C then triethylamine (1.6 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4,4-dimethylamino pyridine (58.3 mg) and acetic anhydride (0.89 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. 10% Citric acid aqueous solution (320 mL) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 160 mL). The organic layer was washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, eluted with CH2CI2 - acetone (20 : 1), and the title compound was obtained as two diastereo mixture (81 : 19, brown foamy amorphous solid. Yield: 2.1 g, 59.9%.
1H NMR (d, CDCI3)S 2.01 (s, 2.43H), 2.24 (s, 0.57H), 3.93-,3.96 (m, 2H), 4.02-4.05 (m, 2H), 4.74-4.76 (m, 2H), 5.28 (d, 1 H, J = 13.5 Hz), 5.28 (s, 2H), 5.45 (d, 1 H, J = 13.5 Hz), 6.07 (s, 0.19H), 6.29 (s, 0.81H), 6.31 (s, 0.81H), 6.80 (s, 0.19H), 6.83 (s, 0.19H), 7.08 (s, 0.81H), 7.43 (s, 0.19H), 7.46 (s, 0.81H), 7.54 (d, 2H, J = 8.6 Hz), 7.61 (d, 2H1 J = 8.8 Hz), 8.24 (d, 4H, J = 8.3 Hz). Step 6: (5R), (62)-7-Oxo-6-(5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazin-2- ylmethylene)-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
(δRJ-θ-IAcetoxy-CT-p-nitrobenzyloxycarbonyl-S.ej.δ-tetrahydroimidazofi^- a]pyrazin-2-yl)-methyl]-6-bromo-7-oxo-4-thia-1azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester (2.0 g) was dissolved in THF (63 ml_). Freshly activated Zn dust (7.9 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 63 imL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction solution was filterd through a pad of Celite and the pad was washed with water (150 mL) and n- butanol (150 mL). The aqueous layer was separated and then the organic layer was extracted with water (2 x 50 mL). The combined aqueous layer was concentrated to 61 g and applied to Diaion HP-21 resin (80 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution. The combined fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid. Yield: 172 mg, 20.1%: mp 150 0C (dec); 1H NMR (d, D2O) 53.02 (t, 2H, J = 5.6 Hz), 3.82 (s, 2H), 3.89 (d, 2H, J = 5.6 Hz)1 6.38 (s, 1H), 6.84 (s, 1H), 6.87 (s, 1H), 7.24 (s, 1H); IR (KBr)
Example 4
Preparation of (5R.6Z)-6-f r5-(4-methoxybenzvπ-4.5.6.7- tetrahvdrothienor3,2-cTpyridin-2-yl)1methylene>-7oxo-4-thia-1- azabicvclor3.2.01hept-2-ene-2-carboχylic acid
Step 1: 5-tert-butyl 2-ethyI 6,7-dihydrothieno[3,2-c]pyridine-2,5(4H)- dicarboxyiate:
5-tert-butyl 2-ethyl 6,7-dihydrothieno[3,2-c]pyridine-2,5(4H)-dicarboxylate was prepared according to the procedure as outlined in Example 1 , (Step 1 ). Starting from tert-butyl-1-piperidinecarboxylate (9.9 g, 50 mmol), POCI3 (6.3 g, 40 mmol) and DMF (3.8 g, 50 mmol). The chloroformyl intermediate was reacted with ethyl mercaptoacetate (6.0 g, 50 mmol) and Et3N. The product was purified by SiO2 column chromatography by eluting it with 3:1 hexane; ethylacetae. Yield: 8.7 g, 56%; White liquid. (M+H) 312. Step 2: tert-butyl 2-(hydroxymethyi)-6,7-dihydrothieno[3,2-c]pyridine-
5(4H)-carboxyIate: tert-butyl 2-(hydroxymethyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)- carboxylate was prepared according to the procedure outlined in Example 1, (Step
2). Starting from 5-tert-butyl 2-ethyl 6,7-dihydrothieno[3,2-c]pyridine-2,5(4H)- dicarboxylate (1.0 g, 3.21 mmol) and LiAIH4 (500 mg , excess), 807 mg (92% yield) of the alcohol derivative was isolated as white liquid. (M+H) 270.
Step 3: tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)- carboxylate: tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate was prepared according to the procedure outlined in Example 1, (Step 3). Starting from tert-butyi 2-(hydroxymethyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate (1.0 g
3.7 mmol) in methylene chloride (100 ml) and active MnO2 (5 g, excess), 800 g (81%
Yield) of the aldehyde derivative was isolated as brown solid. (M+H) 268.
Step 4: 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine: 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine was prepared starting from tert-butyl 2-(formyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate (1.0 g 3.7 mmol) was dissolved in CH2CI2 (20 ml), MeOH (90% 20 ml) and 1N. HCI in dioxane (10 ml). The reaction mixture was stirred at room temperature for 48 hrs. At the end reaction mixture was concentrated to dryness and taken to next step without purification. Yield: 750 mg (HCI salt, Quantitative); M+H 168.
Step 5: 2-Formyl [5-(4-methoxybenzyl)-4,5,6,7-tetrahydrothieno][3,2- c]pyridine: To a stirred solution of 2-(formyl)-6I7-dihydrothieno[3,2-c]-5(4H)-pyridine (1.4 g, 5.2 mmol) in DMF ( 20 ml) , 4-methoxybenzyl chloride (0.94 g, 6.2 mmol) and N1N- diisopropylethylamine (10 ml, excess) was added at room temperature. The reaction mixture was stirred for 24 hrs and quenched with water. The reaction mixture was extracted with chloroform; washed well with water and dried over anhydrous MgSO4. It was filtered and concentrated. The product was purified by SiO2 column chromatography by eluting it with ethylacetate. Pale yellow oil. Yield: 470 mg , 35%; M+H 288.
Step 6: 4-Nitrobenzy-6-[(acetyloxy)[5(4-methoxybenzyl)-4,5,6,7- tetrahydrothieno[3,2-c]pyridin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylate:
2-Formyl [5-(4-methoxyben2yl)-4,5,6,7-tetrahydrothieno][3,2-c]pyridine (574 mg, 2.0 mmol) and the dry THF solution (20 ml_) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (772 mg, 2.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (390 mg, 1.5 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1:1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 550 mg, 40%; M+H 714 and 716. Step-7: (5R,6Z)-6-{[5-(4-methoxybenzyJ)-4,5,6,7-tetrahydrothieno[3,2- c]pyridin-2-yl)]methylene}-7oxo-4-thia-1-azabIcyclo[3.2.0]hept-2-ene-2- carboxylic acid:
^Nitrobenzy-β-fCacetyloxyJfδC^methoxybenzylJ^.S.βJ-tetrahydrothienop^- cJpyridin^-yOmethylJ-e-bromo-T-oxo^-thia-i-azabicyclop.a.Olhept^-ene^- carboxylate ( 300 mg, 0.42 mmol) was dissolved in THF (20 mL) and acetonitrile (10 ml_). Freshly activated Zn dust (5.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 28 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 18%; as yellow crystals; mp. 127°C; (M+H) 441 .
1H NMR (DMSO-d6)δ d 2.7 (m, 2H), 2.8 (bm, 2H), 3.4 (m, 2H), 3.74 (s, 3H) 3.8 (s, 2H), 6.6 (s, 1 H), 6.88 (dd, 2H), 7.14(s, 1H), 7.24(dd, 2H), 7.4 (s, 1H), 7.59 (s, 1H).
Example 5 Preparation of (5R), (6Z)-6-(5.6<Hhvdro-8A7-imidazor2.1-ciri.41thiazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid. sodium salt
Step 1: 5-Methylthio-3,6-dihydro-2«-[1,4]thiazine hydroiodide
5-Methylthio-3,6-dihydro-2H-[1 ,4]thiazine hydroiodide may be prepared by the method as outlined in US 2004-0077622A1. Step 2: 3-lminothiomorpholin hydrochloride
5-Methylthio-3,6-dihydro-2H-[1 ,4]thiazine hydroiodide (7.1 g) is dissolved with 10% K2CO3 aqueous solution (150 mL) and the aqueous layer is extracted with CH2CI2 (5 x 70 mL). The combined organic layer is dried (MgSO4), filtered and concentrated under reduce pressure. Ammonium chloride (1.7 g) is added to the obtained residue in dry ethanol (128 mL) and heated to reflux for 1 h. The reaction mixture was cooled to room temperature. The reaction solution is removed in vacuo and the lminothiomorpholin hydrochloride is obtained as brown solid (4.3 g, quant).
1H NMR (d, DMSO-d6) 53.15 (t, 2H, J = 5.9 Hz), 3.74 (t, 2H1 J = 5.9 Hz), 3.83 (s, 2H), 8.97 (brs, 1 H), 9.38 (brs, 1 H), 9.99 (brs, 1 H).
Step 3: 5,6-Dihydro-8H-imidazo[2,1-c][1,4]thiazine-2-carbardehyde and 5,6-Dihydro-8H-imidazo[2,1 -c][1 ,4]thiazine-3-carbardehyde
The mixture of 2-bromo-3-hydroxypropenal (7, 4.3 g), p- toluenesulfonic acid monohydrate (52 mg) and 2-propanol (5.3 mL) in cyclohexane (43 mL) is azeotroped until the vaper temperature rose to 800C. The reaction mixture is concentrated under reduce pressure. The residue is dissolved in dry ethanol (28 mL). The mixture of the dry ethanol (143 mL) solution of 3-iminothiomorpholin hydrochloride ( 4.3 g) and 28% methanol solution of sodium methylate (5.0 mL) are added at room temperature. The reaction mixture is stirred at room temperature for 1 h, and then the reaction solution is removed in vacuo. The residue is dissolved in chloroform (128 mL) and triethylamine (3.6 mL) is added, then the reaction mixture is heated to reflux for 2.5 h. The reaction mixture was cooled to room temperature and then concentrated under reduce pressure. The residue is dissolved with dichloromethane (300 mL) and washed with 50% K2CO3 aqueous solution (2 x 100 mL). The organic layer is dried (MgSO4) and filtered. The filtrate is concentrated under reduce pressure. The residue is applied to silica gel column chromatography, eluted with CHCI3 - acetone (10 : 1), and 5,6-Dihydro-8H-imidazo[2,1-c][1,4]thiazine- 2-carbardehyde (brown solid, 445 mg, 10.3%) and 5,6-Dihydro-8H-imidazo[2,1- c][1 ,4]thiazine-3-carbardehyde (brown solid, 872 mg, 20.2%) are obtained.
5,6-Dihydro-8H-imidazo[2,1-c][1,4]thiazine-2-carbardehyde: 1H NMR (d, CDCI3)δ 3.07 (t, 2H, J = 5.7 Hz), 3.95 (s, 2H), 4.33 (t, 2H, J = 5.7 Hz), 7.55 (s, 1H), 9.83 (s, 1 H). 5,6-Dihydro-8H-imidazo[2,1-c][1 ,4]thiazine-3-carbardehyde: 1H NMR (d,
CDCI3) 53.05 (t, 2H, J = 5.7 Hz), 3.98 (s, 2H), 4.61 (t, 2H, J = 5.7 Hz), 7.73 (s, 1H), 9.69 (s, 1 H).
Step 4: (5R), (6Z)-6-(5,6-dihydro-8H-imidazo[2,1-c][1,4]thiazin-2- ylmethyIene)-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt:
The dry acetonitrile (20 mL) solution of 5,6-dihydro-8H-imidazo[2,1- c][1,4]thiazine-2-carbardehyde ( 392 mg) is added to the dry acetinitrile (20 mL) solution of MgBr2 (1.1 g) under a nitrogen atmosphere at room temperature then the mixture is stirred for 10 min. The dry THF (40 mL) solution of (5R, 6S)-6-bromo-7- oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester ( 1.0 g) is added and the mixture is cooled to -20 0C then triethylamine (0.8 mL) is added in one portion. The reaction vessel is covered with foil to exclude light. The reaction mixture is stirred for 3.5 h at -20 0C and treated with 4-dimethylamino pyridine (30 mg) and acetic anhydride (0.44 mL) in one portion. The reaction mixture is warmed to 0 0C and stirred for 14 h at 0 0C. 10% Citric acid aqueous solution (240 mL) is added to the reaction mixture and the aqueous layer is extracted with ethyl acetate (3 x 100 mL). The combined organic layer is washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate is concentrated under reduced pressure. The residue is roughly purified by silica gel column chromatography, eluted with CH2CI2 - acetone (50 : 1), and crude (5R)-6-[acetoxy- (5,6-dihydro-8H-imidazo[2,1-c][1 ,4]thiazin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester is obtained as solid. The solid obtained above is purified by SiO2 column chromatography by eluting it with 505 ethylacetae:hexane. The pale yellow solid obtained is dissolved in THF (17 ml_). Freshly activated Zn dust (2.2 g) is added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 17 ml_). The reaction vessel is covered with foil to exclude light. The reaction mixture is vigorously stirred for 2 h at room temperature.
The reaction solution is filterd through a pad of Celite and the pad is washed with water (40 mL) and n-butanol (30 mL). The aqueous layer is separated and then the organic layer is extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 10 mL). The combined aqueous layer is concentrated to 23 g, 1 mol/L NaOH is added to adjust pH to 7.25 and applied to Diaion HP-21 resin (30 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column is eluted with water and then 10% acetonitrile aqueous solution. The combined active fractions are concentrated under high vacuum at 350C and lyophiiized to give (5R), (6Z)-6-(5,6-dihydro-8/-/- imidazo[2, 1 -c][1 ,4]thiazin-2-ylmethylene)-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene- 2-carboxylic acid, sodium salt as a yellow amorphous solid (168 mg, 20.9%). mp 135 0C (dec); 1H NMR (d, D2O) 53.00 (t, 2H, J = 5.7 Hz), 3.80 (AB, 2H, J = 16.7, 18.1 Hz), 4.19 (t, 2H, J = 5.7 Hz), 6.44 (d, 1 H, J = 0.8 Hz), 6.89 (s, 1H), 6.93 (s, 1H), 7.29 (s, 1H); M+H = 322.
Example 6 Preparation of (5R). (6Z)-6-(6.7-Dihvdro-5H-Pyrroloπ.2-a1imidazol-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
Step 1 : 6,7-Dihydro-5H-pyrrolo[1 ,2-a]imidazole-2-carbaldehyde
28% Sodium methoxide (5.26g) was added to the EtOH (250 mL) solution of 4,5-dihydro-3H-pyrrol-2-ylamine hydrochloride ( 3.27g) at room temperature. After stirring for 5 min at room temperature, 2-bromo-3-propoxy-propenal (5.79g) was added to the mixture at room temperature, then the reaction mixture was stirred for 1 h at room temperature. The reaction mixture was taken to dryness in vacuo. The residue was dissolved in CHCI3 (300 mL) and triethylamine (3.8 mL) was added. The mixture was heated to reflux for 3 hours. The reaction mixture was cooled to room temperature, washed with 50% K2CO3, dried over anhydrous K2CO3, filtered, and evaporated under reduced pressure. The residue was applied with silicagel column chromatography, eluted with CHCI3-acetone (2:1), and 6,7-Dihydro-5H-pyrrolo[1 ,2- a]imidazole-2-carbaldehyde (41%, 1.51g) was obtained as a pale yellow solid.
1H NMR (d, CDCI3):δ 2.62-2.7 (m, 2H)1 2.90-2.94 (m, 2H), 4.07 (t, 2H, J = 7.2 Hz), 7.59 (s, 1 H), 9.80 (s, 1H). Step 2: [5R), (6Z)-6-(6,7-Dihydro-5H-pyrrolo[1,2-a]imidazol-2- ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt
6,7-Dihydro-5H-pyrrolo[1 ,2-a]imidazole-2-carbaldehyde ( 1.36 g) was added to the dry acetonitrile (155 ml.) solution of anhydrous MgBr2 (5.64 g) under an argon atmosphere at room temperature. The dry THF solution (155 mL) of (5R, 6S)-6- bromo-7-oxo-4-thia-1 -aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester ( 3.86 g) was added to the mixture, cooled to -20 0C, and Et3N (4.18 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with acetic anhydride (1.89 mL) and DMAP (370 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 14.5 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 1 M citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was dissolved in THF (166 mL) and acetonitrile (77 mL). Freshly activated Zn dust (23.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 243 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered, cooled to 3 0C, and 1 M NaOH was added to adjust pH to 8. The filtrate was washed with ethyl acetate and the aqueous layer was separated. 1 M NaOH was added to the aqueous layer again to adjust pH to 8. The resultant mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (20 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN(1/0 ~ 9/1) to give the purified active fractions of (5R), (6Z)-6-(6,7-Dihydro-5H-pyrrolo[1 ,2-a]imidazol-2-ylmethylene)-7-oxo-4-thia-1 -aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt . The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the titled as a yellow amorphous solid (681 mg, 24%, pH 7.8). mp 190 0C (dec); 1H NMR(d, D2O): δ: 2.48-2.56 (m, 2H), 2.74-2.79 (m, 2H), 3.94-3.99 (m, 2H), 6.47 (d, 1H, J = 0.7 Hz), 6.94 (s, 1H), 6.95 (s, 1H), 7.36 (s, 1H); (M+H) 291.
Example 7
Preparation of (5R). (6Z)-6-(5.6-Dihvdro-8W-imidazor2.1-ciri.41oxazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
STEP 1: MORPHOLIN-3-ONE Morpholin-3-one was prepared in the method of USP 5,349,045.
STEP 2: MORPHOLIN-3-THIONE
A mixture of morpholin-3-one (4.7 g) and Lawesson's reagent (10.3 g) in dry THF (94 mL) was heated to reflux for 1.5 h. The reaction mixture was cooled to room temperature and the reaction solvent was removed in vacuo. The residue was applied to silica gel column chromatography and eluted with CHCI3 - methanol (50 : 1) to obtain a yellow solid. Recrystallization of the crude product from hexane-ethyl acetate gave the title (4.0 g, 72.2%) as yellow powder.
1H NMR (CDCI3) δ 3.45 (t, 2H, J = 5.1 Hz), 3.91 (t, 2H, J - 5.1 Hz), 4.55 (s, 2H). Step 3: 5-Methylthio-3.6-dihvdro-2H-π.41oxazine
A mixture of morpholin-3-thione (4.7 g) and methyl iodide (13 mL) in dry CH2CI2 (140 mL) was stirred at room temperature for 15 h. The reaction mixture was filtered and the solid was washed with CH2CI2. The obtained solid was dissolved with 50% K2CO3 aqueous solution (150 mL) and the aqueous layer was extracted with CH2CI2 (8 x 100 mL). The combined CH2CI2 layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduce pressure and the title was obtained as pale yellow oil (3.6 g, 67.8%).
1H NMR (CDCI3) δ 2.32 (s, 3H), 3.71-3.74 (m, 4H), 4.14-4.15 (m, 2H).
STEP 4: 3-IMINOMORPHOLIN HYDROCHLORIDE A mixture of 5-methylthio-3,6-dihydro-2H-[1,4]oxazine ( 3.6 g) and ammonium chloride (1.5 g) in dry ethanol (136 mL) was heated to reflux for 1 h. The reaction mixture was cooled to room temperature. The reaction solvent was removed in vacuo and the title was obtained as a pale brown solid (3.6 g, 97.7%).
1H NMR (DMSO-d6) δ 3.34 (m, 2H), 3.86 (t, 2H, J = 5.2 Hz), 4.47 (s, 2H). Step 5: 5.6-Dihvdro-8H-imidazor2.1-cin.41oxazine-2-carbaldehvde (9) and 5,6-dihydro-8H-imidazor2,1 -clM ,41oxazine-3-carbaldehyde
The mixture of 2-bromo-3-hydroxypropenal (4.1 g), p-toluenesulfonic acid monohydrate (52 mg) and 2-propanol (5.2 mL) in cyclohexane (42 ml_) was azeotroped until the vapor temperature rose to 800C. The reaction mixture was concentrated under reduce pressure. The residue was dissolved in dry ethanol (50 mL). A mixture of the dry ethanol (200 mL) solution of 3-iminomorpholin hydrochloride (3.4 g) and 28% methanol solution of sodium methylate (4.8 g) was added at room temperature. The reaction mixture was stirred at room temperature for 2 h, and then the reaction solvent was removed in vacuo. The residue was dissolved in chloroform (125 mL) and triethylamine (3.5 mL) was added, then the reaction mixture was heated to reflux for 2 h. The reaction mixture was cooled to room temperature and then concentrated under reduce pressure. The residue was dissolved in dichloromethane (300 mL) and washed with 50% K2CO3 aqueous solution (2 x 100 mL). The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduce pressure. The residue was applied to silica gel column chromatography and eluted with CHCI3 - acetone (4 : 1 ) to obtain the title (pale orange solid, 1.4 g, 36.3%) and the other regio isomer, (pale orange solid, 609 mg, 16.1%).
Desired product: 1H NMR (CDCI3) δ 4.08-4.15 (m, 4H), 4.88 (s, 2H), 7.58 (s, 1H), 9.85 (s, 1H).
The unwanted regio isomer: 1H NMR (CDCI3) δ 4.06 (t, 2H, J = 5.2 Hz), 4.40 (t, 2H, J = 5.2 Hz), 4.90 (s, 2H), 7.75 (s, 1H), 9.72 (s, 1 H).
Step 6: 5R). /6Z^-6-(5.6-Dihvdro-8H-imidazor2.1-ciπ.41oxazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
The dry acetonitrile (66 mL) solution of 5,6-dihydro-8H-imidazo[2,1- c][1 ,4]oxazine-2-carbaldehyde (1.2 g) was added to the dry acetonitrile (66 mL) solution of MgBr2 (3.6 g) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 min. The dry THF (132 mL) solution of p-nitrobenzyl (5R, 6S)-6-bromopenem-3-carboxylate (3.4 g) was added and the mixture was cooled to - 20 0C then triethylamine (2.8 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 4 h at -20 0C and treated with 4-dimethylamino pyridine (100 mg) and acetic anhydride (1.5 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 18 h at 0 0C. 10% Citric acid aqueous solution (1 L) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 500 mL). The combined organic layer was washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude (5f?)-6-[acetoxy-(5,6-dihydro-8H-imidazo[2, 1 -c][1 ,4]oxazin-2-yl)methyl]-6- bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester was obtained as brown amorphous solid.
Freshly activated Zn dust (14 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 72 mL) to the THF (72 mL) solution of (5f?)-6-[acetoxy- (δ.δ-dihydro-δH-imidazop.i-cHi^loxazin^-yOmethyll-e-bromo^-oxo^-thia-i- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2.5 h at room temperature. The reaction solution was filtered through a pad of Celite and the pad was washed with water (170 mL) and n-butanol (170 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL). The combined aqueous layer was concentrated to 90 g, 1mo!/L NaOH was added to adjust pH to 7.5 and applied to Diaion HP-21 resin (120 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution. The combined active fractions was concentrated under high vacuum at 35°C and lyophilized to give the title as a yellow amorphous solid (756 mg, 29.1%).
Mp 130 0C (dec); 1H NMR (DMSO-d6) δ 3.98-4.01 (m, 2H), 4.04-4.07 (m, 2H), 4.74 (AB, 2H, J = 15.3, 22.9 Hz), 6.40 (d, 1H1 J = 0.8 Hz), 6.55 (s, 1H), 6.95 (d, 1 H, J = 0.6 Hz), 7.54 (s, 1H); IR (KBr) 3412, 1741, 1672, 1592, 1549 cm"1; λmax (H2O) 304 nm.
Example 8 Preparation of (5R),(6Z)-6-(5.6-Dihvdro-4H-pyrroloH .2-fr|pyrazol-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
Step 1 : 5.6-Dihvdro-4H-pyrrolori,2-foipyrazole-2-carboxyHc acid ethyl ester
The titled compound was prepared in the same way of Ranganathan and co-workers (Indian J. Chem. 1991, 30 B, 169-175).
Step 2: (5,6-Dihvdro-4H-pyrrolori,2-frTpyrazol-2-yl)methanol MeOH (2.73 mL) was added to the THF (180 mL) solution of LiBH4 (1.63 g) under a nitrogen atmosphere at room temperature, and then 5,6-dihydro-4H- pyrrolo[1 ,2-fc]pyrazole-2-carboxylic acid ethyl ester (8.11 g) was added to the suspension and stirred for 2 h at 40 0C. The mixture was quenched with 1 mol/L HCI at pH 1 and stirred for 1 h at room temperature. Solid K2CO3 was added to the solution to adjust pH to 8 and the mixture was extracted with AcOEt. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure to afford the title compound as brown crystals (4.87 g, 78%).
1H NMR (CDCI3) δ 2.44 (t, 1H, J = 5.8 Hz), 2.54 - 2.62 (m, 2H), 2.87 (t, 2H, J = 7.4 Hz), 4.10 (t, 2H, J = 7.2 Hz), 4.63 (d, 2H, J = 5.8 Hz), 5.96 (s, 1 H). Step 3: 5,6-Dihvdro-4H-pyrrolof1,2-toipyrazole-2-carbaldehyde MnO2 (activated) (24.4 g) was added to the CHCI3 (350 mL) solution of (5,6- dihydro-4H-pyrrolo[1 ,2-/)]pyrazol-2-yl)methanol (4.87 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was reduced under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 1/2). The title compound was obtained as yellow oil (4.35 g, 91 %).
1H NMR (CDCI3) δ 2.63 - 2.71 (m, 2H), 2.95 (t, 2H, J = 7.4 Hz), 4.22 (t, 2H, J = 7.4 Hz), 6.52 (s, 1H), 9.89 (s, 1H).
Step 4: (5/?).(6Zi-6-(5.6-Dihvdro-4H-pyrroloπ .2-frlPyrazol-2-ylmethylene)- 7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt 5,6-Dihydro-4H-pyrrolo[1,2-jb]pyrazole-2-carbaldehyde (1.36 g) was added to the dry acetonitrile (148 mL) solution of anhydrous MgBr2 (5.52 g) under a nitrogen atmosphere at room temperature. The dry THF solution (148 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4- nitrobenzyl ester (cont. 97%) (3.97 g) was added to the mixture, cooled to -20 0C, and Et3N (4.18 ml_) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 4 h at -20 0C and treated with acetic anhydride (1.89 ml_) and DMAP (123 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 14 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure.
The residue was dissolved in THF (106 tnl_) and acetonitrile (49 ml_). Freshly activated Zn dust (22.5 g) was added rapidly with 0.5 M phosphate buffer (pH
6.5, 155 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (79 mL,
Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 9/1). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (848 mg, 29%, pH 7.1 ).
Mp 190 0C (dec); 1H NMR (D2O) δ 2.49 (m, 2H), 2.78 (t, 2H, J = 7.4 Hz), 4.02 (t, 2H, J = 7.4 Hz), 6.01 (s, 1 H), 6.29 (s, 1H), 6.90 (s, 2H).
Example 9
Preparation of (5/?U6Z)-7-Oxo-6-(4,5.6,7-tetrahvdropyrazoloH.5- a1pyridin-2-ylmethylene)-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt Step 1 : TβtrahvdropyridinoH,2-ciri,2,31oxadiazolone
Cone. HCI (1.96 mL) and NaNO2 (2.2 g) were added to the H2O (21 mL) solution of DL-pipecolic acid (3.04 g) under a nitrogen atmosphere at 0 0C and stirred for 1 h. The solution was extracted with CH2CI2 and organic layer was washed with brine. The mixture was dried over Na2SO4 and concentrated under reduced pressure to afford crude (2RS)-1-nitrosopiperidine-2-carboxylic acid as pale yellow crystals.
Trifluoroacetic anhydride (1.93 g) was added to the THF (92 ml_) solution of crude (2RS)-1-nitrosopiperidine-2-carboxylic acid under a nitrogen atmosphere at 0 0C and stirred for 5 h at 0 0C and for 2 h at room temperature. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 0/1). The titled compound was obtained as colorless crystals (1.10 g, 33%). 1H NMR (CDCI3) δ 1.93 - 1.99 (m, 2H), 2.08 - 2.15 (m, 2H), 2.65 (t,
2H, J = 6.5 Hz)1 4.26 (t, 2H, J = 6.1 Hz).
Step 2: 4.5.6,7-Tetrahvdropyrazolof1.5-a1pyridine-2-carboxylic acid ethylester:
Ethyl propiolate (804 mg) was added to the o-xylene (15 ml_) solution of tetrahydropyridino[1 ,2-c][1 ,2,3]oxadiazolone (1.04 g) under a nitrogen atmosphere and refluxed for 16 h. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (2/1 - 1/1). The titled compound was obtained as yellow oil (871 mg, 65%), and 4,5,6,7-tetrahydropyrazoIo[1 ,5-a]pyridine-3-carboxyiic acid ethyl ester was obtained as yellow oil (345 mg, 26%).
1H NMR (CDCI3) δ 1.39 (t, 3H, J = 7.1 Hz), 1.84 - 1.91 (m, 2H), 2.02 - 2.09 (m, 2H), 2.82 (t, 2H, J = 6.4 Hz), 4.22 (t, 2H, J = 6.2 Hz), 4.39 (q, 2H, J = 7.1 Hz), 6.53 (s, 1H).
Step 3: (4.5.6.7-TetrahvdropyrazoloH,5-a1pyridin-2-yl)methanol
MeOH (0.29 ml_) was added to the THF (19 mL) solution of LiBH4 (cont. 90%) (174 mg) under a nitrogen atmosphere at room temperature, then 4,5,6,7- tetrahydropyrazolo[1 ,5-a]pyridine-2-carboxylic acid ethyl ester (862 mg) was added to the suspension and stirred for 1 h at room temperature and 1.5 h at 40 0C. The mixture was quenched with 1 mol/L HCI at pH 1 and stirred for 1 h at room temperature. Solid K2CO3 was added to the solution to adjust pH to 8 and the mixture was extracted with AcOEt. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure to afford titled compound as pale yellow oil (691 mg, 95%).
1H NMR (CDCI3) δ 1.80 - 1.87 (m, 2H), 1.98 - 2.05 (m, 2H), 2.77 (t, 2H, J = 6.4 Hz), 2.81 - 2.84 (br, 1 H), 4.09 (t, 2H, J = 6.1 Hz), 4.62 (d, 2H, J = 5.3 Hz), 5.96 (s, 1H).
Step 4: 4.5.6.7-Tetrahvdropyrazoloπ .S-alpyridine^-carbaldehvde
MnO2 (activated) (3.36 g) was added to the CHCI3 (44 ml_) solution of (4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyridin-2-yl)methanol (673 mg) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was reduced under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (2/1 - 1/2). The titled compound was obtained as pale yellow oil (510 mg, 77%). 1H NMR (CDCI3) δ 1.90 (m, 2H), 2.10 (m, 2H), 2.84 (t, 2H, J = 6.4 Hz), 4.23 (t,
2H1 J = 6.2 Hz), 6.52 (s, 1 H), 9.92 (s, 1H).
Step 5: f5/?)(6Z)-7-Oxo-6-f4.5.6,7-tetrahvdropyrazolori ,5-a1pyridin-2- ylmethylene)-4-thia-1 -azabicvclorS^.Olhept-Σ-ene-Σ-carboxylic acid, sodium salt 4,5,6,7-Tetrahydropyrazolo[1 ,5-a]pyridine-2-carbaldehyde (483 mg) was added to the dry acetonitrile (48 mL) solution of anhydrous MgBr2 (1.81 g) under a nitrogen atmosphere at room temperature. The dry THF solution (48 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4- nitrobenzyl ester (cont. 97%) (1.28 g) was added to the mixture, cooled to -20 °C, and Et3N (1.35 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (0.61 mL) and DMAP (40 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 16 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure.
The residue was dissolved in THF (35 mL) and acetonitrile (16 mL). Freshly activated Zn dust (7.43 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 51 ml_). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (105 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 85/15). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (427 mg, 41%, pH 7.7).
Mp 190 0C (dec); 1H NMR (D2O) δ 1.67 - 1.71 (m, 2H), 1.85 - 1.89 (m, 2H)1 2.64 (t, 2H, J = 6.3 Hz)1 3.97 (t, 2H, J = 6.1 Hz), 5.97 (s, 1 H), 6.25 (s, 1H), 6.85 (s, 1 H), 6.88 (s, 1H).
Example 10
Preparation of (5ffl.(6Z)-6-(7-Methyl-6-oxo-5.6.7.8-tetrahvdro-imidazon .2- aipyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid sodium salt
Step 1: 5-Methoxy-1-methyl-3.6-dihvdro-1H-Pyrazin-2-one
The titled compound was prepared in the same way of S.Rajappa and
B.G.Advani (Tetrahedron. 1973, 29, 1299-1302).
Step 2: 5-Amino-1-methyl-3.6-dihvdro-1H-pyrazin-2-one A mixture of 5-methoxy-1-methyl-3,6-dihydro-1 H-pyrazin-2-one (2.3 g) and ammonium chloride (936 mg) in dry ethanol (32 ml_) was stirred at room temperature for 1 h and then refluxed for 2 h. The reaction mixture was cooled to room temperature and evaporated under reduced pressure. The residue was triturated with chloroform at room temperature for 30 min. The precipitate was filtered off and dried in vacuo. The 5-amino-1-methyl-3,6-dihydro-1H-pyrazin-2-one hydrochloride was obtained as a pale brown powder (1.7 g, 66%).
A solution of 5-amino-1-methyl-3,6-dihydro-1H-pyrazin-2-one hydrochloride (662mg) in methanol (10 mL) was added 10% potassium carbonate aqueous solution at On and then stirred for 40 min at On. The mixture was concentrated under reduced pressure. The residue was triturated with chloroform (18ml_) and methanol (2 mL) at room temperature for 30 min. The precipitate was filtered off and dried in vacuo. The compound was obtained as a pale brown powder (515 mg, quantitative).
1H NMR (DMSO-d6) δ 2.88 (s, 3H), 3.94 (s, 2H), 4.42 (s, 2H). Step 3: 7-Methyl-6-oxo-5.β.7,8-tetrahvdro-imidazo H,2-aipyrazine-2- carbaldehvde and 7-Methyl-6-oxo-5.6.7.8-tetrahvdro-imidazoH .2-a1Pyrazine-3- carbaldehvde
The solution of 2-bromo-3-isopropoxy-propenal (1.3 g) in dry acetonitrile (60 mL) was added to the solution of 5-amino-1-methyl-3,6-dihydro-1H-pyrazin-2-one (782 mg) in dry acetonitrile (60 mL) at room temperature. The reaction mixture was stirred at room temperature for 20 h, added triethylamine (0.95 mL) and then refluxed for 2 h. The reaction mixture was cooled to room temperature and then evaporated under reduce pressure. The residue was dissolved in chloroform (1OmL) and washed with 50% K2CO3 aqueous solution (1OmL). The aqueous layer was extracted with chloroform. The organic layer was dried (MgSO4) and filtered. The filtrate was evaporated under reduce pressure. The residue was applied to silica gel column chromatography and eluted with CHCI3 - MeOH (95 : 5) to obtain the title compound 7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo [1 ,2-a]pyrazine-2-carbaldehyde as a pale yellow solid (541 mg, 49.1%) and its regio isomer 7-Methyl-6-oxo-5,6,7,8- tetrahydro-imidazo[1 ,2-a]pyrazine-3-carbaldehyde as a pale yellow solid (128 mg, 11.6%).
7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo [1 ,2-a]pyrazine-2-carbaldehyde: 1H NMR (CDCI3) δ 3.17 (s, 3H), 4.68 (s, 2H), 4.78 (s, 2H) , 7.66 (s, 1H) , 9.83 (s, 1H). 7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1 ,2-a]pyrazine-3-carbaldehyde: 1H
NMR (CDCI3) δ 3.16 (s, 3H), 4.70 (s, 2H), 5.03 (s, 2H) , 7.82 (s, 1H) , 9.73 (s, 1H).
Step 4: (5R 6RS)- 6- rAcetoxy-(7-methyl-6-oxo-5,6J,8-tetrahydro- imidazori,2-alpyrazin-2-vO-methyll-6-bromo-7-oxo-4-thia-1-aza- bicyclor3.2.01hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester 7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo [1 ,2-a]pyrazine-2-carbaldehyde
(319 mg) was added to the dry acetonitrile (32 mL) solution of anhydrous MgBr2 (786 mg) under a nitrogen atmosphere at room temperature. The dry THF solution (32 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (687 mg) was added to the mixture, cooled to -20 0C, and triethylamine (0.60 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4-dimethylaminopyridine (44 mg) and acetic anhydride (0.35 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 20 h at 00C. The mixture was diluted with ethyl acetate and H2O. After separating organic layer, the aqueous layer was extracted with ethyl acetate. The organic layers were combined and washed with 5% citric acid aqueous solution and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then eluted with chloroform. The title compound was obtained as diastereo mixture (yellow amorphous solid ; 410 mg, 38%).
1H NMR (δ, CDCI3) 2.03 (s, 0.7 x 3 H)1 2.09 (s, 0.3 x 3H), 3.15 (s, 3H), 4.59-4.62 (m, 2H), 4.66 (s, 0.3 x 2H), 4.67 (s, 0.7 x 2H), 5.28 (d, 1 H, J = 13.5 Hz), 5.43 (d, 0.3 x 1H, J = 13.5 Hz), 5.45 (d, 0.7 x 1H, J = 13.5 Hz), 6.07 (s, 0.3 x 1H), 6.28 (S, 0.7 X 1 H), 6.32 (s, 0.7 X 1H), 6.83 (s, 0.3 X 1H)1 6.86 (s, 0.3 X 1 H), 7.10 (s, 0.7 x 1H), 7.44 (s, 0.3 x 1H), 7.47 (s, 0.7 x 1 H), 7.60 (d, 0.7 x 2H, J = 8.6 Hz), 7.61 (d, 0.3 x 2H, J = 8.6 Hz), 8.24 (d, 2H, J = 8.6 Hz)1
Step 5: l5RU6Z)-6-l 7-Methyl-6-oxo-5.6.7.8-tetrahvdro-imidazoπ .2- aiPyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclor3.2.01hept-2-ene-2-carboxylic acid sodium salt and (5ffl,f6E)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahvdro-imidazoπ.2- aipyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid sodium salt
(5R, 6RS)- 6- [Acetoxy-(7-methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1 ,2- a]pyrazin-2-yl)-methyl]-6-bromo-7-oxo-4-thia-1 -aza-bicyclo[3.2.0]hept-2-ene-2- carboxylic acid 4-nitro-benzyl ester (481 mg) was dissolved in THF (6.7 ml_) and acetonitrile (3.1 ml_). Freshly activated Zn dust (1.92 g) and 0.5 M phosphate buffer (pH 6.5, 9.9 mL) were added to the mixture. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction solution was mixed with ethyl acetate and filtered through a pad of Celite. The pad was washed with water and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C and lyophilized. The residue was separated by the preparative HPLC (Inertsil ODS-2, GL Science Inc., 10 x 250 mm, 0.05 mol/L phosphate buffer (pH 7.1) : CH3CN = 93 : 7, 4.0 mL/min.). The separated fractions of (5R),(6Z)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1,2- a]pyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid sodium salt and (5R),(6£)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1 ,2-a]pyrazin- 2-ylmethylene)-7-oxo-4-thia-1 -aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid sodium salt were cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0 respectively. Each solution was concentrated under high vacuum at 35 0C. Each concentrate was applied to Diaion HP-21 (60 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with water and then with 5% acetonitrile-water. The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound(5R),(6Z)-6-(7-Methyl-6-oxo-5,6,7,8- tetrahydro-imidazoti^-alpyrazin^-ylmethyleneH-oxo^-thia-i-aza-bicycloIS^.OJhept- 2-ene-2-carboxylic acid sodium salt as a yellow amorphous solid (125 mg, 44.4 %, Mp 115-117 0C (dec)) and compound (5R),(6E)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahydro- imidazoII ^-alpyrazin^-ylmethyleneJ-T-oxo^-thia-i-aza-bicyclofS^.Olhept^-ene^- carboxylic acid sodium salt as yellow amorphous solid (19 mg, 6.7 %) respectively.
Compound (5R),(6Z)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1 ,2- a]pyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid sodium salt 1H NMR (δ, D2O) 2.99 (s, 3H), 4.54 (s, 2H), 4.66 (s, 2H), 6.38 (s, 1H), 6.85 (s, 1H), 6.90 (s 1H) , 7.30 (s, 1H).
Compound (5R),(6E)-6-(7-Methyl-6-oxo-5,6,7,8-tetrahydro-imidazo[1 ,2- a]pyrazin-2-ylmethylene)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid sodium salt 1H NMR (δ, D2O) 2.94 (s, 3H), 4.45 (s, 2H), 4.56 (s, 2H), 6.22 (s, 1 H), 6.48 (s, 1 H), 6.94 (s, 1 H), 7.69 (s 1 H).
Example 11
Preparation of (5R)16Zl-6-(6.7-Dihvdro-4H-pyrazolor5.1 -cU1 ,41thiazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.0lhept-2-ene-2-carboxylic acid. sodium salt: Step 1 : Offl-Thiomorpholine-S-carboxylic acid
The titled compound was prepared in the same way of Shiraiwa and co-workers (Biosci. Biotechnol. Biochem. 1998, 62, 2382-2387).
Step 2j 3-Oxo-3a.4.6,7-tetrahvdro-3H-2-oxa-5-thia-1-aza-7a- azonioindenide
NaNO2 (3.14 g) was added to the 1 mol/L HCI (33.7 ml_) solution of (SRHhiomorpholine-S-carboxylic acid (4.96 g) under a nitrogen atmosphere at 0 0C and stirred for 0.5 h. The solution was extracted with CHCI3 (5 times) and the organic layer was washed with brine. The mixture was dried over MgSO4 and concentrated under reduced pressure to afford crude (3R)-4-nitrosothiomorpholine-3- carboxylic acid as pale yellow crystals.
Trifluoroacetic anhydride (7.07 g) was added to the THF (169 mL) solution of crude (3R)-4-nitrosothiomorpholine-3-carboxylic acid under a nitrogen atmosphere at 0 0C and stirred for 3 h at 0 0C and for 17 h at room temperature. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1/1 - 0/1). The titled compound was obtained as pale brown crystals (3.41 g, 64%).
1H NMR (CDCI3) δ 3.15 (t, 2H, J = 5.5 Hz), 3.71 (s, 2H), 4.54 (t, 2H, J
= 5.5 Hz). Step 3: e.y-Dihvdro^H-pyrazolorδ.i-ciπ^ithiazine^-carboxylic acid ethyl ester
Ethyl propiolate (2.33 g) was added to the o-xylene (72 ml_) solution of 3-oxo- 3a,4,6,7-tetrahydro-3/-/-2-oxa-5-thia-1-aza-7a-azonioindenide (3.41 g) under a nitrogen atmosphere and refluxed for 15 h. The solution was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (2/1 - 1/1). The titled compound was obtained as yellow oil (3.13 g, 68%), and the other unwanted regio isomer 6,7- dihydro-4/-/-pyrazolo[5,1-c][1 ,4]thiazine-3-carboxylic acid ethyl ester was obtained as yellow oil (556 mg, 12%).
1H NMR (CDCI3) δ 1.31 (t, 3H, J = 7.1 Hz), 3.04 (t, 2H J = 5.7 Hz), 3.81 (s, 2H), 4.32 (q, 2H, J = 7.1 Hz), 4.40 (t, 2H, J = 5.7 Hz), 6.54 (s, 1H).
Step 4: (6.7-Dihvdro-4H-pyrazolor5.1 -clH .41thiazin-2-v0methanol
LiBH4 (cont. 90%) (536 mg) and MeOH (0.9 ml_) was added to the THF (59 ml_) solution of ΘJ-dihydro^Hφyrazolotδ.i-clti ^thiazine^-carboxylic acid ethyl ester (3.13 g) under a nitrogen atmosphere at room temperature and stirred for 3 h at 40 0C. The mixture was quenched with 1 mol/L HCI at pH 1 and stirred for 1 h at room temperature. Solid K2CO3 was added to the solution to adjust pH to 8 and the mixture was extracted with AcOEt. The organic layer was dried (K2CO3) and filtered. The filtrate was concentrated under reduced pressure to afford titled compound as pale yellow oil (2.51 g, quant).
1H NMR (CDCI3) δ 2.58 (br, 1H), 3.07 (t, 2H, J = 5.7 Hz), 3.84 (s, 2H), 4.33 (t, 2H, J = 5.7 Hz), 4.63 (d, 2H, J = 3.9 Hz), 6.05 (s, 1H).
Step 5: 6.7-Dihvdro-4H-pyrazolor5.1-ciπ ,41thiazine-2-carbaldehvde MnO2 (activated) (11.46 g) was added to the CHCI3 (135 mL) solution of (6,7- dihydro-4H-pyrazolo[5,1-c][1,4]thiazin-2-yl)methanol (2.31 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated under a reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n- hexane - AcOEt (1/1). The titled compound was obtained as pale yellow crystals (1.78 g, 78%).
1H NMR (CDCI3) δ 3.15 (t, 2H, J = 5.8 Hz), 3.90 (s, 2H), 4.48 (t, 2H, J = 5.8 Hz), 6.58 (s, 1H), 9.92 (s, 1H). Step 6: (5R)(6Z)-6-(6.7-Dihvdro-4H-pyrazolor5.1 -clh .41thiazin-2- ylmethylene)-7-oxo-4-trιia-1-azabicvclor3.2.0lhept-2-ene-2-carboxylic acid. sodium salt
6,7-Dihydro-4H-pyrazolo[5,1-c][1 ,4]thiazine-2-carbaldehyde (841 mg) was added to the dry acetonitrile (39 mL) solution of anhydrous MgBr2 (1.88 g) under a nitrogen atmosphere at room temperature. The dry THF solution (39 mL) of {5R, 6S)-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4- nitrobenzyl ester (cont. 99.7%) (1.93 g) was added to the mixture, cooled to -20 0C, and Et3N (2.79 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with acetic anhydride (0.94 mL) and DMAP (61 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 17 h at 0 °C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure.
The residue was dissolved in THF (83 mL) and acetonitrile (39 mL). Freshly activated Zn dust (7.72 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 122 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (150 ml_, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 85/15). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (371 mg, 22%, pH 8.0). Mp 190 0C (dec); 1H NMR (D2O) δ 3.03 (t, 2H, J = 5.7 Hz), 3.75 (s,
2H), 4.22 (t, 2H1 J = 5.7 Hz), 6.07 (s, 1 H), 6.27 (s, 1H), 6.86 (s, 1 H), 6.89 (s, 1H).
Example 12
Preparation of (5ftU6Z)-7-Oxo-6-(4H-5-thia-1.6a-diazapentalen-2- ylmethylene)-4-thia-1 -azabicyclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
Step 1: 3-Oxo-3a, 4-dihvdro-3H, 6H-2-oxa-5-thia-1-aza-6a-azonio-3a- pentalenide
Cone. HCI (15 mL) and NaNO2 (16.6 g) were added to the H2O (166 mL) solution of L-thioproline (24.3 g) under a nitrogen atmosphere at 0 0C and stirred for 2 h. The solution was extracted with CH2CI2, organic layer was dried over
MgSO4 and concentrated under reduced pressure to afford the crude N-nitroso derivative as a yellow solid.
Trifluoroacetic anhydride (5.0 mL) was added to the THF (350 mL) solution of crude N-nitrosothioproline under a nitrogen atmosphere at 0 0C and stirred for 5 h at 0 0C. The solution was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (1 : 1). The titled compound was obtained as a pale brown solid (4.0 g, 15.1%). 1H NMR (CDCI3): 54.04 (t, 2H, J = 1.7 Hz), 5.40 (t, 2H, J = 1.7 Hz).
Step 2: 4H-5-Thia-1.6a-diazapentalen-2-carboxylic acid ethylester
Ethyl propiolate (3.1 mL) was added to the o-xylene (130 mL) solution of 3- oxo-3a, 4-dihydro-3H, 6H-2-oxa-5-thia-1-aza-6a-azonio-3a-pentalenide (4.0 g) under a nitrogen atmosphere and refluxed for 19 h. The solution was cooled to room temperature and concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (4 : 1). The titled compound was obtained as a yellow solid (2.7 g, 49.3%), and 4H-5-thia-1 ,6a-diazapentalen-3-carboxylic acid ethylester was obtained as pale yellow crystals (1.2 g, 21.7%).
1H NMR (CDCI3) δ 1.40 (t, 3H, J = 7.1 Hz), 4.11 (d, 2H, J = 2.1 Hz), 4.40 (q, 2H1 J = 7.1 Hz), 5.24 (t, 2H1 J = 1.6 Hz), 6.61 (s, 1H). Step 3: (4H-5-Thia-1,6a-diazapentalen-2-vhmethanol
LiBH4 (cont. 90%) (459 mg) was added to the ether (126 ml_) solution of AH- 5-thia-1,6a-diazapentalen-2-carboxylic acid ethylester (2.5 g) and MeOH (0.77 ml_) under a nitrogen atmosphere at room temperature, then refluxed for 1.5 h. The mixture was quenched with 1 mol/L HCI (25 ml_) and stirred for 1 h at room temperature. The mixture was neutralized by saturated sodium hydrogen carbonate solution and separated. The aqueous layer was extracted with dichloromethane (10 x 25 mL). The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with AcOEt. The titled compound was obtained as a pale yellow solid (1.7 g, 87.9%).
1H NMR (CDCI3) δ 2.95 (t, 1H, J = 5.6 Hz), 4.07 (s, 2H), 4.62 (d, 2H, J = 5.1 Hz)1 5.13 (t, 1 H, J = 1.6 Hz), 6.04 (s, 1H).
Step 4: 4/7-5-Thia-1.6a-diazapentalen-2-carbaldehvde
The dry dichloromethane (8 mL) solution of dimethylsulfoxide (2.2 mL) was added dropwise to the dry dichloromethane (110 mL) solution of oxalyl chloride (2.0 mL) at -78°C. The reaction mixture was stirred for 15 min at the same temperature. The dry dichloromethane (40 mL) solution of (4H-5-thia-1 ,6a-diazapentalen-2- yl)methanol, (1.7 g) was added dropwise to the reaction mixture at -78°C, and stirring was continued for an additional 15 min. The reaction mixture was allowed to warm to -45°C and stirred for 1 h. Triethylamine (11.3 mL) was added dropwise and the reaction mixture was allowed to warm to 00C. After 20min, saturated ammonium chloride solution (50 mL) and water (100 mL) were added and separated. The aqueous layer was extracted with AcOEt (3 x 150 mL). The combined organic layers were washed with water (200 mL) and brine (200 mL), dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with hexane - AcOEt (1 : 1). The titled compound was obtained as a yellow solid (1.7 g, quant.).
1H NMR (CDCI3) 54.13 (s, 2H), 5.26 (d, 2H1 J = 1.4 Hz), 6.59 (s, 1H), 9.90 (s, 1H). Step 5: (5f?H6Z)-7-Oxo-6-(4H-5-thia-1.6a-diazapentalen-2-ylmethylene)-4- thia-1 -azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
The dry acetonitrile (92 mL) solution of 4H-5-thia-1 ,6a-diazapentalen- 2-carbaldehyde (1.7 g) was added to the dry acetinitrile (92 mL) solution of MgBr2 (5.0 g) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 min. The dry THF (184 mL) solution of p-nitrobenzyl (5R, 6S)-6- bromopenem-3-carboxylate (4.3 g) was added and the mixture was cooled to -20 0C then triethylamine (7.4 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4-dimethylamino pyridine (138 mg) and acetic anhydride (2.1 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The 1mol/L Citric acid aqueous solution (1000 mL) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 400 mL). The combined organic layers were washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude (5R)-6-[acetoxy-(4H-5-thia-1,6a-diazapentalen-2-yl)methyl]-6- bromo-7-oxo-4-thia-1-azabicyclo [3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester was obtained as a brown amorphous solid.
Freshly activated Zn dust (19.3 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 100 mL) to the THF (100 mL) solution of crude (5R)-6- [acetoxy-(4H-5-thia-1 ,6a-diazapentalen-2-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo [3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2.5 h at room temperature. The reaction solution was filtered through a pad of Celite and the pad was washed with water (200 mL) and n-butanol (200 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL). The combined aqueous layers were concentrated to 90 g, 1 mol/L NaOH was added to adjust pH to 8.0 and applied to Diaion HP-21 resin (180 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 15% acetonitrile aqueous solution. The combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid (634 mg, 17.4%, pH 7.25). Mp 150 0C (dec); 1H NMR (D2O) 64.00 (s, 2H), 5.09 (s, 2H), 6.14 (s,
1H), 6.36 (s, 1 H)1 6.91 (s, 1H), 6.92 (s, 1H); IR (KBr) 3381 , 1752, 1683, 1600, 1558 cm'1; λmax (H2O) 292, 196 nm.
Example 13 Preparation of (5f?)(6Z)-6-(7W-lmidazoπ .2-clthiazol-2-ylmethylene)-7- oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
Step 1 : Thiazolidin-4-one
The titled compound was prepared in the same way of Marvin M. and Allen R. Harkness. (Tetrahedron Letters. 1994, 35, 6971-6974). Step 2: Thiazolidine-4-thione Lawesson's reagents (33.5 g) added to the solution of thiazolidin-4-one (14.2 g) in dry THF (690 ml_) and the reaction mixture was refluxed for 2 h. The mixture was cooled to room temperature and evaporated under reduced pressure. The residue was triturated with CHCI3:MeOH=7:3 solution (65 mL) at room temperature for 30 min. The precipitate was filtered off, washed with CHCI3:n-hexane=7:3 solution (15 mL) and dried in vacuo. The thiazolidine-4-thione was obtained as a pale yellow powder (10.7 g, 65%).
1H NMR (CDCI3) δ 4.08 (s, 2H), 4.70 (s, 2H). Step 3: 4-Methylthio-2.5-dihvdro-thiazole
Methyl iodide (28.4 g) was added to the boiling solution of thiazolidine-4- thione (9.5 g) in chloroform (400 mL), and the reaction mixture was refluxed for 1.5 h. To the reaction mixture, an additional methyl iodide (56.8 g) was added in 5 portions at 30-60 min intervals. After refluxing for additional 1 h, the reaction mixture was cooled to room temperature. Then 10% potassium carbonate aqueous solution (200 mL) was added and stirred for 15min at room temperature. After separating organic layer, the aqueous layer was extracted with CHCI3 (100 mL x 3). Organic layers were combined, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and dried in vacuo. After drying, the title compound was obtained as brown oil (11.0 g, quant.). 1H NMR (CDCI3) δ 2.51 (s, 3H), 3.91 (t, 2H, J = 3.5 Hz)1 5.21 (t, 2H, J = 3.5 Hz). Step 4: Thiazolidin-4-ylideneamine
A mixture of 4-methylthio-2,5-dihydrothiazole (10.7 g) and ammonium chloride (6.4 g) in dry ethanol (400 mL) was refluxed for 27.5 h. The reaction mixture was cooled to room temperature and evaporated under reduced pressure.
The residue was dissolved in chloroform (300 mL) and 10% potassium carbonate aqueous solution (200 mL), then stirred for 20 min at room temperature. After separating organic layer, the aqueous layer was extracted with chloroform (100 mL x 5). Organic layers were combined, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and dried in vacuo to obtain crude thiazolidin-
4-ylideneamine (5.5g) as a brown solid that included by product, which is an ethoxy derivative and 4-methylthio-2,5-dihydrothiazole, which is the starting material . The ratio of these three compounds was determined to be 61 :34:5 respectively by 1H- NMR.
1H NMR (CDCI3) δ 3.75 (t, 2H, J = 2.8 Hz), 4.97 (t, 2H, J = 2.9 Hz).
Step 5: 7H-lmidazoπ,2-c1thiazole-2-carbaldehvde
The solution of 2-bromo-3-isopropoxypropenal (6.9 g) in dry acetonitrile (326 mL) was added to the solution of crude thiazolidin-4-ylideneamine (3.3 g) in dry acetonitrile (326 mL) at room temperature. The reaction mixture was stirred at room temperature for 19.5 h, added triethylamine (4.9 mL) and then refluxed for 2 h. The reaction mixture was cooled to room temperature and then evaporated under reduce pressure. The residue was dissolved in dichloromethane (300 mL) and washed with
50% potassium carbonate aqueous solution (20 g). After filtration and separation, the aqueous layer was extracted with dichloromethane (50 mL x 4). The organic layers were combined, dried (MgSO4) and filtered. The filtrate was evaporated under reduced pressure. The residue was applied to silica gel column chromatography and eluted with CHCI3 - MeOH (100 : 3) to obtain crude IH- lmidazo[1,2-c]thiazole-2-carbaldehyde as a brown solid. The crude product was re- crystallized twice from CHCI3 - n-hexane (1st: 30:5, 2nd: 30:60) at 0 0C to give the required aldehyde as pale brown crystals (Yield: 1.84 g, 15 %).
1H NMR (CDCI3) δ 4.09 (t, 2H, J = 1.3 Hz), 5.08 (t, 2H, J = 1.2 Hz), 7.63 (s, 1H), 9.81 (s, 1H). Step 6: (5RU6Z)-6-(7H-lmidazoπ .2-c1thiazol-2-ylmethylene)-7-oxo-4-thia- 1-azabicyclo r3.2.01hept-2-ene-2-carboxylic acid, sodium salt
7H-lmidazo[1 ,2-c]thiazole-2-carbaldehyde (841 mg) was added to the dry acetonitrile (116 mL) solution of anhydrous MgBr2 (2.93 g) under a nitrogen atmosphere at room temperature. The dry THF solution (116 mL) of (5R, 6S)S- bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 99.7%) (2.51 g) was added to the mixture, cooled to -20 0C, and Et3N
(2.20 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 4 h at -20 0C and treated with acetic anhydride (1.26 mL) and DMAP (160 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure.
The residue was dissolved in THF (53 mL) and acetonitrile (25 mL). Freshly activated Zn dust (15.1 g) and 0.5 M phosphate buffer (pH 6.5, 78 mL) were added to the mixture. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (321 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 9/1). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (1.1 g, 51%, pH 7.5).
Mp 145 0C (dec); 1H NMR (D2O) δ 3.85 (s, 2H), 4.88 (s, 2H)1 6.32 (s, 1 H), 6.78 (s, 1H)1 6.85 (s, 1H), 7.27 (s, 1 H). Example 14
Preparation of (5R.6Z)-7-oxo-6-r(4-oxo-6.7-dihvdro-4H-pyrazolor5.1 - ciri^ioxazin^-vhmethylenei^-thia-i-azabicvclorS^.OIhept^-ene-Σ-carboxylic
Acid. Step 1: Diethyl 1-(2-mert-butyl(dimethvnsilvHoxy)ethylMH-pyrazole-3.5- dicarboxylate
To a solution of diethyl 3,5-pyrazoledicarboxylate (2.17 g, 10 mmol) in acetonitrile (10 ml), under nitrogen, was added potassium carbonate (2.07 g, 15 mmol), and 2-bromoethoxy-t-butyldimethylsilane (2.90 g, 12 mmol). The mixture was stirred at reflux for 18 hr. It was then cooled to room temperature, diluted with ethyl acetate (20 ml), and filtered through Magnesol. The filter pad was eluted wtih 2 x 10 ml of ethyl acetate, and the combined filtrate was evaporated. The residue was dissolved in hexanes and passed through a column of silica gel (70 g). After eluting with hexanes (100 ml), the column was eluted with ethyl acetate. The ethyl acetate eluent was evaporated to give 3.71 g of a colorless oil; MS m/e 371 (MH+). Step 2: 1-(2-frtert-butyl(dimethvnsilvπoxy>ethyl)-1 H-pyrazole-3.5-dimethanol
To a solution of diethyl 1-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-1H-pyrazole- 3,5-dicarboxylate (0.74 g, 2 mmol) in methylene chloride (8 ml), under nitrogen, was added 12 ml of a 1.0 M solution of diisobutylaluminum hydride in methylene chloride at 0 0C. After stirring at 0 0C for 0.5 hr, the mixture waas warmed to room temperature for 0.5 hr. It was then quenched with 15 ml of saturated ammonium chloride solution and extracted with ethyl acetate. The organic extract was washed with brine, dried over anhydrous sodium sulfate, and evaporated to give 0.44 g of a white solid; mp 82-83 0C; MS m/e 287 (MH+).
Step 3: 1 -(2-fflert-butyl(dimethyl)silylloxy>ethvn-1 H-pyrazole-3,5- dicarbaldehvde
To a stirred solution of 1-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-1H-pyrazole-3,5- dimethanol (1.18 g, 4 mmol) in methylene chloride (20 ml), was added 4- methylmorpholine-N-oxide (2.89 g, 24 mmol) and molecular sieve 4A (4 g). The reaction mixture was stirred at room temperature for 10 min. and then treated with tetrapropylammonium peruthenate (0.15 g, 0.4 mmol). Stirring was continued for 2 hr. The methylene chloride solution was concentrated and diluted with ether (40 ml). The mixture was filtered through a pad of silica gel (40 g) and the filter pad was eluted with 2 x 20 ml ether. The combined eluent was washed with 1 N HCI and brine, dried over anhydrous sodium sulfate, and evaporated to give 0.79 g of a white solid; mp 63-64 0C; MS m/e 283 (MH+). Step 4: 4-oxo-6,7-dihydro-4H-pvrazolof5.1 -el M .41oxazine-2-carbaldehvde To a solution of 1-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-1H-pyrazole-3,5- dicarbaldehyde (1.02 g, 6.07 mmol) in THF (30 ml) was added 6.68 ml of a 1.0 M solution of tetrabutylammonium fluoride in THF at 0 0C. After stirring for 1 hr, the mixture was treated with 10 ml of saturated ammonium chloride solution and extracted with ethyl acetate. The organic solution was washed with brine, dried over anhydrous sodium sulfate, filtered through Magnesol and evaporated. The crude gum was washed with hexanes, dried in vacuo, and then dissolved in methylene chloride (20 ml). To this solution was added 4-methylmorpholine-N-oxide (2.89 g, 24 mmol) and molecular sieve 4A (6 g). The mixture was stirred at room temperature for 10 min. and then treated with tetrapropylammonium peruthenate (0.11 g, 0.3 mmol). Stirring was continued for 2 hr. The methylene chloride solution was concentrated and diluted with ethyl acetate (40 ml). The mixture was filtered through a pad of silica gel (40 g) and the filter pad was eluted with 2 x 20 ml ethyl acetate. The combined eluent was washed with 1 N HCI and brine, dried over anhydrous sodium sulfate, and evaporated to give 0.30 g of a white solid; mp 135-136 0C; MS m/e 167 (MH+). Step 5: 4-nitrobenzyl f5R)-6-r(acetyloxy)(4-oxo-6J-dihydro-4H-pyrazolor5,1- cU1,41oxazin-2-yl)methvn-6-bromo-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene- 2-carboxylate
To a solution of MgBr2 (0.46 g, 2.52 mmol) in acetonitrile (13 ml) under nitrogen was added 4-oxo-6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazine-2- carbaldehyde (0.14 g, 0.84 mmol) at room temperature with stirring. A solution of
(5R,6S)-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4- nitrobenzyl ester (0.32 g, 0.84 mmole) in THF (13 ml) was then added, and the mixture was cooled to -20 0C. Triethylamine (0.35 ml, 2.52 mmol) was introduced, and the mixture was stirred at -20 0C in the dark for 4 hr. It was then treated with acetic anhydride (0.2 ml, 2.0 mmol), and 4-N,N-dimethylaminopyridine (12 mg, 0.1 mmol), and kept at 0 0C for 18 hr. The mixture was concentrated and the residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with 5% citric acid, saturated sodium bicarbonate solution, and brine, dried over anhydrous sodium sulfate, and evaporated. The crude material was chromatographed with silica gel
(EtOAc-CH2CI2/1 :5) to give 0.27 g of an off-white solid; mp 107-110 0C; MS m/e 595
(MH+). Step 6: (5R.6Z)-7-oxo-6-r(4-oxo-6.7-dihvdro-4H-Pyrazolor5,1 -ciM .41oxazin-2- yl)methylene1-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic Acid
To a solution of 4-nitrobenzyl (5R)-6-[(acetyloxy)(4-oxo-6,7-dihydro-4H- pyrazolo[5,1-c][1,4]oxazin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept- 2-ene-2-carboxylate (0.22 g, 0.37 mmol) in THF (15 ml), under nitrogen, was added
15 ml of a phosphate buffer solution (0.5M, pH 6.5), and 80 mg of 10% Pd/C. The mixture was hydrogenated at 40-50 psi for3 hr, and then filtered through Celite. The filter pad was washed with THF, and the filtrate was extracted with ethyl acetate. The organic extract was dried over anhydrous magnesium sulfate and evaporated. The residue was washed with ether to give 0.07 g of a yellow solid; MS m/e 320 (MH+); 1H
NMR (DMSOd6) δ 4.55-4.57 (m, 2H), 4.76-4.80 (m, 2H), 6.50 (s, 1H), 6.63 (s, 1H),
7.58 (s, 1H), 7.76 (s, 1 H).
EXAMPLE 15
Preparation of 6-(6.7-Dihvdro-4H-thienor3.2-c1pyran-2-ylmethylene)-7-oxo-4- thia-1 -aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid
STEP 1 : PREPARATION OF eJ-DIHYDRCMH-THIENOre.Σ-CIPYRAN^-
CARBALDEHYDE
POCI3 (3.83ml, 50mmol) was added dropwise to ice cooled DMF (3.85ml, 50mmol) within 3 minutes. DCM (20ml) was added and the bath was removed when the reaction media appeared to be pasty. The reaction was kept at 23oC for 2 hrs. Then it was cooled to OoC again. 4H-pyran-4-one (5 gram, 50mmol) in 10ml DCM was then added dropwise within 3 minutes. The reaction was kept at OoC for 2 hrs. Pour the mixture onto ice and sodium acetate solution and extract with DCM (2x200). The combined organic layers were dried over magnesium sulfate. Filter off the drying agent and concentrate gave 5.0 gram of product. The compound was dissolved in DCM (200ml) and was added 6.0 gram of ethyl 2-6,7-Dihydro-4H-thieno[3,2- c]thiopyran-2-carbaldehyde-acetate and 10 ml TEA. The mixture was refluxed for 18 hrs. Then it was washed with water and dried over magnesium sulfate. It was then filtered, concentrated and flash chromatographed with 20 ethyl acetate in hexane. The collected material was dissolved in 100ml THF and LAH (150ml, 0.5M in THF) was injected and left at 23oC for 10 minutes. Then it was refluxed for 18 hrs. Quenched at 23oC by adding water and eventually 1N HCI to clear up the mixture. Extract with ethyl acetate (2x200ml) and combined organic layers dried over magnesium sulfate. Filter and concentrate gave 2.3gram product. The crude material was dissolved in DCM (300ml) and manganese dioxide (15 gram was added). The reaction was carried on at 23oC for 0.5 hr. Then 2x15 gram of oxidant was added each half an hour later. The material was then filtered through a pad of celite concentrated. Flash column chromatography gave 1.206gram (14% yield) oil product.
H-NMR:δ 9.84(s, 1H), 7.41 (s, 1H), 4.74 (s, 2H), 4.00 (t, 2H, J=5.6 Hz)1 2.96 (t, 2H, J=5.6Hz); MS: 169.1(M+H) Step 2: Preparation of 6-(6.7-Dihvdro-4H-thienor3.2-c1pyran-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid
6,7-Dihydro-4H-thieno[3,2-c]pyran-2-carbaldehyde (336mg, 2mmol) was dissolved in 20ml acetonitrile and magnesium bromide (516 mg, 2mmol) was then added under N2 atmosphere. The mixture was stirred at 23oC for half an hour. 6- Bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (770mg, 2mmol) in 20ml THF was then injected all at once and the mixture was immediately cooled to -20oC/ Triethylamine (1ml) was then injected and the mixture stirred at -20oC for three hrs. Then acetic anhydride (0.4ml) was injected and the mixture was stirred at OoC for 18 hrs. The reaction media was then diluted with 400ml ethyl acetate and washed with 100 ml 5% citric acid, 100 ml saturated sodium bicarbonate, and 100ml brine. The organic layer was then dried over magnesium sulfate, filtered and concentrated. Flash column chromatography using 20% ethyl acetate in hexane gave 491 mg (41%) product. This product was then dissolved in 15ml THF and 15ml aqueous phosphate buffer (pH=6.5). The mixture was then subjected to 45psi hydrogen for one hour with 0.5gram 10% palladium on carbon. Then it was filtered through a pad of celite and concentrated in vacuo to remove most of the THF. The solution was then cooled to zero degree and basified to pH=8 with 1 N sodium hydroxide. Then it was purified via reverse phase HPLC using 2 liter of water followed by 5% acetonitrile in water. Water was then removed through concentrate in vacuo and 100 mg (38%) of product was collected; MP: >250° C;
H-NMR: δ 7.36 (s, 1 H), 7.15(s, 1H), 6.55(s, 1H), 6.44(s, 1 H), 4.61 (s, 2H), 3.88(m, 2H), 2.86 (m, 2H), 2.27 (m, 2H), 1.43 (t, 3H) MS: 320.3(M-H) EXAMPLE 16
Preparation of 6-(6.7-Dihvdro-4H-thienor3.2-c1thiopyran-2-ylmethylene)-7-oxo- 4-thia-1 -aza-bicyclore.Σ.OIhept-Σ-ene-Σ-carboxvlic acid
STEP 1 : PREPARATION OF ej-DIHYDRO^H-THIENOre.Z-CITHIOPYRAN-Σ- CARBALDEHYDE
POCI3 (4.02ml, 43mmol) was added dropwise to ice cooled DMF (3.34ml, 43mmol) within 3 minutes. DCM (20ml) was added and the bath was removed when the reaction media appeared to be pasty. The reaction was kept at 23oC for 2 hrs. Then it was cooled to OoC again. Tetrahydro-thiopyran-4-one (5 gram, 43mmol) in 10ml DCM was then added dropwise within 3 minutes. The reaction was kept at OoC for 2 hrs. Dilute with DCM (250 ml) and then wash with ice cold 200ml saturated sodium acetate aqueous solution. The organic layer was dried over sodium sulfate. Filter off the drying agent, concentrate and flash column chromatography using 10% ethyl acetate in hexane gave 1.3 gram (δmmol) of product. The compound was dissolved in DCM (100ml) and was added 1.2ml (11 mmol) of ethyl 2-mercapto- acetate and 1ml TEA. The mixture was refluxed for 18 hrs. Then it was washed with water and dried over magnesium sulfate. Filter, concentrate and flash chromatograph with 20 ethyl acetate in hexane produced 1.1 gram (11% yield) of product
H-NMR:δ 6.68(s, 1H), 4.73 (s, 2H), 3.68(s, 2H), 3.04 (t, 2H, J=7.6 Hz), 2.91 (t, 2H, J=7.6Hz).; MS (El): 185.99 (M+)
The 1.1 gram (4.8mmol) 6,7-Dihydro-4H-thieno[3,2-c]thiopyran-2-carboxylic acid ethyl ester was dissolved in 100ml THF and LAH (40ml, 0.5M in DMG) was injected and the reaction was left at 23oC for 10 minutes. Then it was refluxed for 18 hrs. Quenched at 23oC with water (10ml). The organic layer decanted and the remaining was washed with 20ml DCM. The combined organic layers dried over sodium sulfate. Filter, concentrate and flash column chromatograph with 10-20% ethyl acetate produced 940mg crude product. This crude material was dissolved in DCM (40ml) and manganese dioxide (2 gram was added). The reaction was carried on at 23oC for half an hour. The material was then filtered through a pad of celite concentrated. Flash column chromatography gave 320mg (36%) product. H-NMR:δ 9.82(s, 1H), 7.46 (s, 1H), 3.56 (s, 2H), 3.15 (t, 2H, J=7.2 Hz), 2.95 (t, 2H, J=7.2 Hz).; MS (El): 228.02 (M+)
Step 2: Preparation of 6-^6.7-Dihvdro-4H-thienor3.2-cUhiopyran-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid 6,7-Dihydro-4H-thieno[3,2-c]thiopyran-2-carbaldehyde (320mg, 1.72mmol) was dissolved in 17ml acetonitrile and magnesium bromide etherate (450 mg, 1.74mmol) was then added under N2 atmosphere. The mixture was stirred at 23oC for half an hour. 6-Bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (660mg, 1.72mmol) in 17ml THF was then injected all at once and the mixture was immediately cooled to -20oC/ Triethylamine (1ml) was then injected and the mixture stirred at -20oC for three hrs. Then acetic anhydride (0.4ml) was injected and the mixture was stirred at OoC for 18 hrs. The reaction media was then diluted with 400ml ethyl acetate and washed with 100 ml 5% citric acid, 100 ml saturated sodium bicarbonate, and 100ml brine. The organic layer was then dried over magnesium sulfate, filtered and concentrated. Flash column chromatography using 20% ethyl acetate in hexane gave 461 mg (44%) product. This product was then dissolved in 20ml THF and 20ml aqueous phosphate buffer (pH=6.5). The mixture was then subjected to 40psi hydrogen for one hour and half with 0.5gram 10% palladium on carbon. Then it was filtered through a pad of celite and concentrated in vacuo to remove most of the THF. The solution was then cooled to zero degree and basified to pH=8 with 1 N sodium hydroxide. Then it was purified via reverse phase HPLC using 2 liter of water followed by 5% acetonitrile in water. Water was then removed through concentrate in vacuo and 21 mg (8.6%) of product was collected. MP: >250° C
H-NMR: 7.34 (s, 1H), 7.18(s, 1H), 6.59(s, 1H), 6.44(s, 1 H), 3.71 (s, 2H), 2.93(s, 2H), 2.50 (s, 2H).; MS: 338.0(M+H)
EXAMPLE 17
Preparation of 6-(5-Methyl-4.5.6.7-tetrahvdro-thienor3.2-clpyridin-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01rιept-2-ene-2-carboxylic acid
Step 1 : Preparation of (5-Methyl-4,5,6,7-tetrahvdro-thienor3,2-cipyridin-2-yl)- methanol 6,7-Dihydro-4H-thieno[3,2-c]pyridine-2,5-dicarboxylic acid diethyl ester (46 gram, 163mmol) was dissolved in 200ml THF. The solution was injected LAH (1M, THF) 300ml at 23oC. Then it was stirred at 23oC for 18 hrs. The reaction was quenched with 10ml water and dried directly over sodium sulfate. Filter and concentrate yielded 29.3 gram (160mmol, 98%) crude product.
H-NMR: 6.55(s, 1H), 4.70 (s, 2H), 3.41 (s, 2H), 2.86 (t, 2H, J=5.6 Hz), 2.73 (t, 2H, J=5.6 Hz), 2.38 (s, 3H); MS: 184.0(M+H)
Step 2: Preparation of 5-Methyl-4.5.6,7-tetrahvdro-thienor3.2-cTpyridine-2- carbaldehvde DMSO (1.7ml, 24mmol) in 5ml CH2CI2 was cooled to -50-60OC. Oxalyl chloride (1ml, 11mmol) in 20ml DCM was then added within 5 minutes at 50oC. The mixture was kept at -50oC for 5 minutes and then 1.67 gram (9mmol) of (5-Methyl- 4,5,6,7-tetrahydro-thieno[3,2-c]pyridin-2-yl)-methanol in 20ml DCM was added at 50oC and the mixture was stirred for another 15minutes at 50oC. Triethylamine (7ml ) was then added at -50oC and after 5 minutes the bath was removed and the mixture is naturally warmed up to 23oC. It was washed with 100ml water and extracted with 100ml ethyl acetate. The combined organic layers were dried over magnesium sulfate. Filter. Concentrate and flash column chromatograph using 0- 15% methanol in ethyl acetate yielded 736mg (45% yield) product. H-NMR: 9.81 (s, 1H), 7.42 (s, 1H), 3.56 (s, 2H), 3.00 (t, 2H, J=5.6 Hz), 2.91 (t,
2H, J=5.6 Hz), 2.51 (s, 3H); MS: 182.1(M+H)
Step 3: Preparation of 6-(5-Methyl-4,5,6.7-tetrahvdro-thienof3,2-c1pyridin-2- ylmethylene)-7-oxo-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid
2-formyl-6,7-dihydro-4H-thieno[3,2-c]pyridine-5-carboxylic acid ethyl ester (724mg, 4mmol) was dissolved in 40ml acetonitrile and magnesium bromide etherate (1.2 gram, 4.65mmol) was then added under N2 atmosphere. The mixture was stirred at 23oC for half an hour. 6-Bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2- ene-2-carboxylic acid 4-nitro-benzyl ester (1.54gram, 4mmol) in 40ml THF was then injected all at once and the mixture was immediately cooled to -20oC. Triethylamine (2ml) was then injected and the mixture stirred at -20oC for 3 hrs. Then acetic anhydride (0.66ml) was injected and the mixture was stirred at OoC for 48 hrs. The reaction media was then diluted with 500ml ethyl acetate and washed with 50 ml 5% citric acid, 50 ml saturated sodium bicarbonate, and 50ml brine. Another 300ml ethyl acetate was used to wash each aqueous solution. The combined organic layers were then dried over sodium sulfate. Filter, concentrate, and flash column chromatograph using 20% ethyl acetate in hexane gave 1.56 gram (64% yield) product. This product was then dissolved in 20ml THF and 20ml aqueous phosphate buffer (pH=6.5). The mixture was then subjected to 40psi hydrogen for two hrs with 0.5gram 10% palladium on carbon. Then it was filtered through a pad of celite and concentrated in vacuo to remove most of the THF. The solution was then cooled to zero degree and basified to pH=8 with 1 N sodium hydroxide. Then it was purified via reverse phase HPLC using 2 liter of water followed by 5% acetonitrile in water. Water was then removed through concentrate in vacuo and 112 mg (13%) of product was collected.
MP: >250oC
H-NMR: δ 7.48 (s, 1 H), 7.37(s, 1H), 7.21 (s, 1H), 7.10(s, 1H), 3.41 (s, 2H), 2.88 (s, 2H)1 2.68(s, 2H), 2.37(s, 3H); MS: 335.0(M+H)
EXAMPLE 18
Preparation of 2-(2-Carboxy-7-oxo-4-thia-1 -aza-bicvclore^.Olhept-Σ-en-G- ylidenemethvπ-βJ-dihvdro^H-thienorS.Σ-cipyridine-S-carboxylic acid ethyl ester
2-Formyl-6,7-dihydro-4H-thieno[3,2-c]pyridine-5-carboxylic acid ethyl ester (480mg, 2mmol) was dissolved in 20ml acetonitrile and magnesium bromide etherate
(516mg, 2mmol) was then added under N2 atmosphere. The mixture was stirred at
23oC for half an hour. 6-Bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2- carboxylic acid 4-nitro-benzyl ester (770mg, 2mmol) in 20ml THF was then injected all at once and the mixture was immediately cooled to -20oC. Triethylamine (1ml) was then injected and the mixture stirred at -20oC for 3 hrs. Then acetic anhydride
(0.4ml) was injected and the mixture was stirred at OoC for 48 hrs. The reaction media was then diluted with 200ml ethyl acetate and washed sequentially with 50 ml
5% citric acid, 50 ml saturated sodium bicarbonate, and 50ml brine. The organic layer was then dried over sodium sulfate. Filter, concentrate, and flash column chromatograph using 20% ethyl acetate in hexane gave 690mg (50%, yield) product.
A fraction of this product (456mg, 0.69mmol) was then dissolved in 15ml THF and
15ml aqueous phosphate buffer (pH=6.5). The mixture was then subjected to 40psi hydrogen for two hrs with O.δgram 10% palladium on carbon. Then it was filtered through a pad of celite and concentrated in vacuo to remove most of the THF. The solution was then cooled to zero degree and basified to pH=8 with 1 N sodium hydroxide. Then it was purified via reverse phase HPLC using 2 liter of water followed by 5% acetonitrile in water. Water was then removed through concentrate in vacuo and 18 mg (5%) of product was collected.
MP: >250oC
H-NMR: 7.35 (s, 1 H), 7.24 (s, 1H), 6.61 (s, 1 H), 6.45(s, 1H), 4.48 (s, 2H), 4.08 (quartet, 2H, J=7.2Hz), 3.68 (m, 2H), 2.87(m, 2H), 1.20 (t, 3H, J=7.2Hz); MS: 393.0(M+H)
EXAMPLE 19
Preparation of 7-Oxo-6-(6.7.8.9-tetrahvdro-5H-imidazoH .2-alazepin-2- ylmethylene)-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxvlic acid
STEP 1: PREPARATION OF 6.7.8.9-TETRAHYDRO-SH-IMIDAZOrI^-AIAZEPINE- 2-CARBALDEHYDE
Thiocaprolactam (6.45 gram, 50mmol) was dissolved in 400ml CH2CI2 and methyl iodide (16ml, 5eq) was next added. The mixture was stirred under nitrogen for 18 hrs. Then it was treated with 100ml potassium carbonate (50%, aq.). The organic layer was then dried over magnesium sulfate. After filtration and concentration 7.3 gram of material was obtained. This material was dissolved 300ml ethanol and 2.83 gram of ammonium chloride was added. The mixture was refluxed for 1 hr. Then the solvent was removed in vacuo. Half of the material was added 200ml ethanol and then followed by addition of 1.35gram (25mmol) sodium methoxide and 4.8gram (25mmol) 2-Bromo-3-isopropoxy-propenal and the mixture was stirred at 23oC for 2 hrs. Then the solvent was removed and 200ml chloroform was added along with 10ml triethyl amine. The mixture was refluxed for 2 hrs and then cooled to 23oC. The reaction media was partitioned between 300ml DCM and 2x150 potassium carbonate (50%). The organic layer was dried over magnesium sulfate. After filtration and concentration 2.1 gram of oil product was obtained.
H-NMR: 9.62 (s, 1H), 7.60 (s, 1H), 6.61 (s, 1H), 6.45(s, 1H), 4.58 (s, 2H), 2.96 (2m, H), 1.90(m, 2H), 1.72 (m, 2H); MS: 164.9(M+H) Step 2: Preparation of 7-Oxo-6-(6,7,8.9-tetrahvdro-5H-imidazoH.2-a1azepin-2- ylmethylene)-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid
6,7,8,9-Tetrahydro-5H-imidazo[1 ,2-a]azepine-2-carbaldehyde (1.312gram, δmmol) was dissolved in 80ml acetonitrile and magnesium bromide etherate (2.94gram, δmmol) was then added under N2 atmosphere. The mixture was stirred at 23oC for half an hour. 6-Bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2- carboxylic acid 4-nitro-benzyl ester (1.155gram, 3mmol) in 60ml THF was then injected all at once and the mixture was immediately cooled to -20oC. Triethylamine (4ml) was then injected and the mixture stirred at -20oC for 4 hrs. Then acetic anhydride (1ml) was injected and the mixture was stirred at OoC for 20 hrs. The reaction media was then diluted with 500ml ethyl acetate and washed with 100ml 5% citric acid, 100 ml saturated sodium bicarbonate, and 100ml brine. The organic layer was then dried over sodium sulfate. Filter, concentrate, and flash column chromatograph using 20% ethyl acetate in hexane gave 800mg product. This product was then dissolved in 20ml THF and 20ml aqueous phosphate buffer (pH=6.5). The mixture was then subjected to 40psi hydrogen for 1 hr with O.δgram 10% palladium on carbon. Then it was filtered through a pad of celite and concentrated in vacuo to remove most of the THF. The solution was then cooled to zero degree and basified to pH=δ with 1 N sodium hydroxide. Then it was purified via reverse phase HPLC using 2 liter of water followed by 5% acetonitrile in water. Water was then removed through concentrate in vacuo and 131 mg (31%) of product was collected.
MP: >250° C
H-NMR: δ 7.78 (s, 1H), 7.02 (s, 1H), 6.94 (s, 1H), 6.36 (s, 1H), 3.92(m, 2H), 2.80 (m, 2H), 1.78 (m, 2H), 1.61 (m, 2H), 1.54(m, 2H); MS: 318.2(M+H).
EXAMPLE 20
Preparation of (5f?U6ZV6-(7-Benzyl-5.6.7.8-tetrahvdroimidazoπ .2- a1pyrazin-2-ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2- carboxylic acid, sodium salt Step 1 : 7-Benzyl-5,6.7,8-tetrahvdroimfdazoH ,2-a1pyrazine-2-carboxylic acid ethvl ester Et3N (6.27 mL), PhCHO (4.92 mL) were added successively to the
EtOH (81 mL) solution of 5,6,7,8-tetrahydroimidazo[1 ,2-a]pyrazine-2-carboxylic acid ethyl ester, hydrochloride (9.47 g) at room temperature and stirred for 3 h under a nitrogen atmosphere. Then NaBH3CN (2.97 g) was added to the reaction mixture and stirred for 19 h. The mixture was filtered through a pad of Celite and diluted with
CH2CI2 and washed with 50% K2CO3 aq. The organic layer was dried (K2CO3) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3
- acetone (1/0 ~ 9/1) and CHCI3 - MeOH (19/1 - 9/1). The titled compound was obtained as pale yellow crystals (4.16 g, 36%).
1H NMR(CDCI3) δ 1.36(t, 3H, J = 7.1 Hz)1 2.87(t, 2H, J = 5.2 Hz), 3.71(s, 2H), 3.75(s, 2H), 4.01 (m, 2H), 4.34(q, 2H, J = 7.1 Hz), 7.25-7.34(m, 5H),
7.51 (s, 1 H) .
Step 2: 7-Benzyl-5.6.7.8-tetrahvdroimidazori,2-a1pyrazine-2- carbaldehvde
1.01 M solution of DIBAL in toluene (1 mL + 0.2 mL + 0.3 mL) was added to the dry CH2CI2 (5 mL) solution of 7-benzyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrazine-2-carboxylic acid ethyl ester (283 mg) under a nitrogen atmosphere at -
78 0C and stirred for 1.5 h. The mixture was quenched with 1M HCI (5 mL). The reaction mixture was filtered through a pad of Celite. The filtrate was washed with
50% K2CO3 aq. and the aqueous layer was extracted with CH2CI2. The combined organic layer was dried (K2CO3) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with CHCI3 - acetone (9/1 ~ 4/1) and CHCI3 - MeOH (19/1). The titled compound was obtained as colorless crystals (148 mg, 61%).
1H NMR(CDCI3) δ 2.90(t, 2H, J = 5.5 Hz), 3.74(s, 2H), 3.76(s, 2H), 4.06(t, 2H, J = 5.5 Hz), 7.28 - 7.35(m, 5H), 7.53(s, 1H), 9.80(s, 1H).
Step 3j (5K1 6flS)-6-KftS)-Acetoxy(7-benzyl-5.6.7.8- tetrahvdroimidazori.2-alpyrazin-2-yl)methvπ-6-bromo-7-oxo-4-thia-1- azabicvclor3.2.01hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (diastereo mixture)
7-Benzyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine-2-carbaldehyde (139 mg) was added to the dry acetonitrile (8.7 mL) solution of anhydrous MgBr2 (325 mg) under a nitrogen atmosphere at room temperature. The dry THF solution (8.7 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (223 mg) was added to the mixture, cooled to -20 0C, and Et3N (0.24 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 5 h at -20 0C and treated with acetic anhydride (0.11 mL) and DMAP (7 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (3/1 ~ 1/1). The titled compound was obtained as two diastereo mixture (80/20, purple amorphous solid, 233 mg, 61%).
1H NMR(CDCI3) δ 1.99(s, 0.8x3H), 2.23(s, 0.2x3H), 2.83 ~ 2.89(m, 2H), 3.68(d, 2H, J = 4.9 Hz), 3.71(s, 2H), 3.94 ~ 4.13(m, 2H), 5.27(d, 1H1 J = 13.6 Hz), 5.41 (d, 0.2x1 H, J = 13.6 Hz), 5.45(d, 0.8x1 H, J = 13.6 Hz), 6.05(s, 0.2x1 H), 6.28(s. 0.8x1 H), 6.31 (s, 0.8x1 H), 6.790(s, 0.2x1 H), 6.793(s, 0.2x1 H), 7.01 (s, 0.8x1 H), 7.27 - 7.36(m, 5H), 7.42(s, 0.2x1 H), 7.46(s, 0.8x1 H), 7.61 (d, 2H, J = 8.6 Hz), 8.22(d, 2H, J = 8.6 Hz). Step 4: (5ffl,(6Z)-6-(7-Benzyl-5.6.7.8-tetrahvdroimidazof1.2-a1pyrazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid. sodium salt
(5R, 6RS)-6-[(RS)-Acetoxy(7-benzyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrazin-2-yl) methyl]-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid
4-nitrobenzyl ester (1.27 g) was dissolved in THF (55 mL) and acetonitrile (25 mL). Freshly activated Zn dust (5.08 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 80 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (79 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN(1/0 ~ 4/1). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (390 mg, 49%, pH 7.7).
Mp 180 0C (dec); 1H NMR(D2O) δ 2.84 - 2.95(m, 2H), 3.61 (d, 2H, J = 7.2 Hz), 3.67(s, 2H), 3.96(t, 2H, J = 5.7 Hz), 6.43(s, 1H), 6.89(s, 1H), 6.93(s, 1H), 7.28 -7.37(m, 6H).
Example 21 Preparation of (5R.eZ)-7-oxo-6-fr5-(pyridin-3-ylmethvh-4.5.6.7- tetrahvdrothienor3.2-cipyridin-2-yl)1methylene)-7oxo-4-thia-1- azabicvclor3.2.01hept-2-ene-2-carboxylic acid:
Step 1: 2-Formyl r5-(pyridin-3-ylmethylM.5.6.7-tetrahvdrothienoU3.2- ci pyridine: To a stirred solution of 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine
(1.05 g, 5.2 mmol) in DMF ( 20 ml) , 3-picolyl chloride hydrochloride (0.852 g, 5.2 mmol) and N,N-diisopropylethylamine (10 ml, excess) was added at room temperature. The reaction mixture was stirred for 24 hrs and quenched with water. The reaction mixture was extracted with chloroform; washed well with water and dried over anhydrous MgSO4. It was filtered and concentrated. The product was purified by SiO2 column chromatography by eluting it with ethylacetate. Pale yellow semi-solid. Yield: 800 mg , 59%; M+H 259.
Step 2: 4-Nitrobenzv-6-r(acetyloxyU5(pyridin-3-ylmethvn-4.5.6.7- tetrahvdrothienor3,2-cipyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- azapicvclore.Σ.Olhept-Σ-ene-Σ-carboxylate:
2-Formyl [5-(pyridin-3-ylmethyl)-4,5,6,7-tetrahydrothieno][3,2-c]pyridine (516 mg, 2.0 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (772 mg, 2.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (390 mg, 1.5 mmo!)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1 :1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 700 mg, 51%; M+H 685 and 687. Step-3: (5R.6Z)-6-(r5-(pyridin-3-ylmethyl)-4,5,6.7-tetrahvdrothienor3,2- cipyridin-Σ-vOlmethyleneWoxo-^hia-i-azabicvclore^.Oihept-Σ-ene-Σ- carboxylic acid:
4-Nitrobenzy-6-[(acetyloxy)[5(pyridin-3-ylmethyl)-4,5,6,7-tetrahydrothieno[3,2- clpyridin^-yOmethyll-β-bromo^-oxo^-thia-i-azabicycloIS^.Olhept^-ene^- carboxylate ( 686 mg, 1.0 mmol) was dissolved in THF (20 mL) and acetonitrile (10 ml_). Freshly activated Zn dust (5.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 28 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 12%; as yellow crystals; mp. 134-1360C; (M+H) 412 .
1H NMR (DMSO-d6)δ d 2.8 (m, 2H), 2.92 (bm, 2H), 3.6 (m, 2H), 3.86 (s, 2H), 6.3 (s, 1H), 6.41 (S, 1H), 7.17 (s, 1H), 7.29 (s, 1H), 7.35 (m, 1 H), 7.7 (m, 1H), 8.48 (d,1H ), 8.54 (s, 1H).
Example 22 Preparation of (5R.6Z\-7-oxo-β-ff5-(pyridin-3-ylcarbonvπ -4,5,6,7- tetrahvdrothienor3,2-cipyridin-2-yl)1methylene>-7oxo-4-thia-1- azabicyclor3.2.0^hept-2-ene-2-carboxylic acid:
Step 1 : 2-Formyl f5-( pyridin-3-ylcarbonv^-4.5,β,7-tetrahvdrothienolf3.2- clpyridine:
To a stirred solution of 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine (606 mg, 3.0 mmol) in DMF ( 20 ml) , nicotinoyl chloride hydrochloride (531 mg, 3.0 mmol) and N.N-diisopropylethylamine (10 ml, excess) was added at room temperature. The reaction mixture was stirred for 24 hrs and quenched with water. The reaction mixture was extracted with chloroform; washed well with water and dried over anhydrous MgSO4. It was filtered and concentrated. The product was purified by SiO2 column chromatography by eluting it with ethylacetate. Pale yellow semi-solid. Yield: 600mg , 73%; M+H 273.
Step 2: 4-Nitrobenzv-6-r(acetyloxy)f5(pyridin-3-ylcarbonyl)-4.5.6.7- tetrahvdrothtenore^-cipyridin-Σ-vOcarbonvπ-S-bromo^-oxo^-thia-i- azabicvclore.∑.πihept^-ene^-carboxylate:
2-Formyl [5-(pyridin-3-ylcarbonyl)-4,5,6,7-tetrahydrothieno3[3,2-c]pyridine (400 mg, 1.4 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (772 mg, 2.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (619 mg, 2.4 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Ceiite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1 :1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 300 mg, 30%; M.pt. 710C; M+H 701. Step-3: (5R.6Z)-6-fr5-(pyridin-3-ylcarbonyl)-4,5.β.7-tetrahvdrothienor3.2- cipyridin-Σ-vOimethylenel^oxo^-thia-i-azabicvcloβ^.Oihept^-ene-a- carboxylic acid sodium salt:
4-Nitrobenzy-6-[(acetyloxy)[5(pyridin-3-ylcarbonyl)-4,5,6,7- tetrahydrothieno[3,2-c]pyridin-2~yl)methyl]-6-bromo-7-oxo-44hia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylate ( 800 mg, 1.14 mmol) was dissolved in THF (20 mL) and acetonitrile (10 mL). Freshly activated Zn dust (5.2 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 28 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% CAN: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 50 mg, 12%; as yellow crystals; mp. 1950C; (M+H) 426.
Example 23 Preparation of (5R.6Z)-7-oxo-6-(r5-(phenylacetvπ-4,5,6J-tetrahvdrothienof3,2- cipyridin-Σ-vOimethyleneVToxo^-thia-i^zabicvciore^.O'lhept-Σ-ene-Σ- carboxylic acid:
Step 1: 2-Formyl r5-fphenylacetvn-4,5,6.7-tetrahvdrothienoir3.2- cipyridine: To a stirred solution of 2-(formyl)-6,7-dihydrothieno[3,2-c]-5(4H)-pyridine
(0.41 mg, 2 mmol) in DMF ( 20 ml) , phenyl acetyl chloride (0.35 mg, 2.2 mmol) and N,N-diisopropylethylamine (10 ml, excess) was added at room temperature. The reaction mixture was stirred for 24 hrs and quenched with water. The reaction mixture was extracted with chloroform; washed well with water and dried over anhydrous MgSO4. It was filtered and concentrated. The product was purified by SiO2 column chromatography by eluting it with ethylacetate. White solid. Yield: 510 mg , 89%; M+H 286. Step 2: 4-Nitrobenzy-6-r(acetvioxy)r5(phenylacetyl)-4.5.6.7- tetrahvdrothienor3,2-c1pyridin-2-yl)methvn-6-bromo-7-oxo-4-thia-1- azabicyclorS^.OIhept-Σ-ene^-carboxylate:
2-Formyl [5-(phenylacetyl)-4,5,6,7-tetrahydrothieno][3,2-c]pyridine (340 mg, 1.2 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (390 mg, 1.0 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (310 mg, 1.2 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1:1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 360 mg, 50%; M+H 713.
Step-3: (5R.6Z)-6-fr5-(phenylacetyl)-4.5.6.7-tetrahvdrothienor3.2- cipyridin-Σ-vDimethyleney^oxo^-thia-i-azabicvclors.Σ.OIhept^-ene-Σ- carboxylic acid:
4-Nitrobenzy-6-[(acetyloxy)[5(phenylacetyl)-4,5,6,7-tetrahydrothieno[3,2- φyridin^-yOmethylJ-e-bromo^-oxo^-thia-i-azabicycloβ^.Olhept-^-ene^- carboxylate ( 300 mg, 0.4 mmol) was dissolved in THF (50 mL) and 0.5 M phosphate buffer (pH 6.5, 28 mL). This was hydrogenated at 40 psi pressure, in the presence of 10% Pd/C (80 mg) for 2 hrs. at the end, reaction mixture was filtered through a pad of celite and concentrated. The separated yellow solid was dissolved in ethyl acetate and washed well with water. The organic layer was dried and concentrated. The separated yellow solid was triturated with diethyl ether and filtered. The yellow solid was washed well with diethyl ether and it was found to be 95% pure compound. Yield: 160 mg, 91%; Yellow solid; mp. 166-1690C; (M+H) 439 . Example 24
Preparation of (5ffl.(6Z)-6-( 5.5-Dioxo-4.5.6.7-tetrahvdro-5λ6-Dyrazolor5.1 - ciπ^ithiazin-Σ-ylmethylene^-T-oxo^-thia-i-azabicvclorS.Σ.OIhept-a-ene-Σ- carboxylic acid, sodium salt
Step 1 : 5.5-Dioxo-4,5.6.7-tetrahvdro-5λ6-pyrazolor5,1 -cIM ,41th iazine-2- carbaldehyde m-Chloroperbenzoic acid (cont. 69%) (6.36 g) was added to the
CH2CI2 (111 ml_) solution of 6,7-dihydro-4H-pyrazolo[5,1-c][1 ,4]thiazine-2- carbaldehyde (1.86 g) at 0 0C. The reaction mixture was stirred for 0.5 h at the same temperature and stirred for 18 h at room temperature. The reaction mixture was concentrated under reduced pressure. The residue was triturated with 10 mL of
THF and filtered to obtain crystals. The filtrate was concentrated under reduced pressure. The residue was triturated with 5 mL of THF and filtered to obtain crystals. The combined crystals were dried under reduced pressure to give the titled compound as colorless crystals (1.96 g, 89%).
1H NMR (CDCI3) δ 3.60 (t, 2H1 J = 6.1 Hz), 4.47 (s, 2H), 4.87 (t, 2H1 J = 6.1 Hz)1 6.71 (s, 1H), 9.94 (s, 1H).
Step 2:(5R 6/?S)-6-r(/?S)-Acetoxy-f5.5-dioxo-4.5.6.7-tetrahvdro-5λ6-pyrazolor5.1- ciπΛithiazin-Σ-vπ-methvn-β-bromo^-oxo^-thia-i-azabicvclorS.Σ.Olhept-Σ-ene- 2-carboxylic acid 4-nitrobenzyl ester
5,5-Dioxo-4,5,6,7-tetrahydro-5λ6-pyrazolo[5,1-c][1,4]thiazine-2- carbaldehyde (1.95 g) was added to the dry acetonitrile (112 mL) solution of anhydrous MgBr2 (cont. 98%) (5.48 g) under a nitrogen atmosphere at room temperature. The dry THF solution (112 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 96.5%) (3.88 g) was added to the mixture, cooled to -20 0C, and Et3N (cont. 99%) (3.79 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with acetic anhydride (cont. 97%) (3.79 mL) and DMAP (cont. 99%) (120 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 16 h at 0 0C. To the reaction mixture was added acetic anhydride (cont. 97%) (0.95 mL) and DMAP (cont. 99%) (120 mg) in one portion. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4), followed by concentration under reduced pressure. The residue was purified with a silica-gel column chromatography (CHCI3 : acetone = 19 :1 - 4 : 1) to give the titled compound as a pale brown amorphous solid (diastereo-mixture (8 : 2), 1.35 g, 22%).
1H NMR (CDCI3) δ 2.07 (s, 3H X 0.2), 2.25 (s, 3H x 0.8), 3.45 - 3.60 (m, 2H), 4.39 (d, 1 H, J = 17.0 Hz), 4.44 (d, 1 H, J = 17.0 Hz), 4.65 - 4.78 (m, 2H), 5.28 (d, 1 H, J = 13.5 Hz), 5.43 (d, 1H x 0.8, J = 13.5 Hz), 5.44 (d, 1H x 0.2, J = 13.5 Hz), 6.05 (s, 1 H x 0.8), 6.20 (s, 1 H x 0.8), 6.22 (s, 1 H x 0.2H), 6.38 (s, 1 H x 0.2), 6.39 (s, 1 H x 0.2), 6.79 (s, 1 H x 0.8), 7.42 (s, 1 H x 0.8), 7.44 (s, 1 H X 0.2), 7.60 (d, 2H, J = 8.7 Hz), 8.24 (d, 2H, J = 8.7 Hz).
Step 3: (5ffl.(6Z)-6-(5.5-Dioxo-4,5,6,7-tetrahvdro-5λβ-pyrazolor5.1 - ciri,41thia2in-2-ylmethylene)-7-oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2- carboxylic acid, sodium salt (5R, 6RS)-6-[(RS)-Acetoxy-(5,5-dioxo-4,5,6,7-tetrahydro-5D6-pyrazolo[5,1-
^[i ^l-thiazin^-yO-methyO-e-bromo^-oxo^-thia-i-azabicyclofS^.OJhept^-ene^- carboxylic acid 4-nitrobenzyI ester (1.33 g) was dissolved in THF (19 mL) and acetonitrile (9 mL). Freshly activated Zn dust (5.32 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 27 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The insoluble material was filtered off and was washed with H2O (27 mL). The filtrate was added H2O (27 mL) and washed with ethyl acetate (27 mL) and the aqueous layer was cooled to 3 0C and 1 M HCI was added to adjust pH to 2.5. The mixture was stirred for 1 d at the same temperature and added H2O (55 mL), then stirred for 4 d at the same temperature. The mixture was stirred for 10 h at room temperature. The resultant mixture was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8. The mixture was concentrated under high vacuum at 35 0C. The concentrate was treated to Diaion HP-21 (80 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 9/1). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (306 mg, 38%, pH 7.4). Mp 180 0C (dec); 1H NMR (D2O) δ 3.83 (t, 2H, J = 6.1 Hz), 4.68 (s, 2H), 4.72 (t, 2H, J = 6.1 Hz), 6.37 (s, 1 H), 6.40 (s, 1H), 6.95 (s, 1H), 6.98 (s, 1 H).
Example 25
Preparation of (5ffl.(6Z)-7-Oxo-6-(4.5.6J-tetrahvdropyrazoloH .5- alpyrazin-2-ylmethylene)-4-thia-1-aza-bicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt Piperazine-2-carboxylic acid, dihydrochloride:
The titled compound was prepared in the same way of M. T. Wu and co-workers (Bioorg. Med. Chem. Lett. 1993, 3, 2023-2028). Step 1 : Piperazine-1.3-dicarboxylic acid 1-(4-nitrobenzyl) ester
CuCO3-Cu(OH)2-H2O (15.8 g) was added to the H2O (275 mL) solution of piperazine-2-carboxylic acid, dihydrochloride (22.3 g), then the mixture was refluxed and stirred for 10 min. The insoluble material was filtered off and was washed with hot H2O (165 mL). The filtrate was cooled to room temperature, and NaHCO3 (9.2 g) and 1 ,4-dioxane (220 mL) was added to the dark blue solution. The mixture was cooled to 0 0C and NaHCO3 (18.5 g) and 50% solution of 4-nitrobenzyl chloroformate in 1,4-dioxane (61.7 g) was added to the mixture for 0.5 h. After stirring for additional 1.5 h at 0 0C, the precipitate was filtered and washed with cold H2O (140 mL), EtOH (100 mL), acetone (200 mL) and Et2O (100 mL), then it was allowed to dry under reduced pressure to obtain the pale blue crystals. The crystals were added to the 1 mol/L HCI (330 mL) solution of EDTA-2Na (20.5 g) for 30 min, and stirred for 2 h at room temperature. The suspension was filtered and the filtered material was diluted with EtOH - H2O (7 : 3, 550 mL) and refluxed for 10 min. The reaction mixture was filtered to obtain the colorless crystals. The recrystallization from the filtrate was carried out 3 times to obtain additional crystals. The combined crystals were dried under reduced pressure to obtain the titled compound (26.25 g, 77%) as colorless crystals.
1H NMR (D2O) δ 2.54 - 2.61 (m, 1H), 2.89 (dt, 2H, J = 12.7, 3.4 Hz), 2.97 (br, 1 H), 3.13 (br, 1H), 3.62 - 4.04 (m, 2H), 5.16 (s, 2H), 7.49 (d, 2H, J = 8.6 Hz), 8.14 (d, 2H, J = 8.6 Hz).
Step 2: 5-(4-Nitrobenzyloxycarbonyl)-3-oxo-3a.4,6.7-tetrahvdro-3H-2- oxa-1,5-diaza-7a-azoniainden-3a-ifte The H2O (300 mL) solution of NaNO2 (cont. 98.5 %) (6.66 g) was added to the acetic acid (864 mL) solution of piperazine-1 ,3-dicarboxylic acid 1-(4- nitrobenzyl) ester (26.72 g) under a nitrogen atmosphere at 0 0C for 0.5 h and stirred for 1 h. In addition, the H2O (132 mL) solution of NaNO2 (cont. 98.5 %) (2.41 g) was added to the solution at 0 0C for 0.5 h and stirred for 1 h. The solution was concentrated under reduced pressure and H2O (500 mL) was added to the residue.
The solution was extracted with AcOEt (5 times) and organic layer was washed with brine. The mixture was dried over MgSO4, filtered and concentrated under reduced pressure to afford crude 4-nitrosopiperazine-1 ,3-dicarboxylic acid 1-(4-nitrobenzyl) ester as pale brown amorphous (27.83 g (gross), 25.77 g (net), 88.2%).
The THF (10 mL) solution of trifluoroacetic anhydride (24.0 g) was added to the THF (371 mL) solution of crude 4-nitrosopiperazine-1 ,3-dicarboxylic acid 1-(4-nitrobenzyl) ester under a nitrogen atmosphere at 0 0C for 15 min. The solution was stirred for 1.5 h at 0 0C and for 1h at room temperature. The THF (5 mL) solution of trifluoroacetic anhydride (8.0 g) was added to the solution for 5 min and stirred for 20 h at room temperature. To the solution was added trifluoroacetic anhydride (8.0 g) for 5 min and the solution was stirred for 4h. The precipitate was filtered and washed with THF and Et2O. The filtrate was concentrated under reduced pressure. The residue was triturated with THF, filtered and washed with Et2O. These materials were combined and dried under reduced pressure to afford the titled compound as colorless crystals (22.3 g, 91%).
1H NMR (CDCI3) δ 4.06 (t, 2H, J = 5.4 Hz), 4.37 (t, 2H, J = 5.4 Hz), 4.63 (s, 2H), 5.30 (s, 2H), 7.54 (d, 2H, J = 8.7 Hz), 8.25 (d, 2H, J = 8.7 Hz).
Step 3: 6.7-Dihvdro-4/-/-pyrazolof1,5-a1pyrazine-2.5-dicarboxylic acid 2- ethyl ester 5-(4-nitrobenzyl) ester
Ethyl propiolate (cont. 99%)(8.28 g) was added to the o-xylene (348 mL) solution of 5-(4-nitrobenzyloxycarbonyl)-3-oxo-3a,4,6,7-tetrahydro-3H-2-oxa-1 ,5- diaza-7a-azoniainden-3a-ide (22.3 g) under a nitrogen atmosphere and refluxed for 16 h. The solution was concentrated under reduced pressure, followed by silica-gel column chromatography 3 times (n-hexane /AcOEt = 2/1 - 1/3). The titled compound was obtained as pale yellow crystals (16.78 g, 64%). Besides, 6,7- dihydro-4H-pyrazolo[1 ,5-a]pyrazine-3,5-dicarboxylic acid 3-ethyl ester 5-(4- nitrobenzyl) ester was obtained as pale yellow crystals (6.18 g, 24%). 1H NMR (CDCI3) δ 1.39 (t, 3H, J = 7.1 Hz), 4.01 (t, 2H1 J = 5.5 Hz), 4.31 (t, 2H, J = 5.5 Hz), 4.40 (q, 2H, J = 7.1 Hz), 4.79 (s, 2H), 5.29 (s, 2H), 6.64 (s, 1H), 7.54 (d, 2H, J = 8.6 Hz), 8.24 (d, 2H, J = 8.6 Hz).
Step 4: 2-Hvdroxymethyl-6.7-dihvdro-4H-pyrazoloπ .5-a1pyrazine-5- carboxylic acid 4-nitrobenzyl ester
LiBH4 (640 mg) and MeOH (1.2mL) was added to the THF (267 ml.) solution of 6,7-dihydro-4/-/-pyrazolo[1,5-a]pyrazine-2,5-dicarboxylic acid 2-ethyl ester 5-(4- nitrobenzyl) ester (10 g) under a nitrogen atmosphere at room temperature and stirred for 3 h at 40 0C. Additional LiBH4 (523 mg) and MeOH (1.0 mL) was added to the solution and stirred for 1 h at 40 0C and 1 h at 50 0C. The mixture was acidified with 3 mol/L HCI to pH 2 and stirred for 1 h at room temperature, then solid K2CO3 was added to the solution to adjust pH to 8. The insoluble material was filtered off and the filtrate was extracted with AcOEt. The organic layer was dried (K2CO3), and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (CHCI3 / MeOH =49/1 - 19/1) to afford titled compound as pale yellow crystals (8.44 g, 95%).
1H NMR (CDCI3) δ 1.69 (br, 1H), 3.98 (t, 2H, J = 5.5 Hz), 4.19 (t, 2H, J = 5.5 Hz), 4.65 (s, 2H), 4.75 (s, 2H), 5.28 (s, 2H), 6.08 (s, 1H), 7.53 (d, 2H, J = 8.7 Hz), 8.24 (d, 2H, J = 8.7 Hz).
Step 5; 2-Formyl-β.7-dιhvdro-4/f-pyrazoloH ,5-aiPyrazine-5-carboxylic acid 4-nitrobenzyl ester
MnO2 (activated) (84.2 g) was added to the CHCI3-MeOH (95 : 5, 253 mL) solution of 2-hydroxymethyl-6,7-dihydro-4H-pyrazolo[1 ,5-a]pyrazine-5-carboxylic acid 4-nitrobenzyl ester (8.42 g), and the mixture was refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. Silica-gel (20 g) was added to the filtrate and the solvent was removed under reduced pressure to give the silica-gel coating with crude reactant. The above silica-gel was adsorbed to silica-gel column chromatography and the column was eluted with CHCI3 - MeOH (49/1 to 19/1). The titled compound was obtained as yellow crystals (2.82 g, 34%).
1H NMR (CDCI3) D4.05 (t, 2H, J = 5.5 Hz), 4.32 (t, 2H, J = 5.5 Hz), 4.81 (s, 2H), 5.29 (s, 2H), 6.62 (s, 1H), 7.54 (d, 2H, J = 8.7 Hz), 8.24 (d, 2H, J = 8.7 Hz), 9.93 (s, 1H). Step 6: 2-{(ffS)-Acetoxy-r(5R 6/?S)-6-bromo-2-(4-nitrobenzyloxycarbonvπ-7- oxo^-thia-i-azabicvclorS.Σ.OIhept-Σ-en-G-vn-methyll-ej-dihvdro^f/- pyrazoloH,5-a1pyrazine-5-carboxylic acid 4-nitrobenzyl ester
2-Formyl-6,7-dihydro-4H-pyrazolo[1 ,5-a]pyrazine-5-carboxylic acid A- nitrobenzyl ester (2.71 g) was added to the dry acetonitrile (164 rriL) solution of anhydrous MgBr2 (cont. 98%) (6.17 g) under a nitrogen atmosphere at room temperature. The dry THF solution (164mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 96.5%) (3.27 g) was added to the mixture, cooled to -20 0C, and Et3N (cont. 99%) (9.24 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 1.5 h at -20 0C and treated with acetic anhydride (cont. 97%) (3.19 mL) and DMAP (cont. 99%) (203 mg) in one portion. The reaction mixture was warmed to 0 0C and stirred for 1 h at 0 0C. Acetic anhydride (3.19 mL) was added to the solution and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, water and brine. The organic layer was dried (MgSO4), followed by concentration under reduced pressure. The residue was purified with silica-gel column chromatography three times (n-hexane - AcOEt (1/1 to 2/3), CHCI3 - acetone (29/1 to 19/1) and CHCI3 - acetone (29/1)). The titled compound was obtained as yellow amorphous (diastereo-mixture (64 : 36), 3.30 g, 53%).
1H NMR (CDCI3) δ 2.06 (s, 3H x 0.36), 2.26 (s, 3H x 0.64), 3.95-4.04 (m, 2H), 4.18 (s, 2H), 4.73 (d, 1H, J = 18.2 Hz), 4.78 (d, 1H, J = 18.2 Hz), 5.28 (d, 1H, J = 13.5 Hz), 5.28 (s, 2H), 5.43 (d, 1H x 0.64, J = 13.5 Hz), 5.44 (d, 1H x 0.36), 6.06 (s, 1H x 0.64), 6.08 (s, 1H x 0.64), 6.24 (s, 1H x 0.36), 6.27 (s, 1H x 0.36), 6.41 (s, 1H x 0.36), 6.79 (s, 1H x 0.64), 7.42 (s, 1H x 0.64), 7.44 (s, 1H x 0.36), 7.53 (d, 2H, J= 8.6 Hz), 7.60 (d, 2H, J= 8.8 Hz), 8.24 (d, 2H, J= 8.8 Hz), 8.24 (d, 2H, J= 8.6 Hz).
Step 7: f5ffl.(6Z>-7-Oxo-6-f4.5.6.7-tetrahvdropyrazoloπ .5-aipyrazin-2- ylmethylenei-4-thia-1 -aza-bicvcf or3.2.01hept-2-ene-2-carboxylic acid, sodium sa|t
To the THF (43 mL) and acetonitrile (20 mL) solution of 2-{(RS)-acetoxy-[(5R,6f?S)-6- bromo-2-(4-nitrobenzyloxycarbonyl)-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-en-6-yl]- methyl}-6,7-dihydro-4H-pyrazolo[1 ,5-a]pyrazine-5-carboxylic acid 4-nitrobenzyl ester was added Zn dust (12.36 g) rapidly with 0.5 M phosphate buffer (pH 6.5, 63 ml_). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The insoluble material was filtered off and was washed with H2O (63 ml_). The filtrate was washed with ethyl acetate (63 ml.) and the aqueous layer was cooled to 3 0C and 1 M HCI was added to adjust pH to 2.5. The mixture was stirred for 4 h at the same temperature and added H2O (63 mL) and 1 M HCI to adjust pH to 2.5, then stirred for 17 h at the same temperature. To the mixture was added 1 M NaOH to adjust pH to 8. The mixture was concentrated under high vacuum at 35 0C. The concentrate was treated to Diaion HP-21 (124 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 95/5). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (288 mg, 22%, pH 8.8).
Mp 160 0C (dec); 1H NMR (D2O) δ 2.94(t, 2H, J = 5.6 Hz), 3.67 (d, 1 H, J = 17.2 Hz), 3.70 (d, 1 H, J = 17.2 Hz), 3.82 (t, 2H, J = 5.6 Hz), 5.84 (s, 1H), 6.03 (s, 1H), 6.65 (s, 1H), 6.67 (s, 1 H).
Example 26
Preparation of (5R)(6Z)-6-(5,5-Dimethyl-4H-1 ,6a-diazapentalen-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt 5.5-Dimethyl-2-piperidone
5-5-Dimethyl-2-piperadinone was prepared in the method of Nagasawa (J. Med. Chem., 20, 1176 (1977)). Step 1 : 3,3-Dichloro-5.5-dimethyl-2-piperidone
To a cold (0 "C) stirred solution of 5,5-dimethyl-2-piperidone (30.2 g, 0.24 mol) in 475 mL of CHCI3, PCI5 (57.1 g, 0.26 mol) was added at such a rate that the temperature never exceeded 7 0C. After the addition was complete, stirring was continued for 10 min. Sulfuryl chloride (96.6 g, 0.72 mol) was slowly added and the mixture was heated under reflux for 1 h. The solution was concentrated under reduced pressure. The residue was cooled in ice and diluted with 250 mL of ice- water. The product was then extracted with CHCI3 (6 x 250 mL) and the organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, and then the column was eluted with CHCI3-MeOH (50 : 1). The titled compound was obtained as a white solid (41.3 g, 88.8 %). (J. Med. Chem., 20, 1176 (1977))
1H NMR (CDCI3) δ 1.17 (s, 6H), 2.76 (s, 2H), 3.19 (d, 2H, J = 3.0 Hz)1 6.82 (brs, 1H). Step 2: 3-Chloro-5.5-dimethyl-2-piperidone
To 40.8 g (0.21 mol) of 3,3-dichloro-5,5-dimethyl-2-piperidone dissolved in 410 mL of AcOH was added 10% Pd/C (50% wet, 6.2 g) and NaOAc- 3H2O (62.4g, 0.46 mol) and the mixture was hydrogenated at 300 kPa for 20 min. The pressure of hydrogen was adjusted at 300 kPa every 5 min. The catalyst was removed by filtration and the filtrate concentrated under reduced pressure. CHCI3 (400 mL) and water (300 mL) were added to the residue and the aqueous layer was neutralized with 4 mol/L NaOH. The mixture was separated and the aqueous layer was extracted with CHCI3 (5 x 300 mL) and the organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, and then the column was eluted with hexane-AcOEt (1 : 1). The titled compound was obtained as a white solid (20.4 g, 59.9 %). (J. Med. Chem., 20, 1176 (1977))
1H NMR (CDCI3) δ 1.10 (s, 3H), 1.12 (s, 3H), 2.02 (dd, 1H, J = 10.8, 13.6 Hz), 2.20 (ddd, 1H, J = 2.2, 6.7, 13.6 Hz), 2.97 (ddd, 1 H, J = 2.3, 3.9, 12.1 Hz)1 3.22 (d, 1 H, J = 12.1 Hz), 4.44 (dd, 1 H, J = 6.8, 10.7 Hz), 6.66 (brs, 1H). Step 3: 4.4-Dimethylpyrrolidine-2-carboxylic acid
A suspension of 20.4 g (0.13 mol) of 3-chloro-5,5-dimethyl-2- piperidone and 45.2 g (0.14 mol) of Ba(OH) 3-8H2O in 252 mL of water was heated in a Parr apparatus at 150 0C for 6 h. Then, 18.6 g (0.14 mol) of ammonium sulphate were added. The precipitate was filtered off, and the solution was concentrated under reduced pressure to dryness. Crude 4,4-dimethylpyrrolidine-2-carboxylic acid was obtained as a white solid (37.5 g). (J. Med. Chem., 20, 1176 (1977), EP 0 447 704 A1 , page 17)
1H NMR (D2O) δ 1.10 (s, 3H), 1.11 (s, 3H), 1.88 (dd, 1H, J = 7.8, 13.2 Hz), 2.21 (dd, 1 H, J = 9.2, 13.2 Hz), 3.12 (dd, 2H, J = 11.5, 23.5 Hz), 4.22 (dd, 1H, J = 8.1, 8.9 Hz).
Step 4: 5.5-Dimethy|-3-oxo-3a. 4-dihvdro-3H. 6Af-2-oxa-5-1-aza-6a- azonio-3a- pentalenide To 4.63 g (22.2 mmol) of 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2- fc]pyrazole-2- carboxylic acid ethylester in 222 ml_ of dry THF was added LiAIH4 (0.85 g, 22.3 mmol) under a nitrogen atmosphere at 0 0C, and then stirred for 1 h. The mixture was quenched with water (5.0 mL) and the precipitate was filtered through a pad of Celite and the pad was washed with water (50 mL) and THF (150 mL). The filtrate was concentrated under reduced pressure, and then water (50 mL) was added. The aqueous layer was extracted with CHCI3 (5 x 100 mL). The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude _5,5-Dimethyl-5,6-dihydro-4H-pyrrolo[1 ,2-£]pyrazole-2- yl)methanol was obtained as a yellow solid (3.19 g).
To 3.19 g of the crude (5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1 ,2- fc]pyrazol-2-yl) methanol in 222 mL of CHCI3 was added activated MnO2 (18.5 g) under a nitrogen atmosphere at room temperature, and then refluxed for 1 h. The mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, and then the column was eluted with hexane-AcOEt (3 : 1). The titled compound was obtained as a brown solid (2.48 g, 68.0 % from the ester).
1H NMR (CDCI3) δ 1.32 (s, 6H), 2.73 (s, 2H), 3.95 (s, 2H), 6.52 (s, 1H), 9.90 (s, 1H). Step 7: (5ffl(6Z)-6-(5.5-Dimethyl-4H-1.6a-diazapentalen-2-y[methylene)-7- oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2-carboχylic acid, sodium salt
The dry acetonitrile (16 mL) solution of 5,5-dimethyl-5,6-dihydro-4H- pyrrolo[1 ,2-b] pyrazole-2-carbaldehyde (2.48 g, 15.1 mmol) was added to the dry acetinitrile (90 mL) solution of MgBr2 (3.07 g, 16.4 mmol) under a nitrogen atmosphere at room temperature, and then the mixture was stirred for 15 min. The dry THF (106 mL) solution of p-nitrobenzyl (5R, 6S)-6-bromopenem-3-carboxylate (5.30 g, 13.8 mmol) was added and the mixture was cooled to -20 0C, and then triethylamine (4.6 mL, 33.0 mmol) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4-dimethylamino pyridine (172 mg, 1.4 mmol) and acetic anhydride (2.6 mL, 27.6 mmol) in one portion. The reaction mixture was warmed to 0 0C and stirred for 16 h at 0 0C. Ethyl acetate (420 mL) and 1mol/L citric acid aqueous solution (210 mL) was added to the reaction mixture and separated. The
- 92 - To a suspension of 37.5 g of the crude 4,4-dimethylpyrrolidine- 2-carboxylic acid in 420 mL of AcOH was added a solution of 13.3 g (0.19 mol) of NaNO2 in 210 mL of water over 15 min at room temperature and stirred for 3 h. The solution was concentrated under reduced pressure. Acetone (250 mL) was added to the residue and the precipitate was filtered off, and the solution was concentrated under reduced pressure to dryness and crude 4,4-dimethyI-1-nitrosopyrrolidine-2- carboxylic acid was obtained as brown oil.
To a solution of crude 4,4-dimethyl-1-nitrosopyrrolidine-2-carboxylic acid in 252 mL of dry THF was added trifluoroacetic anhydride (81.3 g, 0.39 mol) under a nitrogen atmosphere at 0 0C and stirred for 6 h at 0 0C. The solution was concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, and then the column was eluted with n-hexane - AcOEt (2 : 1). The titled compound was obtained as a brown solid (12.0 g, 61.7 %).
1H NMR (CDCI3) δ 1.38 (s, 6H), 2.71 (s, 2H), 4.12 (s, 2H). Step 5: 5,5-Dimethyl-5.6-dihvdro-4H-pyrrolori ,2-61pyrazole-2-carboxylic acid ethylester
A solution of 5,5-dimethyl-3-oxo-3a, 4-dihydro-3H, 6H-2-oxa-5-1-aza-
6a-azonio-3a- pentalenide (10.8 g, 0.07 mol) and ethyl propiolate (10.8 mL, 0.11 mol) in o-xylene (350 mL) was refluxed under a nitrogen atmosphere for 16 h. The solution was cooled to room temperature and concentrated under reduced pressure.
The residue was applied to silica gel column chromatography, and then the column was eluted with n-hexane - AcOEt (3 : 1 ). The titled compound was obtained as a pale brown solid (4.63 g, 31.7 %), and 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2- b]pyrazole-3-carboxylic acid ethylester was obtained as a yellow solid (4.73 g, 32.4 %).
5,5-Dimethyl-5,6-dihydro-4H-pyrrolo[1,2-d]pyrazole-2-carboxylic acid ethylester: 1H NMR (CDCI3) δ 1 ,29 (s, 6H), 1.40 (t, 3H1 J = 7.1 Hz), 2.71 (s, 2H), 3.93 (S, 2H), 4.39 (q, 2H, J = 7.1 Hz), 6.54 (s, 1H).
5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1 ,2-ύ]pyrazole-3-carboxylic acid ethylester :1H NMR (CDCI3) δ 1,32 (s, 6H), 1.33 (t, 3H, J = 7.1 Hz), 2.89 (s, 2H), 3.90 (s, 2H), 4.26 (q, 2H, J = 7.1 Hz), 7.90 (s, 1 H).
Step 6: 5.5-Dimethyl-5.6-dihvdro-4H-pyrrololi.2-frlPyrazole-2- carbaldehyde
- 91 - organic layer was washed with saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude (5f?)-6-[acetoxy-(5,5-dimethyl- 4H-1 ,6a-diazapentalen-2-yl)methyl]-6- bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester was obtained as brown amorphous.
Freshly activated Zn dust (32.0 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 167 mL) to the THF (114 mL) and acetonitrile (53 mL) solution of crude (5R)-6-[acetoxy-(5,5-dimethyl- 4H-1 ,6a-diazapentalen-2-yl)methyl]-
6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction solution was cooled at 0 0C, and then the pH was adjusted to 8.0. Ethyl acetate (85 mL) was added to the mixture and filtered through a pad of Celite. The pad was washed with water (120 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL). The combined aqueous layers were cooled at 0 0C, and then the pH was adjusted to 8.5. The mixture was concentrated to 325 g, and then applied to Diaion HP-21 resin (240 mL,
Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water (480 mL) and then acetonitrile aqueous solution (10%; 480 mL, 20%; 720 mL). The combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the titled compound as a yellow amorphous solid (2.00 g, 42.8 %, pH 7.16).
Mp 150 0C (dec); 1H NMR (D2O) δ 1.19 (s, 6H), 2.67 (s, 2H), 3.85 (s, 2H), 6.15 (S, 1 H), 6.45 (s, 1H), 6.96 (s, 1H), 7.03 (s, 1 H); IR (KBr) 3422, 1752, 1683, 1598, 1557 cm"1 ; λmax (H2O) 296, 198 nm.
Example 27
Preparation of (5R) .(6Z)- 6-(5,6-Dihvdro-4H-cvclopentarfrlfuran-2- ylmethylene)-7-oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2-carboxylic acid. sodium salt Step 1: 5,6-Dihvdro-4H-cvclopentarblfuran-2-carboxylic acid methyl ester
The titled compound was prepared according to the procedure of Tim Johnson and co-workers (Synlett 2001, 5, 646 - 648). Step 2: (5.6-Dihvdro-4H-cvclopentafblfuran-2-yl)methanol
5,6-Dihydro-4H-cyclopenta[b]furan-2-carboxylic acid methyl ester (2.24 g) was added to the THF (59 mL) solution of LiAIH4 (511 mg) under a nitrogen atmosphere at 0 0C and stirred for 1 h at 0 0C. The mixture was quenched with 10 mL of water and filtered. The filtrate was concentrated under reduced pressure and the obtained aqueous solution was extracted with CHCI3. The organic layer was washed with brine and dried over MgSO4 and filtered. The filtrate was concentrated to afford titled compound as yellow oil (1.86 g, quant.).
1H NMR (CDCI3) δ 1.66 (t, 1H, J = 5.9 Hz)1 2.38 - 2.46 (m, 2H), 2.50 - 2.55 (m, 2H), 2.65 - 2.70 (m, 2H), 4.54 (d, 2H, J = 5.9 Hz), 6.15 (s, 1H).
Step 3: S.β-Dihydro^H-cvclopentarbifuran-Σ-carbaldehyde Activated MnO2 (9.3 g) was added to the CHCI3 (135 mL) solution of (5,6- dihydro-4H-cyclopenta[£>]furan-2-yl)methanol (1.86 g) and refluxed for 1 h under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with n-hexane - AcOEt (9/1 - 7/1). The titled compound was obtained as yellow crystals (1.51 g, 77%).
1H NMR (CDCI3) δ 2.47 - 2.57 (m, 2H), 2.63 (t, 2H, J = 6.8 Hz), 2.78 (t, 2H, J = 7.3 Hz), 7.06 (s, 1 H), 9.44 (s, 1 H).
Step 4: (5R. 6/?S)-6-r(RS)-Acetoxy(5.6-dihvdro-4H-cvclopentarb1furan-2- yl)methvπ-6-bromo-7-oxo-4-thia-1-azabicvclof3.2.01hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester
The acetonitrile solution (50 mL) of 5,6-dihydro-4H-cyclopenta[6]furan- 2- carbaldehyde (1.33 g) was added to the dry acetonitrile (101 mL) solution of anhydrous MgBr2 (cont. 98%) (5.52 g) under a nitrogen atmosphere at room temperature. The dry THF solution (151 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 96.5%) (3.91 g) was added to the mixture, cooled to -20 0C, and Et3N (cont. 99%) (8.28 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (cont. 97%) (4.13 mL) and DMAP (cont. 99%) (121 mg) in one portion. The reaction mixture was warmed to 0 °C and stirred for 16 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% aqueous solution of citric acid, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4) then filtered. The filtrate was concentrated under reduced pressure. The residue was purified with a silica-gel column chromatography (n - hexane : AcOEt = 4 :1 - 3 : 1) to give the titled compound as a brown amorphous solid (3.34 g, 61%).
1H NMR (CDCI3) δ 2.21 (s, 3H), 2.40 - 2.48 (m, 2H), 2.53 (t, 2H, J = 7.0 Hz), 2.69 (t, 2H, J = 7.0 Hz), 5.28 (d, 1 H, J = 13.5 Hz), 5.43 (d, 1 H, J = 13.5 Hz), 6.00 (s, 1H), 6.37 (s, 1H), 6.71 (s, 1H), 7.41 (s, 1H), 7.60 (d, 2H1 J = 8.1 Hz), 8.24 (d, 2H, J = 8.1 Hz).
Step 5: (5R)AGZ)- 6-(5.6-Dihvdro-4H-cvclopentarfo1furan-2-ylmethylene)- 7-oxo-4-thia-1-azabicvclor3.2.0lhept-2-ene-2-carboxylic acid, sodium salt
(5R, 6RS)-6-[(RS)-Acetoxy(5,6-dihydro-4H-cyclopenta[fe]furan-2-yl)methyl]-6- bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (3.28 g) was dissolved in THF (46 mL) and acetonitrile (21 ml_). Freshly activated Zn dust (13.12 g) was added rapidly with 0.5 M phosphate buffer (pH 6.5, 67 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.25 h at room temperature. The reaction mixture was filtered through a pad of Celite. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was cooled to 3 0C and 1 M NaOH was added to adjust pH to 8.0. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (181 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 85/15). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the titled crude product (288mg). This was purified by Diaion HP-21 (100 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1/0 - 85/15). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the titled compound as a yellow amorphous solid (185 mg, 10%, pH 7.2).
Mp 170 0C (dec); 1H NMR (D2O) δ 2.24 - 2.30 (m, 2H), 2.37 (t, 2H, J = 6.5 Hz), 2.52 - 2.57 (t, 2H, J = 7.1 Hz), 6.32 (s, 1H), 6.55 (s, 1H), 6.73 (s, 1H), 6.86 (s, 1 H). Example 28
Preparation of (5ffl(6Z)-6-(4.5-Dihydro-6-thia-1.7a-diazainden-2- ylmethylene)-7-oxo-4-thia-1-azabicvcior3.2.01hept-2-ene-2-carboxylic acid, sodium salt
Step 1: DL-Tetrahvdro-1.3-thiazine-4-carboxylic acid hydrochloride
DL-Tetrahydro-1,3-thiazine-4-carboxylic acid hydrochloride was prepared according to the method of Lewis (J. Med. Chem., 21, 1070 (1978)).
Step 2: 4.5-Dihvdro-3aH.7H-2-oxa-3-oxo-6-thia-1 -aza-7a-azonioinden To a suspension of DL-tetrahydro-1 ,3-thiazine-4-carboxylic acid hydrochloride (48.6 g, 0.26 mol) in 666 ml_ of AcOH was added to the solution of 27.4 g (0.40 mol) of NaNO2 in 333 mL of water over 16 min at room temperature and stirred for 3 h. The solution was concentrated under reduced pressure. Acetone (300 mL) was added to the residue and the precipitate was filtered off. The filtrate was concentrated under reduced pressure to dryness and crude 3- nitroso[1 ,3]thiazinane-4-carboxylic acid was obtained as brown amorphous solid.
To a solution of crude 3-nitroso[1 ,3]thiazinane-4-carboxylic acid in 530 mL of dry THF was added trifluoroacetic anhydride (168.4 g, 0.80 mol) over 60 min under a nitrogen atmosphere at 0 0C and stirred for 5 h at 0 0C. The solution was concentrated under reduced pressure. The residue was applied to silicagel column chromatography, and then the column was eluted with n-hexane - AcOEt (1 : 2). The titled compound was obtained as brown powder (28.0 g, 67.0 %).
1H NMR (CDCI3) δ 3.00 (t, 2H, J = 5.7 Hz), 3.07 (t, 2H1 J = 5.7 Hz), 5.16 (s, 2H). Step 3: 4.5-Dihydro-6-thia-1,7a-diazaindene-2-carboxylic acid ethylester
A solution of 4,5-dihydro-3aH,7H-2-oxa-3-oxo-6-thia-1-aza-7a- azonioinden (28.0 g, 0.18 mol) and ethyl propiolate (27.0 mL, 0.27 mol) in o-xylene
(590 mL) was refluxed under a nitrogen atmosphere for 16 h. The solution was cooled to room temperature and concentrated under reduced pressure. The residue was applied to silicagel column chromatography, and then the column was eluted with π-hexane - AcOEt (3 : 1). The titled compound was obtained as pale brown needles (22.1 g, 58.7 %), and 4,5-dihydro-6-thia- 1 ,7a-diazaindene-3-carboxylic acid ethylester was obtained as pale brown crystals (12.7 g, 33.9 %). 4,5-Dihydro-6-thia-1,7a-diazaindene-2-carboxylic acid ethylester 1H NMR (CDCI3) δ 1.39 (t, 3H, J = 7.1 Hz), 2.98 (t, 2H, J = 6.1 Hz), 3.21 (t, 2H, J = 6.1 Hz), 4.40 (q, 2H, J = 7.1 Hz), 5.17 (s, 2H), 6.60 (s, 1 H).
4,5-dihydro-6-thia- 1 ,7a-diazaindene-3-carboxylic acid ethylester :1H NMR (CDCI3) δ 1.34 (t, 3H, J = 7.1 Hz), 2.99 (t, 2H, J = 6.1 Hz), 3.45 (t, 2H, J = 6.1 Hz), 4.28 (q, 2H, J = 7.1 Hz), 5.11 (s, 2H), 7.85 (s, 1H). Step 4: 4.5-Dihvdro-6-thia-1.7a-diazaindene-2-carbaldehvde
To a 22.1 gram (0.10 mol) of 4,5-dihydro-6-thia-1 ,7a-diazaindene-2- carboxylic acid ethylester in 520 mL of dry THF was added LiAIH4 (3.95 g, 0.10 mol) under a nitrogen atmosphere at 0 0C, and then stirred for 45 min. The mixture was quenched with water (20 mL) and the precipitate was filtered through a pad of Celite and the pad was washed with water (100 mL) and THF (250 mL). The filtrate was concentrated under reduced pressure, and then water (300 mL) was added. The aqueous layer was extracted with CH2CI2 (6 x 500 mL). The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude was obtained as pale yellow crystals (17.2 g).
To a 17.2 gram of the crude (4,5-dihydro-6-thia-1 ,7a-diazainden-2-yl) methanol in 520 mL of CHCI3 was added activated MnO2 (88.0 g) under a nitrogen atmosphere at room temperature, and then refluxed for 2 h. The mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was applied to silicagel column chromatography, and then the column was eluted with hexane-AcOEt (2 : 1). The titled compound was obtained as yellow crystals (13.O g, 74.5 % )
1H NMR (CDCI3) δ 3.00 (t, 2H, J = 6.0 Hz), 3.23 (t, 2H, J = 6.0 Hz), 5.18 (S1 2H), 6.58 (s, 1H), 9.92 (s, 1H).
Step 5: (5RU6Zl-6-(4.5-Dihvdro-6-thia-1.7a-diazainden-2-ylmethylene)-7- oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
The dry acetonitrile (11 mL) solution of 4,5-dihydro-6-thia-1 ,7a- diazaindene-2- carbaldehyde (1.70 g, 10.1 mmol) was added to the dry acetinitrile (60 mL) solution of MgBr2 (2.03 g, 11.0 mmol) under a nitrogen atmosphere at room temperature, and then the mixture was stirred for 10 min. The dry THF (71 mL) solution of p-nitrobenzyl (5f?, 6S)-6-bromopenem-3-carboxylate (3.55 g, 9.2 mmol) was added and the mixture was cooled to -20 0C, and then triethylamine (3.1 mL, 22.2 mmol) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4- dimethylamino pyridine (0.11 g, 0.9 mmol) and acetic anhydride (1.8 ml_, 18.6 mmol) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. Ethyl acetate (280 mL) and 1mol/L citric acid aqueous solution (140 mL) was added to the reaction mixture and separated. The organic layer was washed with saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude (5R)-6-[acetoxy-(4,5- dihydro- 6-thia-1 ,7a-diazainden-2-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester was obtained as brown amorphous solid.
Freshly activated Zn dust (21.4 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 112 mL) to the THF (76 mL) and acetonitrile (36 mL) solution of crude (5f?)-6-[acetoxy-(4,5-dihydro- 6-thia-1 ,7a-diazainden-2-yI)methyl]-6- bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2- carboxylic acid p-nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction solution was cooled at 0 0C, and then the pH was adjusted to 8.0. Ethyl acetate (56 mL) was added to the mixture and filtered through a pad of Celite. The pad was washed with water (150 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 30 mL). The combined aqueous layers were cooled at 0 0C, and then the pH was adjusted to 8.0. The mixture was concentrated to 236 g, and then applied to Diaion HP-21 resin (480 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water (960 mL) and then acetonitrile aqueous solution (5%; 960 mL, 10%; 960 mL, 20%; 960 mL). The combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the titled compound as a yellow amorphous solid (1.28 g, 40.5 %, pH 7.45).
Mp 200 0C (dec); 1H NMR (D2O) δ 2.95 (t, 2H, J = 6.1 Hz), 3.12 (t, 2H, J = 6.1 Hz), 5.08 (s, 2H), 6.23 (s, 1H), 6.46 (s, 1H), 6.97 (s, 1H), 7.01 (s, 1H); IR (KBr) 3382, 1752, 1684, 1597, 1554 cm"1; λmax(H2O) 366, 292, 197 nm. Example 29
Preparation of (5ff).(6Z)-6-(6.β-Dimethyl-5,6,7.8-tetrahvdroimidazori ,2- aipyrizin-2- ylmethylene)-7-oxo-4-thia-1-azabicyclor3.2.01hept-2-ene-2- carboxylic acid, sodium salt Step 1 : Preparation of 5.5-Dimethyl-2-piperidone
5-5-Dimethyl-2-piperadinone (1) was prepared in the method of Nagasawa (J. Med. Chem., 23, 1176 (1977)). Step 2: Preparation of 3.3-Dimethyl-6-methoxy-2.3 ,4,5-tetrahvdropyridine
Trimethyloxonium tetrafluoroborate (97%, 11.9 g, 78 mmol) was added to the dry dichloromethane (156 ml_) solution of 5,5-dimethyl-2-piperidone
(9.93 g, 78 mmol) at room temperature and stirred for 14 h. The reaction mixture was neutralized with 10% sodium hydrogen carbonate aqueous solution, and the organic layer was separated. The aqueous layer was extracted with ethyl acetate (3 x 120 ml_), then the combined organic layer was washed with 10% sodium hydrogen carbonate aqueous solution and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and the titled compound was obtained as pale yellow oil (9.0 g, 82.0 %).
1H NMR (CDCI3) δ 0.92 (s, 6H), 1.49 (t, 2H, J - 7.0 Hz), 2.18 (t, 2H, J = 7.0 Hz), 3.19 (s, 2H), 3.63 (s, 3H). Step 3: 5,5-Dimethylpiperidine-2-ylideneamine monohvdrochloride
The mixture of 3,3-dimethyl-6-methoxy-2,3,4,5-tetrahydropyridine (9.0 g, 64 mmol) and ammonium chloride (3.4 g, 64 mmol) in dry ethanol (160 mL) was heated to reflux for 2 h. The reaction mixture was then concentrated under reduced pressure and the titled compound was obtained as a white solid (9.9 g, 94.6 %). 1H NMR (DMSO-d6) δ 0.95 (s, 6H), 1.52 (t, 2H, J = 6.9 Hz), 2.55 (t, 2H, J =
6.9 Hz), 2.99 (d, 2H, J = 2.1 Hz).
Step 4: 6,6-Dimethyl-5.6,7.8-tetrahvdroimidazoH .2-alPyridine-2- carbaldehvde &
6,6-Dimethyl-5.6.7.8-tetrahvdroimidazof1,2-a1pyridϊne-3-carbaldehvde The mixture of 2-bromo-3-hydroxypropenal (10.1 g, 67 mmol), p- toluenesulfonic acid monohydrate (0.13 g, 0.6 mmol) and 2-propanol (12.6 mL, 165 mmol) in cyclohexane (100 mL) was azeotroped until the vaper temperature over 800C. The reaction mixture was concentrated under reduced pressure. The residue was dissolved in dry EtOH (200 mL). The dry EtOH (350 mL) solution of
5,5-dimethylpiperidine-2-ylideneamine monohydrochloride (9.9 g, 61 mmol) and the dry EtOH (50 mL) solution of NaOMe (28%, 11.7 g, 61 mmol) were added at room temperature. The reaction mixture was stirred at room temperature for 2 h, and then the reaction solution was removed in vacuo. The residue was dissolved in CHCI3
(300 mL) and triethylamine (8.5 mL, 61 mmol) was added, and then the reaction mixture was heated to reflux for 2 h. The reaction mixture was cooled to room temperature, and then the reaction solution was removed in vacuo. The residue was dissolved in CH2HI2 (600 mL) and washed with 50% K2CO3 aqueous solution (2 x 200 mL). The combined aqueous solution was extracted with CH2CI2 (2 x 200 mL).
The combined organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, eluted with CHCI3 - methanol (50 : 1), and the titled compound 6,6-
Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridine-2-carbaldehyde (brown solid, 4.4 g, 40.7 %) and 6,6-Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridine-3-carbaldehyde
(orange solid, 1.7 g, 15.8 %) were obtained.
6,6-Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridine-2- carbaldehyde: 1H NMR (CDCI3) δ 1.10 (s, 6H), 1.78 (t, 2H, J = 6.9 Hz), 2.95 (t, 2H, J = 6.9 Hz), 3.71 (s, 2H), 7.46 (s, 1H), 9.83 (s, 1 H). 6,6-Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridine-3- carbaldehyde: 1H NMR (CDCI3) δ 1.09 (s, 6H), 1.74 (t, 2H, J = 6.8 Hz), 2.97 (t, 2H, J = 6.8 Hz), 4.05 (s, 2H), 7.74 (s, 1 H), 9.64 (s, 1 H). .
Step 5: (5f?).(6Z)-6-(6.6-Dimethyl-5.6.7,8-tetrahvdroimidazof1 ,2-aipyrizin- 2- ylmethylene)-7-oxo-4-thia-1 -azabicvclor3.2.0'lhept-2-ene-2-carboxylic acid. sodium salt
The dry acetonitrile (28 mL) solution of 6,6-dimethyl-5,6,7,8- tetrahydroimidazo [1 ,2-a]pyridine-2-carbaldehyde (4.55 g, 26 mmol) was added to the dry acetinitrile (152 mL) solution of MgBr2 (5.22 g, 28 mmol) under a nitrogen atmosphere at room temperature, and then the mixture was stirred for 10 min. The dry THF (180 mL) solution of p-nitrobenzyl (5R, 6S)-6-bromopenem-3-carboxyIate (8.94 g, 23 mmol) was added and the mixture was cooled to -20 0C, and then triethylamine (7.8 mL, 56 mmol) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 h at -20 0C and treated with 4-dimethylamino pyridine (0.29 g, 2.4 mmol) and acetic anhydride (4.4 mL, 47 mmol) in one portion. The reaction mixture was warmed to 0 0C and stirred for 16 h at 0 0C. Ethyl acetate (715 mL) was added to the reaction mixture, and then the organic layer was washed with 1mol/L Citric acid aqueous solution, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and crude (5R)-6-[acetoxy-(6,6-dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridin-2- yl)methyl]-6-bromo-7-oxo-4-thia- 1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p- nitrobenzyl ester was obtained as brown amorphous solid. Freshly activated Zn dust (53.6 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 282 mL) to the THF (192 mL) and acetonitrile (90 mL) solution of (5fi)-6-[acetoxy-(6,6-dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2-a]pyridin-2- yl)methyl]-6-bromo-7-oxo-4-thia- 1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p- nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 h at room temperature. The reaction mixture was cooled at 0 0C, and then the pH was adjusted to 7.6. Ethyl acetate (140 mL) was added to the reaction mixture, and then the mixture was filtered through a pad of Celite and the pad was washed with water (200 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 50 mL). The pH of the combined aqueous layer was adjusted to 8.1 and the mixture was concentrated to 584 g. 1 mol/L NaOH was added to adjust pH to 8.2 and applied to Diaion HP-21 resin (420 mL, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with 2.5 % (2 bed volume), 5 % (2 bed volume), 10 % (1 bed volume) and 20 % acetonitrile aqueous solution. The combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the crude (5R),(6Z)-6-(6,6-Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrizin-2- ylmethylene)-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt as a yellow amorphous solid (1.19 g).
The crude (5R),(6Z)-6-(6,6-Dimethyl-5,6,7,8-tetrahydroimidazo[1 ,2- a]pyrizin-2- ylmethylene)-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt was purified by the preparative HPLC (Mightysil RP-18 GP (5 Dm), Kanto Chemical Co. Inc., 35 x 250 mm, 0.05 mol/L phosphate buffer (pH 7.2) : CH3CN = 70 : 30, 20 mL/min.). The purified product was desalted by Diaion HP-21 resin (50 mL) column chromatography and the title compound was obtained 230 mg (2.8 %) as a yellow amorphous solid.
Mp 2100C (dec); 1H NMR (D2O) δ ; 0.91 (s, 3H), 0.93 (s, 3H), 1.63 (t, 2H, J = 6.8 Hz), 2.72 (t, 2H1 J = 6.8 Hz), 3.60 (s, 2H), 6.44 (s, 1H), 6.90 (s, 1H), 6.91 (S, 1H)1 7.19 (S1 1H).
Example 30
Preparation of (5R), (6Z)-6-(5,6-Dihvdro-8-W-imidazor2,1-cU1.41thiazin-3- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid
The dry acetonitrile (40 mL) solution of 5,6-dihydro-8/-/-imidazo[2,1- c][1 ,4]thiazine-3-carbardehyde (813 mg) was added to the dry acetinitrile (40 mL) solution of MgBr2 (2.2 g) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 min. The dry THF (80 mL) solution of p-nitrobenzyl (5R,
6S)-6-bromopenem-3-carboxylate (2.1 g) was added, the mixture was cooled to -20
0C then triethylamine (1.7 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3.5 h at -20 0C and treated with 4,4-dimethylamino pyridine (64 mg) and acetic anhydride (0.9 mL) in one portion. The reaction mixture was warmed to 0 °C and stirred for 14 h at 0 0C.
10% Citric acid aqueous solution (500 mL) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 200 mL). The organic layer was washed with water, saturated sodium hydrogen carbonate and brine, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography and eluted with CH2CI2 - acetone (20 :
1) to obtain crude (5R)-6-[acetoxy-(5,6-dihydro-8H-imidazo[2,1-c][1 ,4]thiazin-3- yl)methyl]-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p- nitrobenzyl ester as a brown solid.
The solid obtained above chromatography was dissolved in THF (11 mL). Freshly activated Zn dust (1.4 g) was added rapidly with 0.5 mol/L phosphate buffer (pH 6.5, 11 mL). The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 h at room temperature. The reaction solution was filterd through a pad of Celite and the pad was washed with water (26 mL) and n-butanol (26 mL). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/L phosphate buffer (pH 6.5, 2 x 5 mL). The combined aqueous layer was concentrated to 18 g, 1 mol/L NaOH was added to adjust pH to 7.3 and applied to Diaion HP-21 resin (20 ml_, Mitsubishi Kasei Co. Ltd.) column chromatography. After adsorbing, the column was eluted with water and then 5% acetonitrile aqueous solution. The combined active fractions was concentrated under high vacuum at 35°C and lyophilized to give the title compound as a yellow amorphous solid (81 mg).
Mp 1450C (dec); 1H NMR (D2O) δ 3.05-3.08 (m, 1H)1 3.83 (s, 1H), 4.13-4.16 (m, 1H), 6.37 (s, 1H), 6.91 (s, 1H), 7.01 (s, 1H)1 7.04 (s, 1H); IR (KBr) 3371 , 1770, 1672, 1613 cm"1; λmax (H2O) 314 nm.
Example 31
Preparation of (5f?)(6Z)-6-(2,3-Dihvdropyrazolor5,1-frlthiazol-6- ylmethylene)-7-oxo-4-thia-1 - azabicvclof3.2.01hept-2-ene-2-carboxylic acid. sodium salt
Step 1: Preparation of 3-Oxo-3a, 4-dihvdro-3H. 6H-2-oxa-4-thia-1-aza-6a- azonio-3a-pentalenide
To a suspension of thiazolidine-2-carboxylic acid (39.9 g, 0.30 mol) in 1 ,000 ml of acetic acid was added a solution of 31.0 g (0.45 mol) of sodium nitrite in 500 ml of water over 13 minutes at room temperature and stirred for 5 hours. The reaction solution was concentrated under reduced pressure. Acetone (500 ml) was added to the residue and the precipitate was filtered through a pad of Celite. The pad was washed with acetone (500 ml). The filtrate was concentrated under reduced pressure to dryness and crude 3-nitrosothiazolidin-2- carboxylic acid was obtained as a yellow solid.
To a solution of crude 3-nitrosothiazolidin-2- carboxylic acid in 600 ml of dry tetrahydrofuran was added trifluoroacetic anhydride (189.6 g, 0.90 mol) over
20 minutes under a nitrogen atmosphere at 0 0C and stirred for 19 hours at 0 0C.
The solution was concentrated under reduced pressure. The residue was applied to a silica-gel column chromatography, and then the column was eluted with π-hexane - ethyl acetate (1 : 1). The titled compound was obtained as a pale brown crystal (19.2 g, 44.5 %).
1H NMR (CDCI3) δ 3.98 (t, 2H, J = 7.7 Hz)1 4.65 (t, 2H, J = 7.7 Hz). Step 2: Preparation of 2.3-Dihvdropyrazolor5.1-frlthiazol-6-carboxylic acid ethyl ester and 2.3- dihydropyrazolor5,1-b1thiazol-7-carboxylic acid ethyl ester
Ethyl propiolate (20.3 ml, 0.20 mol) was added to an o-xylene (600 ml) solution of 3-oxo-3a, 4-dihydro-3H, 6H-2-oxa-4-thia-1-aza-6a-azonio-3a- pentalenide (19.2 g, 0.13 mol) under a nitrogen atmosphere and refluxed for 21 hours. The solution was cooled to room temperature and concentrated under reduced pressure. The residue was applied to a silica gel column chromatography, and then the column was eluted with n-hexane - ethyl acetate (2 :21 to 1 : 1 ). The mixture of 2,3-Dihydropyrazolo[5,1-fc]thiazol-6-carboxylic acid ethyl ester and 2,3- dihydropyrazolo[5,1-/?]thiazol-7-carboxylic acid ethyl ester was obtained as a brown oil in the ratio of 1:1.5 respectively. (21.2 g, Yield: 80.0 %).
2,3-Dihydropyrazolo[5,1-Jb]thiazol-6-carboxylic acid ethyl ester; 1H NMR (CDCI3) δ 1.39 (t, 3H, J = 7.1 Hz), 3.82 (t, 2H, J = 7.5 Hz), 4.39 (q, 2H, J = 7.1 Hz), 4.42 (t, 2H, J = 7.5 Hz), 6.52 (s, 1 H).
2,3- dihydropyrazolo[5,1-b]thiazol-7-carboxylic acid ethyl ester; 1H NMR (CDCI3) δ 1.34 (t, 3H, J = 7.1 Hz), 3.85 (t, 2H, J = 7.8 Hz), 4.28 (q, 2H, J = 7.1 Hz), 4.39 (t, 2H, J = 7.8 Hz), 7.87 (s, 1H).
Step 3: 2.3-Dihvdropyrazolor5.1-fo1thiazol-6-carbaldehvde and 2.3- dihydro- pyrazolof5.1 -bithiazol-7-carbaldehvde
To the mixture [21.2 g (0.11 mol)] of 2,3-dihydropyrazolo[5,1-/j]thiazol- 6-carboxylic acid ethyl ester and 2,3-dihydropyrazolo[5,1-jb]thiazol-7-carboxylic acid ethyl ester in 540 ml of dry tetrahydrofuran was added LiAIH4 (4.05 g, 0.11 mol) under a nitrogen atmosphere at 0 0C, and then stirred for 2.5 hours at room temperature. The mixture was quenched with water (15 ml) and the precipitate was filtered through a pad of Celite. The pad was washed with water (100 ml) and tetrahydrofuran (500 ml). The filtrate was concentrated under reduced pressure, and then water (150 ml) was added. The aqueous layer was extracted with dichloromethane (15 x 250 ml). The combined organic layers were dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and a mixture of (2,3-dihydropyrazolo[5,iHb]thiazol-6-yl) methanol and (2,3-dihydropyrazolo[5,1- b]thiazol-7-yl) methanol was obtained as pale brown oil (15.5 g). To the mixture [15.5 g (0.10 mol)] of (2,3-dihydropyrazolo[5,1- ό]thiazol-6-yl) methanol and (2,3-dihydropyrazolo[5,1-b]thiazol-7-yl) methanol in 500 ml of chloroform was added activated MnO2 (77.7 g) under a nitrogen atmosphere at room temperature, and then refluxed for 3 hours. The mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was applied to a silica gel column chromatography, and then the column was eluted with hexane-ethyl acetate (2 : 1 to 1 : 1). The titled compound 2,3- Dihydropyrazolo[5,1-ib]thiazol-6-carbaldehyde was obtained as a yellow crystal (2.50 g, 15.2 % ) and _2,3-dihydro- pyrazolo[5,1-ϋ]thiazol-7-carbaldehyde was obtained as a pale brown solid (5.57 g, 33.8 )
2,3-Dihydropyrazolo[5,1-b]thiazol-6-carbaldehyde; 1H NMR (CDCI3) 5 3.86 (t, 2H, J = 7.5 Hz), 4.45 (t, 2H, J = 7.5 Hz), 6.50 (s, 1 H)1 9.83 (s, 1 H).
2,3-dihydro- pyrazolo[5,1-6]thiazol-7-carbaldehyde_; 1H NMR (CDCI3) δ 3.92 (t, 2H, J = 7.9 Hz), 4.40 (t, 2H, J = 7.9 Hz), 7.91 (s, 1H), 9.76 (s, 1H). Step 4: Preparation of (5ffl(6Z)-6-(2,3-Dihydropyrazolor5.1-frlthiazol-6- ylmethylene)-7-oxo-4-thia-1 - azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
A dry acetonitrile (19 ml) solution of 2,3-dihydropyrazolo[5,1-ό]thiazol- 6- carbaldehyde (2.50 g, 16.2 mmol) was added to a dry acetinitrile (106 ml) solution of MgBr2 (3.67 g, 19.9 mmol) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 minutes. A dry tetrahydrofuran (125 ml) solution of p- nitrobenzyl (5R, 6S)-6-bromopenem-3- carboxylate (6.23 g, 16.2 mmol) was added and the mixture was cooled to -20 0C then triethylamine (5.4 ml, 38.7 mmol) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 3 hours at -20 0C and treated with 4- dimethylamino pyridine (198 mg, 1.62 mmol) and acetic anhydride (3.1 ml, 32.9 mmol) in one portion. The reaction mixture was warmed to 0 0C and stirred for 16 hours at 0 0C. Ethyl acetate (500 ml) was added to the reaction mixture and then the organic layer was washed with 1mol/l citric acid aqueous solution, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure and the crude (5R)-6- [acetoxy-(2,3-dihydropyrazolo [5,1 -b]thiazol-6-yl)methyl]-6-bromo-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester was obtained as a brown amorphous solid.
Freshly activated Zn dust (37.4 g) was added rapidly with 0.5 mol/l phosphate buffer (pH 6.5, 196 ml) to tetrahydrofuran (134 ml) and acetonitrile (62 ml) solution of (5R)-6-[acetoxy-(2,3-dihydropyrazolo [5,1-6]thiazol-6-yl)methyl]-6-brorno-
7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid p-nitrobenzyl ester. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 1.5 hours at room temperature. The reaction mixture was cooled at 0 0C, and then the pH was adjusted to 8.0. Ethyl acetate (100 ml) was added to the reaction mixture. The mixture was filtered through a pad of Celite and the pad was washed with water (300 ml). The aqueous layer was separated and then the organic layer was extracted with 0.5 mol/l phosphate buffer (pH 6.5, 2 x 50 ml). The pH of the combined aqueous layer was adjusted to 8.0 and the mixture was concentrated to 426 g. The concentrate was adjust pH to 8.0 and applied to Diaion HP-21 resin (540 ml, Mitsubishi Kasei Co. Ltd.) column chromatography.
After adsorbing, the column was eluted with water (1 bed volume) and then 5 % (2 bed volume), 10 % (2 bed volume) and 20 % acetonitrile aqueous solution. The combined active fractions were concentrated under high vacuum at 35°C and lyophilized to give the title compound as a orange amorphous solid (2.09 g, 39.2 %, pH 7.10).
Mp 150 0C (dec); 1H NMR (D2O) δ 3.75 (t, 2H1 J = 7.5 Hz), 4.27 (t, 2H, J = 7.5 Hz), 6.00 (s, 1H), 6.34 (s, 1 H), 6.85 (s, 1H), 6.94 (s, 1H); IR (KBr) 3392, 1755, 1596, 1554 cm"1; λmax (H2O) 290, 223 nm.
Example 32 Preparation of (5f?U6Z)-6-(2,3-Dihvdropyrazolor5,1-frloxazol-6- ylmethylene)-7-oxo-4-thia-1 - azabicvclor3.2.01hept-2-erte-2-carboxylic acid. sodium salt
Step 1: Preparation of ethyl2,3-dihvdropyrazolor5,1-biri.3loxazole-6- carboxylate: To the stirred suspension of ethyl 5-hydroxy-1 H-pyrazole-3-carboxylate (10.34 g, 0.66 mol) and 36.62 g of potassium carbonate in 500 ml of acetonitrile was added 13.68 g of 1 ,2-dibromoethane, and refluxed for 16 hours. The reaction mixture was allowed to cool to room temperature, then filtered, the solid was washed with acetonitrile. The filtrate was concentrated to an oil. The residue was dissolved in ethyl acetate and extracted with water. The organic phase was dried over MgSO4 and evaporated to dryness. 5.80 g of the desired product was obtained (48%). Step 2: Preparation of 2.3-dihvdropyrazolor5.1-biri.3loxazole-6-methanol: To the stirred solution of ethyl2,3-dihydropyrazolo[5,1-b][1,3]oxazole-6- carboxylate
(5.47 g, 35 mmol) of in 100 ml of THF was added 1.05 g of lithium borohydride and 1.54 g of methanol. The solution was heated at 4OC for 2.5 hour. The reaction was quenched by 1 N HCI, and adjusted to pH 1.3 and stirred at room temperature for 1 hour. The reaction mixture was adjusted pH to 8 with k2CO3. The reaction mixture was extracted with ethyl acetate. The organic layer was dried over MgSO4, and concentrated to an oil and column chromatographyed to give 2.68 g of the desired product (65%). Step 3: Preparation of 2.3-dihvdropyrazolor5,1-b1H,31oxazole-6-carbaldehvde: To the stirred solution of 2,3-dihydropyrazolo[5,1-b][1 ,3]oxazole-6-methanol
(2.60 g, 18.5 mmol) in 60 ml of CH3CI was added 12.9 g of MnO2. Th suspension was refluxed for 1.5 hour under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated to give yellow oil. The product was purified by chromatography. 2.15 g of the product was obtained (84.3%).
Step 4: 4-Nitrobenzv (5R)-6-r(acetyloxyH2.3-dihvdropyrazolor5.1- bi H ,31oxazol-6-yl) -)methyll-6-bromo-7-oxo-4-thia-1 -azabicvclor3.2.01hept-2- ene-2-carboxylate: 2,3-dihydropyrazolo[5,1-b][1,3]oxazole-6-carbaldehyde (607 mg, 4.3 mmol) and the dry THF solution (20 mL) of (5R1 6S)-6-bromo-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept- 2-ene-2-carboxylic acid 4-nitro-benzyl ester (1.54 g, 4.6 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (2.21 g , 8.5 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 °C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1 :1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 1.9 g, 81%; M+H 566.
H-NMR(CDCI3) 8.24(2H, d, J= 6.6 Hz), 7.60(2H, d, J= 6.6Hz), 7.44(1 H, s), 6.34(1 H, s), 6.23(1 H, s), 5.56(1 H, s), 5.44(1 H, d, J=10.2 Hz), 5.27(1 H, d J=10.2Hz), 5.04(2H, m), 4.30(2H, m), 2.10(3H, s). Anal.Calcd. for C2i H17BrN4O8S: C, 44.61 , H, 3.03, N, 9.91
Found: C, 45.00, H, 3.14, N, 9.53
Step-5: (5R,6Z)-6-(2.3-dihydropyrazolor5.1 -bϊH .31oxazol-6-ylmethylene>-
7oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid sodium salt:
4-Nitrobenzy-6-[(acetyloxy)(2,3-dihydropyrazolo[5, 1 -b][1 ,3]oxazol-6-yl) Jmethyπ-e-bromo^-oxo^-thia-i-azabicyclop^.Olhept^-ene^-carboxylate (700 mg,
1.2 mmol) was dissolved in THF (20 mL), acetonitrile (10 ml.) and 0.5 M phosphate buffer (pH 6.5, 28 mL) and hydrogenated over 10% Pd/C at 40 psi pressure. After 4 hrs the reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% acetonitrile: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 276 mg, 73%; as yellow amorphous solid; (M+H+Na)314. .
1H-NMR(D2O); δ 6.97(1 H, s), 6.95(1 H, s), 6.46(1H1 s), 5.56(1 H, s) 5.07(2H, d, J= 6.3 Hz), 4.30(2H, t, J=6.3 Hz).
Example 33 Preparation of (5R,6Z)-6-[(5-acetyl-4,5,6,7-tetrahydrothieno[3J2-c]pyridin-2- yl)methylene]-oxo-4-thia-1 -azabicyclo[3.2.0.]hept-2-ene-2-carboxylic acid (E+Z
Isomers mixture,Sodium salt) Step 1 : 5-acetyl-4.5.6 J-tetrahvdrothienore.Σ-clpyridine-Σ-carbaldehvde: To a cold (0° C) suspension of 1.5 g.(7.4 mmol) of 4,5,6,7-tetrahydrothieno[3,2- c]pyridine-2-carbaldehyde hydrochloride in 50 mL methylene chloride, under N2 atm., dry conditions, was added dropwise under stirring 2.6 mL (2.5 eqs) of triethylamine. RM stirred for 30 min at 0° C. and a solution of 0.7 g.(8.1 mmol,1.1 eqs) of acetyl chloride in 15 mL methylene chloride was dropwise added, RM allowed to reach RT and stirred for 3 hours. Filtered trough a celite pad, filtrate washed with 3x 50 mL water, dried, evaporated, gave 1.1g.(71.4 %) of the title compound, viscous oil, (M+H)+ 210.3. Step 2: Preparation of 4-nitrobenzyl(5RΪ-6-F(acetyloxy)(5-acetyl-4.5,6.7- tetrahvdrotienor3.2-cl pyridin-2-yl)methvπ-6-bromo-7-oxo-4-thia-1- azabicvclore.Σ.O.Ihept-Σ-ene-Σcarboxylate δ-acetyM.δ.θJ-tetrahydrothienotS^-clpyridine^-carbaldehyde (540 mg, 2.57 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (950 mg, 2.5 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (2.21 g, 8.5 mmol)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1:1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 870 mg, 53%; m.p. 46-480C; (M+H)+ 637.6. 1HNMR(CDCI3): δ 2.15(t,6H);2.8-3.0(m,2H);3.7-3.9(m,2H);4.58-4.68(m,2H);5.30- 5.45(dd,2H);5.85(d,1H);6.71(s,1H);6.95(s,1H);7.35-7.45(d,1H); 7.60(dd,2H); 8.25(dd,2H).
Step 3: (5R.6Z)-6-r(5-acetyl-4.5.6.7-tetrahvdrothienor3.2-clpyridin-2- vπmethvlenei-oxo^-thia-i-azabicvclora.Σ.O.Ihept^-ene^-p.arhnwIic acid (E+2 Isomers mixture.Sodium salt)
A solution of 0.77g.(1.21 mmol, 4-nitrobenzyl(5R)-6-[(acetyloxy)(5-acetyl-4,5,6,7- tetrahydrotieno[3,2-c] pyridin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1- azabicyclo[3.2.0.]hept-2-ene-2carboxylate in 40 mL THF and 40 m!_ phosphate buffer solution (pH=6.36) was hydrogenated at 40 psi for 3 hours in the presence of 0.4g. Palladium on Carbon 10% catalyst. Reaction mixture was filtrated through celite pad, filtrate adjusted to pH=8.0, concentrated in vacuo, residue purified on a reverse- phase column (amberlite), using 5%..10% ACN/water mixture as solvent, gave 0.107g.(23%) of the title compound, reddish crystals, m.p.362.4° C, (M+H)+ 409.5. 1 H NMR:δ 2.08 (s,3H);2.80-2.95 (m,1H);3.74(m,2H);3.98-4.06(d,2H)6.32-6.42 (s,1H); 6.50-6.60(s,1H);6.98-7.20 (s,1H);7.30-7.40 (s,1H).
Example 34
Preparation of (5f?.6Z)-6-(6.7-dihvdro-4H-pyrazolor5.1 -clH ,41oxazin-2- ylmethylene)-7-oxo-4-thia-1-azabicvclor3.2.01hept-2-ene-2-carboxylic acid
Step 1 : 4-Nitrosomorpholine-3-carboxylic acid
To a solution of morpholine-3-carboxylic acid (6.96 g, 52 mmol) in water (20 ml), at 0 0C under nitrogen, was added concentrated hydrochloric acid (4 ml), followed by sodium nitrite (5.0 g, 72 mmol) in small portions. The mixture was stirred at 0 0C for 1 hr, and then concentrated under vacuum at 30 to 35 0C. The residue was stirred with 200 ml of acetone and filtered. The filtrate was evaporated and the residue treated with 50 ml of THF and concentrated. The process was repeated with 2x50 ml of THF to give 11.87 g of light yellow foam; MS (ESI) m/z 159.2 (M-H). Step 2: 6.7-Dihvdro-4H-π .2.31oxadiazolor4.3-ciπ .41oxazin-8-ium-3-olate The crude 4-nitrosomorpholine-3-carboxylic acid (11.0 g) from step 1 was dissolved in THF (250 ml) and cooled to 0 0C. A solution of trifluoroacetic anhydride (7.4 ml, 52 mmol) in THF (20 ml) was added with stirring over 10 min. The resulting mixture was stirred at 0 0C for 5 hr, and warmed to room temperature for 16 hr. The solvent was evaporated and the residue was diluted with 250 ml of ethyl acetate and stirred with 30 g of anhydrous potassium carbonate. The mixture was filtered through a pad of silica gel and the filtrate evaporated. The residue was washed with a mixture of ethyl acetate-ether to give 3.80 g of a white solid; mp 132-133 0C; MS (ESI) m/z 143.1 (M+H). Step 3: Ethyl 6.7-dihydro-4H-pyrazolor5,1-cU1,41oxazine-2-carboxylate
To a partial solution of 6,7-dihydro-4H-[1 ,2,3]oxadiazolo[4,3-c][1 ,4]oxazin-8-ium-3- olate (3.41 g, 24 mmol) in o-xylene (80 ml), was added ethyl propiolate (2.7 ml, 26 mmol). The mixture was stirred at 140 0C for 3 hr. An additional 2.0 ml (19 mmol) of ethyl propiolate was then added and the mixture was stirred at reflux for 18 hr. The final solution was evaporated under vacuum, and the residue was dissolved in a mixture of methylene chloride and hexanes (1:5). The solution was passed through a pad of silica gel and the filter pad was eluted with methylene chloride-hexanes, followed by ethyl acetate. The ethyl acetate eluent was evaporated and the residue washed with hexanes to give 4.10 g of a white solid; mp 63 0C; MS (ESI) m/z 197.1 (M+H).
Step 4: 6.7-Dihvdro-4H-pyrazolor5,1-ciπ.41oxazin-2-ylmethanol To a solution of ethyl 6,7-dihydro-4H-pyrazolo[5,1-c][1 ,4]oxazine-2-carboxylate (1.57 g, 8.0 mmol) in methylene chloride (30 ml) was added 24 ml of a 1.0 M solution of diisobutylaluminum hydride in methylene chloride at 0 0C, under nitrogen. After stirring for 0.5 hr at 0 °C, the mixture was warmed to room temperature for 2 hr. It was then treated with 30 ml of saturated ammonium chloride solution and extracted with ethyl acetate. The organic solution was washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated to give 1.27 g of a colorless oil; MS (ESI) m/z 155.3 (M+H).
Step 5: 6.7-Dihvdro-4H-pyrazolof5,1-ciri .41oxazine-2-carbaldehyde
To a solution of 6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-ylmethanol (1.08 g, 7.0 mmol) in 1 ,2-dichloroethane (30 ml) was added 5.4 g of activated manganese dioxide at room temperature with stirring. The mixture was heated to 60 0C for 1 hr and then stirred at room temperature for 16 hr. The final mixture was filtered through a column of silica gel topped with celite. The filter pad was eluted with methylene chloride, followed by ethyl acetate. The ethyl acetate eluent was evaporated and the residue triturated with to give 0.81 g of a white solid; mp 91 °C; MS (ESI) m/z 153.2 (M+H). Step 6: 4-Nitrobenzyl f5ffl-6-rfacetyloxyU6.7-dihvdro-4H-pyrazolor5.1- ciri^ioxazin^-vπmethvn-β-bromo^-oxo^-thia-i-azabicvclofS^.OIhept^-ene- 2-carboxvlate To a solution of MgBr2 (0.94 g,' 5.1 mmol) in acetonitrile (25 ml) under nitrogen was added 6,7-dihydro-4H-pyrazolo[5,1-c][1 ,4]oxazine-2-carbaldehyde (0.26 g, 1.7 mmol) at room temperature with stirring. A solution of (5R,6S)-6-bromo-7-oxo- 4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (0.58 g, 1.5 mmol) in THF (25 ml) was then added, and the mixture was cooled to -20 0C. Triethylamine (0.71 ml, 5.1 mmol) was introduced, and the mixture was stirred at -20 0C in the dark for 5 hr. It was then treated with acetic anhydride (0.6 ml, 6.0 mmol), and 4-N,N-dimethylaminopyridine (24 mg, 0.2 mmol), and kept at 0 °C for 18 hr. The mixture was concentrated and the residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with 5% citric acid, saturated sodium bicarbonate solution, and brine, dried over anhydrous sodium sulfate, and evaporated. The crude material was chromatographed with silica gel (EtOAc-CH2CI2/1 :5) to give 0.77 g of a white foam; MS (ESI) m/z 578.9 (M+H).
Step 7: (5/?.βZ)-β-(6.7-dihvdro-4H-pyrazolor5.1 -ciH .41oxazin-2-ylmethyleneϊ-7- oxo-4-thia-1 -azabicvclore.Σ.OIhept-Σ-ene-Σ-carboxylic acid
To a solution of 4-nitrobenzyl (5R)-6-[(acetyloxy)(6,7-dihydro-4H-pyrazolo[5,1- c][1,4]oxazin-2-yl)methyl]-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2- carboxylate (0.35 g, 0.6 mmol) in THF (20 ml), under nitrogen, was added 20 ml of a phosphate buffer solution (0.5M, pH 6.5), and 120 mg of 10% Pd/C. The mixture was hydrogenated at 40-50 psi for3 hr, and then filtered through Celite. The filter pad was washed with THF, and the filtrate was extracted with ethyl acetate. The organic extract was dried over anhydrous magnesium sulfate and evaporated. The residue was washed with ether to give 0.09 g of a yellow solid; HRMS: calcd for C13HnN3O4S, 305.0470; found (ESI+), 306.05434; 1H NMR (DMSOd6) δ 4.07-4.09 (t, 2H), 4.13-4.17 (t, 2H), 4.82 (s, 2H), 6.36 (s, 1H), 6.55 (s, 1H), 7.17 (s, 1H), 7.55 (s, 1H), 12.80 (bs, 1H).
Example 35
Preparation of (5RU6Z)-6-(6J-5H--Dihydropyrazolor5,1 -bioxazin-2- ylmethylene)-7-oxo-4-thia-1 - azabicvclor3.2.01hept-2-ene-2-carboxylic acid. sodium salt
Step 1: Preparation of ethyl 6,7-dihvdro-5H-pyrazolor5,1-biri,31oxazine- 2-carboxvlate: To the stirred suspension of ethyl δ-hydroxy-I H-pyrazole-S-carboxylate (10.34 g, 0.66 mol) and 36.62 g of potassium carbonate in 500 ml of acetonitrile was added 14.7 g of 1 ,3-dibromopropane, and refluxed for 16 hours. The reaction mixture was allowed to cool to room temperature, then filtered, the solid was washed with acetonitrile. The filtrate was concentrated to an oil. The residue was dissolved in ethyl acetate and extracted with water. The organic phase was dried over MgSO4 and evaporated to dryness. 8.80 g of the desired product was obtained (68%), m.p. 44-460C (M+H)+ 197.1. Step 2: Preparation of 2.3-dihvdro-5H-pyrazolor5,1-biπ.31oxazin-2-yl- methanol:
To the stirred solution of 6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-2- carboxylate:
(4.0 g, 20 mmol) of in 100 ml of THF was added 0.71 g of lithium borohydride and 1.03 g of methanol. The solution was heated at 4OC for 2.5 hour. The reaction was quenched by 1 N HCI, and adjusted to pH 1.3 and stirred at room temperature for 1 hour. The reaction mixture was adjusted pH to 8 with k2CO3. The reaction mixture was extracted with ethyl acetate. The organic layer was dried over MgSO4, and concentrated to an oil and column chromatographyed to give 2.08 g of the desired product (67%); (M+H) 155. Step 3: Preparation of 6,7-dihvdro-5H-pyrazolor5,1-blH,31oxazine-2- carbaldehvde: To the stirred solution of 2,3-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-2-yl-methanol
(2.08 g, 13.5 mmol) in 60 ml of CH3CI was added 9.38 g of MnO2. Th suspension was refluxed for 2 hour under a nitrogen atmosphere. The reaction mixture was filtered through a pad of Celite. The filtrate was concentrated to give yellow oil. The product was purified by chromatography. 2.15 g of the product was obtained (78%).
Step 4: 4-Nitrobenzv(5R)-6-r(acetyloxyH6,7-dihvdro-5H-pyrazolor5,1 -
Figure imgf000114_0001
2-carboxylate:
6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-2-carbaldehyde (330 mg, 2 mmol) and the dry THF solution (20 mL) of (5R, 6S)-6-bromo-7-oxo-4-thia-1-aza- bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester (0.794 g, 2.2 mmol) were added successively to the dry acetonitrile (15 mL) solution of anhydrous MgBr2: 0(Et)2 (1.2 g)under an argon atmosphere at room temperature. After cooling to -20 0C, Et3N (2.0 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at -20 0C and treated with acetic anhydride (1.04 mL) in one portion. The reaction mixture was warmed to 0 0C and stirred for 15 h at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered through a pad of Celite. The pad was washed with ethyl acetate. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then the column was eluted with ethyl acetate: hexane (1:1). Collected fractions were concentrated under reduced pressure and the mixture of diastereo isomers were taken to next step. Pale yellow amorphous solid; Yield: 0.76 g, 65%; M+H 579. Step-5: (5ffl(6Z>-6-(6.7-5H-Dihvdropyrazolor5.1-b1oxazin-2-ylmethylene)-
7-oxo-4-thia-1- azabicvclor3.2.01hept-2-ene-2-carboxylic acid, sodium salt
4-Nitrobenzy(5R)-6-[(acetyloxy)(6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazin-2- yl )methyl]-6-bromo-7-oxo-4-thia-1 -azabicyclo[3.2.0]hept-2-ene-2-carboxylate (350 mg, 0.6 mmol) was dissolved in THF (20 mL), acetonitrile (10 mL) and 0.5 M phosphate buffer (pH 6.5, 28 mL) and hydrogenated over 10% Pd/C at 40 psi pressure. After 4 hrs the reaction mixture was filtered, cooled to 3 0C, and 0.1 M NaOH was added to adjust pH to 8.5. The filtrate was washed with ethyl acetate and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C to give yellow precipitate. The product was purified by HP21 resin reverse phase column chromatography. Initially the column was eluted with deionized water (2 lits) and latter with 10% acetonitrile: Water. The fractions containing the product were collected and concentrated at reduced pressure at room temperature. The yellow solid was washed with acetone and filtered. Dried. Yield: 103 mg, 52%; as yellow amorphous solid; (M+H+Na)327. 1H-NMR(D2O); δ 6.97(1 H, s), 6.93(1 H, s), 6.47(1 H, s), 5.65(1 H, s) 4.28(2H, m), 4.10(2H,m), 2.21 (2H,m).
Example 36 Preparation of (5RU6Z)-6-r5-(3-carboxypropionvh-4.5.6.7- tetrahvdropyrazolori.S-aipyrazin-Σ-ylmethylenei-T-oxo^-thia-i- azabicvclor3.2.01hept-2-ene-carboxylic acid.disodium salt
The above mentioned compound was prepared by the procedures outlined in all the above examples. Starting from (5R),(6Z)-6-{5-[3-(4-itrobenzyloxycarbonyl)propionyl]- 4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazin-2-ylmethylene}-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid sodium salt (467 mg) and hydrogenating it over Pd/C (10%), 276 mg of (74%) of (5R),(6Z)-6-[5-(3- carboxypropionyl)-4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazin-2-ylmethylene]-7-oxo-4- thia-1-azabicyclo[3.2.0]hept-2-ene-carboxylic acid.disodium salt was isolated as yellow amorphous solid. Mp. 18O0C (Dec); 1H NMR (D2O) D 2:41 (t, 2H), 2.42 (t, 2H), 2.67 (t, 2H), 2.72 (t, 2H), 3.95-4.09 (m, 2H), 4.18 (t, 2H), 4.28 (t, 2H), 4.75 (s, 2H), 4.87 (s, 2H), 6.33 (s,1H), 6.34 (s, 1 H), 6.53 (s, 1H)1 7.00 (s, 1 H), 7.09 (s, 1H).
Example 37 Preparation of (5R).(6Z)-6-f5-(2-methoxyacetyl)-4.5,6.7-tetrahvdropyrazoloπ .5- a1pyrazin-2-ylmethylenel-7-oxo-44hia-1-azabicvclor3.2.01hept-2-ene-carboxylic acid.sodium salt
(5R),(6Z)-7-Oxo-6-(4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazin-2-ylmethylene)- 4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid, sodium salt (Example 25) To the THF (64 mL) and H2O (64 ml_) solution of (5R),(6Z)-7-Oxo-6-(4,5,6,7- tetrahydropyrazolo[1 ,5-a]pyrazin-2-ylmethylene)-4-thia-1 -aza-bicyclo[3.2.0]hept-2- ene-2-carboxylic acid, sodium salt (Example 25) (638 mg) was added 0.1 M NaOH aq slowly to adjust pH to 12.5 at 0 0C. To the mixture was added methoxyacetyl -chloride (0.28 mL) over 5 min. The mixture was stirred for 0.5 h at 0 0C and methoxyacetylchloride (0.09 mL) was added to the mixture. After stirring the mixture for 0.5 h at the same temperature, 0.1 M NaOH aq was added to adjust pH to 8.05. The mixture was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (78 mL, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with H2O - MeCN (1 :0 to 9:1). The combined fractions were concentrated under high vacuum at 35 0C and lyophilized to give the title compound as a yellow amorphous solid (509 mg, 65%, pH 7.58).
Mp 170 0C (dec); 1H NMR (D2O) p 3.28 (s, 3H x 1/2), 3.29 (s, 3H x 1/2), 3.78 (t, 2H x 1/2, J = 5.4 Hz), 3.89 - 3.93 (m, 2H x 1/2), 4.09 (t, 2H x 1/2, J = 5.4 Hz), 4.14 (t, 2H x 1/2, J = 5.4 Hz), 4.20 (s, 2H X 1/2),.4.25 (s, 2H x 1/2), 4.61 (s, 2H x 1/2), 4.66 (S, 2H x 1/2), 6.19 (s, 1H x 1/2), 6.22 (s, 1H x 1/2), 6.37 (s, 1 H x 1/2), 6.372 (s, 1H x 1/2), 6.87 (s, 1H), 6.93 (S1 1H)
Example 38
Preparation of (5R). f 6Z)-6-r5-(4.5-Dirivdrothiazol-2-vn-4.5.6.7- tetrahydropyrazoloH ,5-aipyrazin- 2-ylmethylene1-7-oxo-4-thia-1 - azabicyclor3.2.01hept-2-ene-2-carboxylic acid sodium salt
(4.5,6.7-Tetrahvdropyrazoloπ.5-aipyraz8n-2-vπ-methanol Methanol (150 ml) was added to the mixture of 2-hydroxymethyl-6,7-dihydro- 4H- pyrazolo[1 ,5-a]pyrazine-5-carboxylic acid 4-nitrobenzyl ester (Example 25) (2.38 g) and 10% Pd-C (50% wet, 1.19 g). The reaction mixture was stirred for 2 hours under a hydrogen atmosphere. The mixture was filtered and concentrated under reduced pressure. The residue was applied to silica-gel column chromatography, then the column was eluted with 50% methanol in chloroform. The titled compound was obtained as a white solid (1.08 g, 98 %). 1H NMR (400 MHz, CD3OD) D3.22 - 3.25 (m, 2H), 3.99 (s, 2H), 4.03 - 4.06
(m, 2H), 4.52 (s, 2H)1 6.06 (s, 1H). r5-(4,5-Dihvdrothiazol-2-vπ-4.5,6J-tetrahvdropyrazoloπ.5-aipyrazin-2- yJt methanol Hydrogen chloride (2 mol/l) solution in diethyl ether (0.7 ml) was added to the methanol (20 ml) solution of (4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazin-2- yl)-methanol (1.08 g) and 2-methylsulfanyl-4,5-dihydrothiazole (1.03 g). The reaction mixture was refluxed for 4 days. The mixture was quenched with small amount of saturated potassium carbonate solution, dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica- gel column chromatography, then the column was eluted with 10% methanol in chloroform. The titled compound was obtained as a white solid (1.49 g, 89 %).
1H NMR (400 MHz, CDCI3) D 2.04 (brs, 1H), 3.39 (t, 2H, J = 7.5 Hz), 3.90 (t, 2H, J = 5.3 Hz), 4.06 (t, 2H, J = 7.5 Hz), 4.21 (t, 2H, J = 5.3 Hz), 4.66 (s, 2H), 4.69 (s, 2H), 6.07 (s, 1H).
(5R). (6Z^-6-r5-(4.5-Dihvdrothiazol-2-vn-4,5.6.7-tetrahvdropyrazolon.5- alpyrazin- 2 -ylmethylenei^-oxo^-thia-i-azabicvclof 3.2.01 hept-2-ene-2- carboxylic acid sodium salt The activated manganese (IV) oxide (16.75 g) was added to the mixture of chloroform (180 ml) solution of [5-(4,5-dihydrothiazol-2-yl)-4,5,6,7- tetrahydropyrazolo[1 ,5-a]pyrazin-2-yl]-methanol (3.35 g) at room temperature. The reaction mixture was refluxed for 1 hour. After refluxing, the mixture was filtered through a pad of Celite and the filtrate was concentrated under reduced pressure. The residue was dried in vacuo and the crude 5-(4,5-dihydrothiazol-2-yl)-4,5,6,7- tetrahydropyrazolo[1,5-a]pyrazine-2-carbaldehyde was obtained as a colorless solid. The crude aldehyde thus obtained(2.56 g) was added to a dry acetonitrile (200 ml) solution of MgBr2 (7.36 g) under a nitrogen atmosphere at room temperature then the mixture was stirred for 10 minutes. A dry THF (200 ml) solution of WLJ 20,014 (4.16 g) was added and the mixture was cooled to -20 0C. Then triethylamine (11.3 ml) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 1.5 hours at -20 °C and treated with 4- dimethylaminopyridine (132 mg) and acetic anhydride (4.2 ml) in one portion. The reaction mixture was warmed to 0 0C and stirred for 20 hours at 0 0C. The mixture was diluted with ethyl acetate and washed with 5% citric acid aqueous solution, saturated sodium hydrogen carbonate, and brine. The organic layer was dried (MgSO4) and filtered. The filtrate was concentrated under reduced pressure. The residue was applied to silica gel column chromatography, then eluted with n-hexane- AcOEt (1 :2) and chloroform - methanol (9: 1 ). The (5R,6RS)-6-{(RS)-acetoxy-[5-(4,5- dihydrothiazol-2-yl)-4,5,6,7-tetrahydropyrazolo[1 ,5-a]pyrazin-2-yl]-methyl}-6-bromo-7- oxo-4-thia-1- azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester was obtained (5.41 g, 75.4%).
The (5R,6RS)-6-{(RS)-acetoxy-[5-(4,5- dihydrothiazol-2-yl)-4,5,6,7- tetrahydropyrazolo[1 ,5-a]pyrazin-2-yl]-methyl}-6-bromo-7-oxo-4-thia-1 - azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (5.41 g) was dissolved in THF (76 ml) and acetonitrile (35 ml). Freshly activated Zn dust (21.6 g) and 0.5 mol/l phosphate buffer (pH 6.5, 111 ml) were added to the mixture. The reaction vessel was covered with foil to exclude light. The reaction mixture was vigorously stirred for 2 hours at 30 to 35 0C. The reaction mixture was cooled at 0 0C, and then the pH was adjusted to 7.6. Ethyl acetate was added to the reaction mixture and filtered through a pad of Celite. The pad was washed with water and the aqueous layer was separated. The aqueous layer was concentrated under high vacuum at 35 0C. The concentrate was applied to Diaion HP-21 (170 ml, Mitsubishi Kasei Co. Ltd.) resin column chromatography. After adsorbing, the column was eluted with water and then with 5% to 15% acetonitrile aqueous solution. The combined active fractions was concentrated under high vacuum at 35 0C and lyophilized to give the titled compound as a crude yellow amorphous solid (1.60 g).
The crude compound was purified by preparative HPLC (Mightysil RP- 18GP, KANTO CHEMICAL CO., INC., 35 x 250 mm, 0.05 mol/l phosphate buffer (pH 7.1) : acetonitrile = 80 : 20, 25 ml/min) followed by desaltation on Diaion HP-21 resin (150 ml, Mitsubishi Kasei Co. Ltd.) to give the titled compound as a yellow amorphous solid (1.06 g, y. 31.5 %, pH 8.33).
Mp 100 0C (dec); 1H NMR (D2O) D 3.18 (t, 2H, J = 7.6 Hz), 3.60 (t, 2H, J = 5.3 Hz), 3.73 (t, 2H, J = 7.6 Hz), 3.94 (t, 2H, J = 5.3 Hz), 4.37 (s, 2H), 6.01 (s, 1H), 6.21 (s, 1H), 6.77 (s, 1H), 6.78 (s, 1H); IR (KBr) 3381 , 1752, 1606 cm"1; Dmax (H2O) 369, 291 , 208 nm. Example 39
Preparation of (5R.6Z)-6-fr6-(ethoxycarbonv0-4.5,6.7-tetrahydrofuror2,3- cipyridin-Σ-yllmethyleneW-oxo^-thia-i-azabicvclorS.Σ.OIhept^-ene-Σ- carboxylic acid
Preparation of Ethyl 2-r(acetyloxy)((5ffl-6-bromo-2-ffl4- nitrobenzvOoxyicarbonyll^-oxo^-thia-i-azabicvclore.Σ.OIhept-Σ-en-θ- vDmethv!1-4.7-dihvdrofuror2,3-ciPyridine-6(5A7)-carboxylate
The titled compound was prepared from 0.669 grams of methyl 2-formyl-4,7- dihydrofuro[2,3-c]pyridine-6(5H)-carboxylate and 1.155 grams of 4-nitrobenzyl (5R)- 6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate yielded 1.65 grams of product (84%), which was used directly for the next step. MS: 652.2(M+H)
Preparation of (5f?,6Z)-6-^r6-(ethoxycarbonvh-4.5.6.7-tetrahvdrofurof2,3- cipyridin-Σ-vπmethylene^^-oxo^-thia-i-azabicvclorS.Σ.OIhept-a-ene-Σ- carboxylic acid
The title compound was prepared fromi .65 g of ethyl 2-[(acetyloxy)((5r)-6-bromo-2- {[(4-nitrobenzyl)oxy]carbonyl}-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-en-6-yl)methyi]- 4,7-dihydrofuro[2,3-c]pyridine-6(5/7)-carboxylate, yielded 0.386 grams of product (41%). Mp: decomposed at 175°c. Ms: 375.0 (m-h). H-nmr(d2o): D 6.91 (s, 1h), 6.84(s, 1h), 6.62(s, 1h), 6.39(s, 1h), 4.41 (b, 2h), 4.04 (q, 2h, j=5hz), 3.52(b, 2h), 2.42(b, 2h), 1.14 (t, 3h, j=5hz),
Brief Description of Biological Test Procedure(s) and Text Summary of Results.
Antimicrobial susceptibility testing. The in vitro activities of the antibiotic, piperacillin in this case, against resistant pathogens expressing class-D enzymes were determined by the microbroth dilution method as recommended by the National Committee for Clinical Laboratory Standards (NCCLS). (NCCLS. 2000. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standards: M7-A5, vol. 19. National Committee for Clinical Laboratory Standards, Villanova, PA). Mueller-Hinton Il broth (MHBII)(BBL Cockeysville, MD), was used for the testing procedure. Microtiter plates containing 50 μL per well of two- fold serial dilutions of piperacillin combined with a constant amount (4ug/ml) of a B- lactamase inhibitor were inoculated with 50 μL of inoculum to yield the appropriate density (105 CFU/mL) in 100 μL final volume. The plates were incubated for 18 - 22 hours at 350C in ambient air. The minimal inhibitory concentration (MIC50) for all isolates was defined as the lowest concentration of antimicrobial agent that completely inhibits the growth of the organism as detected by the unaided eye. The
MIC50 data obtained by the above said procedure are enlisted in Table 1. As a control piperacillin has an MIC50 value of >64 μg/mL. Both OXA-10 and PSE-2 are class D β-lactamases. (Bush, K. Jacoby, G.A., Medeiros, A.A. Antimicrob. Agents
, Chemother., 1995, 39, 1211.) Table 1: Minimal Inhibitory Concentration ( MIC50) (μg/mL) Data: Inc:
35°C for 18 hours
Against class-D producing organism E. coli GC 2883 (OXA-10+PSE-2)
Figure imgf000121_0001
Figure imgf000122_0001

Claims

What is claimed is:
1. A method of inhibiting class D enzymes in the treatment of bacterial infection in a patient in need thereof which comprises providing to said patient an effective amount of a compound of formula I:
Figure imgf000123_0001
I wherein: one of A and B is hydrogen and the other is an optionally substituted fused bicyclic heteroaryl group; X is O or S;
R5 is H, C1 -C6 alkyl, C5 - C6 cycloalkyl, CHR3OCOCI -Cβalkyl; and R3 is hydrogen, C1-C6 alkyl, C5 - C6 cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl; or a pharmaceutically acceptable salt thereof.
2. The method according to claim 1 wherein the compound is co-administered with a β-lactam antibiotic.
3. The method according to claim 2 wherein the ratio of β-lactam antibiotic to the compound is in a range from about 1 : 1 to 100: 1.
4. The method according to claim 3 wherein the ratio of the β-lactam antibiotic to the compound is less than 10:1.
5. The method according to claim 1 wherein the bicyclic heteroaryl group is
Figure imgf000123_0002
wherein Z1 , Z2 and Z3 are independently CR2, N, O, S or N-R1 provided one of Z1 -
Z3 is carbon and is bonded to the remainder of the molecule;
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1; with the proviso that no S-S or 0-0 or S-O bond formation can occur to form the saturated ring system; t= 1 to 4;
R1 is H; optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl or mono or bicyclic saturated heterocycles, optionally substituted C5-C7 cycloalkyl, optionally substituted C3-C6 aikenyl, optionally substituted C3-C6 alkynyl with the proviso that neither the double bond nor the triple bond should be present at the carbon atom which is directly linked to N; optionally substituted C1-C6 perfluoroalkyl,
-S(O)p optionally substituted alkyl or aryl where p is 0-2, optionally substituted
-C=Oheteroaryl, optionally substituted -C=Oaryl, optionally substituted -C=O
(C1-C6) alkyl, optionally substituted -C=O(C5-C6)cycloalkyl, optionally substituted - C=O mono or bicyclic saturated heterocycles, optionally substituted C1-C6 alkylaryl, optionally substituted C1-C6 alkyl heteroaryl, optionally substituted aryl-C1-C6 alkyl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, -CONR6R7, -SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted -alkyl-O-alkyl-aryl, optionally substituted -alkyl-O-alkyl-heteroaryl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, optionally substituted C1-C6alkylaryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl, optionally substituted alkylaryloxyalkylamines, optionally substituted alkoxycarbonyl, optionally substituted aryloxycarbonyl, or optionally substituted heteroaryloxy carbonyl;
R2 is hydrogen, optionally substituted C1-C6 alkyl, optionally substituted C2- C6 aikenyl, optionally substituted C2-C6 alkynyl, halogen, cyano, N-R6R7, optionally substituted C1-C6 alkoxy, hydroxy; optionally substituted aryl, optionally substituted heteroaryl, COOR6, optionally substituted alkyl aryloxy alkylamines, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted C3-C6 alkenyloxy, optionally substituted C3 -C6 alkynyloxy, C1-C6 alkylamino-C1-C6 alkoxy, alkylene dioxy, optionally substituted aryloxy-C1-C6 alkyl amine, C1-C6 perfluoro alkyl, S(O)q-optionally substituted C1-C6 akyl, S(O)q- optionally substituted aryl where q is 0, 1 or 2, CONR6R7, guanidino or cyclic guanidino, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted C1- C6 alkylheteroaryl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, substituted heteroaryloxyaryl, optionally substituted C1-C6alkyl aryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl , optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, or optionally substituted alkylaryloxyalkylamine;
R4 is H, optionally substituted C1-C6 alkyl, one of R4 is OH, C1-C6 alkoxy, - S-C1-C6 alkyl, COOR6, -NR6R7, -CONR6R7 ; or R4R4 may together be =0 or R4R4 together with the carbon to which they are attached may form a spiro system of five to eight members with or without the presence of heteroatoms selected from N, O,
S=(O)n (where n =0 to 2), and N-R1; and
R6 and R7 are independently H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted heteroarylalkyl, optionally substituted C1-C6 alkylheteroaryl, or R6 and R7 can be together to form a 3-7 membered saturated ring system optionally having one or two heteroatoms selected from N, O, or S.
6. The method according to claim 1 wherein the bicyclic heteroaryl group is
Figure imgf000126_0001
1-B
wherein
Z1, Z2 and Z3 are independently CR2, N, O, S or N-R1 provided one of Z1 - Z3 is carbon and is bonded to the remainder of the molecule;
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1; t= 1 to 4;
Y1 and Y2 are independently N or C; with the proviso that if the aromatic ring portion of the bicyclic heteroaryl group is imidazole, the nonaromatic ring portion may not contain a S adjacent to the bridgehead carbon;
R1 is H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl or mono or bicyclic saturated heterocycles, optionally substituted C5-C7 cycloalkyl, optionally substituted C3-C6 alkenyl, optionally substituted C3-C6 alkynyl with the proviso that neither the double bond nor the triple bond should be present at the carbon atom which is directly linked to N; optionally substituted C1-C6 perfluoroalkyl,
-S(O)p optionally substituted alkyl or aryl where p is 0-2, optionally substituted
-C=Oheteroaryl, optionally substituted -C=Oaryl, optionally substituted -C=O
(C1-C6) alkyl, optionally substituted -C=O(C5-C6)cycloalkyl, optionally substituted - C=O mono or bicyclic saturated heterocycles, optionally substituted C1-C6 alkylaryl, optionally substituted C1-C6 alkyl heteroaryl, optionally substituted aryl-C1-C6 alkyl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, -CONR6R7, -SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted -alkyl-O-alkyl-aryl, optionally substituted -alkyl-0-alkyl-heteroaryl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, optionally substituted
C1-C6alkylaryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl, optionally substituted alkylaryloxyalkylamines, optionally substituted alkoxycarbonyl, optionally substituted aryloxycarbonyl, or optionally substituted heteroaryloxy carbonyl;
R2 is hydrogen, optionally substituted C1-C6 alkyl, optionally substituted C2- C6 alkenyl, optionally substituted C2-C6 alkynyl, halogen, cyano, N-R6R7, optionally substituted C1-C6 alkoxy, hydroxy; optionally substituted aryl, optionally substituted heteroaryl, COOR6, optionally substituted alkyl aryloxy alkylamines, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted C3-C6 alkenyloxy, optionally substituted C3 -C6 alkynyloxy, C1-C6 alkylamino-C1-C6 alkoxy, alkylene dioxy, optionally substituted aryloxy-C1-C6 alkyl amine, C1-C6 perfluoro alkyl, S(O)q-optionally substituted C1-C6 akyl, S(O)q- optionally substituted aryl where q is 0, 1 or 2, CONR6R7, guanidino or cyclic guanidino, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted C1- C6 alkylheteroaryl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, substituted heteroaryloxyaryl, optionally substituted C1-C6alkyl aryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl , optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, or optionally substituted alkylaryloxyalkylamine;
R4 is H, optionally substituted C1-C6 alkyl, one of R4 is OH, C1-C6 alkoxy, - S-C1-C6 alkyl, COOR6, -NR6R7, -CONR6R7 ; or R4R4 may together be =O or R4R4 together with the carbon to which they are attached may form a spiro system of five to eight members with or without the presence of heteroatoms selected from N, O,
S=(O)n (where n =0 to 2), and N-R1; and
R6 and R7 are independently H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted heteroarylalkyl, optionally substituted C1-C6 alkylheteroaryl, or R6 and R7 can be together to form a 3-7 membered saturated ring system optionally having one or two heteroatoms selected from N, O, or S.
7. The method according to claim 1 wherein the bicyclic heteroaryl group is
Figure imgf000128_0001
1-C
wherein
Z1 , Z2, Z3 and Z4 are independently CR2 or N provided one of Z1 -Z4 is carbon and is bonded to the remainder of the molecule;
W1, W2 and W3 are independently CR4R4, S, SO, SO2, O, or N-R1; with the proviso that no S-S or 0-0 or S-O bond formation can occur to form the saturated ring system; t= 1 to 4; Y1 and Y2 are independently C or N;
R1 is H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl or mono or bicyclic saturated heterocycles, optionally substituted C5-C7 cycloalkyl, optionally substituted C3-C6 alkenyl, optionally substituted C3-C6 alkynyl with the proviso that neither the double bond nor the triple bond should be present at the carbon atom which is directly linked to N; optionally substituted C1-C6 perfluoroalkyl,
-S(O)p optionally substituted alkyl or aryl where p is 0-2, optionally substituted
-C=Oheteroaryl, optionally substituted -C=Oaryl, optionally substituted -C=O
(C1-C6) alkyl, optionally substituted -C=O(C5-C6)cycloalkyl, optionally substituted - C=O mono or bicyclic saturated heterocycles, optionally substituted C1-C6 alkylaryl, optionally substituted C1-C6 alkyl heteroaryl, optionally substituted aryl-C1-C6 alkyl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, -CONR6R7, -SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted -alkyl-O-alkyl-aryl, optionally substituted -alkyl-O-alkyl-heteroaryl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, optionally substituted C1-C6alkylaryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl, optionally substituted alkylaryloxyalkylamines, optionally substituted alkoxycarbonyl, optionally substituted aryloxycarbonyl, or optionally substituted heteroaryloxy carbonyl;
R2 is hydrogen, optionally substituted C1-C6 alkyl, optionally substituted C2- C6 alkenyl, optionally substituted C2-C6 alkynyl, halogen, cyano, N-R6R7, optionally substituted C1-C6 alkoxy, hydroxy; optionally substituted aryl, optionally substituted heteroaryl, COOR6, optionally substituted alkyl aryloxy alkylamines, optionally substituted aryloxy, optionally substituted heteroaryloxy, optionally substituted C3-C6 alkenyloxy, optionally substituted C3 -C6 alkynyloxy, C1-C6 alkylamino-C1-C6 alkoxy, alkylene dioxy, optionally substituted aryloxy-C1-C6 alkyl amine, C1-C6 perfluoro alkyl, S(O)q-optionally substituted C1-C6 akyl, S(O )q- optionally substituted aryl where q is O, 1 or 2, CONR6R7, guanidino or cyclic guanidino, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted C1- C6 alkylheteroaryl, optionally substituted heteroaryl-C1-C6 alkyl, optionally substituted C1-C6 alkyl mono or bicyclic saturated heterocycles, optionally substituted arylalkenyl of 8 to 16 carbon atoms, SO2NR6R7, optionally substituted arylalkyloxyalkyl, optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, optionally substituted aryloxyaryl, optionally substituted aryloxyheteroaryl, substituted heteroaryloxyaryl, optionally substituted C1-C6alkyl aryloxyaryl, optionally substituted C1-C6 alkylaryloxyheteroaryl , optionally substituted aryloxyalkyl, optionally substituted heteroaryloxyalkyl, or optionally substituted alkylaryloxyalkylamine;
R4 is H, optionally substituted C1-C6 alkyl, one of R4 is OH, C1-C6 alkoxy, -
S-C1-C6 alkyl, COOR6, -NR6R7, -CONR6R7 ; or R4R4 may together be =0 or R4R4 together with the carbon to which they are attached may form a spiro system of five to eight members with or without the presence of heteroatoms selected from N, O,
S=(O)n (where n =0 to 2), and N-R1; and R6 and R7 are independently H, optionally substituted C1-C6 alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C1-C6 alkylaryl, optionally substituted arylalkyl, optionally substituted heteroarylalkyl, optionally substituted C1-C6 alkylheteroaryl, or R6 and R7 can be together to form a 3-7 membered saturated ring system optionally having one or two heteroatoms selected from N, O, or S.
8. The method according to claim 2 wherein the β-lactam antibiotic is selected from the group consisting of a penicillin antibiotic, a carbapenem antibiotic, and a cephalosporin antibiotic.
9. The method according to claim 8 wherein the β-lactam antibiotic is selected from thegroup consisting of piperacillin, amoxycillin, ticarcillin, benzylpenicillins, ampicillin, sulbenicillin, cefatrizine, cephaloridine, cephalothin, cefazolin, cephalexin, cephradine, aztreonam, and latamoxef.
10. The method according to claim 9 wherein the β-lactam antibiotic is piperacillin or amoxycillin.
11. The method according to claim 10 wherein the β-lactam antibiotic is piperacillin and is provided to the patient intravenously.
12. The method according to claim 10 wherein the β-lactam antibiotic is amoxycillin and is provided to the patient orally.
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MX2007015172A (en) 2008-02-19
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US20060276445A1 (en) 2006-12-07
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KR20080016676A (en) 2008-02-21
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