AU736021B2 - Methods for the preparation of biphenyl isozaxole sulfonamides - Google Patents

Methods for the preparation of biphenyl isozaxole sulfonamides Download PDF

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AU736021B2
AU736021B2 AU65360/99A AU6536099A AU736021B2 AU 736021 B2 AU736021 B2 AU 736021B2 AU 65360/99 A AU65360/99 A AU 65360/99A AU 6536099 A AU6536099 A AU 6536099A AU 736021 B2 AU736021 B2 AU 736021B2
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Australia
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alkyl
substituted
salt
aryl
formula
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AU6536099A (en
Inventor
Jeffrey S Depue
Kumar G. Gadamasetti
Eduardo J. Martinez
Chennagiri R. Pandit
Yadagiri Pendri
Richard P. Polniaszek
Xuebao Wang
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Bristol Myers Squibb Co
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Bristol Myers Squibb Co
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AUSTRALIA
Patents Act COMPLETE SPECIFICATION
(ORIGINAL)
Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: e Name of Applicant: Bristol-Myers Squibb Company Actual Inventor(s): YADAGIRI PENDRI, KUMAR G GADAMASETTI, EDUARDO J MARTINEZ, RICHARD P POLNIASZEK, XUEBAO WANG, JEFFREY S DEPUE, CHENNAGIRI R PANDIT Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: METHODS FOR THE PREPARATION OF BIPHENYL ISOXAZOLE SULFONAMIDES Our Ref: 604893 POF Code: 140109/140109 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- If METHODS FOR THE PREPARATION OF BIPHENYL ISOXAZOLE SULFONAMIDES The present application is a divisional application from Australian patent application number 19737/97, the entire disclosure of which is incorporated herein by reference.
Field of the Invention Australian patent application 19737/97 (the "parent application") relates to methods for the preparation of biphenyl isoxazole sulfonamides and intermediates thereof. The biphenyl isoxazole sulfonamides are endothelin antagonists useful, inter alia, for the treatment of hypertension. The present *o invention relates to methods of preparing these intermediates and the S 15 intermediates themselves.
Brief Description of the Invention The parent application described the preparation of biphenyl 20 sulfonamides of the following formula I: S•
(I)
-O
N H 1
Y
R
3
R
4 where the phenyl rings of the biphenyl group may independently be unsubstituted or substituted with one or more substituent groups, enantiomers and diastereomers, and salts, preferably pharmaceutically acceptable salts, thereof. Preferred substituent groups for the biphenyl group include those groups R 11 to R 14 described herein and especially, when the biphenyl group is a 2-biphenyl group, the group R1 K- in the 4'-position.
R
2 (H2)J C:\My Documents\ALISONSPECI\Divisional for 19737-97 BMS.doc 4 4, Preferred methods described in the parent application allow preparation of compounds of the following formula Ia:
R
1
K
(CH2)
R
2 (Ia) 0 s
R
1 4 R 3
R
4 enantiomers and diastereomers, and salts, preferably pharmaceutically acceptable salts, thereof. Throughout this specification, the above symbols are defined as follows: one of X and Y is N and the other is O;
R
1
R
2
R
3 and R 4 are each directly bonded to a ring 20 carbon and are each independently ooo hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with
Z
1
Z
2 and Z 3 halo; hydroxyl; cyano; nitro; -C(O)H or -C(O)R 5 -CO2H or -C02R 5
-Z
4
-NR
6
R
7 -Z4-N(R 1 0)-Z5-NR 8
R
9 or
R
3 and R 4 together may also be alkylene or alkenylene, either of which may be substituted C:My Documents\ALISONSPECIDvisional for 19737-97 BMS.doc 4 with Z 1
Z
2 and Z 3 completing a 4- to 8membered saturated, unsaturated or aromatic ring together with the carbon atoms to which they are attached;
R
5 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z 1
Z
2 and Z3;
R
6
R
7
R
8
R
9 and R 10 are each independently hydrogen; or alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z1, Z 2 and Z 3 or
R
6 and R 7 together may be alkylene or alkenylene, either of which may be substituted with Z 1
Z
2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; or any two of R 8
R
9 and R 10 together are alkylene or alkenylene, either of which may be substituted with Z 1
Z
2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached;
R
11
R
12
R
13 and R 14 are each independently hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 1
Z
2 and Z 3 heterocycle, substituted heterocycle or heterocyclooxy; halo; hydroxyl; cyano; nitro; -C(O)H or -C02H or -C02R 5 -SH, -S(0)nR 5 -S(O)m-OH, -S(0)m-0R 5 -O-S(0)m-0R 5 0 S(O)mQH or -0-S (0)m-0R 5
-Z
4
-NR
6
R
7 or
-Z
4 -N(RlO)-z5-NR8R9.
Zl, Z 2 and Z 3 are each independently hydrogen; halo;.
hydroxy; alkyl; alkenyl; aryl; aralkyl; alkoxy; aryloxy; aralkoxy; heterocycle, substituted heterocycle or heterocyclooxy; -SH, -S(O)nZ 6 -S(O)m-OH, -S(0)m-0Z 6 -0-S(0)m-Z 6 O0S(O)mOH or -SOmZ6 (in) OXO; nitro; cyano; -C H or -C Z 6 -CO2H or -C02Z 6
-Z-NZ
7
Z
8
-Z
4 -N(Zll)-ZS-H;
-Z
4 -N(Zll)-Z5-Z6; or
-Z
4 -N(Zll) -Z 5
-NZ
7
Z
8
Z
4 and Z 5 are each independently a single bond;
-Z
9 S(0)n-Zlo-; z -1 z -1
Z
9 or
-Z
9 -C(0)-O-Z 1 0-;
Z
6 is alkyl; alkyl substituted with one to three groups selected from halogen, aryl, aryloxy and alkoxy; alkenyl; alkynyl; cycloalkyl; cycloalkyl substituted with one to three groups selected from alkyl, aryl, alkenyl and alkoxyaryl; cycloalkyl to which is fused a benzene ring; aryloxy substituted with one or two halogens; cycloalkylalkyl; cycloalkenyl; cycloalkenylalkyl; aryl; aryl substituted with methylenedioxy or one to four groups selected from alkyl, dialkylamino, cyano, halogen, trihaloalkyl, alkoxy and trihaloalkoxy; or heterocycle or substituted heterocycle;
Z
7 and Z 8 are each independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or 15 aralkyl, or Z 7 and Z 8 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached;
Z
9 and Z 10 are each independently a single bond, alkylene, alkenylene or alkynylene; Zll is hydrogen; or alkyl, alkyl substituted with one, two or three halogens, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl; or any two of Z 7
Z
8 and Z 11 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached; J is O, S, N or K and L are N or C, provided that at least one of K or L is C;
R
15 is hydrogen, alkyl, hydroxyethoxy methyl or methoxyethoxy methyl; each m is independently 1 or 2; each n is independently 0, 1 or 2; and p is 0 or an integer from 1 to 2.
As described in the parent application, a compound of the formula I or salt thereof may be prepared by a method comprising the steps of: contacting a pinacol ester of the formula II or salt thereof:
(II)
oooo oooo oo ooo g o oo oo
R
3
R
4 15 where the phenyl ring of said formula II may be further substituted, such as with one or more groups described for the groups R 11 to R 14 herein, with a halophenyl compound of the formula III or salt thereof: halo
(III)
where the phenyl ring of said formula III may be further substituted, such as with one or more groups described for the groups R 11 to R 14 herein, and especially, when the biphenyl group of said compound of the formula I or salt R1
K
L (CH 2
)P-
thereof is a 2-biphenyl, the group R J para to the halo group, in the presence of a palladium(0) catalyst and, preferably, a base, to form a nitrogenprotected compound of the formula IV or salt thereof: C: y Documents\ALISON\SPECIDivsional for 19737-97 BMS.doc \4 x (IV) N
Y
s p rot
R
3
R
4 where the phenyl rings of the biphenyl group may independently be unsubstituted or substituted with one or more substituent groups; and deprotecting the nitrogen of said compound of the formula IV or salt thereof to form said compound of the oo ^formula I or salt thereof.
"Prot", as used in formula II and throughout this 15 specification, denotes a nitrogen-protecting group, which may be any suitable nitrogen-protecting group such as 2ethoxyethyl, 2-methoxypropyl, methoxyethoxymethyl or those described in European Patent Application Publication No.
569,193 (1993), incorporated herein by reference, and is preferably methoxyethoxymethyl The halo group in 20 formula III is preferably bromo or iodo, most preferably iodo.
SIn a preferred embodiment described in the parent application, a a* compound of the formula Ia or salt thereof may be prepared by a method comprising the steps of: contacting a pinacol ester of the formula IIa or salt thereof: C:\y DocmentsvALISONSPECI\Divsional for 19737-97 BMS.doc (Iha) with a halopheny. compound of the formula Il~a or salt thereof: *4e* 4* a .4 1 0 *0 00 0
CS
S 0 *000 Stt 0* a .4 0* I at, a 4 00 0*0*c* 0* 0 00
OS
(CH
2
P
(IIla) halo in the presence of a palladium(O) catalyst and, preferably, a base, to form a nitrogen-protected compound of the formula IVa or salt thereof:.
L
-(CH
2 )p R" R12(IVa) 1 3 0 S0 r Prot
R
3 4 n deprotecting the nitrogen of said formula IVa compound or salt thereof to form said compound of the formula la or salt thereof.
The present application is directed to a method for the preparation of an oxazole phenyl halide of the formula II1a(1) or salt thereof: 0/N R1 R12(IIIa halo wherein
R
1 and R 2 are.e each independently hydrogen; alkyl1, alkenyl, alkynyl, alkoxy, cycloalkyl, ycloalkylalkyl, cycloalkenyl., cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with
Z
1
Z
2 and Z 3 halo; hydroxyl; cyano; nitro; -C(0)H or -CO2H or -C02R 5 Wi -z 4
-NR
6
R
7 or C:VWy Doc ents'ALgSONWSPECIl\ivtionaI for 19737-97 8MS.doc
-Z
4
-N(R
10
)-Z
5
-NR
8
R
9
R
5 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z1, Z 2 and Z3;
R
6
R
7
R
8
R
9 and R 10 are each independently hydrogen; or alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z 1
Z
2 and Z 3 or
R
6 and R 7 together may.be alkylene or alkenylene, either of which may be substituted with ZI, Z 2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; or any two of R 8
R
9 and R 10 together are alkylene or alkenylene, either of which may be substituted with Z 1
Z
2 15 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached;
R
1 1 and R 12 are each independently hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 1
Z
2 and Z 3 heterocycle, substituted heterocycle or heterocyclooxy; halo; hydroxyl; cyano; nitro; -C(O)H or -C(O)R 5 -C02H or -C02R 5 -SH, -S(O)nR 5 -S(O)m-OH, -S(O)m-OR 5 -O-S(O)m-OR 5 -O-S(O)mOH or -O-S(0)m-OR 5 C:\My Documents\ALISON\SPECIDivisional for 19737-97 BMS.doc
-Z
4
-NR
6
R
7 or
-Z
4 -N(Rl 0
)-Z
5
-NR
8 R9; Z1, Z 2 and Z 3 are each independently hydrogen; halo; hydroxy; alkyl; alkenyl; aryl; aralkyl; alkoxy; aryloxy; aralkoxy; heterocycle,,substituted heterocycle or heterocyclooxy; -SH, -S(O)nZ 6 -S(O)m-OH, -S(O)rn-0Z 6 0O-S(O)m-Z 6 O0S(O)mQH or -Q-S(O)m-0Z 6 oxo; nitro; cyano; -C(O)H Oc -C(O)Z 6 -CO2H or -C02Z 6 20(r)
-Z
4
-NZ
7
Z
8 -4N Z l
-Z
4 -N(Zll)-Z5-Z6; or -4NZl-5N78
Z
4 and Z 5 are each independen tly a single bond;
-Z
9 -S(O)n-Zl 0 -9C O -1 -9C S -1 z 1 z -1
-Z
9 -O--C(O)-Zl 0 or
-Z
9
-C(Q)-O-Z
10
Z
6 is alkyl; alkyl substituted with one to three groups selected from halogen, aryl, aryloxy and alkoxy; C:WY DooMenIsALISON\SPECIMDMsional for 19737.97 BMS.doc alkenyl; alkynyl; cycloalkyl; cycloalkyl substituted with one to three groups selected from alkyl, aryl, alkenyl and alkoxyaryl; cycloalkyl to which is fused a benzene ring; aryloxy substituted with one or two halogens; cycloalkylalkyl; cycloalkenyl; cycloalkenylalkyl; aryl; aryl substituted with methylenedioxy or one to four groups selected from alkyl, dialkylamino, cyano, halogen, trihaloalkyl, alkoxy and trihaloalkoxy; or heterocycle or substituted heterocycle;
Z
7 and Z 8 are each independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl -or aralkyl, or Z 7 and Z 8 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or uhsaturated ring together with the nitrogen atom to which they are attached;
Z
9 and Z 10 are each independently a.single bond, alkylene, alkenylene or alkynylene; 15 Zll is hydrogen; or alkyl, alkyl substituted with one, two or three halogens, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl; S or any two of Z 7
Z
8 and Z 11 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached; each m is independently 1 or 2; and each n is independently 0, 1 or 2; comprising the steps of: contacting a phenyl acid halide X or salt thereof: 0 halo
R
11
-R
12 halo C:\My DocumentslALISONMSPECtDivisional for 19737-97 BMS.doc wi"th an amine acetal XI or salt thereof:
R
2
H
2 N 0 -alkyl
(XI)
0-alkyl in the presence of a base and a solvent, to form an amide acetal of the formula XII or salt thereof: 0-alkyl alkyl 2
R
2 0
NH
(XII)
R
1 1 LR12 halo ,and cyclizing the amide acetal of the formula XII or .:salt thereof, in the presence of a cyclization agent, to form said oxazole phenyl halide of the formula II1a(l) or salt thereof.
C:Wy Doc.MenSILISONSPECR'fMsional for 19737-97 BMSAdo 14 Detailed Description of the Invention The present invention is described further as follows.
Listed below are definitions of terms used in this specification. These definitions apply to the terms as used throughout this specification, individually or as part of another group, unless otherwise indicated in specific instances.
Throughout the description and claims of this specification, the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.
The term "alkyl" or'"alk-" refers to straight or branched chain hydrocarbon groups having 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms. The expression 15 "lower alkyl" refers to alkyl groups of 1 to 4 carbon atoms.
The term "alkoxy" refers to alkyl-O-.
The term "aryl" or refers to phenyl, naphthyl and biphenyl.
20 The term "alkenyl" refers to straight or branched chain hydrocarbon groups of 2 to 10 carbon atoms having at least one double bond. Groups of two to four carbon atoms are preferred.
The term "alkynyl" refers to straight or branched chain groups of 2 to 10 carbon atoms having at least one triple bond. Groups of two to four carbon atoms are preferred.
The term "alkylene" refers to a straight chain bridge of 1 to 5 carbon atoms connected by single bonds C:\My Documents\ALISON\SPECDivisional for 19737-97 BMS.doc (CH2)x- wherein x is 1 to which may be substituted with 1 to 3 lower alkyl groups.
The term "alkenylene" refers to a straight chain bridge of 2 to 5 carbon atoms having one or two double bonds that is connected by single bonds and may be substituted with 1 to 3 lower alkyl groups. Exemplary alkenylene groups are -CH=CH-CH=CH-, -CH2-CH=CH-, -CH2-CH=CH-CH 2 -C(CH3)2CH=CH- and The term "alkynylene" refers to a straight chain bridge of 2 to 5 carbon atoms that has a triple bond therein, is connected by single bonds, and may be substituted with 1 to 3 lower alkyl groups. Exemplary alkynylene groups are -CH(CH3)-C=Cand C-CH(C2H5)CH 2 .15 The term "alkanoyl" refers to groups of the formula -C(O)alkyl.
The terms "cycloalkyl" and "cycloalkenyl" refer to cyclic hydrocarbon groups of 3 to 8 carbon atoms.
The term "hydroxyalkyl" refers to an alkyl group including one or more hydroxy radicals such as -CH2CH20H, CH2CH20HCH20H, -CH(CH20H) 2 and the like.
The terms "halogen" and "halo" refer to fluorine, chlorine, bromine and iodine.
The terms "heterocycle", "heterocyclic" and 25 "heterocyclo" refer to an optionally substituted, fully saturated or unsaturated, aromatic or nonaromatic cyclic group, for example, which is a 4 to 7 membered monocyclic, 7 to 11 membered bicyclic, or 10 to 15 membered tricyclic ring system, which has at least one heteroatom in at least one carbon atom-containing ring. Each ring of the heterocyclic group containing a heteroatom may have 1, 2 or 3 heteroatoms selected from nitrogen atoms, oxygen atoms or sulfur atoms, where the nitrogen and sulfur heteroatoms may optionally be oxidized and the nitrogen heteroatoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom.
Exemplary monocyclic heterocyclic groups include pyrrolidinyl, pyrrolyl, pyrazolyl, oxetanyl, pyrazolinyl imidazolyl, imidazolinyl, imidazolidinyl, oxazolyl, oxazolidinyl, isoxazolinyl, isoxazolyl, thiazolyl, thiadiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, furyl, tetrahydrofuryl, thienyl, oxadiazolyl, piperidinyl, piperazinyl, 2 -oxopiperazinyl, 2 -oxopiperidinyl, 2-oxopyrrolodinyl, 2 -oxoazepinyl, azepinyl, 4-piperidonyl, pyridyl, pyrazinyl,- pyrimidinyl, pyridazinyl, tetrahydropyranyl, morpholinyl, thiamorpholinyl, thiaxnorpholinyl sulf oxide, thiamorpholinyl sulf one, 1, 3-dioxolane and tetrahyiro-l, 1-dioxothienyl, and the like.
Exemplary bicyclic heterocyclic groups include indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, *quinuclid inyl, quinolinyl, tetra-hydroisoquinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl, indolizinyl, benzofuryl, chronionyl, coumarinyl, benzopyranyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridyl, furopyridinyl (such as furo[2,3-clpyridinyl, furo(3, 2-bipyridinyl] or furo[2, 3-blpyridinyl), dihydroisoindolyl, dihydroquinazolinyl (such as 3, 4-dihydro-4oxo-quinazolinyl), tetrahydroquinolinyl and the like.
Exemplary tricyclic heterocyclic groups include carbazolyl, benzidolyl, phenanthrolinyl, acridinyl, phenanthridinyl, xanthenyl and the like.
The expression "substituted heterocycle" refers to a heterocycle substituted with 1, 2 or 3 of the following: alkyl, especially lower alkyl; hydroxy (or protected hydroxcy); halo; oxo 0); amino, alkylaxnino or dialkylamino; alkoxy; carbocyclo, such as cycloalkyl; carboxy; heterocyclooxy; alkoxycarbonyl, such as unsubstituted lower alkoxycarbonyl; carbamyl, alkylcarbamyl or dialkylcarbamyl; mercapto; nitro; cyano; carboalkoxy; sulfonamido, sulfonamidoalkyl or sulfonamidodialkyl; O R SR5-C--N
II
0 R 6 15S
R
5 -S0 2 (r)
R
R
6 aryl; alkylcarbonyloxy; arylcarbonyloxy; arylthio; aryloxy; alkylthio; formyl; arylalkyl; or aryl substituted with alkyl, cycloalkyl, alkoxy, hydroxy, amino, alkylamino, dialkylamino, halo or trihaloalkyl.
The term "heterocyclooxy" denotes a heterocyclic group bonded through an oxygen bridge.
Throughout the specification, groups and substituents thereof may be chosen to provide stable moieties and compounds.
The intermediates of the compounds of formula I may form salts which are also within the scope of this invention. Pharmaceutically acceptable (i.e.
non-toxic, physiologically acceptable) salts are preferred, although C:\My Documens\ALISONSPECIDivisional for 19737-97 BMS.doc other salts are also useful, for example, in isolating or purifying the compounds of this invention.
The intermediates of the compounds of formula I may form salts with alkali metals such as sodium, potassium and lithium, with alkaline earth metals such as calcium and magnesium, with organic bases such as dicyclohexylamine, t-butyl amine, benzathine, N-methyl-D-glucamide and hydrabamine, and with amino acids such as arginine, lysine and the like. Such salts may be obtained by reacting these compounds with the desired ion in a medium in which the salt precipitates or in an aqueous medium followed by lyophilization.
When groups such as the R 1 to R 4 or R 11 to R 14 substituents comprise a basic moiety, such as amino or substituted amino, the intermediates of the compounds of formula I may form salts with a variety of organic and inorganic ,acids. Such salts include those formed with hydrochloric acid, hydrogen bromide, methanesulfonic acid, sulfuric acid, acetic acid, maleic acid, benzenesulfonate, toluenesulfonate and various other sulfonates, nitrates, phosphates, borates, acetates, tartrates, maleates, citrates, succinates, benzoates, ascorbates, salicylates and the like. Such salts may be formed by reacting these compounds in an equivalent amount of the acid in a medium in which the salt precipitates or in an aqueous medium followed by lyophilization.
t In addition, when groups such as the R 1 to R 4 or R 11 to R 14 substituents comprise a basic moiety such as amino, zwitterions ("inner salts") may be formed.
Certain groups such as the R 1 to R 4 and R 11 to R 14 substituents of the compounds of the invention may contain asymmetric carbon atoms. The compounds of the invention and salts thereof may exist, therefore, in enantiomeric and diastereomeric forms and in racemic mixtures thereof. All are within the scope of this invention. Additionally, the compounds and salts thereof may exist as enantiomers even C:\My Documents\LISON\SPECI\Divisional for 19737-97 BMS.doc in the absence of asymmetric carbons. All such enantiomers are within the scope of this invention.
U.S. Patent Application Serial No. 08/493,331, filed July 24, 1995 (Attorney Docket No. HA662c) by Murugesan et al. and continuation-in-part thereof U.S. Patent Application Serial No. 08/603,975, filed February 20, 1996 (Attorney Docket No. HA662d) by Murugesan et al., entitled "Substituted Biphenyl Isoxazole Sulfonamides", describing endothelin antagonists, starting materials and methods, are each incorporated herein by reference in its entirety.
Coupling of Formulae II and III Compounds.
and Deprotection As described in the parent application, a compound of the formula I or 15 salt thereof may be prepared by coupling a pinacol ester of the formula II or salt thereof with a halophenyl compound of the formula III or salt thereof, and by deprotecting the nitrogen-protected compound IV or salt thereof formed by the aforementioned coupling.
20 Coupling of compounds of the formulae II and III or salts thereof is conducted in the presence of a palladium(0) catalyst, preferably palladium acetate/triphenylphosphine or other palladium
(II)
salt/triphenylphosphine, tetrakisphenylphosphine palladium or tris(dibenzylideneacetone)dipalladium, and, preferably, o a base, preferably aqueous potassium carbonate or sodium carbonate, to form a nitrogen-protected compound of the formula IV or salt thereof. The preferred molar ratio of palladium (II) salt to triphenylphosphine is between 1:1 and 1:3. See the conditions for catalysis described by A.
Suzuki et al., Pure Applied Chemistry, 63, 419-422 (1991); A. Martin et al., Acta. Chem. Scand., 47, 221 (1993); H. Jendralla et al., Liebig Ann., 1253 (1995), all incorporated herein by reference.
When the halophenyl compound III is a compound IIIa, protection of the heteroatoms J and K or L may be desirable, in certain instances, to facilitate the coupling reaction. For example, when J and K or L are N, one of the groups may be protected by a suitable protecting group such as t-butoxycarbonyl, etc. Specific R 11
R
1 4 groups may be chosen to be compatible with the reaction conditions.
Additionally, specific Rll R 14 groups may be converted into alternative Rll R 1 4 groups, either before or after coupling, using any suitable methods such as those known in the art.
The coupling method is preferably conducted at a temperature of from about 25°C to about 100°C (most preferably from about 45°C to about 75°C), at a pressure of about 1 atm, and under an atmosphere of argon or nitrogen.
Molar ratios of the pinacol ester II or salt thereof to the 5halophenyl compound III or salt thereof are preferably from 15 about 1:1 to about 1:1.2. Amounts of palladium(0) catalyst and base are selected to catalyze the coupling reaction and are preferably from about 2.5 mol% to about 10 mol%, and from about 2.5 equivalents to about 7 equivalents, respectively. Solvents are preferably employed which are 20 selected from aqueous or organic liquids such as acetone, ethanol, toluene, tetrahydrofuran, dimethoxyethane and water, or mixtures thereof, preferably a mixture of toluene 0 and ethanol. Amounts of solvent are preferably those wherein the pinacol ester II or salt thereof is from about 4 to about 9% by weight, based on the combined weight of solvent and pinacol ester II or salt thereof. For example, the following are exemplary ranges for solvent/pinacol ester II/base: tetrahydrofuran (30 to 70 mL), toluene (100 to 200 mL), ethanol (80 to 160 mL)/pinacol ester II (15 to 20 g)/aqueous 2M sodium carbonate (100 to 150 mL).
Residual palladium catalyst is preferably removed, either before or after deprotection of the compound of formula IV or salt thereof, by contact with a chelating agent such as trithiocyanuric acid Crystallization providing a suitable crystalline form of the compound of the formula I or salt thereof, subsequent to deprotection of the compound of the formula IV or salt thereof, is also contemplated by the present invention.
Preferably, crystallization is achieved from a supersaturated ethanolic solution, with or without the presence of co-solvents such as heptane or water, especially where seeded with the desired crystalline form.
Most preferably, crystallization is conducted by the methods of the Examples herein.
Compounds of the formula III and salts thereof may be prepared by methods analogous to those described in U.S.
Patent Application Serial No. 08/493,331 and the aforementioned continuation-in-part thereof. Preferably, 1 oxazole compounds of the formula IIIa or salts thereof are 15 prepared by the novel methods for their preparation described herein. Compounds of the formula II and salts S. thereof are preferably prepared by the novel methods for their preparation described herein.
Deprotection of the formula IV compound or salt 20 thereof formed by the present coupling method may be conducted by any suitable method, such as methods analogous to those described in U.S. Patent Application Serial No.
08/493,331 and the aforementioned continuation-in-part thereof. Preferably, when "prot" is MEM, deprotection is conducted by heating in a mixture of aqueous HC1 and ethanol.
Preparation of Formula II Compounds As described in the parent application, the pinacol esters of the formula II and salts thereof may themselves be formed by novel methods provided herein.
In accordance herewith, a pinacol ester of the formula II or salt thereof may be prepared by a method comprising the steps of: contacting a compound of the formula V or salt thereof: C:\My DocumentsALISONSPECI\Divisional for 19737-97 BMS.doc halo OS
'N
leaving group where the phenyl group of said formula V may be further substituted, such as with one or more groups described for the groups R 11 to R 14 herein, and where halo is preferably bromo, chloro or iodo, most preferably bromo, with an amine of the formula VI or salt thereof:
H
2 NY
(VI)
/Y
R
3
R
4 in the presence of an organic base and an organic solvent, to form a compound of the formula VII or salt thereof: a.
halo O ,0 H 0S X\ S NNHY
'NI
(VII)
where the phenyl group of said formula VII may be further substituted, such as with one or more groups described for the groups R11 to R 14 herein; protecting the nitrogen of said compound of the formula VII or salt thereof to form a compound of the formula VIII or salt thereof: halo 0
SN
'N
prot
R
3
R
4
(VIII)
where the phenyl group of said formula VIII may be further substituted, such as with one or more groups described for the groups
R
11 to R 14 herein; lithiating said compound of the formula VIII or salt thereof with an alkyl or aryl lithium compound and contacting the lithiated product formed with a trialkylborate, followed by hydrolysis, to form a boronic acid of the formula IX or salt thereof:
(HO)
2 B o /0 .XS X\ (IX) pro t
R
where the phenyl group of said formula IX may be further substituted, such as with one or more groups described for the groups
R
11 to R 14 herein; and contacting said compound of the formula IX or salt thereof with pinacol 2,3-dimethyl-2,3butanediol), with removal of water, thereby forming said compound of the formula II or salt thereof.
In a preferred embodiment described in the parent application, a pinacol ester of the formula I I a or salt thereof may be prepared by a method comprising the steps of: contacting a compound of the formula Va or salt thereof: halo 1 S leaving group (Va) R"4 R14 with an amine of the formula VIa or salt thereof:
H
2
N
(VIa) 3 R 4 in the presence of an organic base and organic solvent, to form a compound of the formula VIIa or salt thereof: halo (VIIa) protecting the nitrogen of said compound of the formula VIIa or salt thereof to form a compound of the 10 formula VIIIa or salt thereof: halo 1 °x N
N
R
13 I prot
R
14
R
3 R4 (VIIIa) lithiating said compound of the formula VIIIa or salt thereof with an alkyl or aryl lithium compound and contacting the lithiated product formed with a trialkylborate, followed by hydrolysis, to form a boronic acid of the formula IXa or salt thereof:
(HO)
2
B
I prot
R
3
R
4 (IXa) and contacting said compound of the formula IXa or salt thereof with pinacol, with removal of water, thereby forming said compound of the formula IIa or salt thereof.
The term "leaving group", as used herein, denotes any suitable leaving group such as a halo group, preferably chloro. Any suitable organic base may be employed in step Preferred organic bases include amines such as pyridine or a trialkylamine. The organic solvent employed in step is preferably a haloalkane, such as dichloromethane or 1, 2 -dichloroethane, or the organic base, such as neat pyridine, may also function as the solvent.
As described above, compounds of the formula VIII and salts thereof may be prepared by contacting a compound of the formula V or salt thereof with an amine compound of the 15 formula VI or salt thereof, and by protecting the nitrogen of the product compound VII or salt thereof. The formula VIII compound or salt thereof obtained is then lithiated with an alkyl or aryl lithium compound, preferably with n-butyl lithium or phenyl lithium, at temperatures which 20 are preferably from about -40 0 C to about -105 0
C
(especially, from about -70 0 C to about -100 0 to form the compound: Li 0
O
*.N
Sprot
R
3
R
4 where the phenyl group of said compound may be further substituted, such as with one or more groups described for the groups R11 to R 14 herein, or salt thereof, preferably the compound: Li
XN
R3 prot
R
1 4 R 3 R4 or salt thereof. Treatment of the lithiated compound or salt thereof with a trialkylborate such as triisopropylborate or, preferably, trimethylborate, at temperatures which are preferably from about -40°C to about -105°C (especially, from about -70°C to about -100°C), provides the following boronate ester: (alkyl-O) 2 B 0 prot
R
3
R
4 .o 10 where the phenyl group of said compound may be further oo. substituted, such as with one or more groups described for the groups R 1 1 to R 14 herein, or salt thereof, preferably the boronate ester: (alkyl-O) 2
B
8N y t pro f R prot 14^ 15 R 1 4 R3 R4 or salt thereof, which may then be hydrolyzed with a suitable acid, preferably an aqueous acid such as aqueous hydrochloric acid, or with a suitable base, to form the boronic acid IX or salt thereof. The hydrolysis step, forming the boronic acid IX or salt thereof, is advantageous as the boronic acid possesses enhanced stability relative to the boronate ester from which it is obtained. The aforementioned steps may be conducted by methods analogous to those described in, and with starting materials of the formulae V and VI and salts thereof prepared by methods analogous to those described in, European Patent Application Publication No. 569,193 (1993) and in U.S. Patent Application Serial No. 08/493,331 and the aforementioned continuation-in-part thereof.
The boronic acid IX or salt thereof may then be contacted with pinacol, with the removal of water, to form the corresponding pinacol ester II or salt thereof.
Removal of water may be conducted, for example, by the addition of a drying agent such as magnesium sulfate or by azeotropic removal of water by heating with a solvent such as toluene. This reaction is preferably conducted at a temperature of from about 110 0 C to about 120°C (most preferably from about 112 0 C to about 115 0 at a pressure of about 1 atm, and under an atmosphere of argon or nitrogen. Molar ratios of pinacol to the boronic acid IX or salt thereof are preferably from about 1:1 to about 15 1.1:1. Solvents are preferably employed which are selected from organic liquids such as toluene. Amounts of solvent are preferably those wherein the boronic acid IX or salt thereof is from about 4 to about 10% by weight, based on the combined weight of solvent and boronic acid IX or salt *20 thereof.
The boronic acid IX or salt thereof (preferably, the preferred boronic acid IXa or salt thereof) may be directly coupled with the halophenyl compound III or salt thereof to form a formula IV compound or salt thereof. This method, *6 25 especially where the halophenyl compound III or salt thereof is an iodophenyl compound III or salt thereof (preferably, an iodophenyl compound IIIa or salt thereof), is also contemplated by the present invention. The pinacol ester II or salt thereof in place of the boronic acid IX or salt thereof may be advantageous, however, as the pinacol ester compounds are highly stable, and lesser amounts of impurities may be formed and higher yields of the formula IV compound or salt thereof may be obtained upon coupling with a halophenyl compound III or salt thereof.
Preparation of Formula 111a(1) Compounds Compounds of the formula 111a and salts thereof bearing an oxazole ring may be formed by novel methods provided herein. In accordance herewith, a formula HIIa(1) oxazole or salt thereof may be prepared by a method comprising the steps of: (a) thereof: contacting a phenyl acid halide X or salt halo with an amine acetal XI or salt thereof:
H
2 N 0-alkyl 0-a lkyl
(XI)
in the presence of a base and a solvent, to form an amide acetal of the formula XII or salt thereof: CAlMy Docoments\ALISON\lSPECrflMsiona1 for 19737-97 BMSAdo 0-alkyl alkyl-O
R
O. ,NH
(XII)
halo and *9 9 *c 9.
99 cyclizing the amide acetal of the formula XII or salt thereof, in the presence of a cyclization agent, to 5 form an oxazole phenyl halide of the formula IIIa(1) or salt thereof:
R
2
R
1 R'
N
0 /N
R
1 1 R12 halo (IIIa(1)) The starting phenyl acid halide X or salt thereof is commercially available or may readily be prepared by one of ordinary skill in the art. The halo group of the acid halide moiety is preferably chloro; the halo group in the position para to the acid halide moiety is preferably bromo, chloro, or iodo, most preferably iodo. The starting amine acetal XI or salt thereof is also commercially available or may readily be prepared by one of ordinary skill in the art. The alkyl groups of the acetal moiety are preferably methyl or ethyl, most preferably, methyl.
The base employed in step may be any suitable base, and is preferably an alkali metal carbonate, bicarbonate or hydroxide, most preferably, potassium bicarbonate (in a solvent such as water and/or acetone) or potassium carbonate (in a solvent such as methylene chloride).
Cyclization is conducted by contacting the amide acetal XII or salt thereof with a cyclization agent which may be any compound effecting the cyclization reaction, and is preferably Eaton's reagent methanesulfonic acid and phosphoric oxide) or polyphosphoric acid (PPA), most preferably Eaton's reagent. The cyclization is preferably conducted at a temperature of from about 125 0 C to about 150 0 C (most preferably from about 130 0 C to about 135 0 at 15 a pressure of about 1 atm, and under an atmosphere of argon or nitrogen. Amounts of cyclization agent are selected to achieve cyclization and are preferably from about 4* (catalyst/substrate) 8 mL/g to about 15 mL/g when Eaton's reagent is employed. Eaton's reagent is a solution of P205 in methanesulfonic acid and can also function as a 20 preferred solvent for the cyclization. Exemplary compositions for Eaton's reagent are those containing U to 15% by weight P205 in methanesulfonic acid.
As described in the parent application, the compounds of the formula Ilia and salts thereof may also be used in a further method ("reverse coupling") for the preparation of compounds of the formula la or salts thereof, comprising the steps of: lithiating a compound of the formula Ilia or salt thereof: C:\My Documents\ALISONSPECDivisional for 19737-97 BMS.doc oo o o
R
1
K
L (CH2) P
R
2 R11 (IIIa),
R
1 R12 halo preferably, a compound of the formula IIIa(l) or salt thereof, with an alkyl or aryl lithium compound in the presence of a trialkylborate, followed by hydrolysis, to form a boronic acid of the formula XIII or salt thereof: R2/L'D
(CH
2 )p R n
(XIII);
B(OH)
2 D contacting the boronic acid of the formula XIII or salt thereof with a compound of the formula VIIIa or salt thereof: halo N- Y (VIIIa) R13 I prot
R
1 4 R 3
R
4 where halo is preferably bromo, iodo or chloro, most preferably bromo, in the presence of a palladium(0) catalyst and, preferably, a base, to form a nitrogenprotected compound of the formula IVa or salt thereof:
R
1
K
L
R2
X
prot
R
3
R
4 (IVa); and deprotecting the nitrogen of said formula IVa compound or salt thereof to form said compound of the formula Ia or salt thereof.
With respect to this method, lithiation is conducted in the presence of a trialkylborate, followed by hydrolysis which may be conducted under conditions as described herein for the preparation of boronic acids of the formula IX and salts thereof. Coupling in the presence of a palladium(0) catalyst and, preferably, base, and deprotection of the nitrogen-protected coupled product, may be conducted under conditions as described herein for the coupling of compounds of the formulae II and III and salts thereof, and deprotection of the product thereof. Lithiation provides a compound having the following structure or a salt thereof:
R
1
K
L (CH2) p
R
11 R12 Li contact with a trialkylborate provides the following boronate ester or a salt thereof:
R
1
K
R2 R1 R12 B(O-alkyl) 2 Preferred ComDounds It is preferred that the compounds employed in or prepared by the present methods contain one or more, preferably all where appropriate, of the following substituents: X is 0 and N is Y; 10 the ring bearing K, L and J is 2 -oxazole; p is zero;
R
1 and R 2 are each independently hydrogen, alkyl, alkoxy, aryl, hydroxyalkyl, -C02R 5 or -Z 4
-NR
6
R
7 most preferably lower alkyl or hydrogen; R3 and R4 are each independently alkyl, most preferably lower alkyl, especially methyl; and
R
11 R12 R13 and R 1 4 are each independently hydrogen, hydroxy, amino, heterocyclo, alkenyl, alkoxy, carboxamide Sor substituted lower alkyl, most preferably,
R
1 2 to R 1 4 are 20 hydrogen and R 11 is hydrogen, hydroxy, amino, heterocyclo, alkenyl, alkoxy, carboxamide or substituted lower alkyl.
Compounds of interest include those, inter alia, wherein at least one of to (iv) applies: at least one of R 11
R
12
R
13 or R 14 is heterocycle, substituted heterocycle or heterocyclooxy; (ii) at least one of Z 1
Z
2 or Z 3 is aryl, heterocycle, substituted heterocycle or heterocyclooxy; (iii) Z 6 is alkyl substituted with one to three groups selected from halogen, aryl, aryloxy and alkoxy, wherein at least one substituent is other than aryl; alkyl substituted with two or three aryl groups; cycloalkyl substituted with one to three groups selected from alkyl, aryl, alkenyl and alkoxyaryl; cycloalkyl to which is fused a benzene ring; aryloxy substituted with one or two halogens; aryl substituted with methylenedioxy; aryl substituted with one to four groups selected from alkyl, dialkylamino, cyano, halogen, trihaloalkyl, alkoxy and trihaloalkoxy; or heterocycle or substituted heterocycle; or (iv) Z11 is alkyl substituted with one, two or three halogens.
0 The present invention will now be further described by the following working examples, which illustrate preferred embodiments of the invention.
S
S
S
S*
555 C:Vy Ooaument \AISOWSPECIlflMsional for 19737-97 BMS.doc EXAMPLE 1 PREPARATION -OF PINACOL ESTER 11 N- 2 -Methoxvethoxv)methvll 3 -dimthl....
dioxaborolan-2.v1 )benzenesulfanamidea
H
3 C CH 3 H3C
CH
3
NN
H3 H 3 A. *m -N 0 4 d meh 1 isoxazolyl )benzenesulfonamide B r 0~6~
.H
3 C
CH
3 A 2 L'three necked flask, equipped with an overhead 15 mechanical stirrer, a 250 mL addition funnel and an argon line, was charged with 2 -bromobenzenesulfonyl chloride (150 g, 587 mmol, commercially available) and anhydrous pyridine (150 mL) The resulting light yellow solution was cooled to -18 0 C (internal temperature) by an ice/salt bath. With stirring, a solution of 5-amino-3,4dimethylisoxazole (69.1 g, 616 nimol, commercially available) in anydrous pyridine (195 mL) was added dropwise through the addition funnel in 1 hour. The internal reaction temperature did not exceed -6 0 C during the course of the addition. -After the addition, the ice/salt bath was removed and the reaction mixture was then warmed up to room temperature, stirred for 1 hour, and then stirred at 40 0 C for 21 hours.
The reaction mixture was cooled to room temperature and poured into a mixture of ice water (3 L) and celite (37.5 After stirring for 20 minutes, it was filtered and rinsed with water (250 mL x Charcoal (45 g) was added to the filtrate. The mixture was stirred at room temperature for 40 minutes and was filtered through a pad of celite. The celite pad was rinsed with water (500 mL x The filtrate was acidified by dropwise addition of cold HC1 (6N, 750 mL) with vigorous stirring over 2 hours. Precipitation of the product occurred and the mixture was stirred for another 1 hour after the addition 15 of HC1.
The mixture was filtered, the solid was rinsed with cold water (750 mL x and suction dried for 3 days.
The title compound of this step was obtained as a yellowish white solid (171 g) in 88% yield (HPLC area 20 percent 97.4%).
Thin layer chromatography (TLC): Rf 0.47 (Silica gel from Whatman; Ethyl acetate (EtOAc):hexanes/l:l; Visualization CAM or UV) Alternative preparation for title compound of this Sstep: A 1 L three necked flask was charged with 2bromobenzenesulfonyl chloride (50 g, 196 mmol) and anhydrous 1,2-dichloroethane (125 mL) under an argon atmosphere. The resulting colorless solution was cooled to 0°C and anhydrous pyridine (40 mL, 396 mmol) was added, followed by the addition of 5-amino-3,4-dimethylisoxazole (24.1 g, 196 mmol) as a solid. After the addition, the ice bath was removed and the reaction mixture was heated to for 21 hours, yielding a crude reaction mixture containing the title compound of this step.
B. 2-Bromo-N-(3,4-dimethyl-5-isoxazol 1 -N- 2 -methoxvethoxv)methvllbenzene sulfonamide Br
N
I^JI MEM
H
3 C
CH
3 A 1 L three necked flask, equipped with a mechanical 10 stirrer, was charged with potassium carbonate (130.5 g, 944 nmol) and anhydrous dimethylformamide (DMF, 286 mL) under an argon atmosphere. The heterogeneous mixture was stirred for 15 minutes at room temperature. The title compound of step A (125 g, 378 mmol) was added as a solid. The mixture 15 was stirred again for 15 minutes at room temperature.
"Methoxyethoxymethylchloride (MEMC1, 47.5 mL, 415.8 mmol) Swas added dropwise through an addition funnel in minutes. After the addition, the reaction mixture was stirred for 40 minutes. The reaction was monitored by HPLC.
.e The reaction mixture was diluted with the addition of aethyl acetate (400 mL), stirred for 5 minutes and filtered.
The solid was washed with ethyl acetate (200 mL x 2) and hexanes (250 mL x The filtrate was treated with charcoal (25 stirred at room temperature for 1 hour and filtered through a celite pad. The celite pad was rinsed with ethyl acetate (50 mL x The ethyl acetate layers were combined and washed with Na2CO3 (IM, 500 mL).
Precipitation occurred in the aqueous layer. It was suppressed by addition of water (750 mL). The aqueous layer was separated and discarded. The organic layer was washed with water (750 mL), brine (500 mL x dried over Na2SO 4 filtered and concentrated to a yellowish semi-solid (157.3 g, 99% mass balance).
The residue was dissolved in ethanol (125 mL) and set aside in a freezer (0C) for 20 hours. Crystallization occurred. The solid was filtered and suction dried. The title compound of this step was obtained as a yellowish white solid (75.65% yield, HPLC area percent 98.2%).
TLC: Rf 0.55 (Silica gel from Whatman; EtOAc:hexanes/l:1; visualization: CAM or UV) Alternative preparation for the title compound of this step: The reaction mixture obtained by the alternative method for the preparation of the title compound of Step A was cooled to room temperature and concentrated at reduced *pressure on a rotary evaporator to a dark thick oil (102 g) 15 at 40°C. The dark oil (98 g, 188 mmol) was dissolved in anhydrous dichloromethane (240 mL). Diisopropylethylamine (97 mL, 4 equivalents) was added followed by dropwise addition of methoxyethoxymethyl chloride (25.7 mL, 225.6 mmol). The reaction mixture was stirred at room temperature for 4 hours.
The reaction mixture was concentrated at reduced pressure on a rotary evaporator to a thick oil, dissolved in EtOAc (400 mL) and charcoal (10 g) was added. The charcoal mixture was stirred at room temperature for minutes and was filtered through a celite pad. The celite Spad was rinsed with EtOAc (100 mL x 3) and hexanes (200 mL x The filtrate was transferred to a separatory funnel and washed with water (100 mL x HC1 (0.5N, 100 mL x 2), water (100 mL x 2) and brine (100 mL x dried over Na2SO4, filtered and concentrated to a thick oil (64.9 g, 83% mass balance).
The thick oil was dissolved in ethanol (EtOH, 65 mL), cooled to 0°C with an ice bath, seeded with the title product of this step and stirred at 0 0 C for 6 hours.
Crystallization occured. The solid was filtered and suction dried. The title compound of this step was obtained as a yellowish solid (62% overall yield, HPLC area percent 98.2%).
TLC: Rf 0.55 (silica gel from Whatman; EtOAc:hexanes/l:l; visualization: CAM or UV) C. 2 -Borono-N- (3,4-dimethvl-R-,iso zovl N- (2-methoxyethoxv)methyl benzene..
sulfonamide
(HO)
2
B
o o N N H3C CH A dry 3-necked l-liter round-bottomed flask equipped with an overhead mechanical stirrer, gas adapter, thermocouple, and septum was charged with the title 15 compound of Step B (40.0 g; 95.4 mmol), and then thoroughly degassed and placed under an argon atmosphere.
Tetrahydrofuran (THF, 185 mL) was added via syringe and the mixture was cooled to about -100 0 C (internal temperature).
n-Butyl lithium (n-BuLi, 42.5 mL, 101 mmol, 2.38 M in hexanes) was dropwise added over a period of 16 minutes, Swhile maintaining the internal temperature between -97°C and -101 0 C. The pale yellow-orange solution was stirred at about -98°C to -101 0 C for an additional 16 minutes.
Trimethylborate (16.0 mL, 140.9 mmol) in THF (24 mL) was dropwise added over 14.5 minutes, while maintaining the internal temperature between -96 0 C and -99 0 C. The mixture was stirred for about 44 minutes at about -93 0 C to -101 0
C,
and an additional 39 minutes at about -93 0 C to -72°C. HC1 N, 120 mL, 360 mmol) was added to the reaction (the solution exothermed to about -7 0 C) and was stirred for minutes (-7 0 C to +6 0 The two layers were separated in a separatory funnel, and the aqueous phase was washed with toluene (3 x 120 mL) and t-butyl methyl ether (MTBE, 3 x 100 mL). The combined organic layer was washed with brine (4 x 100 mL), dried over Na2SO4, and concentrated on a rotary evaporator to a volume of about 100 mL containing the title compound of this step (HPLC area percent 97.7%).
Alternative preparation of the title compound of this step: A 500 mL 3-neck flask equipped with a stir bar was charged with the title compound of Step B (20.0 g, 47.7 mmol) and purged with argon for 0.5 hr. Anhydrous THF (200 mL) was added via syringe and the flask was cooled to -78°C in an acetone/dry ice bath. Phenyl lithium (PhLi, 37.1 mL, 48.2 mmol, 1.3 M in cyclohexane-ether, titrated according 15 to J. Organomet. Chem., 186, 155 (1980), and determined to be 1.3 M) was added via an addition funnel over the course of 25 minutes. The rate of addition of PhLi was such that the internal temperature of the reaction mixture was maintained below -75°C. The resulting solution was stirred 20 at -78°C for 15 minutes following which a solution of trimethylborate (10.8 mL, 95.4 mmol) in THF (5 mL) was cannulated dropwise into the reaction mixture over minutes. The trimethylborate/THF solution was cooled in an ice-water bath prior to addition. The rate of addition was maintained such that the internal temperature of the a reaction mixture did not go above -73°C. The reaction mixture was stirred at -78°C for 0.5 hr, and then quenched by the dropwise addition of a solution of acetic acid mL) in THF (10 mL). The acidified solution was stirred at -78°C for 10 minutes following which the solution was warmed to 0°C. To this was added dropwise, IN HCl (25 mL).
(IN HCl was prepared by diluting 42 ml of 12N HCl into 500 mL of water. The excess acid was added in order to ensure complete quenching. The HCl solution was pre-cooled in an ice/water bath prior to addition.) The reaction mixture was then allowed to warm to room temperature and extracted with t-butyl methyl ether (TBME, 4 X 250 mL). The organic layers were combined and extracted with 0.5N aqueous NaOH (4 X 25 mL). The aqueous layers were combined and back extracted with TBME (1 X 100 mL). The aqueous extract was cooled to 0°C and the pH adjusted to 2.0 (pH meter) by the dropwise addition of 6N HC1 with rapid stirring. The acidified solution was extracted with TBME (4 X 250 mL), the organic layers pooled and dried over anhydrous MgSO4.
The suspension was filtered and the solution concentrated to give the boronic acid title compound of this step as a pale brown oil (17.1 g, 93%, HPLC area percent 88%).
HPLC Conditions: Column YMC ODS-A, 6 x 250 mm; Monitored at 233 nm; Flow rate 1.5 mL/min; Solvent A 3 P0 4 90:10:0.2; Solvent B H20/MeOH/H 3
PO
4 10:90:0.2; Gradient: 40% B to 100% B, linear gradient over 15 10 minutes, 100% B for 5 minutes, 40% B for 4 minutes; Retention time for the title compound of this step 8.3 i minutes.
S
D. N-r(2-Methoxvethoxy)methll 20 dimethyl-5-isoxazolyl-2-(4.4.5,5tetramethl-1. 3. 2-dioxaborolan-2- Yl)benzenesulfanamide 0 B 0 SS SN
N
MEM
H
3 C
C
CH3 The mixture from step C was diluted with toluene (170 mL) to bring the total volume to about 270 mL, and the flask was equipped with a Dean-Stark trap and magnetic stir bar. Pinacol (11.6 g, 98.2 mmol) was added and the resulting mixture was heated to reflux for about 1.25 hr.
Water was drained from the Dean-Stark trap and the solution was then used "as is" in Example 3. (98% conversion,
HPLC
area percent 93.6%) Reverse phase HPLC Column: YMC-Pack ODS-A; 150 x 6 mm; mm, 120A and monitored @233 nm; Solvent: A 90% water, methanol and 0.2% H3P04; B 10% water, 90% methanol and 0.1% H3P04; Flow rate: 100 mL per minute; Gradient; 40% B to 100% B in 10 minutes. Hold time: 5 minutes at 100% B. Step down to B and hold for 5 minutes. Retention Time for title product of this Example 11.5 minutes.
Alternative preparation of the title compound of 15 this Example: S.The boronic acid obtained in the alternative method for preparation of the title compound of Step C (17.1 g, 44.5 mmol) was dissolved in a solution of anhydrous toluene (425 mL) and pinacol (5.51 g, 46.7 mmol). The flask was 20 placed in an oil bath and heated to 120°C for 2 hr (note: reaction was complete in first 40 minutes) and water continuously removed by the use of a Dean-Stark trap (flask and trap covered in foil; mixture boiled rapidly in approximately 0.5 hr) and condenser. Analysis of an aliquot (worked up by repeated azeotroping with CDC13) by HPLC indicated complete conversion of the boronic acid starting material to the title compound of this Example. The reaction mixture was cooled to room temperature and concentrated to afford the title compound of this Example as a toluene solution, HPLC area percent 86%. A 100% yield was assumed for conversion of the boronic acid to pinacol ester. A portion of the crude solution of the title compound of this Example was used in Example 3. Retention time of title compound of this Example 12.4 minutes (using HPLC conditions described for boronic acid starting material).
PREARAIONOF RA-OPHNYLCOMPOUND ITT: 2- (4-lodobh nvl)oxazole N- 2-Dimethoxysthyl) -4-iodobenzamide.
0-OH 3 0113-0- KH{C03 (80.0 9, 0.80 mol) was added to a solution of alinoacetaldehyde dimethyl acetal (82.9 g, 86.0 rnL, 0.79 mol, commercially available) in water (900 mL) and acetone (400 niL) and the resulting solution was cooled in an ice bath to 000. A solution of 4-iodobenzoyl chloride (200.0 g, 0.75 mol) in acetone (600 niL) was added dropwise via an addition funnel, to the aminoacetaldehyde dimethyl acetal solution over the course of 1.5 hr, with mechanical stirring. The addition funnel and the walls of the flask were washed with acetone (50 niL) and the ice bath was removed. The reaction mixture was allowed to stir at room temperature for 3 hr (reaction was completed in 1.5 hr).
The reaction mixture was concentrated by removing L of solvent on a rotary evaporator and then extracted with EtOAc (4 X 350 mL). The organic layers were pooled, washed with saturated NaHCO3 (1 X 250 mL) followed by H20 (1 X 250 mL), dried over anhydrous MgSO4 (50.0 filtered and concentrated at reduced pressure to give a white solid (during solvent evaporation, the solid was occasionally scraped off the sides of the flask). The solid was dried under house vacuum for 12 hr (246.5 g, 98%, HPLC area percent 99.7% melting point (mp) 89-90'C Elemental Analysis CjlH14NO3I Calc'd: C, 39.42; H, 4.21; N, 4.18 Found: C, 39.42; H, 4.22; N, 4.07 B. 2- (4-IodoDhenY1)oxazole Eaton's reagent was prepared by adding P205 (200 g) in approximately 50 g portions to methanesulfonic acid (2000 mL) at 95 0 C under argon with vigorous mechanical stirring.
The addition of P205 in portions prevented it from forming :a hard mass at the bottom of the flask. A clear, very pale brown solution was obtained. Eaton et al. J. Org. Chem., 38, 4071-4073 (1973).
A 3 L 3-neck round-bottom flask containing the Eaton's **.:reagent (2000 mL) was equipped with a condenser and charged with the title compound of step A (200.0 g, 0.60 mol). The reaction mixture was placed in an oil bath and heated with stirring, under a positive pressure of argon. (It was found to be beneficial to warm the reaction mixture to the required temperature rather than set it in a pre-heated bath.) Monitoring the reaction by TLC indicated that the first step of the reaction was hydrolysis of the dimethylacetal group to the corresponding aldehyde (Rf= 0.11): 0
H_
0 NH
I
followed by cyclization. The oil bath temperature was adjusted so as to maintain the internal temperature of the 5 reaction mixture between 130-134 0 C. (The temperature of S: the oil bath was maintained between 138-141 0 After hr, analysis of an aliquot (worked up by addition to and extraction with EtOAc) by TLC indicated the complete disappearance of the starting material and the production 10 of a single new spot.
The reaction mixture was cooled to 30 0 C under argon, divided into three approximately equal portions, and each portion was poured onto a slurry of ice/water (approximately 6.0 L) with vigorous stirring using a mechanical stirrer, with external cooling. This resulted in the formation of a brownish-gray precipitate. The resulting suspension was stirred for 2 hr and the solid was collected by suction filtration through a medium porosity sintered glass funnel, washed with ice cold water (1 L) and the filter cake broken. The solid was air dried for 5 days to give a gray powder (151.7 g, The crude material (151.7 g) was dissolved in acetonitrile (2 L) (by warming gently with a heat gun; a small amount of black flocculent solid remained undissolved in the flask) and activated charcoal (15.2 g) was added and the mixture stirred at room temperature for 1 hr. The mixture was filtered through a pad of celite (100.0 The celite pad was washed with acetonitrile (2 X 100 mL). The filtrate was concentrated under reduced pressure to approximately 1180 mL in a 5 L round bottom flask. The flask was warmed with a heat gun until the solid completely dissolved. To the resulting hot solution, boiling water (295 mL) was added in two portions, the flask was heated to near boiling and gently swirled after each addition. The solution was once again heated to near boiling, the flask was covered and allowed to stand at room temperature for 48 hr (some crystals were observed within 1.5 hr), following which it was stored at 4 0 C for 4 days. The crystals which formed were collected by suction filtration and washed with an ice cold solution of acetonitrile:water 150 mL), and air dried for 20 hr.
The title compound of this Example was obtained as very pale yellow crystals which were further dried under house 15 vacuum (107.2 g, 66%, HPLC area percent A second S* crop of the title compound was collected upon recrystallization of the yellow solid obtained upon concentration of the mother liquor (27.4 g, 17%, HPLC area percent 98.4%).
20 m.p. 107-1090C Elemental Analysis C9H6NOI Calcd: C, 39.88; H, 2.23; N, 5.17 Found: C, 40.00; H, 2.09; N, 5.14 EXAMPLE 3 PREPARATION OF FORMULA I COMPOUND N-(3,4-Dimethvl-5-isoxazolvl)-4'-(2-oxazolvl) l,1. biphenyll-2-sulfonamide COUPLING OF PINACOL ESTER II AND HALOPHENYL COMPOUND III 0 NH
N
H
3 C
CH
3 A. N- r( 2 -Methox ethox)methy dimethv1-5-isoxazolyl) -oxazol-2-yl- -binhenylJ- 2 -sulfonamide 0
/N
I
N
CH3 A ciry 3-necked, 2-liter round-bottomed flask equipped with an overhead mechanical stirrer, gas adapter, thermocouple, ref lux condenser, and septum was charged with palladium acetate (Pd(OAc) 2 0.54 g, 2.38 inmol) and triphenyiphosphine (Ph3P, 1.7 g, 6.44 mmol), degassed and placed under an argon atmosphere. THF (85 mL) was added and the mixture was heated at 65"C for 70 minutes. The solution gradually changed from rust orange to bright yellow in color. A degassed, toluene (270 mL) solution of the title compound of Example 2 (25.9 g, 95.6 mmol) and the crude title compound of Example 1 as prepared above (see step D of Example 1, 44.45 g, 95.4 mmol) was added via syringe followed by degassed 95% ethanol (EtOH, 285 mL), and a degassed 2.0 M Na2CO3 solution (306 mL, 612 mmol).
The resultant red colored solution was heated at about 75 0
C
(internal temperature) for about 1.75 hr. The heating bath was removed, and the mixture was allowed to cool to ambient temperature. The layers were separated in a separatory funnel, water (250 mL) was added and the aqueous layer was washed with CH2C12 (6 x 400 mL). The combined organic layers were dried over MgS04, treated with neutral charcoal (Norit, 5.0 filtered through celite, concentrated, and kept under dynamic, high vacuum overnight to afford the title compound of this step (62.4 g, 140%) as a red colored oil. (HPLC area percent Alternative preparation of the title compound of this step: Catalyst Preparation: A 2L three necked flask equipped with overhead mechanical stirrer, reflux condenser, and argon inlet was charged with Pd(OAc)2 and triphenylphosphine. The flask was purged with a slow bleed of argon for 18 hr. Anhydrous, degassed THF (67 mL) was added via syringe, the flask immersed in an oil bath preheated to 75 0 C, and stirred.
After 20 minutes, the internal temperature reached The mixture was stirred for 1 hr at which time it was burgundy in color, then cooled to room temperature under a slight head pressure of argon. See J. Org. Chem., 1994, 59, 8151; Organometallics, 1992, 11, 3009.
Coupling The title compound of Example 2 (10.0 g) was added to a portion of the toluene solution of pinacol boronate prepared in the alternative preparation of the title compound of step D of Example 1 (110 mL, 38.74 mmol of the pinacol boronate, 87% of total volume of crude boronate solution). The mixture was swirled, anhydrous ethanol mL) was added, the flask sealed with a septum and swirled until a solution was obtained. The solution was degassed by bubbling argon into the solution at a moderate rate for 1 hr. The solution was then charged into the reaction vessel containing the cooled solution of catalyst via cannula under a positive pressure of argon. The flask was rinsed with anhydrous, degassed ethanol (55 mL) and transferred via cannula to the reaction vessel under a positive pressure of argon. A degassed 2M Na2CO3 solution (118 mL) was added via cannula, stirring was initiated, the flask *ooo 15 immersed in a preheated oil bath at 78*C, and the internal
V,
temperature brought to 69-70 0 C. HPLC and TLC analysis after 1.75 hr indicated that the reaction was complete. After 2 hr of reaction time, the mixture was cooled to 27°C, and water (100 mL) and EtOAc (100 mL) were added with stirring.
20 The mixture was transferred to a separatory funnel, the layers separated, and the aqueous extracted with EtOAc (3 X 100 mL, 1 X 50 mL). The combined organics were washed with S""half-brine (1 X 60 mL) and dried over anhydrous MgS04 o. g) with stirring. The solution was filtered, and the initial flask and filter funnel washed with EtOAc (2 X 100 mL). This process afforded a crude coupling solution with a total volume of 785 mL. HPLC analysis afforded a crude
HPLC
area percent of 88.9%. The solution was divided into portions for purification evaluation. For example, 5% by volume of the crude coupling solution (39 mL) was taken and concentrated on a rotary evaporator. The residue was dissolved in toluene (12 mL), C (0.9 g, 100 wt was added and the mixture stirred in an 88°C oil bath for 30 min.
Trithiocyanuric acid (TMT, 407 mg, 2.3 mmol, 50 mol equiv relative to assumed Pd content) was added and the mixture stirred for 30 minutes in the oil bath, cooled to 0 0 C in an ice bath, filtered through celite, the celite pad rinsed with toluene (2 X 10 mL), and the filtrate washed with 1N NaOH (2 X 10 mL). The phase separation required 3 minutes. The toluene layer was dried over MgSO4, filtered and concentrated to afford the crude title compound of this step, 0.76 g, 87% mass balance. The palladium content was determined to be <1 ppm. Further experimentation indicated chat 25 equivalents of TMT were adequate to reduce Pd to ppm.
by volume of the crude coupling solution (78 mL) described above was stirred with 50 weight C (0.9 g) to 0 C and allowed to cool for 30 minutes, filtered through celite, rinsed with EtOAc, and this process repeated with a fresh portion of charcoal. The solution was concentrated to afford 2.29 g (131% mass balance). The residue was 15 azeotroped twice with anhydrous ethyl ether. The residue S* was dissolved in ether (11 mL), the solution cooled to 0°C, seeded with the title compound and stirred. A solid precipitated from solution. After 1 hr, hexanes (5 mL) were added dropwise, the mixture stirred at 0°C for 2 hr, 20 collected and washed with ice-cold 2:1 ether:hexane, Saffording the title compound of this step (1.07 g, 58% from the title compound of step B of Example 1) as a faint yellow powder, HPLC area percent 95.8% (in process).
HPLC Conditions: Column YMC ODS-A, 6 X 250 mm Monitored at 233 nm, Flow Rate 1.5 mL/min.
Solvent A H 2 0/MeOH/H 3 P0 4 90:10:0.2 Solvent B H 2 0/MeOH/H 3 P0 4 10:90:0.2 Gradient: 40% B to 100% B; linear gradient over min, 100% B for 5 min, B for 4 min.
Retention time for the title compound of this step: 12.8 min.
Second Alternative preparation of the title compound of this step, Reverse Coupling Method: A 500 L oven dried round bottom flask was charged with the title compound of Example 2 (10 g, 37.3 mmol), anhydrous THF (250 mL), toluene (50 mL) and triisopropylborate (B(OiPr) 3 50 mL) under an argon atmosphere. The resulting colorless solution was cooled to -75°C and n-butyl lithium (36 mL, 1.43 M in hexanes, 51.5 mmol) was added dropwise in 1 hour. The internal temperature was kept below -73°C during the addition.
The reaction was quenched with addition of acetic acid (4 mL) in THF (25 mL) and concentrated on a rotary evaporator. Toluene (100 mL) and methanol (100 mL) were added and the solvent was removed on the rotary *fee evaporator at 40°C. This was repeated one more time.
15 The resulting residue was dissolved in NaOH (100 mL, j ./100 mmol, IN) and extracted with hexanes (25 mL) and TBME (25 mnL) twice. The following compound was obtained: *o
/N
9* 5 L5 m o
N
B(ONa) 2 The aqueous layer was added to a mixture of NaHCO 3 (8.4 g, 100 mmol) in EtOH (100 mL), and a solution of the title compound of step B of Example 1 (14.4 g, 34.4 mmol) in toluene (100 mL) was added. The resulting mixture was bubbled with argon for 15 minutes.
While the above reaction was worked up, a 50 mL round bottom flask was charged with triphenylphosphine (676.8 mg, 2.58 mmol) and THF (30 mL), bubbled with argon for 15 minutes. Pd(OAc)2 (193.4 mg, 0.86 mmol) was added and the mixture was heated to 65°C for 1 hour under argon. The mixture was cooled to room temperature and was added to the above ethanol/toluene/water mixture. The resulting heterogeneous mixture was heated to 75 0 C for 6 hours. HPLC indicated all starting material was consumed.
The reaction mixture was cooled to room temperature and concentrated on a rotary evaporator. Ethyl acetate (250 mL) and charcoal (10 g) were added. The mixture was stirred at room temperature for 30 minutes and filtered through a celite pad. The celite pad was rinsed with ethyl acetate (25 mL x The filtrate was transferred to a 500 mL separatory funnel and washed with water (100 mL x 2) and brine (100 mL x The ethyl acetate layers were combined, mixed with trithiocyanuric acid (TMT, 4 g) and heated at 45*C for 45 minutes. It was filtered through a celite pad. The celite pad was rinsed with ethyl acetate (25 mL x The organic layers were combined and washed with NaOH (200 mL x 2, TMBE (300 mL) was added to minimize emulsion), water (200 mL) and brine (200 mL), dried over Na2SO4, filtered and concentrated to 17.5 g (98% mass balance).
The crude product was dissolved in ethanol (17.5 mL). Half of the solution mL) was put aside in a 0C freezer for 2 days. Crystallization occurred. The solid was filtered and suction dried. The product was obtained as a yellowish solid (6 g, 67% overall yield from the title compound of Example 2, HPLC area percent 99.1%.) HPLC conditions: Column YMC ODS-A, 6 X 250 mm Monitored at 233 nm, Flow Rate 1.5 mL/min.
Solvent A H20/MeOH/H 3
PO
4 90:10:0.2 Solvent B H20/MeOH/H 3 P0 4 10:90:0.2 Gradient: 40% B to 100% B; linear gradient over min, 100% B for 5 min, B for 4 min.
Retention time of the title compound of this step: 12.8 min.
B. N-(3,4-Dimethysl_5_isoxazolvl)_.4,L!2 oxazoil) IHl,1'-biphenMl]-2-sulfo.amide A three-necked, 3-L round-bottomed flask equipped with an overhead mechanical stirrer, a thermocouple, and a reflux condenser was charged with a bright yellow solution of the crude title compound from step A (62.45 g) in ethanol (620 mL). While stirring, 6 N HCl (620 mL) was added rapidly and the mixture was heated to reflux at 87°C for 100 minutes, resulting in a pale orange solution. The reaction mixture was cooled to room temperature followed by 15 cooling to -0-4°C using an ice bath and was then basified to pH -13 using 5 N NaOH (-850 mL). The sodium hydroxide solution was added slowly over 10 minutes without allowing the temperature to rise over 30 0 C. The mixture was recooled to 0 0 C and 250 mL of water was added and the 20 resulting precipitate was filtered and washed with water (200 mL). The filtrate was concentrated under vacuum on a rotary evaporator at -40'C to remove most of the ethanol.
Precipitation of the sodium salt i the title compound of this Example occurred during the concentration. The suspension was cooled to -10°C and filtered and washed with brine (2 x 150 mL). The solid was air dried for 15 minutes and transferred to a 2-L flask and dissolved in 1-L of hot water. The solution was polish filtered and washed with water (150 mL) and transferred to a 2-L separatory funnel.
The aqueous layer was washed with 1:1 ethyl acetate:hexane (2 x 1-L) and hexane (500 mL). The yellow aqueous layer was then cooled to -7*C and while stirring vigorously, very slowly acidified from pH -9.0 to 2.6 to precipitate the the title compound of this Example. After stirring for minutes the slurry was filtered and washed with excess water to remove any residual acid and air dried to afford 31.5 g of product as an off-white solid.
A 5.0 g portion of the above solid was dissolved in ethyl acetate (25 mL) and treated with trithiocyanuric acid (TMT, 0.23 The TMT is a chelating agent added to facilitate removal of residual palladium from the product.
The mixture was gently boiled and then heated in an oil bath for 15 minutes at -65 0 C. Norit charcoal (5.1 g) was added to the mixture and heating was continued for an additional 30 minutes. The mixture was then cooled in an ice bath and filtered through a bed of celite and washed with ethyl acetate (25 mL). The filtrate was transferred to a separatory funnel and washed with 1.0 N HC1 (1 x mL) and water (1 x 75 mL). The HC1 wash removed residual TMT. The organic layer was then treated with Norit charcoal (0.5 heated to a gentle boil and filtered 15 through a bed of celite. The filtrate was concentrated and the residue was dissolved in absolute ethanol (20 mL), boiled and then water (10 mL) was added. The solution was seeded and allowed to cool with stirring and crystallize over 16 hours. The resultant crystals were filtered, 20 washed with ethanol:water 10 mL) and vacuum dried to afford 4.0 g of pure title compound of this Example (overall yield of 66% from the title compound of step A, HPLC area percent 99.02%). m.p. 145.1 0 C (high melt polymorph) Example 4 PREPARATION OF FORMULA I COMPOUND N-(3.4-Dimethyl-5-isoxazolyl)-4 -(2-oxazolyl) biphenyll-2-sulfonamide COUPLING OF BORONIC ACID SALT IX WITH IODOPHENYL COMPOUND III
H
3 C
ACH
3 A 2 -Borono-NM(3. dimethvlS -isoxaz11j) N-fr(2 -methoxvethoxv) methyl] benzenesulfEonamide. disodium salt .NaO ONa B MEM S0 2
-N
\/N
H
3 C
OH
3 A dry 3-necked 100 rnL round-bottomed flask which was equipped with: magnetic stir bar, gas adapter, 10 thermocouple, and septum was charged with the title compound of step B of Example 1 0 g; 11. 9 mmol) and then thoroughly degassed and placed under an argon atmosphere. THF (23 mL) was added via a syringe and the mixture was cooled to -1000C (internal temperature) and vigorously stirred. While vigorously stirring the mixture, n-BuLi (5.30 mL, 12.6 mmol) was dropwise added over a period of 19 minutes, while maintaining the internal temperature between -95 0 C and -1000C. The pale yelloworange solution was stirred for ani additional 12 minutes at about -1000C. Trixethylborate (2.0 mL, 17.6 mmol) dissolved in THF (3.0 mL) was dropwise added over 12.0 minutes, while maintaining the temperature between -95 0
C
and -100 0 C. The mixture was stirred for about 50 minutes at about -95 0 C to -100oC, and then stirred for an additional 40 minutes at about -78 0 C to -72 0 C. The borate ester was hydrolyzed by the addition of 1.0 N HC1 (2.0 mL, mmol) at about -72 0 C, the solution was warmed to ambient temperature and stirred for about 60 minutes. A solution of Na2CO3 (55 mL, 2.0 M, 110 mmol) was added, and the mixture was thoroughly degassed and placed under an atmosphere of argon. This material was then used "as is" in the following steps (purity 95.9%, HPLC). YMC ODS-A column, 150 mm x 6.0 mm, S-3 pm, 120 A; flow rate mL/min. At 0.0 min. the solvent system was composed of A (A 90% MeOH/10% H20/0.1% H3PO4) and B (B 90% H20/10% MeOH/0.2% H3PO4). At 15.0 min the solvent composition was 100% A. From 15.1 min to 20.0 min the solvent composition was A and B Retention time Rt for the title compound of this step was 7.5 min.
20 The detector was operating at 233 nm.
B. N- (2-Methoxvethoxv)methvll dimethyl-5-isoxazolyl)-4'-oxazol-2-vl- [1.1'-biphenyll-2-sulfonamide O0/
MEM
HC
CH
3 A dry 3-necked, 300 mL round-bottomed flask which was equipped with: a mechanical stirrer, gas adapter, thermocouple, reflux condenser, and septum was charged with Pd(OAc) 2 (0.16 g, 0.71 mmol) and Ph3P (0.5 g, 1.93 mmol), degassed and placed under an argon atmosphere. THF (30 mL) was added and the mixture was heated at 65 0 C for about minutes. The color gradually changed from rust-orange to yellow. A degassed solution of toluene (85 mL) and EtOH (64 mL) solution of the title compound of Example 2 (3.23 g, 11.9 mmol) was added via a syringe followed by the degassed solution of the title compound of Step A. The red colored solution was heated at 75 0 C (internal temperature) for 1.5 hr. The heating bath was removed, and the mixture was allowed to cool to ambient temperature.
o *o 15 The layers were separated in a separatory funnel, water mL) was added to the aqueous layer and the aqueous layer was extracted with EtOAc (3 x 200 mL). The combined organic layers were washed with brine (1 x 75 mL), dried with MgS04, treated with 5.0 g of Norit neutral charcoal, 20 filtered through celite, concentrated, and kept under vacuum (about 0.1 mm Hg) overnight to afford the title compound of this step (6.17 g, 111%) as a red colored oil.
(purity 80%, HPLC) C. N-(3,4-DimethYl-5-isoxazolvl)-4'-(2oxazolyl) [rl. 1l' -bihenll-2-sulfonamide A dry 250 mL round-bottomed flask equipped with a reflux condenser and magnetic stir bar was charged with the crude product of step B (6.17 g, theoretical 5.56 g, 11.9 mmol), 95% EtOH (60 mL), 6.0 N HC1 (60 mL) and heated at reflux for 2 hr. The mixture was cooled to approximately aqueous NaOH added to pH approximately 13 with a moderate temperature rise to less than approximately 25 0
C,
polish filtered, and water (50 mL) was added. The solution was concentrated at 40 0 C to remove most of the EtOH mL), whereupon a white solid formed. The mixture was cooled to 0oC for 20 minutes, filtered and the resultant white solid was washed with brine (2 x 50 mL), and then dryed under vacuum 0.1 mm Hg) for 12 hr. The white solid was dissolved in hot water (80 mL) and polish filtered. The aqueous solution was placed in a separatory funnel and washed with 1/1 EtOAc/hexanes (2 x 50 mL) and hexanes (75 mL). The solution was cooled to 0 0 C, stirred vigorously, 1.0 N HC1 was slowly added until pH 1.0, and then the mixture was kept at.0oC for 15 minutes. It was filtered and washed with water (3 x 50 mL) to afford an off-white solid, which was suction dried for 3 hr. The white solid was then dissolved in EtOAc (65 mL), trithiocyanuric acid (0.20 g, 1.13 mmol) was added and the mixture was stirred at 65°C for 30 minutes. Charcoal (Norit neutral, 5.0 g) was added and the mixture was 15 stirred for an additional 30 minutes at 65 0 C. The mixture was cooled to 0OC, filtered through a pad of celite, washed 4O. with EtOAc (3 x 50 mL), and concentrated to a volume of 6 mL. The mixture was washed with 1.0 N NaOH (3 x 50 mL), and to the aqueous layer was added NaCl (3.0 g, 637 mmol) 20 as well as brine (50 mL) The aqueous mixture was cooled to OOC, filtered, and washed with brine (2 x 50 mL). The resultant white solid was dissolved in hot water (200 mL) :..cooled to 0oC, stirred vigorously, and 1.0 N HCl was slowly added until pH 1.0, and the mixture was kept at 0oC for W 25 15 minutes. It was filtered and washed with water (3 x :mL) affording an off-white solid, which was dryed at 45 0
C
under vacuum (0.1 mm Hg) for 16 hr to afford 2.4 g (50 yield) of an off-white solid. The solid (2.25 g) was dissolved in 95% EtOH/water (9.0 mL/5.0 mL) at 70 0 C. Slow cooling to ambient temperature (1.5 hr) followed by cooling to 50C overnight afforded a white crystalline material, which was filtered and washed with cold 95% EtOH/water mL/ 5.0 mL) and dryed under vacuum 0.1 mm Hg) for 48 hr to afford 2.1 g of the title compound of this Example as a white solid (46.9% overall yield from the title compound of step TLC indicated (2/1 hexane/EtOAc, stain KMnO4) that the reaction was completed after 2 hours. m.p.- 143 .07 0
C
:o .0.
0*0 0 0

Claims (8)

1. A--method for the preparation of an oxazole phenyl halide of the formula IIIa(l) or salt thereof: 0/N halo (IIa(1)) wherein R 1 and R 2 are each independently hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Zl, Z 2 and Z 3 halo; hydroxyl; cyano; nitro; -C (0)H or 0 -CO2H or -C020 5 -Z 4 -NR 6 R 7 or C:Wy Dow.ments\ALISONSPECI\DMsiona for 19737-97 Ctairm.doc 0 -4NRO-5N89 R 5 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted'with Z1, Z 2 and Z 3 R 6 R 7 R 8 R 9 and R 10 are each independently hydrogen; or alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be su bstituted with Z1, Z 2 and Z 3 or R 6 and R 7 together may be alkylene or alkenylene, either of. which may be substituted with Z1, Z 2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; or any two of R 8 R5 and R 10 together are alkylene or alkenylene, either of which may be substituted with Z 1 Z 2 and Z 3 completing a 3- to 8-membered saturated or ,unsaturated ring together with the atoms to which they are attached; R 1 1 and R 12 are each independently hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z1, Z 2 and Z 3 heterocycle, substituted heterocycle or heterocyclooxy; halo; hydroxyl; cyano; nitro; -C(O)H or -CO2H or -C02R 5 -SH, -S(O)nR 5 -S(O)m-OH, -S(0)m0OR 5 -0-S(O)m-0R 5 -0S(O)mOH or -0-S m-0R 5 -z 4 -NR 6 R7; or -Z 4 N(RO)Z5-NR8R9; Z1, Z 2 and Z 3 are each independently hydrogen; halo; hydroxy; alkyl; alkenyl; aryl; aralkyl; alkoxy; aryloxy; aralkoxy; heterocycle, Ssbtituted heterocycle or 15 heterocyclooxy; -SH, nZ 6 -S(O)m-OH, -S(0)m-OZ6, -0OS(O)mOH or -SOmZ6 (in) oxo; nitro; 20 cyano; or -C(O)Z 6 -CO2H or -C02Z 6 -Z-NZ 7 Z 8 -Z 4 ~II~ 25 -Z-N(Zll)z5.6 or -Z 4 -N (Zll) -Z 5 -NZ 7 Z 8 Z 4 and Z 5 are each independently a single bond; -Z 9 -S (O)n-Z 1 0 -z- 9 C -Z1O-; -Z- 9 -C (S)-Z 1 0 -Z 9 or -9CO--1- Z 6 is alkyl; alkyl substituted with one to three groups selected from halogen, aryl, aryloxy and alkoxy; alkenyl; alkynyl; cycloalkyl; cycloalkyl substituted with one to three groups selected from alkyl, aryl, alkenyl and alkoxyaryl; cycloalkyl to which is fused a benzene ring; aryloxy substituted with one or two halogens; cycloalkylalkyl; cycloalkenyl; cycloalkenylalkyl; aryl; aryl substituted with methylenedioxy or one to four groups selected from alkyl, dialkylamino, cyano, halogen, trihaloalkyl, alkoxy and trihaloalkoxy; or heterocycle or substituted heterocycle; Z 7 and Z 8 are each independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, or Z 7 and Z 8 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; 15 Z 9 and Z 10 are each independently a single bond, alkylene, alkenylene or alkynylene; Zll is hydrogen; or alkyl, alkyl substituted with one, two or three halogens, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl; or any two of Z 7 Z 8 and Z 11 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached; each m is independently 1 or 2; and each n is independently 0, 1 or 2; comprising the steps of: contacting a phenyl acid halide X or salt thereof: O halo R11 R12 halo 'with an amine acetal XI or salt thereof: O-alkyl (XI) in the presence of a base and a solvent, to form an amide acetal of the formula XII or salt thereof: alkyl-0 S. S S o NH R 11 -R halo (XII) and salt form salt cyclizing the amide acetal of the formula XII or thereof, in the presence of a cyclization agent, to said oxazole phenyl halide of the formula IIIa(l) or thereof.
2. The method of claim 1 wherein, in said formula X, the halo group of the acid halide moiety is chloro, and the halo group in the position para to the acid halide moiety is chloro, bromo, or iodo.
3. The method of claims 1 or 2, wherein said oxazole of the formula IIIa(1) or salt thereof is employed in the preparation of a compound of the following formula Ia: C:AMy Doc enls\ALISONSPECIODMslonal for 19737.97 Claimomdoc 66 4 4 44* 4 4***9 4 44** 4*4* 4
4.4. 4. q 4* .4 4, 9 R 11 (1a) 000 NH 13: R 1 and enantiomers and diastereomers, and salts thereof, wherein: R 3 and R 4 are each directly bonded to a ring carbon and are each 5 independently hydrogen; alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 1 Z 2 and Z 3 [0 halo; hydroxyl; cyano; nitro; -C(0)H or-CI -CO 2 H or -C0 2 R 5 _Z 4 -NR 6 R 7 -Z 4 -N(Rl 0 )-Z 5 -NR 8 R 9 or R 3 and R 4 together may also be alkylene or alkenylene, either of which may be substituted with Z 1 Z 2 and Z 3 completing a 4- to 8- !0 membered saturated, unsaturated or aromatic ring together with the carbon atoms to which they are attached; R 5 is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z1, Z 2 and ~R 6 R 7 R 8 R 9 and R 1 0 are each independently hydrogen; or W:~fion\NKSp~im6536.doc -67- alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, any of which may be substituted with Z 1 Z 2 or Z3; or R 6 and R 7 together may be alkylene or alkenylene, either of which may be substituted with Z 1 Z 2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; or any two of R 8 R 9 and R 10 together are alkylene or alkenylene, either of which may be substituted with Z 1 Z 2 and Z 3 completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached; Z 1 Z 2 and Z 3 are each independently hydrogen; halo; hydroxy; alkyl; o* j alkenyl; 15 aryl; aralkyl; alkoxy; aryloxy; aralkoxy; heterocycle, substituted heterocycle or heterocyclooxy; -SH, -S(O)nZ 6 -S(O)m-OH, -S(O)m-OZ 6 -O-S(O)m-Z 6 -O-S(O)mOH or S(O)m-OZ 6 oxo; nitro; cyano; -C(O)H or -C()Z6; -CO 2 H or -C0 2 Z 6 -Z 4 -NZ 7 Z 8 -Z 4 -N(Z 1 1 )-Z 5 -H; -Z 4 -N(Z 1 1 )-Z 5 -Z 6 or S(u) -Z 4 -N(Z 11 )-Z 5 -NZ 7 Z 8 Z 4 and Z 5 are each independently a single bond; -Z9-S(O)n-Zio-; W:\fional I\Spcies\65360.doc -68- -Z 9 -C(O)-Z 1 0 -Z 9 -Z 9 -O-ZO-; -Z 9 -S-Zo-; -Z 9 -O-C(O)-Z 0 or -Z 9 -C(O)-O-Z 0 Z 6 is alkyl, alkyl substituted with one to three groups selected from halogen, aryl, aryloxy and alkoxy; alkenyl, alkynyl, cycloalkyl; cycloalkyl substituted with one to three groups selected from alkyl, aryl, alkenyl and alkoxyaryl; cycloalkyl to which is fused a benzene ring; aryloxy substituted with one or two halogens; cycloalkylalkyl; cycloalkenyl; cycloalkenylalkyl; aryl, aryl substituted with methylenedioxy or one to four groups selected from alkyl, dialkylamino, cyano, halogen, trihaloalkyl, alkoxy and trihaloalkoxy; or heterocycle or substituted heterocycle; S S 15 Z 7 and Z 8 are each independently hydrogen, alkyl, cycloalkyl, S cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl, or Z 7 and Z 8 together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached; Z 9 and Z 10 are each independently a single bond, alkylene, alkenylene or 20 alkynylene; oe Z is hydrogen; or alkyl, alkyl substituted with one, two or three halogens, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or aralkyl; or any two of Z 7 Z 8 and Z" together are alkylene or alkenylene, completing a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached; each m is independently 1 or 2; and each n is independently 0, 1 or 2; R 1 and R 2 are each directly bonded to a ring carbon and are each i~ ndependently selected from those groups through recited above for R 3 and 4. T R 11 R 12 R 13 and R 1 4 are each independently hydrogen; W:\fionaNKI\Spccics\65360.doc 69 alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 2 and Z 3 heterocycle, substituted heterocycle or heterocyclooxy; halo; hydroxyl; cyano; nitro; -C(0)H or -C(0)R 5 -CO 2 H or -C0 2 R 5 SH, -S(O)nR 5 -S(0)m-OH, -S(O)m-OR 5 -0S(0)m-OR 5 -0S()mOH D5. or -0S(0)m0R 5 _Z 4 -NR 6 R 7 or _Z 4 0 )_Z 5 -NR 8 R 9 15 ~J is0, S, Nor NR1 5 9 0 K and L are N or C, provided that at least one of K or L is C; R R 15 is hydrogen, alkyl, hydroxyethoxy methyl or methoxyethoxy methyl; and p is 0or an integer from 1 to 2; comprising the steps of: 20 contacting a pinacol ester of the formula Ha or salt thereof: 0H0 3 C H 3 1-1 3 C CH 3 0cK Bo 0 0 (11a) 131 g R prot R 14 R with a halophenyl compound of the formula lIla or salt thereof: WAr.ow\NKI\Sp.i.\65360.d. Rz" J (ma) R R 12 halo in the presence of a palladium(0) catalyst and, optionally, a base, to form a nitrogen-protected compound of the formula IVa or salt thereof: *4 S 0* 56 S S S S.
5 6SS S S *.SS 5 (IVa) 5 ;and deprotecting the nitrogen of said formula IVa compound or salt thereof to form said compound of the formula Ia or salt thereof. 4. The method of any one of claims 1 to 3, wherein the alkyl groups of the acetal moiety are methyl or ethyl. The method of any one of claims 1 to 4, wherein the base employed in step is an alkali metal bicarbonate, carbonate or hydroxide.
6. The method of any one of claims 1 to 5, wherein the cyclization agent is Eaton's reagent, P 2 0 5 in methanesulfonic acid, or polyphosphoric acid. W:\fionaNKI\Spcics\65360.doc -71
7. The method of any one of claims 1 to 6, wherein said oxazole phenyl halide of the formula Illa(1) or salt thereof is 2-(4-iodophenyl)oxazole, said phenyl acid halide of the formula X or salt thereof is 4-iodobenzoyl chloride, and said amine acetal of the formula X or salt thereof is aminoacetaldehyde dimethyl acetal.
8. A method for preparing said compound of formula Illa as defined in claim 1 and substantially as hereinbefore described with reference to any one of the examples. DATED: 12 April, 2001 0* PHILLIPS ORMONDE FITZPATRICK Attorneys for: 15 BRISTOL-MYERS SQUIBB COMPANY S S S O W:\fona\NK\Spccies\65360,doc
AU65360/99A 1996-02-20 1999-12-21 Methods for the preparation of biphenyl isozaxole sulfonamides Ceased AU736021B2 (en)

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