XANTHINE DERIVATIVES AS SELECTIVE HM74A AGONISTS
The present invention relates to compounds which are xanthine derivatives, processes for the manufacture of said derivatives, pharmaceutical formulations containing these compounds and the use of the compounds in therapy, for example, in the treatment of diseases where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial.
Dyslipidaemia is a general term used to describe individuals with aberrant lipoprotein profiles. Clinically, the main classes of compounds used for the treatment of patients with dyslipidaemia, and therefore at risk of cardiovascular disease are the statins, fibrates, bile-acid binding resins and nicotinic acid. Nicotinic acid (Niacin, a B vitamin) has been used clinically for over 40 years in patients with various forms of dyslipidaemia. The primary mode of action of nicotinic acid is via inhibition of hormone- sensitive triglyceride lipase (HSL), which results in a lowering of plasma non-esterified fatty acids (NEFA) which in turn alters hepatic fat metabolism to reduce the output of LDL and VLDL (low an'd very low density lipoprotein). Reduced VLDL levels are thought to lower cholesterol ester transfer protein (CETP) activity to result in increased HDL (high density lipoprotein) levels which may be the cause of the observed cardiovascular benefits. Thus, nicotinic acid produces a very desirable alteration in lipoprotein profiles; reducing levels of VLDL and LDL whilst increasing HDL. Nicotinic acid has also been demonstrated to have disease modifying benefits, reducing the progression and increasing the regression of atherosclerotic lesions and reducing the number of cardiovascular events in several trials.
The observed inhibition of HSL by nicotinic acid treatment is mediated by a decrease in cellular cyclic adenosine monophosphate (cAMP) caused by the G-protein-mediated inhibition of adenylyl cyclase. Recently, the G-protein coupled receptors HM74 and HM74A have been identified as receptors for nicotinic acid (PCT patent application WO02/84298; Wise et. al. J Biol Chem., 2003, 278 (11 ), 9869-9874). The DNA sequence of human HM74A may be found in Genbank; accession number AY148884. Two further papers support this discovery, (Tunaru et. al. Nature Medicine, 2003, 9(3), 352-255 and Soga et. al. Biochem Biophys Res Commun., 2003, 303 (1 ) 364-369), however the nomenclature differs slightly. In the Tunaru paper what they term human HM74 we term HM74A and in the Soga paper HM74b is identical to HM74A. Cells transfected to express HM74A and/or HM74 gain the ability to elicit G1 G-protein mediated responses following exposure to nicotinic acid. In mice lacking the homologue of HM74A (m-PUMA-G) nicotinic acid fails to reduce plasma NEFA levels.
Certain xanthine derivatives have been synthesised and disclosed in the prior art. For example, EP0389282 discloses xanthine derivatives as potential mediators of cerebrovascular disorders. A range of xanthine derivatives were identified as
adenosine receptor antagonists by Jacobson et. al. in J. Med. Chem., 1993, 36, 2639- 2644.
We now present a group of xanthine derivatives which are selective agonists of the nicotinic acid receptor HM74A and are thus of potential benefit in the treatment, prophylaxis and suppression of diseases where under-activation of this receptor either contributes to the disease or where activation of the receptor will be beneficial.
Summary of the Invention
The present invention provides xanthine derivatives and the use of these derivatives in therapy, for example, in the treatment of diseases where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial. For example, in treatment of diseases of lipid metabolism including dyslipidaemia or hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia. As such, the compounds may also find favour as therapeutics for coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke, as well as the cardiovascular indications associated with type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. The compounds may also be of use in the treatment of inflammatory diseases or conditions, as set out further below.
Intermediates, formulations, methods and processes described herein form further embodiments of the invention.
Detailed Description of the Invention
According to one aspect of this invention we provide at least one chemical entity selected from compounds of formula (I)
(I)
and pharmaceutically acceptable derivatives thereof, wherein
R1 represents -(alkylene)m-X-(alkylene)n-Y;
Wherein X represents A, A1 , A2 or a direct link;
A represents a group selected from cycloalkylene, cycloalkenylene, aryl, heteroaryl, heterocyclyl, and -CH2-OC(O)-;
A1 represents a group selected from
-CH2-O-(CH2)qaryl-O-, -CH2-O-(CH2)WN(R5)C(O)O-, -CH2-N(R5)C(O)O-, -CH2-N(R5)C(O)- , -CH2-(O)p-(CH2)qC(O)NR5-, -CH2-N(R5)C(O)N(R5)-,
-CH2-C(O)N((CH2)WOH)-, -CH2-NR5-S(O)2-, CH2-S(O)2NR5-, -CH2-C(O)O-, -0-, -NR5-, and -S-;
A2 represents -CH(OH)-;
When X is A, A1 or A2, Y represents a group selected from heteroaryl, heterocyclyl, aryl, cycloalkyl, cycloalkenyl, -NH-aryl, -O(CH2)n-aryl,
-O-heteroaryl, -OR5, -C(O)OR5, -C(O)O-C6aryl, -OC(O)R4, -CH(aryl)2,
-CH(heteroaryl)2, and -C1-6 haloalkyl;
When X is A1 and Y is selected from
-O(CH2)n-aryl, -O-heteroaryl, -OR5, -OC(O)R4, and -NH-aryl, n is an integer selected from 2, 3, 4 and 5;
When X is A1 and Y is -C1-6 haloalkyl, or when X is A2, n is an integer selected from
1 , 2, 3, 4 and 5;
When X is a direct link, (m + n) is an integer selected from 2 to 10;
When X is a direct link and (m + n) is an integer selected from 3 to 10, Y represents a group selected from
-C(O)(CH2)qOR4, -C(O)-aryl, -C(O)-heteroaryl, -C(O)-heterocyclyl, heteroaryl, heterocyclyl, Aryl, 3 or 4 ring fused system, -CH(aryl)2, -CH(heteroaryl)2, -OR5,
-NR5R6, -NR5C(O)OR7, -(O)PC(O)NR5R7, and -NR5C(O)R7;
When X is a direct link and (m + n) is 2, Y represents a group selected from
-OR5, -NH2, and -NR5C(O)OR8;
When Y incorporates a ring, that ring may be optionally substituted by one or more of C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, halogen, -(CH2)q NR5R7,
-(CH2)q-(O)p-(CH2)q-N(R5)C(O)OR8, -(CH2)q-N(R5)C(O)R8, -(CH2)q-(O)p-(CH2)q-C(O)NR5R6, -(CH2)q-N(R5)C(O)N(R5)R6,
-(CH2)q-C(O)N((CH2)mOH)R5, -(CH2)q-N(R5)-S(O)2R8, -CH2-S(O)2N(R5)R6, -d-β haloalkyl, -OCF3, -OCH(F)2, -OCH2F, -C(O)OR5, -OR5, -R8CN, -CN, -SO2R9, -(CH2)nheteroaryl, -(CH2)nheterocycyl, -(CH2)ncycloalkyl, -(CH2)ncycloalkenyl, and -(CH2)naryl;
Provided that when X is A1 , A1 is -O- and Y is a ring which is substituted by aryl or heteroaryl, then m is an integer selected from 3, 4 and 5;
R2 is selected from hydrogen, CLIO alkyl, C2-10 alkenyl, C2-10 alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, aryl, and heteroaryl, each of which may be optionally substituted by one or more of a group independently selected from: C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, C1-6 haloalkyl, halogen, -CN, -OR4, -(CH2JnCOR4, -C(O)OR4, -OCOR4, -(CH2X1NR5R6, -(NH)PCONR5R6, -OCONR5R7, and -NR5C(O)OR7;
R3 represents a group selected from halogen and CN;
R4 is selected from hydrogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, -(CH2Jn cycloalkyl, -(CH2)n cycloalkenyl, -(CH2)n heterocyclyl, -(CH2Jn aryl, and -(CH2)n heteroaryl;
R5 and R6 are independently selected from hydrogen and C1-4 alkyl;
R7 represents a group selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, -(CH2X cycloalkyl, -(CH2)n cycloalkenyl, -(CH2)t heterocyclyl, -(CH2)taryl, and -(CH2X heteroaryl;
R8 represents a group selected from C1-4 alkyl;
R9 represents a group selected from C1-6 alkyl C2-6 alkenyl, C2-6 alkynyl, -(CH2)n cycloalkyl, -(CH2)ncycloalkenyl, -(CH2)nheterocyclyl, -(CH2Jn aryl,
-(CH2)nheteroaryl, and CN;
m represents an integer selected from 1 , 2, 3, 4 and 5;
n represents an integer selected from O, 1 , 2, 3, 4 and 5;
p represents an integer selected from O and 1 ;
q represents an integer selected from O, 1 and 2;
t represents an integer selected from 1 and 2; and
w represents an integer selected from 2, 3 and 4.
The compounds are of use in the treatment of diseases where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial. For example in treatment of diseases of lipid metabolism including dyslipidaemia or hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia. As such, the compounds may also find favour as therapeutics for coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke, as well as the cardiovascular indications associated with type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. As such the compounds of the present invention may find use as agonists or partial agonists of HM74A.
According to another aspect of this invention we provide at least one chemical entity selected from compounds of formula (I)
(I)
and pharmaceutically acceptable derivatives thereof, wherein
R1 represents -(alkylene)m-X-(alkylene)n-Y
Wherein X represents A, A1 , A2 or a direct link;
A represents a group selected from: cycloalkylene, cycloalkenylene, aryl, heteroaryl, heterocyclyl, and -CH2-OC(O)-;
A1 represents a group selected from:
-CH2-O-(CH2)qaryl-O-, -CH2-O-(CH2)WN(R5)C(O)O-, -CH2-N(R5)C(O)O-, -CH2- N(R5)C(O)- , -CH2-(O)p-(CH2)qC(O)NR5-, -CH2-N(R5)C(O)N(R5)-, -CH2-C(O)N((CH2)mOH)-, -CH2-N R5-S(O)2-, CH2-S(O)2NR5-, -CH2-C(O)O-, -O-, -NH-, and -S-;
A2 represents: -CH(OH)-;
When X is A, A1 or A2, Y represents a group selected from: heteroaryl, heterocyclyl, aryl, cycloalkyl, cycloalkenyl, -NH-aryl, -O(CH2)n-aryl, -O-heteroaryl, -OR5, -C(O)OR5, -C(O)O-C6 aryl, -OC(O)R5, -CH(aryl)2, -CH(heteroaryl)2, and -C1-6 haloalkyl;
When X is A1 and Y is selected from: -O(CH2)n-aryl, -O-heteroaryl, -OR5, -OC(O)R5, and -NH-aryl, n is an integer selected from 2, 3, 4 and 5;
When X is A1 and Y is -CF3, or when X is A2, n is an integer selected from 1 , 2, 3, 4 and 5;
When X is a direct link, (m + n) is an integer selected from 2 to 10;
When X is a direct link and (m + n) is an integer selected from 3 to 10, Y represents a group selected from: -C(O)(CH2)qOR5, -C(O)-aryl, -C(O)-heteroaryl, -C(O)-heterocyclyl, heteroaryl, heterocyclyl, Aryl, 3 or 4 ring fused system, -CH(aryl)2, -CH(heteroaryl)2, -
OR5, -NR5R6, -NC(O)OR8, -(O)PC(O)NR5R6, and -NR5C(O)R8;
When X is a direct link and (m + n) is 2, Y represents a group selected from:
-OR5, -NH2, and -NC(O)OR8;
When Y incorporates a ring, that ring may be optionally substituted by one or more of: C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, halogen, -NH2, -(CH2)q-(O)p-(CH2)q-N(R5)C(O)OR8, -(CH2)q-N(R5)C(O)R8, -(CH2)q-(O)p-(CH2)q-C(O)NR5R6, -(CH2)q-N(R5)C(O)N(R5)R6, -(CH2)q-C(O)N((CH2)mOH)R5, -(CH2)q-N(R5)-S(O)2R8, -CH2-S(O)2N(R5JR6, -C1-6 haloalkyl, -OCF3, -OCH(F)2, -OCH2F, -C(O)OR5, -OR5, -(R8)PCN, -SO2R9, -(CH2)nheteroaryl, -(CH2)nheterocycyl, -(CH2)ncycloalkyl, -(CH2)ncycloalkenyl, and -(CH2)naryl;
Provided that when X is A1 , A1 is -O- and Y is a ring which is substituted by aryl or heteroaryl, then m is an integer selected from 3, 4 and 5;
R2 is selected from: H; or Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, cycloalkyl, cycloalkenyl heterocyclyl, aryl, and heteroaryl, each of which may be optionally substituted by one or more of: C1-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, C1-6 haloalkyl, halogen, -CN, -OR4, -(CH2JnCOR4, -C(O)OR4, -OCOR4, - (CH2)nNR5R6, -(NH)PCONR5R6, -OCONR5R7, and -NHC(O)OR7;
R3 is selected from: halogen and CN;
R4 is selected from: H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, -(CH2)n cycloalkyl, -(CH2)n cycloalkenyl, -(CH2)n heterocyclyl, -(CH2)n aryl, and -(CH2)n heteroaryl;
R5 and R6 are selected from: hydrogen and C1-4 alkyl;
R7 is selected from: H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, -(CH2)tcycloalkyl, -(CH2)n cycloalkenyl, -(CH2)t heterocyclyl, -(CH2)taryl, and -(CH2)t heteroaryl;
R8 is selected from C1-4 alkyl;
R9 is selected from, C1-6 alkyl C2-6 alkenyl, C2-6 alkynyl, -(CH2)n cycloalkyl, -(CH2)ncycloalkenyl, -(CH2)nheterocyclyl, -(CH2)n aryl, and -(CH2)nheteroaryl, CN;
m represents an integer selected from: 1 , 2, 3, 4 and 5;
n represents an integer selected from: 0, 1 , 2, 3, 4 and 5;
p represents an integer selected from: 0 and 1 ;
q represents an integer selected from: 0, 1 and 2;
t represents an integer selected from: 1 and 2;
w represents an integer selected from: 2, 3 and 4.
In one embodiment, X represents A or A1. In a further embodiment, A is selected from heteroaryl, heterocyclyl, and A1 is selected from CH2-O-(CH2)WN(R5)C(O)O-, for example CH2O(CH2)2NHC(O)O-, CH2-N(R5)C(O)O- for example CH2-NHC(O)O, CH2-N(R5JC(O)- for example, CH2-NHC(O)-, CH2-(O)p-(CH2)qC(O)NR5- for example CH2C(O)NCH3- , CH2-N(R5JC(O)N(R5)- for example CH2-NHC(O)NCH3-,
CH2-C(O)N((CH2)mOH)- for example CH2-C(O)N((CH2)2OH)-, CH2-NR5-S(O)2- for example CH2-NH-S(O)2-, CH2-S(O)2NR5- for example CH2-S(O)2NCH3-, and CH2-C(O)O-. In another embodiment, X represents A and A represents a heteroaryl. In another embodiment A represents a heteroaryl comprising a nitrogen heteroatom, for example, triazolyl, furazanyl, oxadiazolyl, tetrazolyl, imidazolyl or pyrazolyl.
In one embodiment, Y represents an optionally substituted group selected from: aryl, for example phenyl or napthyl, heteroaryl, for example pyridinyl, thiazolyl, thienyl, benzofuranyl or indolyl, and O-aryl, for example O-phenyl.
In a further embodiment, Y is substituted by one or more groups selected from OR5 for example OH or OCH3, halogen, for example F or Cl, aryl, for example phenyl,
Ci-6 haloalkyl for example CF3Or CH2CF3 , OCF3, (R8)PCN for example CN, (CH2)q-N(R5)-S(O)2R8 , for example NHSO2CH3 and SO2R9, for example SO2CH3.
In yet a further embodiment Y is substituted by one or more groups selected from OR5, halogen, C1-6 haloalkyl, and -(CH2)q-N(R5)C(O)R8.
In another embodiment, Y is substituted by one or more groups selected from halogen, and C1-6 haloalkyl.
In yet a further embodiment, wherein Y is a ring, it is not further substituted.
In one embodiment of the invention, when X represents A or A1 , and A represents cycloalkyl, cycloalkenyl, aryl, heteroaryl or heterocyclyl, and A1 represents -CH2-O-(CH2)WN(R5)C(O)O-, -CH2-N(R5)C(O)O-, -CH2-N(R5)C(O)- , -CH2-(O)p-(CH2)qC(O)NR5-, -CH2-N(R5)C(O)N(R5)-, or -CH2-C(O)N((CH2)mOH)-, and Y represents a ring, for example when X represents oxadizolyl, tetrazolyl or pyrazolyl and Y represents phenyl, pyridinyl, or thienyl, m is an integer selected from 3 and 4 and n is an integer selected from O and 1 , for example m is 4 and n is 0, or m is 3 and n is 1 ;
In one embodiment R2 represents C1-10 alkyl which may be optionally substituted by one or more of: cycloalkyl, heterocyclyl, aryl, heteroaryl, C1-6 haloalkyl, halogen, -CN, -OR4, -(CH2)nCOR5, -C(O)OR4, -OCOR4, -(CH2)nNR5R6, and -(NH)PCONR5R6. In a further embodiment, R2 is selected from C1-10 alkyl which may be optionally substituted by one or more of: cycloalkyl, aryl, heteroaryl, C1-6 haloalkyl, halogen, -CN, -OR4, -(CH2)nCOR5, -C(O)OR4 and -OCOR4. In yet a further embodiment R2 is selected from C1-6 alkyl which may be optionally substituted by one or more of: cycloalkyl, C1-6 haloalkyl, halogen, -CN or -OR4. In yet another further embodiment, R2 is selected from C3-6 alkyl, for example butyl or pentyl.
In one embodiment, R3 represents halogen. In a further embodiment, R3 is selected from: chlorine and bromine. In another embodiment, R3 represents chlorine.
With regard to stereoisomers, the compounds of formula (I) may have one or more asymmetric carbon atom and may occur as recemates, racemic mixtures and as individual enantiomers or diastereomers. All such isomeric forms are included within the present invention, including mixtures thereof.
Where a compound of formula (I) contains an alkenyl or alkenylene group, cis (E) and trans (Z) isomerism may also occur. The present invention includes the individual stereoisomers of the compound of the invention and, where appropriate, the individual tautomeric forms thereof, together with mixtures thereof.
Separation of diastereoisomers or cis and trans isomers may be achieved by conventional techniques, e.g. by fractional crystallisation, chromatography or HPLC of a stereoisomeric mixture of the agent may also be prepared from a corresponding optically pure intermediate or by resolution, such as HPLC of the corresponding racemate using a suitable chiral support or by fractional crystallisation of the diastereoisomeric salts formed by reaction of the corresponding racemate with a suitable optically active acid or base, as appropriate.
Furthermore, some of the crystalline forms of the compounds of formula (I) may exist as polymorphs, which are included in the present invention. One form may have an advantage over another form, for example one form may have improved stability over another form.
It is to be understood that the present invention includes any combination of particular embodiments and covers all combinations of particular substituents described hereinabove.
Throughout the present specification and the accompanying claims the words "comprise" and "include" and variations such as "comprises", "comprising", "includes" and "including" are to be interpreted inclusively. That is, these words are intended to convey the possible inclusion of other elements or integers not specifically recited, where the context allows.
As used herein, the term "alkyl" (when used as a group or as part of a group) refers to a straight or branched hydrocarbon chain unless specified otherwise, containing the specified number of carbon atoms. For example, C3-C10alkyl means a straight or branched hydrocarbon chain containing at least 3 and at most 10 carbon atoms. Examples of alkyl as used herein include, but are not limited to methyl (Me), ethyl (Et), n-propyl and i-propyl.
The term "alkylene" or as used herein means both straight and branched chain, or cyclic saturated hydrocarbon linker groups. Examples of alkylene groups include methylene (-CH2-), ethylene (-CH2CH2-), ethene (-CH=CH-), or cyclopropylene and the like. For example, as used herein, -(alk)n-, where n is 3 represents -(CH2)3-, -C(CH3)2-, -CH2CH=CH-, or -cyclopropylene- and the like. For example as used herein, -(alk)m- where m is 4 represents -(CH2)4-, -CH2C(CH3)2-, -CH2CH=CHCH2-, or -CH2cyclopropylene- and the like.
The term "alkenyl" as used herein refers to a straight or branched hydrocarbon chain containing the specified number of carbon atoms which contains one or more double bonds.
The term "alkynyl" as used herein refers to a straight or branched hydrocarbon chain containing the specified number of carbon atoms which contains one or more triple bonds.
The term "cycloalkyl" as used herein refers to a saturated monocyclic hydrocarbon ring of 3 to 8 carbon atoms. Examples of such groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl and the like.
The term "cycloalkylene" as used herein refers to a saturated monocyclic hydrocarbon ring of 3 to 8 carbon linker goups. Examples of such groups include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene or cyclooctylene and the like.
The term "cycloalkenyl" as used herein refers to an unsaturated non-aromatic monocyclic hydrocarbon ring of 3 to 8 carbon atoms containing one or more carbon- carbon double bonds. Examples of such groups include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl or cyclooctenyl and the like.
The term "cycloalkenylene" as used herein refers to an unsaturated non-aromatic monocyclic hydrocarbon ring of 3 to 8 carbon linker groups containing one or more carbon-carbon double bonds. Examples of such groups include cyclopropenylene, cyclobutenylene, cyclopentenylene, cyclohexenylene, cycloheptenylene or cyclooctenylene and the like.
The term "aryl" as used herein refers to a C6-i2 monocyclic, bicyclic or tricyclic hydrocarbon ring wherein at least one ring is aromatic. Examples of such groups include phenyl, naphthyl or tetrahydronaphthalenyl and the like.
The term "heteroaryl" as used herein refers to a 5-6 membered monocyclic aromatic ring or a fused 8-10 membered bicyclic aromatic ring, containing 1 to 4 heteroatoms selected from oxygen, nitrogen and sulphur. There may be one or more optional oxo substituents on the ring carbon atoms. Examples of such monocyclic aromatic rings include thienyl, furyl, furazanyl, pyrrolyl, triazolyl, tetrazolyl, imidazolyl, oxazolyl, thiazolyl, oxadiazolyl, isothiazolyl, isoxazolyl, thiadiazolyl, pyranyl, pyrazolyl, pyrimidyl, pyridazinyl, pyrazinyl, pyridyl, triazinyl, tetrazinyl and the like. Examples of such fused aromatic rings include quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pteridinyl, cinnolinyl, phthalazinyl, naphthyridinyl, indolyl, isoindolyl, azaindolyl, indolizinyl, indazolyl, purinyl, pyrrolopyridinyl, furopyridinyl, benzofuranyl, isobenzofuranyl, benzothienyl, benzoimidazolyl, benzoxazolyl, benzoisoxazolyl, benzothiazolyl, benzoisothiazolyl, benzoxadiazolyl, benzothiadiazolyl and the like.
The term "heterocyclyl" as used herein refers to a 4-7 membered monocyclic ring or a fused 8-12 membered bicyclic ring which may be saturated or partially unsaturated containing 1 to 4 heteroatoms selected from oxygen, nitrogen or sulphur. There may be one or more optional oxo substituents on the ring carbon atoms. Examples of such monocyclic rings include pyrrolidinyl, azetidinyl, pyrazolidinyl, oxazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, dioxolanyl, dioxanyl, oxathiolanyl, oxathianyl, dithianyl, dihydrofuranyl, tetrahydrofuranyl, dihydropyranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, diazepanyl, azepanyl and the like. Examples of such bicyclic rings include indolinyl, isoindolinyl, benzopyranyl, quinuclidinyl, 2,3,4,5-tetrahydro-1H-3-benzazepine, tetrahydroisoquinolinyl and the like.
The term "3 or 4 ring fused system" as used herein refers to a fused 12-18 membered tricyclic or tetracyclic ring which contains 1 to 4 heteroatoms of N and wherein at least one ring is aromatic. There may be one or more optional oxo substituents on the ring carbon atoms. Examples of such fused aromatic rings include carbazolyl, acenaphthyl, naphthotriazolyl and the like.
The terms "halogen" or "halo" as used herein refer to a fluorine, chlorine, bromine or iodine atom.
The term "C1-6 haloalkyl" as used herein refers to a C1-6 alkyl group as defined herein wherein at least one hydrogen atom is replaced with halogen. Examples of such groups include fluoroethyl, trifluoromethyl or trifluoroethyl and the like.
As used herein, where a group is referred to as being "substituted" by another group or having "one or more substituents" unless a particular position for such a substitution is specified it is to be understood that a substitution may be present at any position in the group.
The term "pharmaceutically acceptable derivative" as used herein refers to any pharmaceutically acceptable derivative of a compound of the present invention, for example, salts, solvates or esters, which upon administration to a mammal, such as a human, is capable of providing (directly or indirectly) such a compound or an active metabolite thereof. Such derivatives are clear to those skilled in the art, without undue experimentation, and with reference to the teaching of Burger's Medicinal Chemistry And Drug Discovery, 5th Edition, VoI 1 : Principles And Practice, which is incorporated herein by reference.
As used herein, the term "pharmaceutically acceptable" used in relation to an ingredient (active ingredient, diluent, excipient or carrier) which may be included in a
pharmaceutical formulation for administration to a patient, refers to that ingredient being acceptable in the sense of being compatible with any other ingredients present in the pharmaceutical formulation and not being deleterious to the recipient thereof.
As used herein, the term "solvate" refers to a complex of variable stoichiometry formed by a solute (in this invention, a compound of formula (I) or a pharmaceutically acceptable derivative thereof) and a solvent. Such solvents for the purposes of the present invention may not interfere with the biological activity of the solute. The solvent used may be a pharmaceutically acceptable solvent. Examples of suitable pharmaceutically acceptable solvents include water, ethanol and acetic acid. An example of a solvent that may be used is water, in which case the solvate may be referred to as a hydrate of the solute in question.
It will be appreciated that, for pharmaceutical use, the "salt or solvate" referred to above will be a pharmaceutically acceptable salt or solvate. However, other salts or solvates may find use, for example, in the preparation of a compound of formula (I) or in the preparation of a pharmaceutically acceptable salt or solvate thereof.
Pharmaceutically acceptable salts include those described by Berge, Bighley and Monkhouse, J. Pharm. ScL, 1977, 66, 1-19. Suitable pharmaceutically acceptable salts include alkali metal salts formed from the addition of alkali metal bases such as alkali metal hydroxides. Examples of suitable alkali metal salts include sodium salts and potassium salts. Other suitable pharmaceutically acceptable salts include alkaline earth metal salts such as calcium salts and magnesium salts, ammonium salts; or salts with organic bases such as ethanolamine, triethanolamine, ethylene diamine, triethylmine, choline and meglumine; or salts with amino acids such as arginine, lysine and histidine.
Esters may be active in their own right and/or be hydrolysable under in vivo conditions in the human body. Suitable pharmaceutically acceptable in vivo hydrolysable ester groups include those which break down readily in the human body to leave the parent acid or its salt. An ester may be formed at a carboxylic acid (-C(O)OH) group, by methods well known in the art involving reaction with the corresponding alcohol. For example, esters may be C1-6alkyl esters, e.g. methyl esters, ethyl esters, and the like.
As used herein, the term "compounds of the invention" means the compounds according to Formula I and the pharmaceutically acceptable derivatives thereof. The term "a compound of the invention" means any one of the compounds of the invention as defined above.
As used herein the term "at least one chemical entity" means at least one chemical substance chosen from the group of compounds consisting of compounds of formula I and pharmaceutically acceptable derivatives thereof.
In one aspect of the invention there is provided substantially crystalline 3-Butyl-8- chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 1. In another aspect of the invention there is provided substantially crystalline 3- Butyl-8-chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine- 2,6-dione form 2.
Thermal analysis on samples of substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2- pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione forms 1 and 2 was carried out. Thus, there is provided substantially crystalline 3-Butyl-8-chloro-1-{4- [5-(2-py rid i ny I )- 1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione (form 1 or form 2) having a melting point onset measured by DSC (± 0.50C) of: 160 0C or greater and 1470C or greater, respectively.
Samples of substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4- oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 1 , and 3-Butyl-8-chloro-1-{4- [5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 2, prepared as described hereinafter, gave the X-ray powder diffraction patterns of Figures 1-2. The X-ray diffraction pattern is unique to the crystalline form. The substantially crystalline forms exhibit diffraction patterns with a unique set of diffraction peaks which can be expressed in 2 theta angles (°).
2 Theta diffraction angles account for positions of various peaks in the X-ray diffraction pattern. Slight variations in observed 2 theta angles are expected based on the specific diffractometer employed and the analyst's sample preparation technique.
The substantially crystalline forms of 3-Butyl-8-chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4- oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione can be identified by the presence of a characteristic 2 theta angle peak, or by multiple 2 theta angles which are reasonably characteristic of the particular crystalline forms. To identify substantially crystalline 3-Butyl-8-chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro- 1 H-purine-2,6-dione (form 1), these peaks occur at the following positions, expressed in 2 theta angles (±0.1 degrees): 5.4, 6.7, 9.7, 11.1 , 12.9, 14.0, 15.6, 16.3, 16.7, 23.1 degrees. To identify substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4- oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione (form 2), these peaks occur at the following positions, expressed in 2 theta angles (±0.1 degrees): 5.2, 6.6, 10.4, 11.2, 13.4, 15.6, 18.1 , 19.5, 20.9 degrees. In one embodiment at least one of the foregoing 2 theta angles are employed to identify substantially crystalline 3-Butyl-8- chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione
form 1 and substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4- oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 2. In other embodiments at least 2, 3, 4 or 5 (where applicable) of the foregoing 2 theta angles are employed to identify substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3- yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 1 , substantially crystalline 3-Butyl-8- chloro-1 -{4-[5-(2-py rid iny I )- 1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 2.
Some margin of error is present in each of the 2 theta angle assignments. The margin of error in the foregoing 2 theta angles is approximately ±0.1 degrees for each of the foregoing peak assignments.
Since some margin of error is possible in the assignment of 2 theta angles, the preferred method of comparing X-ray powder diffraction patterns in order to identify a particular crystalline form is to overlay the X-ray powder diffraction pattern of the unknown form over the X-ray powder diffraction pattern of a known form. For example, one skilled in the art can overlay an X-ray powder diffraction pattern of an unidentified form of 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H- purine-2,6-dione, obtained using the methods described herein, see Figure 3 for example, and readily determine whether the X-ray diffraction pattern of the unidentified form is substantially the same as the X-ray powder diffraction pattern of substantially crystalline 3-Butyl-8-chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro- 1 H-purine-2,6-dione Form 1 or 2. If the X-ray powder diffraction pattern is substantially the same as that shown in any of Figures 1-2, the previously form can be readily and accurately identified.
As used herein, the term "substantially crystalline form" means that it is substantially free of amorphous form 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3- yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione. By "substantially free" is meant containing less than 50% of the amorphous form, in one aspect less than 20% of the amorphous form, in another aspect less than 10% of the amorphous form, in another aspect less than 5% of the amorphous form, in another aspect less than 2% of the amorphous form, in another aspect less than 1% of the amorphous form.
The present invention provides a method for the preparation of substantially crystalline 3-Butyl-8-chloro-1 -{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine- 2,6-dione form as described herein.
Compounds of formula (I) are of potential therapeutic benefit in the treatment and amelioration of the symptoms of many diseases of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including
atherosclerosis, arteriosclerosis, and hypertriglyceridaemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. As such, the compounds may also find favour as therapeutics for coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke.
It has been reported that the HM74 and HM74A receptors are involved in inflammation (WO02084298). Inflammation represents a group of vascular, cellular and neurological responses to trauma. Inflammation can be characterised as the movement of inflammatory cells such as monocytes, neutrophils and granulocytes into the tissues. This is usually associated with reduced endothelial barrier function and oedema into the tissues. Inflammation with regards to disease typically is referred to as chronic inflammation. Such chronic inflammation may manifest itself through disease symptoms. The aim of anti-inflammatory therapy is therefore to reduce this chronic inflammation and allow for the physiological process of healing and tissue repair to progress.
Examples of inflammatory diseases or conditions for which the compounds of the present invention may demonstrate utility include those of the joint, for example arthritis (e.g. rheumatoid arthritis, osteoarthritis, prosthetic joint failure), or the gastrointestinal tract (e.g. ulcerative colitis, Crohn's disease, and other inflammatory bowel and gastrointestinal diseases, gastritis and mucosal inflammation resulting from infection, the enteropathy provoked by non-steroidal anti-inflammatory drugs), of the lung (e.g. adult respiratory distress syndrome, asthma, cystic fibrosis, or chronic obstructive pulmonary disease), of the heart (e.g. myocarditis), of nervous tissue (e.g. multiple sclerosis), of the pancreas, (e.g. inflammation associated with diabetes melitus and complications thereof, of the kidney (e.g. glomerulonephritis), of the skin (e.g. dermatitis, psoriasis, eczema, urticaria, burn injury), of the eye (e.g. glaucoma) as well as of transplanted organs (e.g. rejection) and multi-organ diseases (e.g. systemic lupus erythematosis, sepsis) and inflammatory sequelae of viral or bacterial infections and inflammatory conditions associated with atherosclerosis and following hypoxic or ischaemic insults (with or without reperfusion), for example in the brain or in ischaemic heart disease.
In one embodiment, the compounds of this invention are useful in the treatment and prevention of inflammation, diabetes and cardiovascular diseases or conditions including atherosclerosis, arteriosclerosis, hypertriglyceridemia, and mixed dyslipidaemia.
Nicotinic acid has a significant side effect profile, possibly because it is dosed at high level (gram quantities daily). The most common side effect is an intense cutaneous flushing. In certain embodiments of the present invention the compounds may exhibit reduced side effects compared to nicotinic acid. HM74A has been identified as a high
affinity receptor for nicotinic acid whilst HM74 is a lower affinity receptor. The compounds of the present invention show greater affinity for HM74A than for HM74 therefore may find use as selective HM74A agonists or partial agonists.
The potential for compounds of formula (I) to activate HM74A may be demonstrated, for example, using the following in vitro whole cell assays:
In-vitro testing
For transient transfections, HEK293T cells (HEK293 cells stably expressing the SV40 large T-antigen) were maintained in DMEM containing 10% foetal calf serum and 2mM glutamine. Cells were seeded in 90mm culture dishes and grown to 60-80% confluence (18-24h) prior to transfection. Human HM74A (GenBank™ accession number AY148884) was subcloned in to a mammalian expression vector (pcDNA3; Invitrogen) and transfected using Lipofectamine reagent. For transfection, 9μg of DNA was mixed with 30μl Lipofectamine in 0.6ml of Opti-MEM (Life Technologies Inc.) and was incubated at room temperature for 30min prior to the addition of 1.6ml of Opti-MEM. Cells were exposed to the Lipofectamine/DNA mixture for 5h and 6ml of 20% (v/v) foetal calf serum in DMEM was then added. Cells were harvested 48h after transfection. Pertussis toxin treatment was carried out by supplementation into media at 50ngml'1 for 16h. All transient transfection studies involved co-transfection of receptor together with the Gi/0 G protein, Goiα.
For generation of stable cell lines the above method was used to transfect CHO-K1 cells seeded in six well dishes grown to 30% confluence. These cells were maintained in DMEM F-12 HAM media containing 10% foetal calf serum and 2mM glutamine. 48h post-transfection the media was supplemented with 400μg/ml Geneticin (G418, Gibco) for selection of antibiotic resistant cells. Clonal CHO-K1 cell lines stably expressing
HM74A were confirmed by [35S]-GTPyS binding measurements, following the addition of nicotinic acid.
P2 membrane preparation - Plasma membrane-containing P2 particulate fractions were prepared from cell pastes frozen at -800C after harvest. All procedures were carried out at 4°C. Cell pellets were resuspended in 1 ml of 1 OmM Tris-HCI and 0.1mM EDTA, pH 7.5 (buffer A) and by homogenisation for 20s with a Ultra Turrax followed by passage (5 times) through a 25-gauge needle. Cell lysates were centrifuged at 1 ,000g for 10 min in a microcentrifuge to pellet the nuclei and unbroken cells and P2 particulate fractions were recovered by microcentrifugation at 16,00Og for 30min. P2 particulate fractions were resuspended in buffer A and stored at -800C until required.
[35S]-GTPyS binding - assays were performed at room temperature in 384-well format based on methods described previously, (Wieland, T. and Jakobs, K.H. (1994)
Methods Enzymol. 237, 3-13). Briefly, the dilution of standard or test compounds were prepared and added to a 384-well plate in a volume of 10μl. Membranes (HM74A or HM74) were diluted in assay buffer (2OmM HEPES, 10OmM NaCI, 1OmM MgCI2, pH7.4) supplemented with saponin (60μg/ml), Leadseeker WGA beads (Amersham; 250μg/well) and 10μM GDP1 so that the 20μl volume added to each well contains 5μg of membranes. [35S]-GTPyS (1170 Ci/mmol, Amersham) was diluted (1 :1500) in assay buffer and 20μl added to each well. Following the addition of the radioligand, the plates were sealed, pulse spun and incubated for 4hours at room temperature. At the end of the incubation period the plates were read on a Leadseeker machine (VIEWLUX PLUS; Perkin-Elmer) to determine the levels of specific binding.
These assays were refined by reducing the final assay volume to 10 μl. For this 10 μl assay a revised protocol was used. This involved the use of only 100 nl of standard or test compound per well of a 384-well plate and 1.5 μg membrane and 100 μg Leadseeker WGA beads. For the low volume protocol, membrane, beads and [35S]- GTPγS were mixed together and then 10 μl of this mix were dispensed to each well. Incubation and plate read were identical for the 10μl and 50 μl assays.
All exemplified compounds were tested in one or both of the [35S]-GTPyS binding assays described above (i.e. the 10μl and 50μl assays).
Data was analysed by curve fitting as carried out using a Four Parameter Logistical equation using the XC50 software package (max 2 points deleted from any one curve). Specific binding is expressed as pEC50 and as % efficacy compared to the maximal response of nicotinic acid binding.
In-vivo testing
HM74A agonists can be tested in male Spague-Dawley rats (200-25Og) which have been fasted for at least 12 hours prior to the study. The compounds are dosed intravenously at either 1 or 3mg/kg (5ml/kg) or by oral gavage at doses ranging from 1- 30mg/kg (10ml/kg). Blood samples (0.3ml tail vein bleed) can be taken pre-dose and at three times post-dose (times ranging from 15 minutes to 6 hours post-dose). Each blood sample is transferred to a heparin tube (Becton Dickinson Microtainer, PST LH) and centrifuged (10,000g for 5 minutes) to produce a plasma sample. The plasma samples are assayed for levels of non-esterified fatty acids (NEFA) using a commercially available kit (Randox). Inhibition of plasma NEFA levels, relative to pre- dose levels, are used as a surrogate for HM74A agonist activity.
In order to determine whether HM74A compounds exhibit the flushing response associated with nicotinic acid they can be dosed to conscious guinea-pigs. Male
Dunkin Hartley guinea pigs (300-60Og; n=10-20 per group) are fasted for at least 12 hours, but not in excess of 24 hours prior to experimention. Pre-study blood samples (0.5ml) are taken from each animal by cardiac puncture under recovery anaesthesia (Isoflurane 3.5% with additional 02 (1 Umin)). Ear temperature measurements are taken by placing the left ear of each animal over an infra-red temperature probe. Measurements are taken at one minute intervals from 5 minutes pre-dose to 30 minutes post-dose. Temperature measurements are then taken at 15 minute intervals up to 2 hours post-dose. Animals receive test compounds by oral gavage (5ml/kg). Blood samples (0.5ml) are taken by cardiac puncture under terminal anaesthesia. Blood samples are taken from individual animals to provide data at 0.5, 1 , 2, 3, and 4 hours post-dose. All blood samples are placed on a blood roller for 5 minutes then stored on ice until the end of the study. Following centrifugation (1200Og for 5min) the plasma is transferred into fresh tubes and stored at -200C until assayed for NEFA concentrations.
Compounds according to Formula (I) have been synthesised (see synthetic examples below) and tested in the [35S]-GTPyS binding assays discussed above.
Some compounds according to formula (I) including:
3-butyl-8-chloro-1-[3-(dimethylamino)propyl]-3,7-dihydro-1 H-purine-2,6-dione;
8-chloro-3-(3,3-dimethylbutyl)-1-[2-(ethyloxy)ethyl]-3,7-dihydro-1 H-purine-2,6-dione;
3-butyl-8-chloro-1 -[3-(5-phenyl-1 ,2,4-oxadiazol-3-yl)propyl]-3,7-dihydro-1 H-purine-2,6- dione; 1 -[3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)propyl]-1 H- naphthoβ.S-dHI ^.Sltriazole^.θ-dione;
2-({4-[3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1- yl)propyl]phenyl}oxy)ethyl acetate.
have utility as intermediates in the production of other compounds according to formula (I)-
The exemplified compounds (Examples 1 - 894) have a pEC50 of 4.3 (+/- 0.3 log unit) or greater and an efficacy of 30% or greater (in relation to nicotinic acid) in the [35S]- GTPγS binding assays described above, in which they were tested.
The following compounds were tested and found to have activity lower than a pEC50 of 4.3 (+/- 0.3 log unit) and an efficacy of less than 30% (in relation to nicotinic acid) in the [35S]-GTPyS binding assays described above, in which they were tested.
8-chloro-1 -(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[2-(1 - piperidinyl)ethyl]-3,7-dihydro-1H-purine-2,6-dione;
8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[2- (hexahydro-1 H-azepin-1 -yl)ethyl]-3,7-dihydro-1 H-purine-2,6-dione; 8-chloro-1 -(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[2-(1 - pyrrolidinyl)ethyl]-3,7-dihydro-1H-purine-2,6-dione; 8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[2- (dimethylamino)-2-methylpropyl]-3,7-dihydro-1H-purine-2,6-dione; 8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[3- (dimethylamino)propyl]-3,7-dihydro-1H-purine-2,6-dione; 8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[3-(4- methyl-1 -piperazinyl)propyl]-3,7-dihydro-1 H-purine-2,6-dione;
8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-[2- (dimethylamino)ethyl]-3,7-dihydro-1/-/-purine-2,6-dione.
General purification and analytical methods:
LC/MS: Method
Analytical HPLC was conducted on a Supelcosil™ ABZ+PLUS column (Supelco) (3μm, 3.3cm x 4.6mm ID) eluting with 0.1% HCO2H and 0.01 M ammonium acetate in water (solvent A), and 95% MeCN and 5% water (containing 0.5% HCO2H) (solvent B), using the following elution gradient 0-0.7min 0%B, 0.7-4.2min 0→100%B, 4.2-4.6minutes 100%B, 4.6-4.8min 100→0%B at a flow rate of 3 ml/min. The diode array UV detection was carried out in the range 215 to 330nm. The mass spectra (MS) were recorded on a Waters ZQ mass spectrometer using electrospray positive ionisation [(ES+ve to give MH+ and M(NH4)* molecular ions] or electrospray negative ionisation [(ES-ve to give (M- H)" molecular ion] modes. Only the parent ion of major isotopes quoted.
1H NMR spectra were recorded using a Bruker DPX 400MHz spectrometer using tetramethylsilane as the standard.
Biotage™ chromatography refers to purification carried out using either the Flash 4Oi or Flash 15Oi purification systems, sold by Biotage AB, using cartridges pre-packed with KPSiI (silica).
Companion™ system refers to the Teledyne lsco Combiflash Companion™ purification system. This is a gradient controlled purification system with integral, variable wavelength UV detection with the capability to trigger automated fraction collection by UV threshold.
Mass directed autoprep (MDAP) refers to methods where the material was purified by high performance liquid chromatography using either a Supelcosil ABZ+ 5μm column
(10cm x 20mm i.d.) or a Supelcosil ABZ+ 10μm column (15cm x 30mm i.d.) with a suitable gradient of solvent A: 0.1% HCO2H in water and solvent B: 95% MeCN, 5%
water (containing 0.5% HCO2H). The Waters 2767 inject / collector was triggered by a MicroMass ZQ Mass Spectrometer on detecting the mass of interest (using Micromass MassLynx software).
Preparative HPLC (Autoprep HPLC or Autoprep) refers to methods where the material was purified by high performance liquid chromatography on a Supelcosil ABZ+ 5μm column (10cm x 21.2mm i.d.) with a suitable gradient of 0.1% HCO2H in water and MeCN (with 0.5% HCO2H). The Gilson 233 fraction collector was triggered by UV detection.
SPE (solid phase extraction) refers to the use of polyethylene cartridges which are prepacked with sorbent used for purification. The sorbent contained in these cartridges will be specified. Examples used are detailed below: C18 SPE refers to the use of cartridges pre-packed with 40μM C18 funtionalised silica sorbent (sold by by Varian Inc.). The compound was loaded, typically in 50:50 DMSO / MeOH, onto a cartridge previously conditioned with MeCN and equilibrated with 5% MeCN in water. The product was eluted with a suitable gradient of 0.1% HCO2H in water and MeCN (0.5% HCO2H). Aminopropyl SPE or column refers to the use of cartridges pre-packed with 40μm- 120μm aminopropyl functionalized silica (sold by Varian Inc.). The crude product is typically loaded in DCM / MeOH mixtures onto a cartridge previously conditioned with MeOH. The neutral components were eluted with MeOH and/or DCM (3 or 4 column volumes) and the acidic components usually eluted with an eluent containing a proportion of AcOH (2-20%).
Oasis™ Cartridges / Oasis™ SPE's refer to SPE cartridges packed with a polymeric sorbent manufactured by the Waters Corporation. These are typically conditioned with 3 column volumes of MeOH and equilibrated with water before the sample is loaded. Salts and inorganics are eluted with water and the product typically eluted with MeOH or MeCN.
GreenHouse™ refers to a 24 reaction parallel synthesiser platform available from RDT Ltd, UK
As indicated above, compounds of Formula (I) may find use in human or veterinary medicine, for example as activators of HM74A, in the management of dyslipidaemia and hyperlipoproteinaemia.
Thus, there is provided as another embodiment of the present invention at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof, for use in human or veterinary medicine, for example in the treatment of disorders of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia such as diabetic
dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa and obesity. As such, the compounds are also provided for use in the treatment of coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke.
There is provided as a further embodiment of the present invention at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof, for use in the manufacture of a medicament for the treatment of disorders of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. As such, the compounds are also provided for use in the treatment of coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke.
It will be appreciated that references herein to treatment extend to prophylaxis, prevention of recurrence and suppression of symptoms as well as the treatment of established conditions.
In one embodiment of the invention, there is provided at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof for use in the treatment of disorders of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia. For example, the use is provided of at least one compound of Formula (I) or a pharmaceutically acceptable derivative thereof in the treatment of diabetic dyslipidaemia, mixed dyslipidaemia, heart failure, hypercholesteraemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa, obesity, coronary artery disease, thrombosis, angina, chronic renal failure, stroke and cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia.
It is to be understood that this embodiment of the present invention includes any combination of particular embodiments and covers all combinations of particular substituents described herein above for compounds of Formula (I).
Additionally, the present invention provides the use of at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof, in the manufacture of a medicament for the treatment of inflammatory diseases or conditions of the joint, for example, arthritis (e.g. rheumatoid arthritis, osteoarthritis, prosthetic joint failure), or of the gastrointestinal tract (e.g. ulcerative colitis, Crohn's disease, and other
inflammatory bowel and gastrointestinal diseases, gastritis and mucosal inflammation resulting from infection, the enteropathy provoked by non-steroidal anti-inflammatory drugs), of the lung (e.g. adult respiratory distress syndrome, asthma, cystic fibrosis, or chronic obstructive pulmonary disease), of the heart (e.g. myocarditis), of nervous tissue (e.g. multiple sclerosis), of the pancreas, (e.g. inflammation associated with diabetes melitus and complications thereof, of the kidney (e.g. glomerulonephritis), of the skin (e.g. dermatitis, psoriasis, eczema, urticaria, burn injury), of the eye (e.g. glaucoma) as well as of transplanted organs (e.g. rejection) and multi-organ diseases (e.g. systemic lupus erythematosis, sepsis) and inflammatory sequelae of viral or bacterial infections and inflammatory conditions associated with atherosclerosis and following hypoxic or ischaemic insults (with or without reperfusion), for example in the brain or in ischaemic heart disease.
In a further or alternative embodiments there is provided a method for the treatment of a human or animal subject with a condition where under-activation of the HM74A receptor contributes to the condition or where activation of the receptor will be beneficial, which method comprises administering to said human or animal subject an effective amount of at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof.
Again, it is to be understood that this embodiment of the present invention includes any combination of particular embodiments and covers all combinations of particular substituents described herein above for compounds of Formula (I).
In one embodiment, the present invention provides a method for the treatment of disorders of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa and obesity, which method comprises administering to said human or animal subject an effective amount of at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof. As such, these compounds may also find favour in methods for the treatment of coronary artery disease, thrombosis, angina, chronic renal failure, peripheral vascular disease and stroke, which methods comprise administering to said human or animal subject an effective amount of at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof.
The amount of a compound of formula (I) or a pharmaceutically acceptable derivative thereof which is required to achieve the desired biological effect will, of course, depend on a number of factors, for example, the mode of administration and the precise clinical condition of the recipient. In general, the daily dose will be in the range of 0.1 mg -
1 g/kg , typically 0.1 - 100mg/kg. An intravenous dose may, for example, be in the range of 0.01 mg to 0.1g/kg, typically 0.01mg to 10mg/kg, which may conveniently be administered as an infusion of from 0.1 μg to 1mg, per minute. Infusion fluids suitable for this purpose may contain, for example, from 0.01 μg to 0.1 mg, per millilitre. Unit doses may contain, for example, from 0.01 μg to 1g of a compound of the invention. Thus ampoules for injection may contain, for example, from 0.01μg to 0.1g and orally administrable unit dose formulations, such as tablets or capsules, may contain, for example, from 0.1 mg to 1g, for example from 5mg to 50mg.
A compound of formula (I) or a pharmaceutically acceptable derivative thereof may be employed as the compound per se in the treatment of a disease where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial, an example of this is where a compound of the present invention is presented with an acceptable carrier in the form of a pharmaceutical formulation. The carrier must, of course, be acceptable in the sense of being compatible with the other ingredients of the formulation and must not be deleterious to the recipient. The carrier may be a solid or a liquid, or both, and may be formulated with the compound of the invention as a unit-dose formulation, for example, a tablet, which may contain from 0.05% to 95% by weight of the compound of the invention.
The formulations include those suitable for oral, rectal, topical, buccal (e.g. sub-lingual) and parenteral (e.g. subcutaneous, intramuscular, intradermal or intravenous) administration.
There is also provided according to the invention a process for preparation of such a pharmaceutical composition which comprises mixing the ingredients.
Formulations suitable for oral administration may be presented in discrete units, such as capsules, cachets, lozenges or tablets, each containing a predetermined amount of a a compound of formula (I) or a pharmaceutically acceptable derivative thereof; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water or water-in-oil emulsion. In general, the formulations are prepared by uniformly and intimately admixing the compound of formula (I) or a pharmaceutically acceptable derivative thereof, with a liquid or finely divided solid carrier, or both, and then, if necessary, shaping the product. For example, a tablet may be prepared by compressing or moulding a powder or granules of the compound of formula (I) or a pharmaceutically acceptable derivative thereof optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing, in a suitable machine, the compound in a free-flowing form, such as a powder or granules optionally mixed with a binder, lubricant, inert diluent and/or surface active/dispersing agent(s). Moulded tablets may be made by moulding, in a suitable machine, the powdered compound moistened with an inert liquid diluent.
Tablets and capsules for oral administration may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, mucilage of starch or polyvinyl pyrrolidone; fillers, for example, lactose, microcrystalline cellulose, sugar, maize- starch, calcium phosphate or sorbitol; lubricants, for example, magnesium stearate, stearic acid, talc, polyethylene glycol or silica; disintegrants, for example, potato starch, croscarmellose sodium or sodium starch glycollate; or wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in the art. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example, sorbitol syrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxymethyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose, aluminium stearate gel or hydrogenated edible fats; emulsifying agents, for example, lecithin, sorbitan mono-oleate or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters, propylene glycol or ethyl alcohol; or preservatives, for example, methyl or propyl β- hydroxybenzoates or sorbic acid. The preparations may also contain buffer salts, flavouring, colouring and/or sweetening agents (e.g. mannitol) as appropriate.
Formulations suitable for buccal (sub-lingual) administration include lozenges comprising a compound of the invention in a flavoured base, usually sucrose and acacia or tragacanth, and pastilles comprising the compound of the invention in an inert base such as gelatin and glycerin or sucrose and acacia.
Formulations of the present invention suitable for parenteral administration conveniently comprise sterile aqueous preparations of a compound of formula (I) or a pharmaceutically acceptable derivative thereof, the formulation may be isotonic with the blood of the intended recipient. These preparations could be administered intravenously, although administration may also be effected by means of subcutaneous, intramuscular, or intradermal injection. Such preparations may conveniently be prepared by admixing the compound of formula (I) or a pharmaceutically acceptable derivative thereof with water and rendering the resulting solution sterile and isotonic with the blood. Injectable compositions according to the invention will generally contain from 0.1 to 5% w/w of the compound of formula (I) or a pharmaceutically acceptable derivative thereof.
Thus, formulations of the present invention suitable for parenteral administration comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof may be formulated for parenteral administration by bolus injection or continuous infusion and may be presented in unit dose form, for instance as ampoules, vials, small
volume infusions or pre-filled syringes, or in multi-dose containers with an added preservative. The compositions may take such forms as solutions, suspensions, or emulsions in aqueous or non-aqueous vehicles, and may contain formulatory agents such as anti-oxidants, buffers, antimicrobial agents and/or toxicity adjusting agents. Examples of formulations suitable for oral administration include formulations comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof, in 10% DMSO and 90% sodium hydrogen carbonate in sterile saline. Examples of formulations suitable for intravenous administration include formulations comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof, in 5% or 10% DMSO and 95% or 90% sodium hydrogen carbonate in sterile water. Alternatively, the therapeutically active agent may be in powder form for constitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use. The dry solid presentation may be prepared by filling a sterile powder aseptically into individual sterile containers or by filling a sterile solution aseptically into each container and freeze-drying.
Formulations suitable for rectal administration may be presented as unit-dose suppositories. These may be prepared by admixing a a compound of formula (I) or a pharmaceutically acceptable derivative thereof with one or more conventional solid carriers, for example, cocoa butter or glycerides and then shaping the resulting mixture.
Formulations suitable for topical application to the skin may take the form of an ointment, cream, lotion, paste, gel, spray, aerosol, or oil. Carriers which may be used include vaseline, lanolin, polyethylene glycols, alcohols, and combinations of two or more thereof. The compound of formula (I) or a pharmaceutically acceptable derivative thereof is generally present at a concentration of from 0.1 to 15% w/w of the composition, for example, from 0.5 to 2%.
By topical administration as used herein, we include administration by insufflation and inhalation. Examples of various types of preparation for topical administration include ointments, creams, lotions, powders, pessaries, sprays, aerosols, capsules or cartridges for use in an inhaler or insufflator or drops (e.g. eye or nose drops).
Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and/or gelling agents and/or solvents. Such bases may thus, for example, include water and/or an oil such as liquid paraffin or a vegetable oil such as arachis oil or castor oil or a solvent such as a polyethylene glycol. Thickening agents which may be used include soft paraffin, aluminium stearate, cetostearyl alcohol, polyethylene glycols, microcrystalline wax and beeswax.
Lotions may be formulated with an aqueous or oily base and will in general also contain one or more emulsifying agents, stabilising agents, dispersing agents, suspending agents or thickening agents.
Powders for external application may be formed with the aid of any suitable powder base, for example, talc, lactose or starch. Drops may be formulated with an aqueous or non-aqueous base also comprising one or more dispersing agents, solubilising agents or suspending agents.
Spray compositions may be formulated, for example, as aqueous solutions or suspensions or as aerosols delivered from pressurised packs, with the use of a suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, 1 ,1 ,1 ,2,3,3,3-heptafluoropropane, 1 ,1 ,1 ,2- tetrafluorethane, carbon dioxide or other suitable gas.
Capsules and cartridges for use in an inhaler or insufflator, of for example gelatin, may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.
The pharmaceutical compositions according to the invention may also be used in combination with other therapeutic agents, for example in combination with other classes of dyslipidaemic drugs (e.g. statins, fibrates, bile-acid binding resins or nicotinic acid).
The compounds of the instant invention may be used in combination with one or more other therapeutically active agents for example in combination with other classes of dyslipidaemic drugs e.g. 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) or fibrates or bile acid binding resins or nicotinic acid. The invention thus provides, in a further embodiment, the use of such a combination in the treatment of diseases where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial and the use of at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof in the manufacture of a medicament for the combination therapy of disorders of lipid metabolism including dyslipidaemia and hyperlipoproteinaemia such as diabetic dyslipidaemia and mixed dyslipidaemia, heart failure, hypercholesteraemia, cardiovascular disease including atherosclerosis, arteriosclerosis, and hypertriglyceridaemia, type Il diabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa and obesity.
When the compounds of the present invention are used in combination with other therapeutically active agents, the compounds may be administered either together or separately, sequentially or simultaneously by any convenient route.
The combinations referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above optimally together with a pharmaceutically acceptable carrier or excipient comprise a further embodiment of the invention. The individual components of such combinations may be administered either together or separately, sequentially or simultaneously in separate or combined pharmaceutical formulations.
When combined in the same formulation it will be appreciated that the two components must be stable and compatible with each other and the other components of the formulation and may be formulated for administration. When formulated separately they may be provided in any convenient formulation, conveniently in such a manner as are known for such compounds in the art.
When in combination with a second therapeutic agent active against the same disease, the dose of each component may differ from that when the compound is used alone. Appropriate doses will be readily appreciated by those skilled in the art.
The invention thus provides, in a further embodiment, a combination comprising at least one compound of formula (I) or a pharmaceutically acceptable derivative thereof together with another therapeutically active agent.
The combination referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above together with a pharmaceutically acceptable carrier thereof represent a further embodiment of the invention.
The compounds of the present invention and pharmaceutically acceptable derivatives thereof may be prepared by the methodology described hereinafter, constituting a further embodiment of this invention.
In one embodiment the present invention provides a method for the preparation of compound(s) of formula (I) from an appropriate starting material, for example compound(s) of formula (II):
wherein PG = protecting group, the method comprising:
(i) alkylation at N1 of an N7 protected xanthine; (ii) alkylation at N3 of an N7 protected xanthine; (iii) halogenation at C8; and (iv) de-protection of N7; in any order providing de-protection is carried out after alkylation.
Process 1 :
A process according to the invention for preparing compound(s) of formula (I) in which
R1 incorporates a cycloalkyl, heterocyclyl, cycloalkenyl, heteroaryl or aryl.
Pd(PPh3J4 (vi) moφholine or
N,N-dιmethylbarbιtuπc acid
i) Alkylation of guanine with allyl bromide ii) Diazotisation with sodium nitrite followed by hydrolysis to form the xanthine iii) Chlorination iv) Alkylation at N3 v) Alkylation at N1 vi) Palladium catalysed removal of the allyl group
wherein L represents a leaving group, for example halogen.
Process 2:
A process according to the invention for preparing compound(s) of formula (I) in which R1 incorporates an amide, carbamate or urea
wherein L represents a leaving group, for example halogen, d represents (m-1 ) (i.e. d together with the preceding methylene = m), R represents -(alkylene)n-Y and Q may or may not be present, and if present represents either O or NR5.
Process 3:
A process according to the invention for preparing compound(s) of formula (I) in which R1 incorporates a 'reverse' carbamate or ester
wherein L represents a leaving group, for example halogen, d represents (m-1), and R represents -(alk)
n-Y.
Process 4:
A process according to the invention for preparing compound(s) of formula (I) in which
R1 incorporates an ester or amide
wherein L represents a leaving group, for example halogen, d represents (m-1), and R represents -NR5R7 or -OR5.
Process 5:
A process according to the invention for preparing compound(s) of formula (I) in which
R1 incorporates a pyrazole, imidazole or tetrazole.
wherein L represents a leaving group, for example halogen, d represents (rπ-1), and R represents -(alk)n-Y.
Process 6:
A process according to the invention for preparing compound(s) of formula (I) in which
R1 incorporates an oxadiazole.
wherein L represents a leaving group, for example halogen, d represents (m-1 ), R represents an alkyl group and R' represents -(alk)n-Y.
Process 7:
A process according to the invention for preparing compound(s) of formula (I) in which
R1 incorporates an oxadiazole
wherein L represents a leaving group, for example halogen, d represents (m-1), R represents an alkyl group and R' represents -(alk)n-Y.
Process 8:
A process according to the invention for preparing compound(s) of formula (I) in which
R3 is CN comprises steps (i) and (ii) of Process 1 followed by:
HCI
iii) Alkylation at N3 iv) Alkylation at N1 v) Formation of aldehyde at C8 by lithiation with LiHMDS and DMF quench vi) Conversion of the aldehyde to the nitrile vii) Palladium catalysed removal of the allyl group
wherein L represents a leaving group.
Process 9:
A process according to the invention for preparing compound(s) of formula (I) in which
R3 is Cl or Br comprises steps (i) to (iv) of Process 8 followed by:
R3 = Cl or Br i) Halogenation at C8 using NCS or NBS ϋ) Palladium catalysed removal of the allyl group
Process 10:
A process according to the invention for preparing compound(s) of formula (I) in which R
3 is CN comprises steps (i) to (iv) of Process 8 followed by:
DIPEA PyBOP
(VIl) 2M NH3
DMF
v) Formation of ester vi) Hydrolysis of the methyl ester vii) Conversion of the acid to the amide. viii) Conversion of the amide to the nitrite ix) Palladium catalysed removal of the allyl group
Process 11 : A process according to the invention for preparing compound(s) of formula (I) in which R3 is Cl comprises:
Pd(OH)2/ H250 Psι
i) Alkylation at N3 ii) Alkylation at N1 iii) Debenzylation iii) Chlorination at C8
wherein L represents a leaving group
Process 12:
A process according to the invention for preparing compound(s) of formula (I) in which R1 differs from R2 and R3 is Cl comprises steps (i) to (v) of Process 1 (where R2 from process 1 is specifically SEM or MEM) followed by:
1) R2-L, base
vi) Cleavage of MEM or SEM protecting group group vii) Alkylation of N3 followed by palladium catalysed removal of the allyl group
wherein L represents a leaving group
Process 13: A process according to the invention for preparing compound(s) of formula (I) in which R3 is Cl, Br or I comprises steps (i) to (iv) of Process 8 followed by:
NIS
v) Palladium catalysed removal of allyl group vi) Halogenation at C8 using NCS, NBS or NIS
Process 14: A process according to the invention for preparing compound(s) of formula (I) comprises:
i) Pyrimidinedione formation ii) Alkylation at N1 iii) Nitrosation iv) Reduction using Na2S2O4 or a similar reducing agent v) Xanthine formation vi) Halogenation at C8 using NCS
wherein L represents a leaving group
Process 15:
A process according to the invention for preparing compound(s) of formula (I):
wherein L represents a leaving group.
As an additional step to the general processes described above, and in particular for use in the preparation of the examples below, there are several ways of purifying resulting compounds, one or more of which may be of use in the present invention, for example the use of MDAP, by recrystallisation from one or more suitable solvents such as ethyl acetate, absolute ethanol, acetonitrile or methanol, or by use of purification column such as Silica Redisep cartridges and subsequent eluting with a suitable solvent such as dichloromethane containing ethyl acetate.
Where desired or necessary, as a final stage in any of the above synthetic processes, a resultant compound of formula (I) can be converted into a pharmaceutically acceptable salt form or vice versa or converting one salt form into another pharmaceutically acceptable salt form.
ABBREVIATIONS
AcOH Acetic acid atm Atmosphere br Broad (NMR)
CDI Carbonyldiimidazole d Doublet (NMR)
DBAD Di-f-butylazodicarboxylate
DCM Dichloromethane
DIPEA Diisopropylethylamine
DMSO Dimethylsulfoxide
DMF N,N-Dimethylformamide
EtOAc Ethyl acetate
EtOH Ethanol h Hour(s)
IPA lsopropyl alcohol m Multiplet (NMR)
MDAP Mass directed autoprep
MeCN Acetonitrile
MeOH Methanol min Minute(s)
NCS N-Chlorosuccinimide
NBS N-bromosuccinimide
NIS N-iodosuccinimide q Quartet (NMR) rt Room temperature
RT Retention time
S Singlet (NMR)
SPE Solid phase extraction cartridge t Triplet (NMR)
TFA Trifluoroacetic acid
THF Tetrahydrofuran
DMEM Dulbecco's Modified Eagle's Medium
HEPES 4-(2-Hydroxyethyl)piperazine-1 -ethanesulphonic acid
LiHMDS Lithium hexamethyldisilylamide
Δ Heat
SEM 2-(trimethylsilyl)ethoxymethyl
MEM 2-methoxyethoxymethyl
Boc t-butoxycarbonyl
THP tetrahydropyran
Brief description of Figures
Figure 1 : XRPD data of substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)- 1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 1.
Figure 2: XRPD data of substantially crystalline 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)- 1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione form 2.
Figure 3: Overlay of XRPD data for substantially crystalline 3-Butyl-8-chloro-1 -{4-[5-(2- pyridinyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione Form 1 and Form 2.
The following non-limiting examples illustrate the present invention:
Synthetic Examples
It should be noted that the assignment of (Z)-stereochemistry set out in the compounds exemplified below has not been confirmed by experimental data. The person skilled in the art will also recognise that there can be interconversion between E & Z isomers. (Dondoni, Alessandro; Lunazzi, Lodovico; Giorgianni, Patrizia; Macciantelli, Dante. Carbon-nitrogen rotational barrier as a stereochemical probe of benzamidoximes. Journal of Organic Chemistry (1975), 40(20), 2979-80)
Example 1 : 8-Chloro-1 -(2-hvdroxyethyl)-3-pentyl-3,7-dihydro-1 H-purine-2.6-dione
a) 8-Chloro-1 -(2-hydroxyethyl)-3-pentyl-3,7-dihydro-1 /-/-purine-2,6-dione
8-Chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5g, 5.1mmol), Cs2CO3 (1.8g, 5.6mmol) and 2-chloroethanol (509μL, 7.7mmol) were reacted together in DMF (20ml) at 6O0C for 18h. The reaction was allowed to cool to rt and the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (428mg, 0.37mmol) was added and the mixture degassed once more. Morpholine (2.1ml, 24.7mmol) was added and the mixture was stirred under nitrogen for 3h, and then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The residue was taken up into MeOH and then passed down an aminopropyl column with the product eluting with 3% AcOH/MeOH. The product fractions were combined and concentrated then purified by recrystallisation from EtOAc. The resulting solid was collected by filtration and washed with EtOAc to give the title compound as a white solid (713mg, 47%). LC/MS: m/z 301 [MH]+, RT 2.7min.
1H NMR (DMSO-d6) δ: 0.86 (t, 3H, J = 7Hz), 1.22-1.36 (m, 4H), 1.63 (m, 2H), 3.50 (br t, 2H, J = 6Hz), 3.90 (t, 2H, J = 7.5Hz), 3.95 (t, 2H, J = 6.5Hz)1 4.75 (br s, 1 H), 14.5 (br s, 1 H).
b) 8-Chloro-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione
To a solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (100mg, 0.44mmol) in anhydrous DMF (3ml) was added sodium carbonate (0.051 g, 0.484mmol). After 10min stirring at rt pentyl iodide (0.063ml, 0.484mmol) was added and stirring continued under nitrogen at rt for 18h. The reaction mixture was diluted with water (25ml) and extracted with EtOAc (2x25ml). The combined organic extracts were dried (MgSO4) filtered and evaporated. Purification by SPE (Si, 5g) eluting with 4:1 EtOAc/cyclohexane afforded the title compound as a white solid (96mg, 74%). LC/MS: m/z 297 [MH]+.
c) 8-Chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione
To a solution of 7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione) (10.52g, 54.7mmol) in anhydrous DMF (60ml) was added NCS (8.04g, 60.2mmol). The reaction mixture was left to stir under nitrogen at 2O0C for 6h. The reaction mixture was concentrated in vacuo to give an amber oil. MeOH was added and left to stand for 18h. The resulting residue was filtered and dried under vacuum to give the title compound (7.69g, 62%). LC/MS: m/z 227 [MH]+.
d) 7-(2-Propen-1-yl)-3,7-dihydro-1 /-/-purine-2,6-dione
A mixture of 2-amino-7-(2-propen-1-yl)-1 ,7-dihydro-6H-purin-6-one (4Og, 0.209mol) in AcOH (900ml) and water (100ml) was heated at 550C. Sodium nitrite (57.74g, 0.837mol) in water (100ml) was added dropwise. Care; toxic fumes. After the addition was complete (ca. 25min) the reaction mixture was allowed to cool to ambient temperature and then concentrated to ca. 1/3 of its original volume. Water (500ml) was added and the resulting precipitate collected by filtration. The residue was washed with water then dried at 5O0C over P2O5 and under vacuum for 2h to give the title compound (17.2Og). The aqueous fraction was concentrated and water added (100ml). Again the resulting solid was filtered and dried. This gave more of the title compound (2.31 g). Combined product (19.52g, 49%).
LC/MS: m/z 193 [MH]+.
e) 2-Amino-7-(2-propen-1 -yl)-1 ,7-dihydro-6/-/-purin-6-one
A mixture of guanosine (2Og1 0.071mol), allyl bromide (14.7ml, 0.169mol) and anhydrous DMSO (100ml) was stirred at rt, under nitrogen, for 18h. Cone. HCI (50ml of 37%) was added in one portion and the mixture stirred for 45min then poured into MeOH (600ml). The methanolic solution was neutralised with 2M NaOH (aq) solution and the resulting white precipitate collected by filtration. The white solid was dried under vacuum at 5O0C for 18h to afford the title compound (16g) which was used without further purification. LC/MS: m/z 192 [MH]+.
Example 2: 8-Chloro-3-(2-cvclobutylethyl)-1 -(2-hydroxyethyl)-3,7-dihvdro-1 H- purine-2,6-dione
7-(2-Propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (575mg, 2.54mmol) was stirred in dry THF (20ml) with 2-cyclobutylethanol (c.73 mol%, remainder 1-butanol) (254mg). Dibenzyl azodicarboxylate (94%, 1.57g, 4.95mmol) was added, the mixture cooled to O0C and a solution of triphenylphosphine (1.302g, 4.97mmol) in dry THF (10ml) was added dropwise. The mixture was stirred for 30min. at O0C then at rt for 18h under nitrogen. The solvent was evaporated and the residue purified on a Biotage system (100g) eluting with EtOAc-cyclohexane (2:3). The material thus obtained (0.53g) was a mixture of the required compound, the corresponding n-butyl analogue and dibenzyl hydrazinedicarboxylate, and was alkylated without further purification. This mixture (256mg) and Cs2CO3 (326mg, 1 mmol) were stirred in dry DMF (5ml). 2- Chloroethanol (80.5mg, 1mmol) was added and the mixture was stirred and heated at 55 0 C for 65h. After cooling, it was thoroughly degassed, tetrakis(triphenylphosphine)palladium(0) (200mg) and morpholine (0.7ml) were added, and the mixture was stirred for 6h. EtOAc and 2M HCI were added and the mixture filtered, the organic phase washed with brine, dried (Na2SO4) and evaporated and the residue separated from non-acidic material by aminopropyl SPE (5g, MeOH-THF and MeOH wash, elution with DCM-MeOH with 5% added AcOH). The material obtained
from the acid wash (105mg) was further purified by MDAP to provide the title compound (42.7mg). LC/MS: m/z 313 [MH]+, RT 2.58min.
1H NMR (DMSOd6) δ: 1.53-1.64 (m, 2H), 1.71-1.84 (m, 4H), 1.94-2.02 (m, 2H), 2.21- 2.30 (m, 1 H), 3.47-3.53 (m, 2H)1 3.84 (t, 2H, J = 7Hz), 3.95 (t, 2H, J = 7Hz), 4.76 (br s, 1 H), 14.45 (br s, 1 H)
Example 3: 8-Chloro-1-r3-(2-furanyl)propyπ-3-pentyl-3.7-dihydro-1 H-purine-2.6-
A GreenHouse™ tube equipped with a stirrer was charged with a 0.25ml aliquot of a 0.54M solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (0.13mmol) in THF. To the mixture was added 3-(2-furanyl)-1-propanol (21 mg, 0.16mmol, 1.2eq) in THF (0.25ml), followed by a 0.25ml aliquot of a 0.71 M solution of bis(1,1-dimethylethyl) (E)-1 ,2-diazenedicarboxylate (0.18mmol) in THF and then a 0.25ml aliquot of a 0.71 M solution of triphenylphosphine (0.18mmol) in THF. The solution was stirred in a GreenHouse™ under nitrogen for 16h. To the mixture was added a further 0.25ml aliquot of a 1.4M solution of bis(1,1-dimethylethyl) (E)-1 ,2- diazenedicarboxylate (0.36mmol) in THF and then a further 0.25ml aliquot of a 1.4M solution of triphenylphosphine (0.36mmol) in THF. The mixture was stirred for 16h under a stream of nitrogen.
Tetrakis(triphenylphosphine)palladium(0) (16mg, 0.014mmol) and morpholine (0.12ml, 1.35mmol) were added to the mixture which was stirred for 16h under a stream of nitrogen. The reaction mixture was concentrated under nitrogen and the crude material dissolved in aqueous NaOH solution (0.5ml, 2M). The resulting solution was purified using aminopropyl SPE (eluting with AcOH in DCM and MeOH). Further purification using C18 SPE (eluting with a water, ammonia and MeCN mixture) afforded the title compound as a clear gum (22mg, 45%). LC/MS: m/z 365 [MH]+, RT 3.48min.
1H NMR (DMSO-de) δ: 0.85 (t, 3H, J = 7Hz), 1.35-1.19 (m, 4H), 1.62 (m, 2H), 1.79 (m, 2H)1 2.59 (t, 2H, J = 8Hz), 3.93 - 3.80 (m, 4H), 6.14 (d, 1 H, J = 3Hz)1 6.32 (dd, 1 H, J = 3 and 2Hz), 7.48 (d, 1H, J = 2Hz).
Example 4: 5-(8-Chloro-2.6-dioxo-3-pentyl-2,3.6.7-tetrahvdro-1 H-purin-1 - vπ-Λ/-f(3-methylphenyl)methyllpentanamide
a) 5-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)-Λ/-[(3- methylphenyl)methyl]pentanamide
A mixture of 5-(8-chloro-2, 6-dioxo-3-pentyl-2, 3, 6, 7-tetrahydro-1 H-purin-1 -yl)pentanoic acid (50mg, 0.14mmol) in DCM (3ml) was treated with CDI (27mg, 0.17mmol) and left to stir at rt for 1h. [(3-Methylphenyl)methyl]amine (25μl, 0.20mmol) was added and left to stir for a further 1 h. The mixture was concentrated then purified by aminopropyl SPE. The title compound was eluted with 2-3% AcOH/MeOH then concentrated to give the title compound as a white solid (56mg, 87%). LC/MS: m/z 460 [MH]+, RT 3.3min.
b) 5-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoic acid
A mixture of methyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 - yl)pentanoate (8.4Og, 0.023mol), LiOH (1.63g, 0.068mol), MeOH (150ml) and water (10ml) was left to stir at ambient temperature for 64h. The mixture was partitioned between water and EtOAc and the aqueous acidified. The organic layer was separated and the aqueous extracted again with EtOAc. The combined extracts were washed with brine, dried (MgSO4) and concentrated, giving the title compound as an off-white solid (9.09g). LC/MS: m/z 357 [MH]+, RT 3.0min.
c) Methyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate
A solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (2.Og1 6.7mmol) in anhydrous DMF (40ml) was treated with Cs2CO3 (2.42g, 7.4mmol) and methyl 5-bromovalerate (1.16ml, 8.1 mmol). The mixture was heated at 5O0C for 18h then allowed to cool to rt and degassed under a gentle vacuum, then nitrogen introduced. This was repeated twice. Pd(PPh3)4 (779mg, 0.67mmol) was added and the mixture degassed once more. Morpholine (5.9ml, 67mmol) was added and left to stir for 3h at rt. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving a yellow residue/oil (5.16g). The residue was taken up in MeOH and divided into two equal portions, and then each passed down an aminopropyl SPE (2Og), eluting with MeOH followed by 5% AcOH/MeOH then 10% AcOH/MeOH and finally 15% AcOH/MeOH. The product fractions were combined and concentrated giving the title compound as an off-white solid (2.28g, 91%). LC/MS: m/z 371 [MH]+, RT 3.1min.
Example 5 : 5-(8-Chloro-2,6-dioxo-3-pentyl-2.3,6.7-tetrahydro-1H-purin-1-yl)-Λ/-r(3-
A mixture of 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanoic acid (50mg, 0.14mmol) in DCM (3ml) was treated with CDI (27mg, 0.17mmol) and left to stir at rt for 1h. [(3-ethylphenyl)methyl]amine (25μl 0.20mmol) was added and left to stir for a further 1 h. The mixture was concentrated then purified on an aminopropyl SPE. The title compound was eluted with 2-3% AcOH/MeOH to give a white solid (61 mg, 92%). LC/MS: m/z 474 [MH]+, RT 3.5min.
Example 6 : 5-(8-Chloro-2.6-dioxo-3-pentyl-2.3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-r(4- fluoro-3-methylphenyl)methvHpentanamide
A mixture of 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 /-/-purin-1-yl)pentanoic acid (50mg, 0.14mmol) and DCM (3ml) was treated with CDI (27mg, 0.17mmol) and stirred at rt for 1 h. 1-(4-Fluoro-3-methylphenyl)methanamine (27mg, 0.20mmol) and DIPEA (24μl 0.14mmol) were added. After 1 h the mixture was concentrated and then the residue taken up into MeOH and passed down an aminopropyl SPE. The product was eluted with 2% AcOH/MeOH and further purified by MDAP to give the title compound as a solid (15mg, 22%). LC/MS: m/z 478 [MH]+, RT 3.4min.
Example 7: Phenylmethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3.6,7-tetrahydro-1H- purin-1 -vDpentanoate
A mixture of 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanoic acid (50mg, 0.14mmol) in DCM (3ml) was treated with CDI (27mg, 0.17mmol) and left to stir at rt for 1 h. Benzyl alcohol (21 μl, 0.20mmol) was added and left to stir for a further 1h. The reaction mixture was concentrated and DMF (3ml) was added then heated at 5O0C for 2h. The mixture was concentrated then purified by MDAP giving the title compound as a white solid (33mg, 53%). LC/MS: m/z 447 [MH]+, RT 3.7min.
Example 8: (3-Methylphenyl)methyl r3-(8-chloro-2,6-dioxo-3-pentyl-2,3.6,7- tetrahvdro-1 H-purin-1 -vPpropyHcarbamate
a) (3-Methylphenyl)methyl [3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H- purin-1 -yl)propyl]carbamate
A solution of 3-methylbenzyl alcohol (16μl, 0.13mmol) in DCM (3ml) was treated with CDI (24mg, 0.15mmol) and allowed to stir at rt for 1 h. 1-(3-aminopropyl)-8-chloro-3- pentyl-3,7-dihydro-1/-/-purine-2,6-dione trifluoroacetate (50mg, 0.16mmol) was added followed by DIPEA (28μl, 0.16mmol) then heated at 5O0C for 56h. The reaction mixture was concentrated, the residue taken up into MeOH and purified by aminopropyl SPE. The title compound eluted with 2% AcOH/MeOH and a white solid collected (40mg, 58%). LC/MS: m/z 462 [MH]+, RT 3.6min.
b) 1-(3-Aminopropyl)-8-chloro-3-pentyl-3,7-dihydro-1 H-purine-2,6-dione trifluoroacetate
A solution of 1 ,1-dimethylethyl [3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H- purin-1-yl)propyl]carbamate (1.59g, 4.38mmol) in DCM (16ml) was treated with TFA (16ml) and stirred at rt for 2h then concentrated in vacuo. Residual TFA was removed by azeotroping with DCM then the residue was triturated with Et2O to give the title compound as a solid (1.48g, quant.). LC/MS: m/z 314 [MH]+, RT 2.1 min.
c) 1 ,1-Dimethylethyl [3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1A7-purin-1- yl)propyl]carbamate
A solution of 1 ,1-dimethylethyl (3-hydroxypropyl)carbamate (1.0ml, 6.1mmol) in THF (40ml) was treated with 8-chloro-3-pentyl-1-[3-(tetrahydro-2H-pyran-2-yloxy)propyl]-
3,7-dihydro-1H-purine-2,6-dione (1.5g, 5.1mmol) and PPh3 (1.73g, 6.6mmol) at rt under nitrogen. DBAD (1.52g, 6.6mmol) was added in one portion and stirred for 18h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (586mg, 0.51 mmol) was added and the mixture degassed once more. Morpholine (4.4ml, 50.7mmol) was added and the mixture was stirred under nitrogen for 3h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving a yellow oil. MeOH was added and then passed down an aminopropyl SPE with the product eluting with 2-3% AcOH/MeOH. The product fractions were combined and concentrated, giving the title compound as a clear gummy solid (1.59g, 75%). LC/MS: m/z 414 [MH]+, RT 3.4min.
Example 9 : Phenylmethyl f3-(8-chloro-2.6-dioxo-3-pentyl-2,3.6,7-tetrahvdro-1H- purin-1 -vDpropyllcarbamate
1 -(3-Aminopropyl)-8-chloro-3-pentyl-3,7-dihydro-1 /-/-purine-2,6-dione trifluoroacetate (50mg, 0.12mmol) in DCM (3ml) was treated with DIPEA (51 μl, 0.29mmol) and benzyl chloroformate (20μl, 0.14mmol). After 1h the reaction mixture was concentrated and purified on an aminopropyl SPE. The title compound eluted with 2% AcOH/MeOH and a white solid collected (35mg, 67%). LC/MS: m/z 448 [MH]+, RT 3.4min.
Example 10 : (2-FluorophenyPmethyl r3-(8-chloro-2.6-dioxo-3-pentyl-2.3.6.7- tetrahydro-1 H-purin-1 -vOpropyllcarbamate
(2-Fluorophenyl)methanol (11 μl, O.IOmmol) in DCM (3ml) was reacted with CDI (17mg, 0.11 mmol) under nitrogen for 1 h. 1-(3-Aminopropyl)-8-chloro-3-pentyl-3,7-dihydro-1H-
purine-2,6-dione trifluoroacetate (50mg, 0.16mmol) was added followed by DIPEA (20μl, 0.12mmol) then heated at reflux for 18h. THF (3ml) was added and heated at 750C for 5h. After cooling, the mixture was concentrated in vacuo and purified by MDAP to give the title compound as a solid (21 mg, 39%). LC/MS: m/z 466 [MH]+, RT 3.4min.
Example 11 : (2,4-Difluorophenyl)methyl r3-(8-chloro-2,6-dioxo-3-pentyl-2.3,6,7- tetrahvdro-1 H-purin-1 -vDpropylicarbamate
(2,4-Difluorophenyl)methanol (11μL, O.IOmmol) in DCM (3ml) was reacted with CDI (17mg, O.Ummol) under nitrogen for 1 h. 1-(3-Aminopropyl)-8-chloro-3-pentyl-3,7- dihydro-1H-purine-2,6-dione trifluoroacetate (50mg, 0.16mmol) was added followed by DIPEA (20μl, 0.12mmol) then heated at reflux for 18h. THF (3ml) was added and heated at 750C for 5h. After cooling, the mixture was concentrated in vacuo and purified by MDAP to give the title compound as a solid (29mg, 21%). LC/MS: m/z 484 [MH]+, RT 3.4min.
Example 12 : 2-(3-Pyridinyl)ethyl r3-(8-chloro-2.6-dioxo-3-pentyl-2.3.6.7- tetrahydro-1 H-purin-1 -vDpropyllcarbamate
a) 2-(3-Pyridinyl)ethyl [3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin- 1 -yl)propyl]carbamate
A solution of CDI (21 mg, 0.13mmol) in THF (2ml) was treated with 2-(3- pyridinyl)ethanol (16mg, 0.13mmol) and heated at reflux for 1 h before the addition of 1-
(S-aminopropyO-δ-chloro-S-pentyl-Sy-dihydro-IH-purine^.θ-dione hydrochloride
(50mg, 0.14mmol) and DIPEA (25μl, 0.14mmol). The reaction was left at reflux for 18h then concentrated and purified by MDAP to provide the title compound as a solid (30mg, 24%). LC/MS: m/z 463 [MH]+, RT 2.6min.
b) 1-(3-Aminopropyl)-8-chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione hydrochloride
A mixture of 1 ,1-dimethylethyl [3-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H- purin-1-yl)propyl]carbamate (5.19g, 12.5mmol) and 4M HCI in 1 ,4-dioxane (80ml) was stirred at rt for 3h. The mixture was concentrated in vacuo and dried under vacuum to provide the title product as a white solid (4.49g, quant.). LC/MS: m/z 314 [MH]+, RT 2.2min.
Example 13 : 2-(3-Fluorophenyl)ethyl f3-(8-chloro-2.6-dioxo-3-pentyl-2.3,6,7- tetrahydro-1 H-purin-1 -vDpropylicarbamate
A solution of CDI (21 mg, 0.13mmol) in THF (2ml) was treated with 2-(3- fluorophenyl)ethanol (16μl, 0.13mmol) and heated at reflux for 1h before the addition of 1 -(3-aminopropyl)-8-chloro-3-pentyl-3,7-dihydro-1 /-/-purine-2,6-dione hydrochloride (50mg, 0.14mmol) and DIPEA (25μL, 0.14mmol). The reaction was left at reflux for 18h then concentrated and purified by MDAP to provide the title compound as a solid (27mg, 39%). LC/MS: m/z 480 [MH]+, RT 3.5min.
Example 14 : 2-(2-Thiertyl)ethyl r3-(8-chloro-2.6-dioxo-3-pentyl-2,3.6.7-tetrahvdro- 1 H-purin-1 -vDpropyllcarbamate
A solution of CDI (21 mg, 0.13mmol) in THF (2ml) was treated with 2-(2-thienyl)ethanol (15μl, 0.13mmol) and heated at reflux for 1h before the addition of 1-(3-aminopropyl)-8- chloro-3-pentyl-3,7-dihydro-1 /-/-purine-2,6-dione hydrochloride (50mg, 0.14mmol) and DIPEA (25μl_, 0.14mmol). The reaction was left at reflux for 18h then concentrated and purified by MDAP to provide the title compound as a solid (34mg, 51%). LC/MS: m/z 468 [MH]+, RT 3.4min.
Example 15 : 3-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1/V-purin-1- vQpropyl (1 -phenylcvclopropyPcarbamate
a) 3-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)propyl (1- phenylcyclopropyl)carbamate
A solution of 8-chloro-1-(3-hydroxypropyl)-3-pentyl-3,7-dihydro-1/-/-purine-2,6-dione (50mg, 0.16mmol) was treated with CDI (28mg, 0.18mmol) and allowed to stir at rt for 1h. 1-Phenylcyclopropanamine (30mg, 0.20mmol) was added and the mixture heated at reflux under nitrogen for 18h. Another aliquot of 1-phenylcyclopropanamine (30mg, 0.20mmol) was added followed by THF (3ml). The reaction was heated at 750C for 18h then concentrated and purified by MDAP. This gave the title compound as a white solid (13mg, 18%). LC/MS: m/z 474 [MH]+, RT 3.5min.
b) 8-Chloro-1 -(3-hydroxypropyl)-3-pentyl-3,7-dihydro-1 H-purine-2,6-dione
A solution of 8-chloro-3-pentyl-1-[3-(tetrahydro-2/-/-pyran-2-yloxy)propyl]-3,7-dihydro- 1/-/-purine-2,6-dione (5.87g, 14.8mmol) in EtOH (100ml) was treated with pTsOH (2.8g, 14.8mmol) and stirred at rt for 18.5h. The mixture was partitioned between 1 M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted once more. The combined extracts were washed with water (x5), brine, then dried (MgSO4) and concentrated, giving a pale yellow solid. The solid was washed with Et2O and collected by filtration giving a white solid (2.42g, 52%). LC/MS: m/z 315 [MH]+, RT 2.7min.
c) 8-Chloro-3-pentyl-1 -[3-(tetrahydro-2/-/-pyran-2-yloxy)propyl]-3,7-dihydro-1 H-purine- 2,6-dione
8-Chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (5.Og, 16.8mmol), Cs
2CO
3 (6.Og, 18.5mmol) and 2-(3-bromopropoxy)tetrahydro-2H-pyran (3.4ml, 20mmol) were reacted together in DMF (100ml) at 5O
0C under nitrogen for 24h. The reaction was allowed to cool to rt and the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh
3)
4 (1.4g, 1.2mmol) was added and the mixture degassed once more. Morpholine (14.7ml, 170mmol) was added and the mixture was stirred under nitrogen for 3h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated, giving a yellow residue (5.16g). MeOH was added and then passed down an aminopropyl SPE with the product eluting with 5% AcOH/MeOH. The product fractions were combined and concentrated, giving the title compound as a pale yellow solid (5.97g, 89%). LC/MS: m/z 399 [MH]
+, RT 3.3min.
Example 16 : 3-(8-Chloro-2.6-dioxo-3-pentyl-2,3,6.7-tetrahydro-1H-purin-1- yl) propyl (phenylmethyl)carbamate
A solution of 8-chloro-1-(3-hydroxypropyl)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione (50mg, 0.16mmol) in THF (3ml) was treated with triphosgene (47mg, 0.16mmol) and pyridine (13μl, 0.16mmol). After 30min benzylamine (217μl, 2.0mmol) was added and left to stir for a further 30min. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The residue was taken up into MeOH and purified by passing down an aminopropyl SPE, the product eluted with 2-5% AcOH/MeOH. The title compound was obtained as an off-white solid (67mg, 94%). LC/MS: m/z 448 [MH]+, RT 3.2min.
Example 17 : 3-(8-Chloro-2.6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1- vDpropyl r(3-methylphenyl)methyllcarbamate
A solution of 8-chloro-1-(3-hydroxypropyl)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione (50mg, 0.16mmol) in DCM (3ml) was treated with CDI (31 mg, 0.19mmol) and stirred at rt for 1h. 3-Methylbenzylamine (26μl, 0.21 mmol) was added and heated at reflux for 18h. Another aliquot of methylbenzylamine (4μl, 0.03mmol) was added and the mixture left for 4h at reflux. The mixture was concentrated then taken up into MeOH and passed down an aminopropyl SPE. The product was eluted with 2% AcOH/MeOH and then purified further by MDAP. This gave the title compound as a white solid (42mg, 57%).
LC/MS: m/z 462 [MH]+, RT 3.5min.
Example 18 : S-Chloro-i-Q-^i-^-chloro-B-fluorophenvDmethvn-IH-pyrazoM- yl>propyh-3-pentyl-3,7-dihydro-1H-purine-2.6-dione
a) 8-Chloro-1-(3-{1-[(2-chloro-6-fluorophenyl)methyl]-1/-/-pyrazol-4-yl}propyl)-3-pentyl- -dione
8-Chloro-3-pentyl-7-(2-propen-1 -yl)-1 -[3-(1 H-pyrazol-4-yl)propyl]-3,7-dihydro-1 H- purine-2,6-dione (61 mg, 0.15mmol) in dry DMF (2ml) was stirred with sodium carbonate (64mg, O.θmmol) and 2-chloro-6-fluorobenzyl bromide (134mg, O.θmmol) and heated at 450C for 18h under nitrogen. After cooling to rt the mixture was degassed by evacuating and readmitting nitrogen, and stirred with tetrakis(triphenylphosphine)palladium(0) (35mg, 0.303mmol) and morpholine (0.13ml) for 5.5h. The mixture was partitioned between EtOAc and 2M HCI, the organic phase separated and evaporated and the residue purified by aminopropyl SPE (5g, washing with THF-MeOH (1:1) then neat MeOH and finally eluting with DCM-MeOH (1:1) containing 5% AcOH) to give the title compound (57mg) as a solid. LC/MS: m/z 507 [MH]+, RT 3.64min.
b) 8-Chloro-3-pentyl-7-(2-propen-1 -yl)-1 -[3-(1 /-/-pyrazol-4-yl)propyl]-3,7-dihydro-1 H- purine-2,6-dione
3-Pentyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (5g, 16.86mmol) and 3-(1/-/-pyrazol-4-yl)propan-1-ol (2.12g, 16.8mmol) were stirred in dry THF (150ml) at 30C. Dibenzyl azodicarboxylate (10.05g, 33.7mmol) was added followed by the dropwise addition of triphenylphosphine (8.83g, 33.7mmol) in dry THF (70ml). The mixture was allowed to warm to rt and stirred for 18h. Water (1ml) was added and the solvents evaporated. The residue was taken up in Et2O (200ml) from which a white solid, mostly triphenylphosphine oxide, crystallised and was filtered off. The filtrate was concentrated and further by-products crystallised from ether-cyclohexane. The remaining filtrate was concentrated (19.2g) and purified on a Biotage™ system (40Og) eluting with EtOAc-cyclohexane (2:1 ) to afford the title compound as a white solid (2.89g). LC/MS: m/z 405 [MH]+, RT 3.19min.
The following compounds (Table 1 ) were prepared using a method analogous to that for Example 18, from the corresponding benzyl halides.
* after additional purification by MDAP.
NMR details for selected examples from Table 1
Example 19: 8-chloro-3-pentyl-1 -(3-{1 -[(2 ,4,6-trifluorophenyl)methyl]-1 H-pyrazol-4- yl}propyl)-3,7-dihydro-1H-purine-2,6-dione
1H NMR (DMSO-de) δ: 0.85 (t, 3H, J = 7 Hz), 1.20-1.40 (m, 4H), 1.60-1.70 (m, 2H), 1.70-1.82 (m, 2H), 2.39 (t, 2H, J = 8 Hz), 3.83-3.94 (m, 4H), 5.24 (s, 2H), 7.18-7.30 (m, 3H), 7.57 (s, 1 H).
Example 23: 8-Chloro-1 -(3-{1 -[(2,4-dif luorophenvDmethylH H-pyrazol-4- yl)propyl)-3-pentyl-3,7-dihvdro-1H-purine-2,6-dione
8-Chloro-3-pentyl-7-(2-propen-1 -yl)-1 -[3-(1 H-pyrazol-4-yl)propyl]-3,7-dihydro-1 H- purine-2,6-dione (81 mg, 0.2mmol) and sodium carbonate (85mg, O.δmmol) were stirred in dry DMF (2ml) with 2,4-difluorobenzyl bromide (166mg, O.δmmol) at 45
0C for 18h. The mixture was degassed and stirred with tetrakis(triphenylphosphine)palladium(0) (46mg, 0.04mmol) and morpholine (176mg, 2mmol) at rt for 6h. The reaction was worked up and purified by aminopropyl SPE (5g, washing with THF-MeOH (1 :1) then neat MeOH, eluting with DCM-MeOH (1 :1 ) with 5% added AcOH) to yield the title compound (37.7mg) as a solid.
LC/MS: m/z 491 [MH]+, RT 3.42min.
1H NMR (d6 DMSO) 0.85 (3H, t, J = 7Hz), 1.21-1.34 (4H, m), 1.58-1.68 (2H, m), 1.71- 1.80 (2H, m), 2.41 (2H, t, J = 8Hz), 3.84-3.93 (4H, m), 5.26 (2H, s), 7.02-7.09 (1 H, m), 7.15-7.29 (2H, m), 7.31 (1 H, s), 7.61 (1 H, s).
The following compounds (Table 1) were prepared using a method analogous to that for Example 23, from the corresponding benzyl halides.
*after additional purification by MDAP.
NMR details for selected examples from Table 2
Example 24: 8-chloro-3-pentyl-1-{3-[1-(phenylmethyl)-1H-pyrazol-4-yl]propyl}-3,7- dihydro-1H-purine-2,6-dione; 1H NMR (DMSO-d6) δ: 0.87 (t, 3H, J = 7 Hz), 1.20-1.36 (m, 4H), 1.60-1.70 (m, 2H), 1.72-1.85 (m, 2H), 2.42 (t, 2H, J = 8 Hz), 3.83-3.95 (m, 4H), 5.24 (s, 2H), 7.13-7.38 (m, 6H), 7.61 (s, 1 H).
Example 28: 8-Chloro-1 -(3-(1 -r(2-chlorophenyl)methvn-1 H-pyrazol-4-yl}propyl)-3- pentyl-3,7-dihydro-1H-purine-2,6-dione
Prepared by the method for 8-chloro-1-(3-{1-[(2,4-difluorophenyl)methyl]-1H-pyrazol-4- yl}propyl)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione but from 2-chlorobenzyl bromide (164mg, O.δmmol). However, in order to complete the deprotection step further tetrakis(triphenylphosphine)palladium(0) (40mg) and morpholine (0.15ml) were added and stirring continued for a further 5.5h. Purification by aminopropyl SPE as above afforded the title compound as a solid (42mg).
LC/MS: m/z 489 [MH]+, RT 3.67min.
Example 29: 3-Butyl-8-chloro-1 -13-H -(phenylmethvD-1 H-imidazol-4-yllpropyl>- 3.7-dihvdro-1 H-purine-2.6-dione
a) 3-Butyl-8-chloro-1 -{3-[1 -(phenylmethyl)-i /-/-imidazol-4-yl]propyl}-3,7-dihydro-1 H- purine-2,6-dione
A solution of 3-butyl-8-chloro-1-[4-(1/-/-imidazol-4-yl)butyl]-7-(2-propen-1-yl)-3,7- dihydro-1H-purine-2,6-dione (300mg, 0.77mmol) in anhydrous THF (5ml) was treated with benzyl bromide (144mg, 0.84mmol) and DIPEA (147μl, 0.84mmol). The mixture was left to stir at rt under nitrogen for 4 days. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated. The crude was purified by a silica SPE column using a 0.5- 5% MeOH/DCM gradient. The product fractions were combined and concentrated under high vacuum. The product was dissolved in THF (5ml) then Pd(PPh
3J
4 (88mg, 0.077mmol) and morpholine (670μl, 7.67mmol) were added and the mixture left to stir at rt under nitrogen for 3h. 88mg of Pd(PPh
3J
4 (0.077mmol) was added and the mixture was left to stir at rt under nitrogen for 16h. The mixture was partitioned between EtOAc and H
2O. The organic layer was separated and the aqueous layer was extracted with EtOAc (x2). The organic layers were combined, washed with brine, dried (MgSO
4) and concentrated. The crude product was purified by MDAP to give the title compound as a white solid (9mg, 2%). LC/MS: m/z 441 [MH]
+, RT 2.50min.
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7.5 Hz), 1.28 (m, 2H), 1.60 (m, 2H), 1.79 (m, 2H), 2.48 (t overlapping with DMSO, 2H, J =7.5 Hz), 3.89 (m, 4H), 5.17 (s, 2H), 7.08 (s, 1 H), 7.31 , (m, 6H), 8.03 (s, 1 H).
b) 3-Butyl-8-chloro-1-[3-(1 /-/-imidazol-4-yl)propyl]-7-(2-propen-1-yl)-3,7-dihydro-1H- purine-2,6-dione
A solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (2.8g, 9.9mmol) in anhydrous THF (60ml) was treated with 3-(1 /-/-imidazol-4-yl)-1-propanol (1.5g, 12mmol) in anhydrous THF (10ml) and PPh3 (3.4g, 13mmol). DBAD (2.9g, 13mmol) was added in one portion and the mixture was left to stir at rt, under nitrogen for 18h. The mixture was partitioned between EtOAc and H2O. The aqueous layer was extracted and washed with EtOAc. The organic layers were combined, washed with brine, dried (MgSO4) and concentrated. The crude product was purified by a silica SPE cartridge using a MeOH/EtOAc gradient (0.5%-7% MeOH). The product fractions were combined and concentrated by to give the title compound as a white solid (2.16g, 55%). LC/MS: m/z 391 [MH]+, RT 2.40min.
c) 3-Butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione
To a solution of 3-butyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (3.34g, 13.4mmol) in anhydrous DMF (19ml) was added NCS (1.97g, 14.8mmol) and left to stir at rt under nitrogen for 22h. The mixture was concentrated in vacuo to give a yellow solid which was filtered and washed with MeOH to provide a first crop. The filtrate was concentrated to a solid and washed with MeOH to provide a second crop and repeated a further two occasions to provide the title compound. On the final wash the filtrate was further purified by SPE (Si, 2Og) cartridge eluting with EtOAσcyclohexane (1 :1). The combined solids were dried under vacuum to afford the title compound (2.42g, 64%). LC/MS: m/z 283 [MH]+.
Example 30: 3-Butyl-8-chloro-1-(3-(1-r(2.3-difluorophenyl)methyll-1H-imidazol-4- yl)propyl)-3,7-dihvdro-1H-purine-2,6-dione
A solution of 3-butyl-8-chloro-1-[4-(1/-/-imidazol-4-yl)butyl]-7-(2-propen-1-yl)-3,7- dihydro-1H-purine-2,6-dione (150mg, 0.38mmol) in anhydrous DMF (3ml) was treated with 1-(bromomethyl)-2,4-difluorobenzene (54μl, 0.42mmol) and DIPEA (73μl, 0.42mmol). The mixture was left to stir at rt under nitrogen for 3 days. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The crude product was purified on a silica SPE column using a DCM to load the material onto the column and wash through the impurities then a 0-5% MeOH/DCM gradient to elute the compound. The product fractions were combined and concentrated and the residues dissolved in anhydrous DMF (3ml). The solution was degassed then Pd(PPh3J4 (39mg, 0.034mmol) and morpholine (200μl, 2.3mmol) were added and the mixture left to stir at rt under nitrogen for 3h. The crude product was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities then a 0-5% AcOH/MeOH gradient to elute the product. The product fractions were combined and concentrated by high vacuum to leave the title compound as a white solid (14mg, 7%). LC/MS: m/z 477 [MH]+, RT 2.54min.
Example 31 : 3-Butyl-8-chloro-1-r3-(1-{r2-(trifluoromethyl)phenvnmethylMH- imidazol-4-yl)propyn-3J-dihvdro-1H-purine-2,6-dione
A solution of 3-butyl-8-chloro-1-[4-(1H-imidazol-4-yl)butyl]-7-(2-propen-1-yl)-3,7- dihydro-1H-purine-2,6-dione (150mg, 0.38mmol) in anhydrous DMF (3ml) was treated with 1-(chloromethyl)-2-(trifluoromethyl)benzene (61 μl, 0.42mmol) and DIPEA (73μl, 0.42mmol). The mixture was left to stir at rt under nitrogen for 3 days. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The crude product was purified on a silica SPE column using DCM to load the material onto the column and wash through the impurities then a 0-5% MeOH/DCM gradient to elute the compound. The product
fractions were combined and concentrated and the residues dissolved in anhydrous DMF (3ml). The solution was degassed then Pd(PPh3J4 (35mg, 0.030mmol) and morpholine (174μl, 2.0mmol) were added and the mixture left to stir at rt under nitrogen for 3h. The crude product was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities then a 0-5% AcOH/MeOH gradient to elute the product. The product fractions were combined and concentrated by high vacuum to leave the title compound as a white solid (50mg, 26%). LC/MS: m/z 509 [MH]+, RT 2.64min.
Example 32 : 3-Butyl-8-chloro-1-r3-(1-(r3-(trifluoromethyl)phenvnmethyl)-1H- imidazol-4-yl)propyl1-3,7-dihvdro-1H-purine-2.6-dione
A solution of 3-butyl-8-chloro-1-[4-(1H-imidazol-4-yl)butyl]-7-(2-propen-1-yl)-3,7- dihydro-1H-purine-2,6-dione (150mg, 0.38mmol) in anhydrous DMF (3ml) was treated with 1-(chloromethyl)-3-(trifluoromethyl)benzene (65μl, 0.42mmol) and DIPEA (73μl, 0.42mmol). The mixture was left to stir at rt under nitrogen for 3 days. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The crude product was purified on a silica SPE column using a DCM to load the material onto the column and wash through the impurities then a 0-5% MeOH/DCM gradient to elute the compound. The product fractions were combined and concentrated and the residues dissolved in anhydrous DMF (3ml). The solution was degassed then Pd(PPh3)4 (30mg, 0.027mmol) and morpholine (156μl, 1.8mmol) were added and the mixture left to stir at rt under nitrogen for 3h. The crude product was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities then a 0-5% AcOH/MeOH gradient to elute the product. The product fractions were combined and concentrated by high vacuum to leave the title compound as a white solid (18mg, 9%). LC/MS: m/z 509 [MH]+, RT 2.78min.
Example 33 : 3-Butyl-8-chloro-1-l3-r3-(phenylmethvn-1H-1,2,4-triazol-1- vπpropyl}-3,7-dihvdro-1H-purine-2.6-dione
a) 3-Butyl-8-chloro-1 -{3-[3-(phenylmethyl)-1 H-1 ,2,4-triazol-1 -yl]propyl}-3,7- dihydro-1 H-purine-2,6-dione
A solution of 3-butyl-8-chloro-1-{3-[3-(phenylmethyl)-1/-/-1 ,2,4-triazol-1-yl]propyl}-7-(2- propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (669mg, 1.39mmol) in THF (7ml) was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (160mg, 0.14mmol) was added and the mixture degassed once more. Morpholine (1.2ml, 13.9mmol) was added and the mixture was stirred under nitrogen for 18h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The combined extracts were washed with brine, dried (MgSO4) and concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl SPE with the product eluting with 2-3% AcOH/ MeOH. The product fractions were combined and concentrated giving a pale yellow solid (380mg). Approximately a quarter of the material was purified by autoprep HPLC and rest was crystallised from MeOH:DMSO (1 :1) giving the title compound as a white solid (125mg, 31%). LC/MS: m/z 442 [MH]+, RT 3.0min.
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.30 (m, 2H), 1.62 (m, 2H), 2.07 (m, 2H), 3.90 (m, 6H), 4.13 (t, 2H, J = 7Hz), 7.24 (m, 5H), 8.36 (1 H, s), 14.5 (br s, 1 H).
b) 3-Butyl-8-chloro-1 -{3-[3-(phenylmethyl)-1 H-1 ,2,4-triazol-1 -yl]propyl}-7-(2-propen-1 - yl)-3,7-dihydro-1/-/-purine-2,6-dione
A solution of 3-(phenylmethyl)-1H-1 ,2,4-triazole (2.1g, 13.2mmol) in MeOH (40ml) was treated with 0.5M NaOMe in MeOH (29ml) followed by 1 ,3-dibromopropane (1.7ml). After stirring for 5h at 5O0C the mixture was partitioned between 2M HCI (aq) and
EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving an oily residue (1.Og). To this was added butyl-8-chloro-7-(2- propen-1-yl)-3,7-dihydro-1 A7-purine-2,6-dione (917mg, 3.2mmol) and Cs2CO3 (1.2g, 3.6mmol). DMF (15ml) was added and the mixture was stirred at 500C for 2Oh then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The resulting oil (1.52g) was passed down a silica SPE (5Og) column eluting with EtOAc/ cyclohexane mixtures. Two isomeric products of the triazole were obtained as a 2:1 mixture, in favour of the title compound, as a yellow paste (697mg, 67% based on ratio of isomers present). LC/MS: m/z 482 [MH]+, RT 3.3min.
Example 34 : 8-Chloro-3-pentyl-1-(3-r5-(phenylmethyl)-2H-tetrazol-2-yllpropyl)- 3,7-dihvdro-1 H-purine-2.6-dione
A solution of 5-benzyl-1 H-tetrazole (1.Og, 6.24mmol) in MeOH (5ml) was treated with 1- chloro-3-iodopropane (1.0ml, 9.36mmol) and a solution of 0.5M NaOMe in MeOH (4.7ml, 9.36mmol). The reaction was heated at reflux for 18h then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted once more with EtOAc. The combined extracts were washed with brine, dried (MgSO4) and concentrated, giving a yellow solid. (796mg). 700mg of this material was reacted with 8-chloro-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (732mg, 2.47mmol) and Cs2CO3 (967mg, 3.0mmol) in DMF (20ml) at 750C for 24h. The reaction was allowed to cool to rt and the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (428mg, 0.37mmol) was added and the mixture degassed once more. Morpholine (2.1 ml, 24.7mmol) was added and the mixture was stirred under nitrogen for 3h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted once more. The combined extracts were concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl SPE, the product eluting with 2-3% AcOH/MeOH. The product fractions were combined and concentrated then purified by the MDAP to give the title compound as a white solid (35mg, 3%). LC/MS: m/z 457 [MH]+, RT 3.5min.
1H NMR; (DMSO-d6) δ: 0.85 (t, 3H, J = 7Hz), 1.21-1.34 (m, 4H), 1.62 (m, 2H), 2.22 (m, 2H), 3.88 (t, 2H, J = 7Hz), 3.97 (t, 2H, J = 7Hz), 4.17 (s, 2H), 4.67 (t, 2H, J = 7Hz), 7.20-7.32 (m, 5H), 14.5 (br s, 1 H).
Example 35: 3-Butyl-8-chloro-1 -l3-r5-(phenylmethyl)-2H-tetrazol-2-yllpropyl}-3.7- dihydro-1 H-purine-2.6-dione
A solution of 5-benzyl-1 H-tetrazole (1.8g, 11.2mmol) in MeOH (30ml) was treated with 1 ,3-dibromopropane (5.7ml, 56.2mmol) and 0.5M NaOMe in MeOH (31.5ml) then stirred at 4O0C under nitrogen for 6Oh. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. Partial purification by SPE (2Og silica, cyclohexane/EtOAc mixtures) and by the Companion™ system (silica SPE, cyclohexane/EtOAc mixtures) gave an oil (1.98g, 62% of a mixture of isomers, 2:1 in favour of 2-(3-bromopropyl)-5- (phenylmethyl)-2/-/-tetrazole) which was taken on crude in the next step. A mixture of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (1.74g, 6.1 mmol), crude 2-(3-bromopropyl)-5-(phenylmethyl)-2H-tetrazole) (1.9g, 6.8mmol), Cs2CO3 (2.2g, 6.8mmol) and DMF (60ml) was stirred at 450C under nitrogen for 24h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (705mg, 0.61 mmol) was added and the mixture degassed once more. Morpholine (5.4ml, 61.4mmol) was added and the mixture was stirred under nitrogen for 4h, and then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl column with the product eluting with 2% AcOH/MeOH. The product was further purified by the Companion™ system using EtOAc/cyclohexane mixtures. The resulting solid was stirred with boiling Et2O and filtered after cooling to rt. The title compound was collected as a white solid (1.01g, 37%) and dried at 5O0C under vacuum. LC/MS: m/z 443 [MH]+, RT 3.3min.
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.29 (m, 2H), 1.61 (m, 2H), 2.22 (m, 2H), 3.89 (t, 2H, J = 7Hz), 3.97 (t, 2H, J = 7Hz), 4.17 (s, 2H), 4.67 (t, 2H, J = 7Hz), 7.20-7.32 (m, 5H), 14.5 (br s, 1 H).
Example 36: 8-Chloro-1 -(3-f 5-M4-f luorophenyl)methyll-2H-tetrazol-2-yl}propyl)-3- (4.4.4-trifluorobutyl)-3.7-dihydro-1H-purine-2,6-dione
a) 8-Chloro-1-(3-{5-[(4-fluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)-3-(4,4,4- trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione
5-[(4-Fluorophenyl)methyl]-1H-tetrazole (75mg, 0.4mmol) was treated with potassium carbonate (100mg, 0.7mmol) and DMF (3ml). The mixture was treated with a solution of 3-[8-chloro-2,6-dioxo-7-(2-propen-1 -yl)-3-(4,4)4-trifluorobutyl)-2,3,6,7-tetrahydro-1 H- purin-1-yl]propyl methanesulfonate (100mg, 0.2mmol) in DMF (0.5ml). The mixture was stirred and heated at 6O0C 3 hours then cooled and evaporated. The residue was partitioned between chloroform (4ml) and water (2cm3). 1cm3 of saturated aqueous sodium bicarbonate (3ml) was added to each. The mixture was separated and the organic phase evaporated. The residue was dissolved in anhydrous THF (3ml) and the mixture degassed by the cautious successive application of vacuum and nitrogen pressure to the mixture. The mixture was treated with tetrakis(triphenylphosphine)palladium(0) (10mg, O.OOδmmol) and morpholine (0.2ml, 2.3mmol) and then stirred in a nitrogen atmosphere for 2h. The mixture was evaporated and partitioned between chloroform (4ml) and saturated aqueous ammonium chloride (3ml). The mixture was separated, and the aqueous phase re- extracted with chloroform. The organic phase was evaporated and the residue dissolved in MeOH (3ml). The solution was added to the top of a 2g aminopropyl SPE and washed with MeOH (15ml). The desired product was eluted from the cartridge with a 3% v/v solution of AcOH in MeOH (20ml). Product containing fractions were combined and evaporated and the residue subjected to purification by flash column chromatography (gradient elution from 10:1 cyclohexane/EtOAc to EtOAc). Product- containing fractions were combined and evaporated to yield the product as a colourless oil. Trituration in minimal diethyl ether caused the product to solidify and this was thoroughly dried to yield the title compound as a white solid (18.7mg, 18%). LC/MS: m/z 515 [MH]+, RT 3.31 min. 1H NMR (CDCI3) δ: 2.06 (m, 2H), 2.21 (m, 2H), 2.45 (m, 2H), 4.17 (m, 4H), 4.24 (t, 2H, J = 7.0Hz), 4.70 (t, 2H, J = 7.2Hz), 6.96 (m, 2H), 7.25 (m, 2H).
b) 3-[8-Chloro-2,6-dioxo-7-(2-propen-1 -yl)-3-(4,4,4-trifluorobutyl)-2,3,6,7-tetrahydro-1 H- purin-1 -yl]propyl methanesulfonate
A solution of 8-chloro-1-(3-hydroxypropyl)-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7- dihydro-1 H-purine-2,6-dione (0.82g, 2.1mmol) in DCM (20ml) was treated with triethylamine (0.42ml, 3.1 mmol) and methanesulfonic anhydride (0.4Og, 2.3mmol). After 1h the mixture was treated with saturated aqueous sodium bicarbonate (20ml). The mixture was separated and the organic phase dried (MgSO4), filtered and evaporated to give the title compound (0.91g), which was used without further purification.
LC/MS: m/z 473 [MH]+, RT 3.17min.
c) 8-Chloro-1-(3-hydroxypropyl)-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro- 1 H-purine-2,6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1 H-purine- 2,6-dione (1.0g, 3.0mmol) in DMF (15ml) was treated with caesium carbonate (1.16g, 3.6mmol) and 3-bromo-1 -propanol (0.3ml, 3.3mmol). The mixture was heated at 6O
0C for 4h and then cooled and evaporated. The residue was partitioned between EtOAc (50ml) and water (50ml). The organic phase was dried (MgSO
4), filtered and evaporated. The product was purified by flash chromatography using a gradient elution from cyclohexane to EtOAc. Product-containing fractions were combined and evaporated to give the title compound as a colourless oil (0.82g, 75%). LC/MS: m/z 395 [MH]
+, RT 2.90min.
d) 8-Chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (2.Og, 8.8mmol) in DMF (20ml) was treated with sodium carbonate (1.15g, 10.8mmol) and 4- bromo-1 ,1 ,1-trifluorobutane (1.86g, 9.7mmol). The mixture was stirred at 5O0C for 18h then cooled and evaporated. The residue was partitioned between EtOAc (100ml) and saturated aqueous sodium bicarbonate (50ml). The organic phase was dried (MgSO4), filtered and evaporated. The residue was triturated in a mixture of diethyl ether and cyclohexane then the product filtered off and dried to yield the title compound as a white solid (1.18g, 40%). LC/MS: m/z 337 [MH]+, RT 2.83min.
e) 5-[(4-Fluorophenyl)methyl]-1 H-tetrazole
A mixture of triethylammonium chloride (4.14g, 30mmol) and sodium azide (1.95g, 30mmol) was treated with a solution of (4-fluorophenyl)acetonitrile (1.35g, 10mmol) in toluene (14ml) and the mixture was stirred and heated at 1000C for 5h. The cooled mixture was treated with water (10ml) and the mixture separated. The aqueous phase was stirred and treated dropwise with concentrated hydrochloric acid until the product had precipitated from solution. The precipitated product was filtered off, washed with water and dried to yield the title compound as a white solid (1.27g, 72%). LC/MS: m/z 179 [MH]+, RT 2.24min.
The compounds in Table 3 were prepared using a method analogous to that for Example 36: 8-chloro-1-(3-{5-[(4-fluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)-3-(4,4,4- trifluorobutyl)-3,7-dihydro-1/-/-purine-2,6-dione, with the appropriate methanesulfonate and tetrazole. MDAP was employed to further purify those compounds insufficiently pure following normal phase chromatography.
Methanesulfonates intermediates and their precursor alcohols were prepared according to the following procedures:
3-[8-Chloro-2,6-dioxo-7-(2-propen-1 -yl)-3-propyl-2,3,6,7-tetrahydro-1 H-purin-1 -yljpropyl methanesulfonate
A solution of 8-chloro-1-(3-hydroxypropyl)-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1H- purine-2,6-dione (1.99g, 6.1mmol) in DCM (50ml) was treated with triethylamine (1.2ml, 8.6mmol) and methanesulfonic anhydride (1.2g, 6.9mmol). After 1.5h the mixture was treated with water (50ml). The mixture was separated and the aqueous phase extracted with DCM (25ml), the combined organic phases dried (MgSO4), filtered and evaporated to give the title compound as a pale yellow oil (2.38g), which was used without further purification. LC/MS: m/z 405 [MH]+, RT 2.93min.
3-[3-Butyl-8-chloro-2,6-dioxo-7-(2-propen-1 -yl)-2,3,6,7-tetrahydro-1 /-/-purin-1 -yljpropyl methanesulfonate
Prepared according to the method used for 3-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-3- propyl-2,3,6,7-tetrahydro-1 H-purin-1 -yljpropyl methanesulfonate to give the title compound as a pale yellow oil (2.44g). LC/MS: m/z 419 [MH]+, RT 3.14min.
8-Chloro-1 -(3-hydroxypropyl)-7-(2-propen-1 -yl)-3-propyl-3,7-dihydro-1 H-purine-2,6- dione
A solution of 8-chloro-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1/-/-purine-2,6-dione (3.Og, 11.1mmol) in DMF (20ml) was treated with caesium carbonate (3.7g, 11.4mmol) and 3- bromo-1-propanol (1.6g, 11.5mmol). The mixture was heated at 6O0C for 4h and then cooled and evaporated. The residue was partitioned between EtOAc (60ml) and saturated aqueous sodium bicarbonate (50ml). The aqueous phase was extracted with EtOAc (60ml), the combined organic phases were dried (MgSO4), filtered and evaporated. The product was purified using the Companion™ system and a gradient elution from cyclohexane to EtOAc. Product containing fractions were combined and evaporated to give the title compound as a colourless oil (2.6g). LC/MS: m/z 327 [MH]+, RT 2.62min.
3-Butyl-8-chloro-1 -(3-hydroxypropyl)-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione
Prepared according to the method used for 8-chloro-1-(3-hydroxypropyl)-7-(2-propen- 1-yl)-3-propyl-3,7-dihydro-1/-/-purine-2,6-dione to give the title compound as a colourless oil (2.3g). LC/MS: m/z 341 [MH]+, RT 2.85min.
Table 3
NMR details for selected examples from Table 3:
Example 37: 8-Chloro-1 -(3-{5-[(4-fluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)-3- propyl-3,7-dihydro-1A7-purine-2,6-dione
1H NMR (CDCI3) δ: 0.99 (t, 3H, J = 7.5 Hz), 1.80 (m, 2H)1 2.46 (m, 2H), 4.06 (m, 2H),
4.18 (s, 2H), 4.25 (t, 2H, J = 7Hz), 4.70 (t, 2H, J = 7.5Hz), 6.96 (m, 2H), 7.26 (m, 2H),
13.15 (br s, 1 H).
Example 40 : 8-Chloro-3-(4,4,4-trifluorobutyl)-1-(3-{5-[(2,4,6-trifluorophenyl)methyl]- 2H-tetrazol-2-yl}propyl)-3,7-dihydro-1 H-purine-2,6-dione : 1H NMR (CDCI3) δ: 2.07 (m, 2H), 2.21 (m, 2H), 2,44 (m, 2H), 4.18 (t, 2H, J = 7.1 Hz), 4.20 (s, 2H), 4.24, (t, 2H, J = 6.8Hz), 4.68 (t, 2H, J = 7.3Hz), 6.67 (t, 2H, J = 8.1 Hz), 13.04 (br s, 1 H).
Example 41 : 1H NMR (CDCI3): 2.03-2.10 (m, 2H), 2.16-2.28 (m, 2H), 2.43-2.50 (m, 2H), 4.16-4.19 (m, 2H), 4.17 (s, 2H), 4.24 (t, 2H, J=7.1 Hz), 4.71(t, 2H, J=7.1 Hz), 7.00-7.13 (m, 3H), 13.06 (bs, 1 H).
Example 44: 1H NMR (CDCI3): 0.99 (t, 3H, J=7.5Hz), 1.76-1.86 (m, 2H), 2.40-2.47 (m, 2H), 4.05-4.09 (m, 2H), 4.23-4.26 (m, 2H), 4.54 (s, 2H), 4.65-4.69 (m, 2H), 7.14-7.18 (m, 1 H), 7.31-7.33, (m, 2H), 13.18 (bs, 1 H).
Example 45: 1H NMR (CDCI3): 0.97 (t, 3H, J=7.5Hz), 1.36-1.46 (m, 2H), 1.71-1.79 (m, 2H), 2.42-2.49 (m, 2H), 4.08-4.11 (m, 2H), 4.25 (s, 2H), 4.24-4.27 (m, 2H), 4.68-4.71 (m, 2H), 7.02-7.09 (m, 2H), 7.20-7.26, (m, 2H), 13.14 (bs, 1 H).
Example 46: 1H NMR (CDCI3): 0.97 (t, 3H, J=7.5Hz), 1.36-1.45 (m, 2H), 1.71-1.79 (m, 2H), 2.42-2.49 (m, 2H), 4.09 (t, 2H, J=7.5Hz), 4.26 (t, 2H, J=7.5Hz), 4.34 (s, 2H), 4.70 (t, 2H, J=7.3Hz), 7.18-7.21 (m, 2H), 7.25-7.27, (m, 1 H), 7.35-7.37, (m, 1 H), 13.34 (bs, 1 H).
Example 47: 3-Butyl-8-chloro-1 -(3-{5-[(3-fluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)- 3,7-dihydro-1 /-/-purine-2,6-dione
1H NMR (CDCI3) δ: 0.97 (t, 3H, J = 7Hz), 1.40 (m, 2H), 1.75 (m, 2H), 2.46 (m, 2H), 4.10 (t, 2H, J = 7.5Hz), 4.21 (s, 2H), 4.26 (t, 2H 1 J = 6.5Hz), 4.70 (t, 2H, J = 7.5Hz), 6.90 (m, 1 H)1 6.99 (m, 1 H), 7.07 (m, 1 H), 7.25 (m, 1 H), 13.25 (br s, 1 H).
Example 48: 1H NMR (CDCI3): 0.99 (t, 3H, J=7.5Hz), 1.38-1.48 (m, 2H), 1.73-1.81 (m, 2H), 2.44-2.51 (m, 2H), 4.12 (t, 2H, J=7.5Hz), 4.20 (s, 2H), 4.27 (t, 2H, J=7.5Hz), 4.70 (t, 2H, J=7.3Hz), 6.95-7.00 (m, 2H), 7.26-7.30, (m, 2H), 13.35 (bs, 1 H).
Example 49: 3-Butyl-8-chloro-1 -(3-{5-[(4-fluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)- 3,7-dihydro-1 H-purine-2,6-dione
1H NMR (CDCI3) δ: 0.99 (t, 3H, J = 7Hz), 1.43 (m, 2H), 1.77 (m, 2H), 2.48 (m, 2H), 4.12 (t, 2H, J = 7.5Hz), 4.20 (s, 2H), 4.27 (t, 2H 1 J = 7Hz), 4.72 (t, 2H, J = 7.5Hz), 6.98 (m, 2H), 7.27 (m, 2H), 13.35 (br s, 1 H). Example 50: 3-Butyl-8-chloro-1-(3-{5-[(4-chlorophenyl)methyl]-2H-tetrazol-2-yl}propyl)- 3,7-dihydro-1 /-/-purine-2,6-dione
1H NMR (CDCI3) δ: 1.02 (t, 3H, J = 7.5Hz), 1.45 (m, 2H), 1.79 (m, 2H), 2.50 (m, 2H), 4.14 (t, 2H, J = 7.5Hz), 4.22 (s, 2H), 4.29 (t, 2H 1 J = 7Hz), 4.75 (t, 2H, J = 7.5Hz), 7.27 (S, 4H), 13.35 (br s, 1 H).
Example 55: 3-Butyl-8-chloro-1 -{3-[5-(1 -phenylcyclopropyl)-2H-tetrazol-2-yl]propyl}-3,7- dihydro-1 H-purine-2,6-dione: 1H NMR (CDCI3) δ: 0.93 (t, 3H, J = 7.3Hz)1 1.36 (m, 4H), 1.55 (m, 2H), 1.71 (m, 2H), 2.38 (m, 2H), 4.06 (t, 2H1 J = 7.5Hz), 4.20 (t, 2H, J =
6.7Hz), 4.59 (t, 2H, J = 7.5Hz), 7.25 (m, 3H)1 7.36 (m, 2H), 13.30 (br s, 1H).
Example 67: 8-Chloro-1 -(3-{5-[(2,4-difluorophenyl)methyl]-2H-tetrazol-2-yl}propyl)-3- propyl-3,7-dihydro-1/-/-purine-2,6-dione
1H NMR (CDCI3) δ: 0.99 (t, 3H1 J = 7.5 Hz)1 1.80 (m, 2H), 2.45 (m, 2H), 4.06 (m, 2H), 4.20 (S1 2H)1 4.25 (t, 2H, J = 7Hz), 4.70 (t, 2H, J = 7.5Hz), 6.80 (m, 2H), 7.23 (m, 1 H).
Example 70: 8-Chloro-3-propyl-1 -(3-{5-[(2,4,6-trifluorophenyl)methyl]-2H-tetrazol-2- yl}propyl)-3,7-dihydro-1 H-purine-2,6-dione : 1H NMR (CDCI3) δ: 0.99 (t, 3H, J = 7.3 Hz), 1.80 (m, 2H)1 1.98 (m, 2H), 2.01 (m, 2H), 4.20 (s, 2H), 4.25 (t, 2H, J = 6.5Hz), 4.67 (t, 2H, J = 7.3Hz), 6.68 (t, 2H, J = 8.1 Hz).
Example 71 : 1H NMR (CDCI3): 0.99 (t, 3H, J=7.3Hz), 1.76-1.85 (m, 2H)1 2.39-2.46 (m, 2H)1 4.05-4.08 (m, 2H), 4.24 (t, 2H, J=7.1 Hz), 4.39 (s, 2H), 4.64 (t, 2H, J=7.1 Hz), 7.29- 7.32 (m, 1 H), 7.38-7.44, (m, 1 H), 7.49-7.51 , (m, 1H), 13.17 (bs, 1 H).
Example 78: 1H NMR (CDCI3): 0.99 (t, 3H, J=7.6Hz), 1.36-1.45 (m, 2H), 1.71-1.79 (m, 2H), 2.42-2.49 (m, 2H), 4.09 (t, 2H, J=7.5Hz), 4.17 (s, 2H), 4.24 (t, 2H, J=7.5Hz), 4.71 (t, 2H, J=7.3Hz), 7.00-7.14 (m, 3H)1 13.07 (bs, 1 H).
Example 80: 1H NMR (CDCI3): 0.96 (t, 3H, J=7.2Hz), 1.32-1.47 (m, 2H), 1.68-1.80 (m, 2H), 2.40-2.51 (m, 2H), 4.06-4.12 (m, 2H)1 4.22 (s, 2H), 4.22-4.27 (m, 2H), 4.67-4.73 (m, 2H), 6.84-7.04 (m, 3H), 13.05 (bs, 1 H).
Example 83: 3-Butyl-8-chloro-1 -(3-{5-[(2,4,6-trifluorophenyl)methyl]-2H-tetrazol-2- yl}propyl)-3,7-dihydro-1 H-purine-2,6-dione : 1H NMR (CDCI3) δ: 0.97 (t, 3H, J = 7.3Hz), 1.41 (m, 2H), 1.75 (m, 2H), 2.44 (m, 2H), 4.10 (t, 2H1 J = 7.5Hz)1 4.20 (s, 2H), 4.25 (t, 2H 1 J = 6.5Hz), 4.67 (t, 2H, J = 7.4Hz), 6.67 (t, 2H, J = 8.0Hz), 13.25 (br s, 1 H).
Example 87 : 8-Chloro-3-pentvH-{3-r3-(phenylmethyl)-1.2.4-oxadiazol-5- yllpropyl}-3.7-dihvdro-1/V-purine-2.6-dione
a) 8-Chloro-3-pentyl-1 -{3-[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7-dihydro- 1H-purine-2,6-dione
A solution of 3-[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]-1-propanol (88mg, 0.4mmol) in THF (4ml) was treated with 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine- 2,6-dione (100mg, 0.34mmol) and PPh3 (115mg, 0.44mmol) under nitrogen. DBAD (101mg, 0.44mmol) was added in one portion and the reaction left to react for 5h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (39mg, 0.034mmol) was added and the mixture degassed once more. Morpholine (294μl, 3.4mmol) was added and the mixture was stirred under nitrogen for 3h. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The title compound was obtained as a white solid after purification by MDAP (64mg, 42%). LC/MS: m/z 457 [MH]+, RT 3.4min. 1H NMR (DMSO-d6) δ: 0.85 (t, 3H, J = 7Hz), 1.22-1.34 (m, 4H), 1.62 (m, 2H), 2.02 (m, 2H), 2.91 (t, 2H, J = 7Hz), 3.88 (t, 2H, J = 7Hz), 3.95-4.00 (m, 4H), 7.22-7.33 (m, 5H), 14.5 (br s, 1 H).
b) 3-[3-(Phenylmethyl)-1 ,2,4-oxadiazol-5-yl]-1-propanol
A mixture of γ-butyrolactone (223μl, 2.9mmol), benzamidine oxime (480mg, 3.2mmol), 21% solution of NaOEt in EtOH (1.3ml) and EtOH (3ml) was heated in the microwave at 14O0C for 10min. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The title product was purified over silica using the Companion™ system to give a pale yellow oil (143mg, 23%). LC/MS: m/z 219 [MH]+, RT 2.4min.
Example 88 : 8-Chloro-1-(3-{3-f(4-chlorophenyl)methvn-1,2,4-oxadiazol-5- yl)propyl)-3-pentyl-3.7-dihydro-1H-purine-2,6-dione
a) 8-Chloro-1 -(3-{3-[(4-chlorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-pentyl-3,7-
A solution of 8-chloro-1-(3-{3-[(4-chlorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3- pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (0.18g, 0.34mmol) in DMF (5ml) was degassed by sequential evacuation of the flask and admission of nitrogen (x3) and morpholine (0.5ml, 5.8mmol), and Pd(PPh3)4 (80mg, 0.068mmol) added. The solution was stirred for 72h then concentrated and the residues loaded onto an aminopropyl SPE (10g) with MeOH. Elution with MeOH followed by 5% AcOH/MeOH provided the title compound as a pale yellow solid, which was washed with ether to yield a white solid (0.053g, 32%). LC/MS: m/z 491 [MH]+, RT 3.69min
b) 8-Chloro-1 -(3-{3-[(4-chlorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}propyl)-3-pentyl-7-(2- propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione
i) A mixture of γ-butyrolactone (8ml, 104mmol), 4-chlorobenzamidine oxime (3.Og, 16.25mmol), 30% solution of NaOMe in MeOH (5ml) and MeOH (80ml) was refluxed for 3Oh, cooled and concentrated. The residues were purified by flash chromatography over silica eluting with DCM/EtOH/0.88 aq ammonia (200:8:1 ) to provide a yellow oil (13g). This material was dissolved in DCM (150ml) and washed with 2M sodium hydroxide (100ml) and the organics separated, dried and concentrated to yield 3-{3-[(4- chlorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}-1-propanol as a viscous oil (3.95g, 96%) which was used in the next step.
ii) To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (0.1Og, 0.34mmol), 3-{3-[(4-chlorophenyl)methyl]-1 ,2,4-oxadiazol-5-yl}-1-propanol (0.086g, 0.34mmol) and triphenylphosphine (0.186g, 0.69mmol) in THF (5ml) was added dibenzylazodicarboxylate (0.204g, 0.68mmol) and the solution stirred for 18h. The solution was then concentrated and the residues chromatographed over silica (2Og, SPE) eluting with DCM initially then DCM/Et2O mixtures to yield the title
compound contaminated with dibenzylazodicarboxylate by-products (0.18g). Material used crude in deprotection step. LC/MS: m/z 531 [MH]+, RT 3.83min.
Example 89 : 8-Chloro-3-pentyl-1-(3-f3-(2-phenylethyl)-1,2.4-oxadiazol-5- yllpropyl}-3,7-dihvdro-1H-purine-2,6-dione
a) 8-Chloro-3-pentyl-1-{3-[3-(2-phenylethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7-dihydro- 1H-purine-2,6-dione
A solution of 3-[3-(2-phenylethyl)-1 ,2,4-oxadiazol-5-yl]-1-propanol (150mg, 0.65mmol) in THF (6ml) was treated with 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1 H- purine-2,6-dione (160mg, 0.54mmol) and PPh3 (183mg, 0.70mmol) under nitrogen. DBAD (161mg, 0.70mmol) was added in one portion and the reaction left to react for 18h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (39mg, 0.034mmol) was added and the mixture degassed once more. Morpholine (294μl, 3.4mmol) was added and the mixture was stirred under nitrogen for 3h. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The residue was taken up into MeOH and purified by passing down an aminopropyl SPE, the product eluted with 2-5% AcOH/MeOH. The title compound was obtained as an off- white solid (185mg, 73%). LC/MS: m/z 471 [MH]+, RT 3.6min.
1H NMR; (DMSO-d6) δ: 0.85 (t, 3H, J = 7Hz), 1.23-1.34 (m, 4H), 1.63 (m, 2H), 2.06 (m, 2H), 2.87 (m, 4H), 2.93 (t, 2H, J = 7Hz), 3.89 (t, 2H, J = 7Hz), 4.00 (t, 2H, J = 6.5Hz), 7.16-7.29 (m, 5H), 14.5 (br s, 1 H).
b) 3-[3-(2-Phenylethyl)-1 ,2,4-oxadiazol-5-yl]-1 -propanol
A mixture of γ-butyrolactone (426μl, 5.5mmol), phenethylamidine oxime (1.0g, 6.1 mmol), 21% solution of NaOEt in EtOH (2ml) and EtOH (3ml) was heated in the microwave at 14O
0C for 10min. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated. The title product was purified by Si-SPE eluting with EtOAc/cyclohexane mixtures to give the title compound as a pale yellow oil (390mg, 31%). LC/MS: m/z 233 [MH]
+, RT 2.5min.
Example 90 : 8-Chloro-1-J3-r3-(phenylmethyl)-1.2.4-oxadiazol-5-yllpropyl)-3- propyl-3.7-dihvdro-1H-purine-2.6-dione
a) 8-Chloro-1 -{3-[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3-propyl-3,7-dihydro-
A solution of 8-chloro-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1H-purine-2,6-dione
(200mg, 0.74mmol) in THF (4ml) was treated with 3-[3-(phenylmethyl)-1 ,2,4- oxadiazol-5-yl]-1 -propanol (195mg, 0.89mmol) and PPh3 (254mg, 0.96mmol). DBAD (223mg, 0.96mmol) was added in one portion and the mixture was left to stir at rt under nitrogen for 18h. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The crude product was purified by a silica SPE column using a 0-70% cyclohexane/EtOAc gradient. The product fractions were combined, concentrated and further purified by a silica SPE column using a 0-60% cyclohexane/EtOAc gradient. The product fractions were combined and concentrated then dissolved in anhydrous THF (4ml). The solution was degassed by high vacuum then Pd(PPh3)4 (86mg, 0.074mmol) and morpholine (644μl, 7.4mmol) were added and the mixture left to stir at rt under nitrogen for 1 day. The mixture was partitioned between EtOAc and HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated by high vacuum. The crude product was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities then a 2-4% AcOH/MeOH gradient to elute the product. The product fractions were combined and concentrated by high vacuum to leave the title compound as a white solid (74mg, 23%). LC/MS: m/z 429 [MH]+, RT 3.14min.
1H NMR; (DMSO-de) δ: 0.87 (t, 3H1 J = 7.5 Hz), 1.65 (m, 2H), 2.02 (m, 2H), 2.91 (t, 2H, J = 7.5Hz), 3.86 (t, 2H, J = 7Hz), 3.97 (s,t overlapping, 4H), 7.27 (m, 5H) 14.46 (s, 1 H).
b) 8-Chloro-7-(2-propen-1 -yl)-3-propyl-3,7-dihydro-1 H-purine-2,6-dione
A mixture of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5g, 6.6mmol), 1-iodopropane (1.2g, 6.9mmol) and sodium carbonate (0.9g, 8.5mmol) in DMF (40ml) was heated at 5O0C for 18h. The reaction mixture was concentrated in vacuo and the residue treated with water (60ml) and extracted with EtOAc (3x 80ml). The combined organic extracts were dried (MgSO4) filtered and evaporated. The residue was triturated with ether/cyclohexane, the solid was filtered off and dried to afford the title compound (0.82g, 46%). LC/MS: m/z 269 [MH]+.
Example 91 : 8-Chloro-3-pentyl-1-(3-r3-(3-thienylmethyl)-1.2.4-oxadiazol-5- yllpropyl>-3.7-dihvdro-1fV-purine-2.6-dione
a) 8-Chloro-3-pentyl-1 -{3-[3-(3-thienylmethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7-dihydro-
A mixture of ethyl 4-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1- yl)butanoate (70mg, 0.19mmol), Λ/-hydroxy-2-(3-thienyl)ethanimidamide (36mg, 0.23mmol), 21% solution of NaOEt in EtOH (78μL, 0.21 mmol) and EtOH (1.5ml) was heated in the microwave at 14O0C for 10min. After cooling the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The combined extracts were concentrated and purified by MDAP. The title compound was freeze dried from 1 ,4-dioxane to give a white solid (27mg, 31%). LC/MS: m/z 463 [MH]+, RT 3.4min.
b) Ethyl 4-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)butanoate
A solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (3.Og, 10.1 mmol) in anhydrous DMF (35ml) was treated with Cs2CO3 (3.6g, 11.1mmol) and ethyl 4-bromobutyrate (1.6ml, 11.1mmol). The mixture was stirred at rt for 18h then degassed under a gentle vacuum, then nitrogen introduced. This was repeated twice. Pd(PPh3)4 (1.17g, I .Ommol) was added and the mixture degassed once more. Morpholine (8.8ml, 101mmol) was added and left to stir for 3 h at rt. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving a yellow solid (5.16g). The residue was taken up in MeOH and divided into two equal portions, and then each passed down an aminopropyl SPE (2Og), eluting with MeOH followed by 5% AcOH/MeOH. The product fractions were combined and concentrated giving the title compound as a near white solid (3.01g, 80%). LC/MS: m/z 371 [MH]+, RT 3.2min.
Example 92 : 8-Chloro-3-pentyl-1-{3-r3-(1-phenylethyl)-1,2.4-oxadiazol-5- yllpropyl)-3,7-dihvdro-1H-purine-2,6-dione
A mixture of ethyl 4-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1- yl)butanoate (70mg, 0.19mmol), Λ/-hydroxy-2-phenylpropanimidamide (38mg, 0.23mmol), 21% solution of NaOEt in EtOH (78μl, 0.21 mmol) and EtOH (1.5ml) was heated in the microwave at 14O
0C for 10min. After cooling the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The combined extracts were concentrated and purified by the MDAP. The title compound was freeze dried from 1 ,4-dioxane to give a white solid (44mg, 49%). LC/MS: m/z 471 [MH]
+, RT 3.6min.
Example 93 : 3-Butyl-8-chloro-1-f3-r3-(2,3-difluorobenzyl)-1,2,4-oxadiazol-5- yllpropyl)-3,7-dihvdro-1H-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -{3-[3-(2,3-difluorobenzyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7-dihydro-
2,3-Difluorophenylacetonitrile (23mg, 0.15mmol) was dissolved in EtOH (1ml). Hydroxylamine hydrochloride (14mg, 0.20mmol) was added, followed by water (0.5ml) and potassium carbonate (41 mg, 0.3mmol). The mixture was heated at reflux overnight and then cooled and partitioned between EtOAc and brine. The organic phase was evaporated and the crude amidoxime thus obtained was dissolved in EtOH (1 ml). Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1 -yl)butanoate (43mg,
0.12mmol) and 21 % by wt. ethanolic sodium ethoxide ((0.067ml, 0.18mmol) was added and the mixture heated in the microwave reactor at 14O0C for 10min. The mixture was partitioned between EtOAc and 2M HCI, the organic phase evaporated and the product purified by MDAP to provide the title compound as a solid (13mg). LC/MS: m/z 479 [MH]+, RT 3.52min.
1H NMR (MeOH-d4) δ: 0.96 (t, 3H, J = 7Hz), 1.34-1.45 (m, 2H), 1.65-1.75 (m, 2H), 2.13- 2.22 (m, 2H), 2.97 (t, 2H, J = 7Hz), 4.00 (t, 2H, J = 7Hz), 4.05 (s, 2H), 4.12 (t, 2H, J = 7Hz), 7.03-7.25 (m, 3H).
b) Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1 -yl)butanoate
To 3-butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (6.Og, 21.24mmol) in dry DMF (100ml) was added Cs2CO3 (7.62g, 23.36mmol) followed by ethyl 4-bromobutyrate (4.556g, 23.36mmol). The mixture was heated at 550C for 18h and allowed to cool then degassed by repeatedly evacuating and readmitting nitrogen. Morpholine (14.9g, 171 mmol) was added followed by tetrakis(triphenylphosphine)palladium(0) (4.Og, 3.46mmol) and the mixture was stirred for 4h. EtOAc (300ml) and 2M HCI (150ml) and water (100ml) were added and the organic phase separated, washed with brine (3 x 100ml) and filtered. The filtrate was dried (Na2SO4) and evaporated. The crude product (10g) was purified by aminopropyl SPE (3 x 2Og), loading in THF/MeOH (1 :1), washing with THF/MeOH (1 :1 ) and neat
MeOH and eluting the product with DCM/MeOH (1 :1) containing 5% added AcOH to afford the title compound (5.08g).
LC/MS: m/z 357 [MH]+, RT 3.06min.
1H NMR (d4 MeOH) 0.96 (3H, t, J = 7Hz), 1.33-1.42 (2H1 m), 1.64-1.74 (2H, m), 2.12- 2.21 (2H, m), 2.95 (2H, t, J = 8Hz), 3.99 (2H, t, J = 7Hz), 4.03 (2H, s), 4.11 (2H, t, J = 7Hz), 7.03-7.21 (3H, m).
Example 94 : S-Butyl-S-chloro-i-fS-re-β-chlorobenzylH.ΣΛ-oxadiazol-S- vπpropyl)-3.7-dihvdro-1H-purine-2.6-dione
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)butanoate (53mg, 0.15mmol) and (1Z)-2-(2-chlorophenyl)-Λ/-hydroxyethanimidamide (30mg, 0.18mmol; Entry 1 , table 7) were heated in EtOH (0.75ml) with 21% ethanolic sodium ethoxide (0.083ml, 0.22mmol) at 14O0C for 10min. The mixture was then partitioned between EtOAc and 2M HCI and the organic phase evaporated. The product was purified by MDAP to yield the title compound as a solid (34.8mg).
LC/MS: m/z 477 [MH]+, RT 3.59min. 1H NMR (d6 DMSO) 0.89 (3H, t, J = 8Hz), 1.24-1.34 (2H, m), 1.56-1.65 (2H, m), 1.98- 2.07 (2H, m), 2.92 (2H, t, J = 7Hz), 3.89 (2H, t, J = 7Hz), 3.98 (2H, t, J = 7Hz), 4.09 (2H, s), 7.28-7.48 (4H, m).
Example 95 : 3-Butyl-8-chloro-1-{3-r3-(4-fluorobenzyl)-1.2.4-oxadiazol-5- yllprc)Pyl}-3.7-dihvdro-1Af-purine-2.6-dione
Starting from (12)-2-(4-fluorophenyl)-Λ/-hydroxyethanimidamide (28mg, 0.18mmol; Entry 2, Table 7) was similarly obtained the title compound as a solid (10.0mg). LC/MS: m/z 461 [MH]+, RT 3.49min.
Example 96 : S-Butyl-β-chloro-i-te-rS-re.S-dichlorobenzvO-i.∑Λ-oxadiazol-S- yl1propyl)-3.7-dihvdro-1H-purine-2.6-dione
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)butanoate (53mg, 0.15mmol) and (1Z)-2-(2,3-dichlorophenyl)-Λ/-hydroxyethanimidamide (36mg, 0.165mmol; Entry 3, Table 7) and 21% ethanolic sodium ethoxide (0.083ml, 0.22mmol) were heated together in EtOH (0.75ml) in the microwave reactor at 14O0C for 10min. The mixture was then partitioned between EtOAc and 2M HCI, the organic phase separated, evaporated and the product purified by MDAP to give the title compound as a solid (42.1 mg). LC/MS: m/z 51 1 , 513, 515 (isotopes) [MH]+, RT 3.66min.
The following compounds (Table 4) were prepared using a method analogous to that for Example 96, using the appropriate amidoxime, (with the exceptions that for Example 110 (Table 4) during workup the pH was adjusted to 5 prior to extraction with EtOAc; and in the case of Example 111 (Table 4) the crude product was stirred for 18h with EtOH (1 ml) and 2M NaOH (0.5ml) and Example 112 (Table 4) was stirred for 18h with EtOH (0.75ml) and 2M NaOH (0.5ml) prior to repeat workup and purification by MDAP).
NMR details for selected examples from Table 4:
Example 97: 3-butyl-8-chloro-1-{3-[3-(3-fluorobenzyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7- dihydro-1 H-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.90 (t, 3H1 J = 7Hz), 1.25-1.36 (m, 2H), 1.56-1.67 (m, 2H), 2.0-
2.1 (m, 2H), 2.94 (t, 2H, J = 7Hz), 3.90 (t, 2H, J = 7 Hz), 3.98 (t, 2H, J = 7Hz), 4.02 (s, 2H), 7.05-7.15 (m, 3H), 7.32-7.40 (m, 1 H).
Example 98: 3-Butyl-8-chloro-1-{3-[3-(3,4-difluorobenzyl)-1 ,2,4-oxadiazol-5-yl]propyl}- 3,7-dihydro-1 H-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7.5Hz), 1.25-1.34 (m, 2H), 1.56-1.65 (m, 2H), 1.99-2.07 (m, 2H), 2.92 (t, 2H, J = 7Hz), 3.89 (t, 2H, J = 7 Hz), 3.98 (t, 2H, J = 7Hz),
4.02 (s, 2H), 7.10-7.15 (m, 1 H), 7.32-7.39 (m, 2H), 14.45 (br s, 1 H).
Example 100: 3-butyl-8-chloro-1-{3-[3-(1-phenylcyclopropyl)-1 ,2,4-oxadiazol-5- yl]propyl}-3,7-dihydro-1H-purine-2,6-dione
1H NMR (MeOH-Cl4) δ: 0.95 (t, 3H, J = 7Hz)1 1.25-1.30 (m, 2H), 1.30-1.45 (m, 4H), 1.64- 1.75 (m, 2H), 2.15-2.25 (m, 2H), 2.94 (t, 2H, J = 7Hz), 3.98 (t, 2H, J = 7Hz), 4.10 (t, 2H, J = 7Hz), 7.20-7.37 (m, 5H).
Example 102: 1-{3-[3-(1 ,3-benzodioxol-5-ylmethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3-butyl-
8-chloro-3,7-dihydro-1H-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.90 (t, 3H, J = 7Hz), 1.25-1.36 (m, 2H), 1.58-1.68 (m, 2H),
1.98-2.09 (m, 2H), 2.92 (t, 2H, J = 7Hz), 3.88-3.95 (m, 4H), 3.99 (t, 2H, J = 7Hz), 5.98
(S1 2H), 6.70-6.86 (m, 3H).
Example 110: 3-butyl-8-chloro-1 -{3-[3-(1 H-indol-3-ylmethyl)-1 ,2,4-oxadiazol-5- yl]propyl}-3,7-dihydro-1H-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.23-1.36 (m, 2H), 1.56-1.67 (m, 2H)1
1.96-2.08 (m, 2H), 2.90 (t, 2H, J = 7Hz), 3.90 (t, 2H, J = 7 Hz), 3.99 (t, 2H, J = 7Hz), 4.04 (s, 2H), 6.92-7.50 (m, 5H), 10.95 (s, 1 H).
Example 111 : 3-butyl-8-chloro-1-(3-{3-[(3-hydroxyphenyl)methyl]-1 ,2,4-oxadiazol-5- yl}propyl)-3,7-dihydro-1A7-purine-2,6-dione
1H NMR (DMSO-de) δ: 0.90 (t, 3H, J = 7Hz), 1.25-1.38 (m, 2H), 1.57-1.68 (m, 2H), 1.96-2.07 (m, 2H), 2.92 (t, 2H1 J = 7Hz), 3.86 (s, 2H), 3.89 (t, 2H, J = 7Hz)1 3.99 (t, 2H, J = 7Hz), 6.58-6.68 (m, 3H), 7.08 (m, 1 H), 9.40 (s,1 H).
Example 112: Λ/-[3-({5-[3-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1- yl)propyl]-1 ,2,4-oxadiazol-3-yl}methyl)phenyl]methanesulfonamide 1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7.5Hz), 1.24-1.34 (m, 2H), 1.56-1.65 (m, 2H), 1.97-2.06 (m, 2H)1 2.91 (t, 2H, J = 7.5Hz), 2.97 (s, 3H), 3.90 (t, 2H, J = 7.5Hz), 3.96 (s, 2H), 3.97 (t, 2H, J = 7Hz), 6.96-6.99 (m, 1 H), 7.06-7.13 (m, 2H), 7.26 (t, 1 H, J = 8Hz)1 9.75 (s, 1 H)1 14.45 (br s, 1H).
Example 114: 3-Butyl-8-chloro-1-(3-m(3.4-dichlorophenyl)methyll-1,2,4- oxadiazol-5-yl}propyl)-3,7-dihvdro-1H-purine-2,6-dione
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)butanoate (71 mg, 0.2mmol), (1Z)-2-(3,4-dichlorophenyl)-Λ/-hydroxyethanimidamide (48mg, 0.22mmol) and 21% by wt. ethanolic sodium ethoxide (0.111 ml, 0.3mmol) were heated together in
EtOH (1ml) in the microwave reactor at 14O0C for 10min. The mixture was then partitioned between EtOAc and 2M HCI, the organic phase separated and evaporated, and the crude product was purified by MDAP to give the title compound as a solid (48.8mg).
LC/MS: m/z 511 , 513 [MH]+, RT 3.65min.
The following compounds (Table 5) were prepared using a method analogous to that for Example 114, using the appropriate amidoxime (with the exception that for Example 115 and Example 125, 0.185ml, (O.δmmol) of 21% sodium ethoxide was added in order to allow for the amidoximes being the hydrochloride salts).
NMR details for selected examples from Table 5
Example 115: 1H NMR (d6 DMSO) 0.88 (3H1 1, J = 7Hz), 1.24-1.33 (2H, m), 1.56-1.65 (2H, m), 1.98-2.06 (2H, m), 2.92 (2H, t, J = 7Hz), 3.89 (2H, t, J = 7Hz), 3.97 (2H, t, J = 7Hz), 4.14 (2H, s), 7.52-7.70 (4H, m).
Example 117: 3-butyl-8-chloro-1-{3-[3-(1-phenylethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7- dihydro-1 /-/-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.22-1.35 (m, 2H), 1.52 (d, 3H, J = 8Hz), 1.56-1.68 (m, 2H), 1.95-2.08 (m, 2H), 2.91 (t, 2H, J = 7Hz), 3.89 (t, 2H, J = 7Hz), 3.95 (t, 2H, J = 7Hz), 4.18 (q, 1 H, J = 8Hz), 7.17-7.32 (m, 5H).
Example 119: 3-butyl-8-chloro-1 -(3-{3-[(4-chlorophenyl)methyl]-1 ,2,4-oxadiazol-5- yl}propyl)-3,7-dihydro-1H-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.23-1.37 (m, 2H), 1.55-1.67 (m, 2H),
1.97-2.09 (m, 2H), 2.90 (t, 2H, J = 7Hz), 3.88 (t, 2H, J = 7Hz), 3.97 (t, 2H, J = 7Hz),
4.00 (s, 2H), 7.27-7.40 (m, 4H).
Example 122: 3-butyl-8-chloro-1-(3-{3-[(4-hydroxyphenyl)methyl]-1 ,2,4-oxadiazol-5- yl}propyl)-3,7-dihydro-1tf-purine-2,6-dione
1H NMR (DMSO-d6) δ: 0.90 (t, 3H, J = 7Hz), 1.23-1.37 (m, 2H), 1.57-1.68 (m, 2H),
1.96-2.08 (m, 2H), 2.90 (t, 2H, J = 7Hz), 3.82 (s, 2H), 3.90 (t, 2H, J = 7Hz), 3.98 (t, 2H,
J = 7Hz), 6.68 (d, 2H, J = 9Hz), 7.04 (d, 2H, J = 9Hz), 9.32 (s, 1 H).
Example 123: 3-butyl-8-chloro-1 -[3-(3-{[3-(trifluoromethyl)-1 H-pyrazol-1 -yl]methyl}- 1 ,2,4-oxadiazol-5-yl)propyl]-3,7-dihydro-1 H-purine-2,6-dione
1H NMR (DMSOd6) δ: 0.90 (t, 3H, J = 7Hz), 1.23-1.36 (m, 2H), 1.57-1.69 (m, 2H), 1.95-2.08 (m, 2H), 2.95 (t, 2H, J = 7Hz), 3.91 (t, 2H, J = 7Hz), 3.97 (t, 2H, J = 7Hz), 5.62 (s, 2H), 6.79 (s, 1 H), 8.10 (s, 1 H).
Example 125: 3-butyl-8-chloro-1-(3-{3-[1-(4-chlorophenyl)ethyl]-1 ,2,4-oxadiazol-5- yl}propyl)-3,7-dihydro-1H-purine-2,6-dione
1H NMR (DMSO-CJ6) δ: 0.90 (t, 3H, J = 7Hz), 1.23-1.38 (m, 2H), 1.51 (d, 3H1 J = 6Hz), 1.55-1.69 (m, 2H), 1.96-2.10 (m, 2H), 2.92 (t, 2H, J = 7Hz), 3.89 (t, 2H, J = 7Hz), 3.98 (t, 2H, J = 7Hz), 4.24 (q, 1 H, J = 6Hz), 7.27-7.40 (m, 4H).
Example 126 : 3-Butyl-8-chloro-1-r3-(3-ff3-(ethyloxy)-4-hvdroxyphenyllmethyl>- 1.2,4-oxadiazol-5-yl)propyl1-3,7-dihvdro-1 H-purine-2.6-dione
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1-yl)butanoate (53mg, 0.15mmol) and (1Z)-2-[3-(ethyloxy)-4-hydroxyphenyl]-Λ/-hydroxyethanimidamide (35mg, 0.165mmol; entry 11 , Table 7) were mixed in EtOH (0.75ml). Ethanolic sodium ethoxide (21% by wt., 0.083ml, 0.22mmol) was added and the mixture was heated in the microwave at 14O0C for 10min. A further 0.055ml (0.15mmol) of NaOEt solution was then added and the mixture heated for a further 10min period at 14O0C. The mixture was partitioned between EtOAc and 2M HCI and the organic phase evaporated and purified by MDAP to give the title compound as a solid (29.6mg). LC/MS: m/z 503 [MH]+, RT 3.15min.
The following compounds (Table 6) were prepared using a method analogous to that for Example 126, using the appropriate amidoxime (with the exception that for Example 127 (Table 6), the crude product after workup was stirred with EtOH (1 ml) and 2M NaOH (0.5ml) overnight in order to hydrolyse residual starting ester, prior to repeat HCI workup and purification by MDAP).
Table 6
NMR details for selected examples from Table 6
Example 129: Λ/-[3-({5-[3-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 - yl)propyl]-1 ,2,4-oxadiazol-3-yl}methyl)phenyl]acetamide
1H NMR (DMSO-d6) δ: 0.90 (t, 3H, J = 7Hz), 1.25-1.38 (m, 2H), 1.57-1.68 (m, 2H),
1.95-2.07 (m, 5H), 2.92 (t, 2H, J = 7Hz), 3.91 (t, 2H, J = 7Hz), 3.94 (s, 2H), 3.98 (m,
2H), 6.88-7.50 (m, 4H), 9.90 (s, 1 H).
Example 130: 3-Butyl-8-chloro-1-(3-(3-r(2-chloro-4-fluorophenyl)methvn-1,2.4-
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)butanoate (1 OOmg, 0.28mmol) and (1Z)-2-(2-chloro-4-fluorophenyl)-Λ/-hydroxyethanimidamide (62.4mg, 0.308mmol) and 21% by wt. ethanolic sodium ethoxide (0.157ml, 0.42mmol) were heated together in a microwave reactor in EtOH (1.5ml) at 1400C for 10min. The mixture was worked up by partitioning between EtOAc and 2M HCI. The organic phase was evaporated and purified by MDAP to afford the title compound as a solid (73mg). LC/MS: m/z 495 [MH]+, RT 3.55min.
Example 131 : 8-Chloro-3-ethyl-1-f3-r3-(phenylmethyl)-1.2.4-oxadiazol-5- vnpropyl>-3.7-dihvdro-1H-purine-2.6-dione
a) 8-Chloro-3-ethyl-1 -{3-[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]propyl}-3,7- dihydro-1 H-purine-2,6-dione
A solution of 8-chloro-3-ethyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (150mg, 0.59mmol) in anhydrous THF (4ml) was treated with 3-[3-(phenylmethyl)- 1 ,2,4-oxadiazol-5-yl]-1-propanol (154mg, 0.71 mmol) and triphenylphosphine (200mg, 0.76mmol). DBAD (162mg, 0.71 mmol) was added in one portion and the mixture was left to stir at rt, under nitrogen for 18h. The mixture was degassed by high vacuum then Pd(PPh3)4 (68mg, 0.059mmol) and morpholine (515μl, 5.9mmol) were added. The mixture was left to stir at rt, under nitrogen, for 3h. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated by high vacuum. The crude material was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities, then with 2% AcOH/MeOH to elute the compound. The UV active fractions were combined and concentrated by high vacuum. The product was further purified by MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (61 mg, 25%). LC/MS: m/z 415 [MH]+, RT 3.01 min
1H NMR; (DMSO-d6) δ: 1.19 (t, 3H, J = 7Hz), 2.93 (m, 2H), 2.91 (t, 2H1 J = 7.5Hz), 3.96 (m, 6H), 7.27 (m, 5H) 14.46 (s, 1 H).
b) 8-Chloro-3-ethyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1Og, 0.044mol) in anhydrous DMF (100ml) was treated with iodoethane (5.4ml, 0.068mol) and Na2CO3 (4.9g, 0.046mol). The reaction mixture was left to stir at rt under nitrogen for 2 days. Iodoethane (0.35ml, 0.0044mol) was added and the mixture was left to stir at rt for 1 day. The mixture was partitioned between EtOAc and 2M HCI. The organic layer was separated, washed sequentially with saturated sodium sulphite solution and
brine, dried (MgSO4) and concentrated. The crude solid was washed with Et2O to give the title compound as a white solid (8.37g, 75%). LC/MS: m/z 255 [MH]+, RT 2.35min.
Example 132 : 8-Chloro-3-pentyl-1-(3-(3-r(1S.2S)-2-phenylcyclopropyl1-1.2.4- oxadiazol-5-yl}propyl)-3,7-dihvdro-1H-purine-2.6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate (70mg, 0.19mmol) was dissolved in EtOH (1.5ml). The solution was treated with a 21% solution of NaOEt in EtOH (78μl, 0.21 mmol) and (1S,2S)-Λ/-hydroxy-2- phenylcyclopropanecarboximidamide (37mg, 0.21 mmol). The reaction was heated in the microwave at 14O0C for 10min. The mixture was partitioned between EtOH and 2M HCI (aq). The organic layer was separated and concentrated, the resulting crude product was purified by MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (35mg, 38%). LC/MS: m/z 483 [MH]+, RT 3.67min.
Example 133 : S-Chloro-i-O-^-rtS-chlorophenvDmethyll-i^^-oxadiazol-S- yl>propyl)-3-pentyl-3.7-dihydro-1W-purine-2,6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate (70mg, 0.19mmol) was dissolved in EtOH. The solution was treated with a 21% solution of NaOEt in EtOH (78μl, 0.21 mmol) and (1Z)-2-(3-chlorophenyl)-Λ/- hydroxyethanimidamide (38mg, 0.21 mmol). The reaction was heated in the microwave at 14O0C for 10min. The mixture was partitioned between EtOH and 2M HCI (aq). The organic layer was decanted off and concentrated. The crude product was purified on the MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (46mg, 49%).
LC/MS: m/z 491 [MH]+, RT 3.64min.
1H NMR (DMSO-de) δ: 0.85 (t, 3H, J = 7Hz), 1.27 (m, 4H)1 1.62 (m, 2H), 2.02 (m, 2H), 2.92 (t, 2H, J = 7.5Hz), 3.88 (t, 2H, J=7 Hz), 3.97 (t, 2H, J = 6.5Hz), 4.02 (s, 2H), 7.23 (d, 1 H, J = 7Hz), 7.34 (m, 3H).
Example 134: 8-Chloro-1 -(3-(3-r(3.4-dichlorophenyl)methyll-1 ,2.4-oxadiazol-5- yl>propyl)-3-pentyl-3.7-dihvdro-1H-purine-2,6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate (70mg, 0.19mmol) was dissolved in EtOH. The solution was treated with a 21% solution of NaOEt in EtOH (78μl, 0.21 mmol) and (1Z)-2-(3,4-dichlorophenyl)-Λ/- hydroxyethanimidamide (46mg, 0.21 mmol). The reaction was heated in the microwave at 14O0C for 10min. The mixture was partitioned between EtOH and 2M HCI (aq). The organic layer was decanted off and concentrated. The crude product was purified on the MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (66mg, 66%). LC/MS: m/z 527 [MH]+, RT 3.80min.
Example 135 : S-Chloro-i-O-O-rfΣ.β-dichlorophenvDmethvn-i^^-oxadiazol-S- yl>propyl)-3-pentyl-3,7-dihvdro-1H-purine-2,6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate
(70mg, 0.19mmol) was dissolved in EtOH. The solution was treated with a 21% solution of NaOEt in EtOH (78μl, 0.21 mmol) and (1Z)-2-(2,6-dichlorophenyl)-/V- hydroxyethanimidamide (46mg, 0.21 mmol). The reaction was heated in the microwave at 14O0C for 10min. The mixture was partitioned between EtOH and 2M HCI (aq). The organic layer was decanted off and concentrated by nitrogen blowdown. The crude
product was purified on the MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (80mg, 80%). LC/MS: m/z 526 [MH]+, RT 3.6 min.
Example 136 : δ-Chloro-i-Q-O-^-chloro^-fluorophenvπmethvn-I.Σ^-oxadiazol- 5-yl)propyl)-3-pentyl-3,7-dihvdro-1H-purine-2.6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate
(70mg, 0.19mmol) was dissolved in EtOH. The solution was treated with a 21 % solution of NaOEt in EtOH (78μl, 0.21 mmol) and (1Z)-2-(2-chloro-4-fluorophenyl)-Λ/- hydroxyethanimidamide (42mg, 0.21 mmol). The reaction was heated in the microwave at 14O0C for 10min. The mixture was partitioned between EtOH and 2M HCI (aq). The organic layer was decanted off and concentrated. The crude product was purified on the MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (65mg, 67%). LC/MS: m/z 509 [MH]+, RT 3.63min.
Example 137 : S-Butyl-δ-chloro-i-re-re-fphenylmethylH^.Φ-oxadiazol-S- vHpropyl)-3.7-dihydro-1H-purine-2,6-dione
A solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (205mg, 0.73mmol) in anhydrous THF (4ml) was treated with 3-[3-(phenylmethyl)-
1,2,4-oxadiazol-5-yl]-1-propanol (190mg, 0.87mmol) and PPh3 (247mg, 0.94mmol).
DBAD (217mg, 0.94mmol) was added in one portion and the mixture was stirred at rt under nitrogen for 18h. The mixture was degassed by high vacuum then Pd(PPh3J4
(84mg, 0.073mmol) and morpholine (636μl, 7.3mmol) were added. The mixture was stirred at rt under nitrogen for 3h. The mixture was partitioned between EtOAc and 2M
HCI (aq) and the organic layer separated, washed with brine, dried (MgSO4) and
concentrated. The crude material was purified by an aminopropyl column using MeOH to load the compound onto the column and wash through the impurities, then with 2-4% AcOH/MeOH gradient to remove the compound from the column. Further purification was effected by MDAP to give the title compound as a white solid (75mg, 23%). LC/MS: m/z 443 [MH]+, RT 3.37min.
1H NMR; (DMSO-de) δ: 0.89 (t, 3H, J = 7.5 Hz), 1.29 (m, 2H), 1.61 (m, 2H), 2.02 (m, 2H), 2.91 (t, 2H, J = 7.5Hz), 3.89 (t, 2H, J = 7Hz)1 3.97 (m, 4H), 7.27 (m, 5H) 14.46 (s, 1 H).
Example 138: 8-Chloro-1-(3-(3-r(4-hvdroxyphenyl)methvn-1,2,4-oxadiazol-5- yl)propyl)-3-pentyl-3.7-dihvdro-1H-purine-2.6-dione
Ethyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanoate (29mg, 0.078mmol) and (1Z)-Λ/-hydroxy-2-(4-hydroxyphenyl)ethanimidamide (14mg, 0.084mmol) were heated in EtOH (1ml) with 21% ethanolic sodium ethoxide (0.043ml, 0.117mmol) under microwave irradiation at 14O0C for 10min. The mixture was partitioned between EtOAc and 2M HCI and the organic phase evaporated. This material was stirred with EtOH (1 ml) and 2M NaOH (0.5ml) for 18h, before being worked up again by partition between EtOAc and 2M HCI. Purification by MDAP afforded the title compound (6.5mg). LC/MS: m/z 473 [MH]+, RT 3.34min.
1H NMR (MeOH-d4) δ: 0.92 (t, 3H, J = 7Hz), 1.25-1.45 (m, 4H), 1.68-1.78 (m, 2H), 2.11- 2.21 (m, 2H), 2.93 (t, 2H, J = 7Hz), 3.82 (s, 2H), 3.98 (t, 2H, J = 7Hz), 4.10 (t, 2H, J = 7Hz), 6.70 (d, 2H, J = 10Hz), 7.02 (d, 2H, J = 10Hz).
Example 139: 3-Butyl-8-chloro-1 -(3-{3-r(phenyloxy)methyll-1 ,2.4-oxadiazol-5- yl)propyl)-3.7-dihvdro-1H-purine-2,6-dione
To ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)butanoate (26mg, 0.073mmol) and (1Z)-Λ/-hydroxy-2-(phenyloxy)ethanimidamide hydrochloride (16mg, 0.079mmol) in EtOH (1ml) was added 21%wt. ethanolic sodium ethoxide solution (0.068 ml, 0.183mmol) and the mixture was heated under microwave
irradiation at 14O0C for 10min. The mixture was partitioned between EtOAc and 2M HCI, the organic phase dried (Na2SO4) evaporated and purified by MDAP to give title compound as a gum which solidified upon trituration with ether (5.9mg). LC/MS: m/z 459 [MH]+, RT 3.39min. 1H NMR (DMSO-d6) δ: 0.90 (t, 3H1 J = 8Hz), 1.22-1.36 (m, 2H), 1.57-1.68 (m, 2H), 2.02-2.14 (m, 2H), 3.00 (t, 2H, J = 8Hz), 3.90 (t, 2H, J = 7Hz), 4.00 (t, 2H, J = 7Hz), 5.18 (s, 2H), 6.95-7.35 (m, 5H).
Example 140: 3-Butyl-8-chloro-1 -(3-(3-r(3.5-dichlorophenvhmethyll-1.2.4- oxadiazol-5-yl)propyl)-3.7-dihvdro-1H-purine-2.6-dione
To ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1 -yl)butanoate (185mg, 0.52mmol) and (1Z)-2-(3,5-dichlorophenyl)-Λ/-hydroxyethanimidamide (126mg, 0.58mmol; Entry 23, Table 7) in dry EtOH (2ml) was added 21%wt. ethanolic sodium ethoxide solution (0.29ml, 0.78mmol) and the mixture was heated by microwaves at 14O0C for 10min. The reaction was worked up by partition between EtOAc and 2M HCI and evaporating the organic phase. Purification by MDAP afforded the title compound as a solid (135mg). LC/MS: m/z 511 [MH]+, RT 3.71 min.
Example 141 : 3-Butyl-8-chloro-1-(3-{3-f(2.4.6-trifluorophenyl)methyl1-1.2.4- oxadiazol-5-yl}propyl)-3.7-dihvdro-1H-purine-2,6-dione
Similarly prepared starting from (1Z)-Λ/-hydroxy-2-(2,4,6- trifluorophenyl)ethanimidamide (119mg, 0.58mmol; Entry 24, Table 7) in a yield of 135mg.
LC/MS: m/z 497 [MH]+, RT 3.39min. 1H NMR (DMSO-d6) δ: 0.90 (t, 3H, J = 7Hz), 1.24-1.36 (m, 2H), 1.55-1.66 (m, 2H), 1.96-2.06 (m, 2H), 2.91 (t, 2H, J = 8Hz), 3.91 (t, 2H, J = 8 Hz), 3.94 - 4.02 (m, 4H), 7.18-7.28 (m, 2H).
Amidoximes: These are available by the methods detailed below and exemplified by analogues in Table 7.
Table 7 (Intermediates)
Method A
The corresponding nitrile (0.5mmol) was stirred in EtOH (1.5ml) with 50% aqueous hydroxylamine solution (0.08ml, 1.3mmol) and heated at 65°C for 4.5h. After cooling the crude reaction mixture was loaded onto an SCX SPE cartridge (2g) and washed with MeOH, then the amidoxime product was eluted with 2M ammonia in MeOH.
Method B Similar to Method A except that the product crystallised out from the crude reaction mixture and was isolated by filtration instead of by SCX.
Method C
Similar to Method A except that the product was purified on a 5g SCX cartridge.
Method D
Similar to Method C except that the heating period was 18h.
Method E
Similar to Method C except that the scale was 0.753mmol of nitrile.
Method F Similar to Method A except that the scale was 1.5mmol of nitrile and purification was on a 1Og SCX cartridge.
Method G
Similar to Method A except that the heating time was 2.75h and the scale was 0.25mmol of nitrile.
It should be noted that the above assignment of (Z)-stereochemistry has not been confirmed by experimental data. The person skilled in the art will also recognise that there can be interconversion between E & Z isomers. (Dondoni, Alessandro; Lunazzi, Lodovico; Giorgianni, Patrizia; Macciantelli, Dante. Carbon-nitrogen rotational barrier as a stereochemical probe of benzamidoximes. Journal of Organic Chemistry (1975), 40(20), 2979-80)
Example 142: S-Butyl-S-chloro-i-O-IS-rO-chlorophenvDmethvn-I.Σ^-oxadiazol-a- yl}propyl)-3.7-dihvdro-1H-purine-2.6-dione
a) 3-Butyl-8-chloro-1-(3-{5-[(3-chlorophenyl)methyl]-1 ,2,4-oxadiazol-3-yl}propyl)-3,7-
(3-Chlorophenyl)acetic acid (O.immol), Λ/-[3-(dimethylamino)propyl]-Λ/'- ethylcarbodiimide hydrochloride (21 mg, O.Hmmol) and 1H-1 ,2,3-benzotriazol-1-ol (15mg, O.H mmol) were stirred in 1-methyl-2-pyrrolidinone (1 ml). To this was added (1Z)-4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)-Λ/- hydroxybutanimidamide (34mg, O.immol) and the mixture stirred at rt for 17h and then at 80
0C for 24h. The reaction mixture was purified, without further modification, by preparative HPLC (auto prep) to give the title compound (13mg, 27%). LC/MS: m/z 477, 479 [MH]
+, RT 3.5min.
1H NMR (CDCI3) δ: 0.96 (t, 3H, J = 7Hz), 1.32-1.47 (m, 2H), 1.68-1.80 (m, 2H), 2.12- 2.24 (m, 2H), 2.83 (t, 2H, J = 7.5Hz), 4.05-4.24 (m, 6H), 7.16-7.30 (m, 4H).
b) (1 Z)-4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1-yl)-/V- hydroxybutanimidamide
4-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1-yl)butanenitrile (1g,
0.0032mol) was stirred in EtOH (3.5ml) and water (1.8ml). Hydroxylamine hydrochloride (344mg, 0.0049mol) and potassium carbonate (652mg, 0.0049mol) were added and the mixture heated at 800C for 3 days. After cooling the crude reaction mixture was evaporated. The crude product was dissolved in water, neutralised to pH7 with HCI, and loaded onto an Oasis™ cartridge (2g). This was eluted with water to remove the salts and then with MeOH, to give the title compound (957mg, 86%). LC/MS: m/z 343, 345 [MH]+, RT 2.04min.
-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)butanenitrile
4-[3-Butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6>7-tetrahydro-1 H-purin-1- yl]butanenitrile (2.1g, 6mmol) was stirred in a mixture of nitrogen degassed DCM (20ml) and AcOH (2ml). Tetrakis(triphenylphosphine)palladium (675mg, 0.6mmol) and phenyl silane (7.4ml, ΘOmmol) were added and the mixture stirred at rt for 2d. This was then evaporated and the residue triturated with a mixture of diethyletheπcyclohexane (1 :1 ) to afford the title compound (1.47g, 60%) as a white solid.
LC/MS: m/z 310 [MH]+, RT 2.66min.
d) 4-[3-Butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1/-/-purin-1- yl]butanenitrile
3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (2.Og, 0.0072mol) in dry MeCN (20ml) was added Cs2CO3 (4.68g, 0.0144mol) followed by bromobutyronitrile (1.38g, 0.0094mol). The mixture was heated at 800C for 18h and then allowed to cool. The reaction mixture was evaporated and the crude product partitioned between EtOAc and HCI (2N). The organic phase was separated and washed with brine, dried (MgSO4) and evaporated to give the crude product. This was purified by silica SPE (5Og), eluting with cyclohexaneiethylacetate (2:1 to 1 :1) to afford the title compound as a clear oil (2.1g, 85%). LC/MS: m/z 350 [MH]+, RT 3.10min.
The following compounds (Table 8) were prepared using a method analogous to that for Example 142, from the corresponding acids and (1Z)-4-(3-butyl-8-chloro-2,6-dioxo- 2,3,6, 7-tetrahydro-1 /-/-purin-1 -yl)-Λ/-hydroxybutanimidamide.
Table 8
NMR details for selected examples from Table 8
Example 145: 1H NMR (CDCI3) 0.96 (3H, t, J = 7.5Hz), 1.32-1.47 (2H, m), 1.65-1.81 (2H, m), 2.12-2.25 (2H, m), 2.84 (2H1 1, J = 7.5 Hz), 4.02 (2H, t, 7.5Hz), 4.22 (2H, t, 7Hz), 4.24 (2H, s), 7.40-7.62 (4H, m).
Example 152: 8-Chloro-3-pentyl-1 -(3-f5-(phenylmethyl)-1 ,2.4-oxadiazol-3- vπpropyl>-3.7-dihvdro-1H-purine-2,6-dione
a) 8-Chloro-3-pentyl-1 -{3-[5-(phenylmethyl)-1 ,2,4-oxadiazol-3-yl]propyl}-3,7-dihydro-
To a stirred solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6- dione (0.20, 0.67mmol) in THF (5ml) was added 3-[5-(phenylmethyl)-1 ,2,4-oxadiazol-3- yl]-1-propanol (0.162g, 0.74mmol), DBAD (0.186g, 0.81 mmol) and triphenylphosphine (0.212g, 0.81 mmol) and the solution stirred for 18h. To the solution was added Pd(PPh3J4 (75mg, 0.067mmol) and morpholine (600μl, 6.7mmol) were added and stirred for at rt under nitrogen for a further 3h. 75mg of Pd(PPh3J4 was added and the mixture left to stir for another 3h. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The crude material was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities, then with 2-4% AcOH/MeOH to elute the compound. The product fractions were combined and concentrated then further purified by MDAP. The product fractions were combined and concentrated give the title compound as a white solid (51 mg, 20%). LC/MS: m/z 457 [MH]+, RT 3.54min.
b) 3-[5-(Phenylmethyl)-1 ,2,4-oxadiazol-3-yl]-1-propanol
A mixture of (1E)-4,4-bis(ethyloxy)-Λ/-hydroxybutanimidamide (3.2g, 16.8mmol), ethyl phenylacetate (2.3ml, 14.4mmol) and sodium ethoxide (21% solution in EtOH, 6.4ml) was heated in a microwave at 14O0C for 10min. The material was combined with that from a second reaction (using 1.2g of (1£)-4,4-bis(ethyloxy)-Λ/-hydroxybutanimidamide and conducted as above) and partitioned between 1 M HCI solution and EtOAc. The organic layer was separated, washed with brine, dried and concentrated to provide 5- [3,3-bis(ethyloxy)propyl]-5-(phenylmethyl)-1 ,2,4-oxadiazole which was used without purification in the next stage.
Crude 3-[3,3-bis(ethyloxy)propyl]-5-(phenylmethyl)-1 ,2,4-oxadiazole (5.63g, 19.4mmol) in EtOH (75ml) was stirred with p-toluenesulphonic acid (0.738g, 3.9mmol) for 21 h and the mixture partitioned between EtOAc and water. The organics were isolated washed
with water and brine, dried and concentrated to a red oil. This material contained significant amounts of acetal, therefore the oil was dissolved in THF (15ml) and treated with 2M HCI solution for 2h then partitioned between EtOAc and water. The organics were isolated washed with brine, dried and concentrated to yield 3-[5-(phenylmethyl)- 1 ,2,4-oxadiazol-3-yl]propanal as a red/brown oil (3.77g) which was used crude in the next stage.
A solution of crude 3-[5-(phenylmethyl)-1 ,2,4-oxadiazol-3-yl]propanal (3.76g, 17.4mmol) in MeOH (60ml) was cooled to O0C and sodium borohydride (0.724g, 19.1mmol) added portionwise over 30min. The cooling bath was removed and the solution stirred for a further 1h then partitioned between 1 M HCI and EtOAc. The organic layer was separated and the aqueous extracted with EtOAc. The combined extracts were washed with brine, dried and concentrated to an orange liquid. This was purified on a 5Og silica SPE eluting with cyclohexane/EtOAc (20% to 80% gradient elution) to provide the title compound as a yellow oil (2.24g). LC/MS: m/z 210 [MH]+.
c) (1 £)-4,4-bis(ethyloxy)-Λ/-hydroxybutanimidamide
A mixture of 3-cynopropionaldehyde diethylacetal (6.12g, 39mmol), hydroxylamine hydrochloride (4.06g, 58.4mmol), potassium carbonate (10.76g, 77.9mmol) in water (20ml) and EtOH (40ml) was refluxed for 24h. The mixture was allowed to cool and then partitioned between water and EtOAc. The organic layer was separated and the aqueous extracted with EtOAc. The combined organic fractions were washed with brine, dried and concentrated to provide the title compound as a colourless oil contaminated with -20% starting nitrile (6.03g, 81%). LC/MS: m/z 191 [MH]+.
Example 153 : 8-Chloro-1-(3-r5-(phenylmethyl)-1,2.4-oxadiazol-3-vnpropyl>-3- propyl-3,7-dihvdro-1H-purine-2.6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1H-purine-2,6-dione (200mg, 0.74mmol) in THF (4ml) was treated with 3-[5-(phenylmethyl)-1 ,2,4-oxadiazol- 3-yl]-1-propanol (195mg, 0.89mmol) and PPh
3 (254mg, 0.96mmol). DBAD (223mg, 0.96mmol) was added in one portion and the mixture was left to stir at rt under nitrogen for 18h. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated by high vacuum. The crude product was purified on a silica SPE column using a 0-70% cyclohexane/EtOAc gradient. The product fractions were combined, concentrated by high vacuum and purified on a silica SPE column using a 0-60% cyclohexane/EtOAc gradient. The product fractions were combined and concentrated then dissolved in anhydrous THF (4ml). The solution was degassed by high vacuum then Pd(PPh
3J
4 (61 mg, 0.053mmol) and morpholine (460μl, 5.3mmol) were added and the mixture left to stir at rt under nitrogen for 1 day. The mixture was partitioned between EtOAc and 2M HCI (aq). The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated by high vacuum. The crude product was purified by an aminopropyl SPE using MeOH to load the compound onto the column and wash through the impurities then a 2-4% AcOH/MeOH gradient to elute the product. The product fractions were combined and concentrated to leave the title compound as a white solid (36mg, 11%). LC/MS: m/z 429 [MH]
+, RT 3.14min.
1H NMR (DMSO-d
6) δ: 0.86 (t, 3H, J = 7.5Hz), 1.65 (m, 2H), 1.93 (m, 2H), 2.70 (t, 2H, J = 7.5Hz), 3.86 (t, 2H, J = 7Hz), 3.96 (t, 2H, J = 7Hz), 4.28 (s, 2H), 7.32 (m, 5H).
Example 154 : 3-Butyl-8-chloro-1-(3-f5-(phenylmethyl)-1.2.4-oxadiazol-3- yl1propyl)-3.7-dihvdro-1H-purine-2.6-dione
A solution of 3-[5-(phenylmethyl)-1,2,4-oxadiazol-3-yl]-1-propanol (594mg, 2.7mmol) in THF (25ml) was treated with 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine- 2,6-dione (700mg, 2.48mmol) and PPh3 (779mg, 2.97mmol) under nitrogen. DBAD (684mg, 2.97mmol) was added in one portion and the reaction left to react for 6Oh. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. MeOH was added to the residue and then passed down an aminopropyl column with the product eluting with 2-4% AcOH/MeOH. Product fractions were combined and concentrated. The off-white residue was recrystallised from EtOAc:cyclohexane (1 :1 ), giving the title compound as a white solid (696mg, 63%). LC/MS: m/z 443 [MH]+, RT 3.4min.
1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.29 (m, 2H), 1.61 (m, 2H), 1.93 (m, 2H), 2.70 (t, 2H, J = 7.5Hz), 3.90 (t, 2H, J = 7Hz), 3.96 (t, 2H, J = 7Hz), 4.28 (2H, s), 7.31 (m, 5H), 14.4 (br s, 1 H).
Example 155 : 3-Butyl-8-chloro-1-(3-{5-f(3-chloro-4-hvdroxyphenyl)methvn-1.2,4- oxadiazol-3-yl>propyl)-3.7-dihvdro-1H-purine-2,6-dione
A solution of S-chloro^-hydroxyphenylacetic acid (24mg, 0.13mmol) in DMSO (1ml) was treated with CDI (21 mg, 0.13mmol) and left to react for 30min. (1Z)-4-(3-Butyl-8- chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)-Λ/-hydroxybutanimidamide (50mg,
0.15mmol) was added and the mixture heated in the microwave at 12O0C for 15min.
The solution was directly purified by MDAP to obtain the title compound as a white solid (12mg, 17%). LC/MS: m/z 493 [MH]+, RT 3.2min.
Example 156 : 3-Butyl-8-chloro-1-f3-(5-<r3-chloro-2-(methyloxy)phenvnmethyl>- 1.2.4-oxadiazol-3-yl)propyn-3.7-dihvdro-1 H-purine-2.6-dione
A mixture of [3-chloro-2-(methyloxy)phenyl]acetic acid (32mg, 0.16mmol) in DMF (1.5ml) was treated with CDI (26mg, 0.16mmol) and left to react for 45min. (1Z)-4-(3- Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/-hydroxybutanimidamide (60mg, 0.18mmol) was added and the mixture heated in the microwave at 14O0C for 15min. After cooling, the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated then concentrated and purified by the MDAP. The title compound was obtained as a white solid (25mg, 28%). LC/MS: m/z 507 [MH]+, RT 3.5min.
Example 157 : 3-Butyl-8-chloro-1-(3-(5-r(3-fluoro-4-hvdroxyphenyl)methvn-1.2,4- oxadiazol-3-yl)propyl)-3.7-dihvdro-1H-purine-2.6-dione
A mixture of (3-fluoro-4-hydroxyphenyl)acetic acid (27mg, 0.16mmol) in DMF (1.5ml) was treated with CDI (26mg, 0.16mmol) and left to react for 45min. (1Z)-4-(3-Butyl-8- chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)-Λ/-hydroxybutanimidamide (60mg, 0.18mmol) was added and the mixture heated in the microwave at 14O
0C for 15min. After cooling, the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated then concentrated and purified by MDAP. The title compound was obtained as a white solid (10mg, 12%). LC/MS: m/z 477 [MH]
+, RT 3.2min.
Example 158 : 8-chloro-3-pentyl-1-r4-(5-phenyl-1.2.4-oxadiazol-3-yl)butvH-3.7- dihydro-1 H-purine-2.6-dione
a) Preparation of 8-chloro-3-pentyl-1-[4-(5-phenyl-1 ,2,4-oxadiazol-3-yl)butyl]-3,7- dihydro-1 H-purine-2,6-dione
Benzoic acid (18mg, 0.15mmol) was treated with a solution of 1H-1,2,3-benzotriazol-1- ol hydrate (25mg, 0.19mmol) in DMSO (0.3ml). To this was added a solution/suspension of N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide hydrochloride (29mg, 0.15mmol) in DMSO (0.3ml) followed by a solution of 5-(8-chloro-2,6-dioxo-3- pentyl-2, 3,6, 7-tetrahydro-1 H-purin-1 -yl)-N-hydroxypentanimidamide (55mg, 0.15mmol) in DMSO (0.3ml). The mixture was heated at 4O0C for 1h, then at 8O0C for 5h and then cooled. The mixture was subjected to purification by MDAP. Product-containing fractions were blown to dryness by a stream of nitrogen to yield the title compound as a white solid (17.2mg, 25%). LC/MS: m/z 457 [MH]+, RT 3.67min.
1H NMR (CDCI3) δ: 0.90 (t, 3H1 J = 6.8Hz), 1.35 (m, 4H), 1.76 (m, 2H), 1.89 (m, 4H), 2.88 (t, 2H, J = 7.2Hz), 4.08 (t, 2H1 J = 7.5Hz), 4.17 (t, 2H, J = 6.7Hz), 7.50 (m, 2H), 7.57 (m, 1H)1 8.08, (d, 2H, J = 7.3Hz).
b) 5-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)-N- hydroxypentanimidamide
A solution of 5-(8-chloro-2, 6-dioxo-3-pentyl-2, 3, 6, 7-tetrahydro-1 H-purin-1 - yl)pentanenitrile (3.Og, 8.9mmol) in EtOH (30ml) was treated with water (15ml), potassium carbonate (1.48g, 10.7mmol) and hydroxylamine hydrochloride (0.74g,
10.7mmol)and then heated at 7O0C overnight. A further potassium carbonate (1.5g,
10.9mmol) and hydroxylamine hydrochloride (1.0g, 14.5mmol) were cautiously added to the mixture which was then heated to 9O0C for 24h. The mixture was cooled and concentrated in vacuo to remove most of the EtOH. The residual mixture was treated with water (30ml) and acidified to pH 7 by the cautious addition of 2M aqueous hydrochloric acid. The precipitated solid was filtered off, washed with water, then with diethyl ether and thoroughly dried to yield the title compound as a white solid (2.8Og,
85%). LC/MS: m/z 371 [MH]+, RT 2.27min.
c) 5-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanenitrile
A solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (4.Og, 13.5mmol) in DMF (100ml) was treated with caesium carbonate (4.83g, 14.8mmol) and
5-bromopentanenitrile (1.73ml, 14.8mmol). The mixture was heated at 5O0C in a nitrogen atmosphere for 19h and then cooled. The mixture was then degassed by the repeated successive application of a vacuum and then nitrogen pressure. The mixture was then treated with tetrakis(triphenylphosphine)palladium(0) (1.1g, 0.94mmol) and morpholine (11.8ml, 136mmol). The mixture was stirred in a nitrogen atmosphere for
3h and then partitioned between EtOAc and 2M aqueous hydrochloric acid. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated to reveal a yellow, oily residue. This was dissolved in MeOH, divided equally into four portions and each portion applied to a 2Og aminopropyl SPE which was then washed through with MeOH. The desired product was eluted from the cartridge with a 5% v/v solution of AcOH in MeOH. The product-containing fractions were combined and concentrated to yield the title compound as a pale yellow solid (4.03g, 88%). LC/MS: m/2 338 [MH]+, RT 3.05min.
The following compounds were prepared using a method analogous to that for Example 158 (8-chloro-3-pentyl-1-[4-(5-phenyl-1 ,2,4-oxadiazol-3-yl)butyl]-3,7-dihydro- 1H-purine-2,6-dione) from the corresponding acids:
In addition Example 159, 8-chloro-3-pentyl-1-{4-[5-(2-pyridinyl)-1 ,2,4-oxadiazol-3- yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione has the following spectral data: 1H NMR (CDCI3) δ: 0.89 (t, 3H, J = 6.9Hz), 1.75 (m, 4H), 1.89 (m, 6H), 2.92 (t, 2H, J = 7.1 Hz), 4.07 (t, 2H, J = 7.4Hz), 4.16 (t, 2H, J = 6.9Hz), 7.52 (m, 1 H), 7.92 (m, 1 H), 8.18 (m, 1 H), 8.83 (m, 1 H), 13.40 (br s, 1 H).
Example 163: 8-Chloro-14445-(4-hvdroxyphenylH.2.4-oxadiazol-3-yllbutyl}-3- propyl-3,7-dihvdro-1H-purine-2,6-dione
4-Hydroxybenzoic acid (18mg, 0.13mmol) and CDI (24mg, 0.15mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1h. (1Z)-5-(8-Chloro-2,6-dioxo-3-propyl-2,3,6,7- tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (50mg, 0.15mmol; prepared in a manner similar to (1Z)-5-(8-Chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1-yl)- Λ/-hydroxypentanimidamide as described in Example 158(b)) was added and the mixture was stirred at 9O0C for 2h. The reaction mixture was purified by MDAP. The product fraction was combined and concentrated under high vacuum to give the title compound as a white solid (7mg, 11%). LC/MS: m/z 443 [MH]+, RT 3.28min.
Example 164 : 3-Butyl-8-chloro-1-l4-r5-(2,6-difluorophenyl)-1.2,4-oxadiazol-3- yllbutyl)-3,7-dihydro-1W-purine-2.6-dione
2,6-Difluorobenzoic acid (40mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1 h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7- tetrahydro-1/-/-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The reaction mixture was purified by MDAP. The product fraction was combined and concentrated to give the title compound as a white solid (18mg, 15%). LC/MS: m/z 479 [MH]+, RT 3.40min.
Example 165 : 3-Butyl-8-chloro-1-(4-r5-(2-fluorophenyl)-1.2,4-oxadiazol-3- vπbutyl)-3,7-dihydro-1H-purine-2,6-dione
2-Fluorobenzoic acid (36mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo-2, 3,6,7- tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The mixture was purified by MDAP. The product fraction was combined and concentrated to give the title compound as a white solid (33mg, 29%). LC/MS: m/z 461 [MH]+, RT 3.44min.
Example 166 : S-BuWI-S-chloro-i-M-rS-rø-chloro-Σ-pyridinylH^Λ-oxadiazol-S- yllbutyl)-3,7-dihydro-1H-purine-2,6-dione
4-Chloro-2-pyridinecarboxylic acid (40mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1 h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The reaction mixture was purified by MDAP. The product fraction was combined and concentrated to give the title compound as a white solid (13mg, 11%). LC/MS: m/z 478 [MH]+, RT 3.31 min.
1H NMR (DMSO-d6) δH 14.4 (br. s, 1 H), 8.79 (d, 1 H, J=6Hz), 8.24 (d, 1H, J=2Hz), 7.88
(dd, 1 H, J=6Hz & 2Hz), 3.91 (m, 4H), 2.85 (t, 2H, J=7.5Hz), 1.56-1.76 (m, 6H), 1.28 (m, 2H), 0.87 (t, 3H1 J=7.5Hz) ppm.
Example 167 : 3-Butyl-8-chloro-1-{4-r5-(3-methyl-2-pyridinyl)-1,2.4-oxadiazol-3- yllbutyl>-3.7-dihvdro-1H-purine-2,6-dione
S-Methyl^-pyridinecarboxylic acid (35mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1 h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The reaction mixture was purified by MDAP. The product fraction was combined and concentrated to give the title compound as a white solid 14mg, 12%). LC/MS: m/z 458 [MH]+, RT 3.13min.
Example 168 : 3-Butyl-8-chloro-1^4-r5-(2-pyridinv0-1,2,4-oxadiazol-3-yllbutyl)- 3.7-dihydro-1A7-purine-2.6-dione
Method A
2-Pyridinecarboxylic acid (31 mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.5ml) at rt for 1 h. A solution of (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) in DMSO (0.4ml) was added and the mixture was stirred at 9O0C for 16h. The reaction mixture was purified directly by MDAP. The product fractions were combined and concentrated to give the title compound as a white solid (14mg, 12%). LC/MS: m/z 444 [MH]+, RT 3.01 min.
1H NMR (DMSO-de) δ: 0.87 (t, 3H, J = 7 Hz), 1.27 (m, 2H), 1.65 (m, 6H), 2.84 (t, 2H, J = 7 Hz), 3.91 (m, 4H), 7.70 (dd 1 H, J = 5 & 7Hz), 8.07 (m, 1 H), 8.19 (d, 1 H, J = 8Hz), 8.81 (d, 1 H, J = 5Hz), 14.5 (br. s, 1 H).
2-Pyridinecarboxylic acid (675mg, 5.3mmol) and CDI (909mg, 5.6mmol) were stirred in anhydrous DMF (30ml) at rt under nitrogen for 90mins. (1Z)-5-(3-Butyl-8-chloro-2,6- dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1-yl)-Λ/-hydroxypentanimidamide (2.Og, 5.6mmol) and DMF (10ml) were added and the mixture was stirred at 100°C for 2Oh. The reaction mixture was cooled to rt then partitioned between sat. NH4CI(aq) solution and EtOAc. The organic layer was separated, and the aqueous solution extracted with EtOAc. The combined extracts were washed with brine, dried MgSO4 and concentrated giving an orange liquid. This was purified using the Companion™ system giving two identical white solids (649mg; 240mg). LC/MS: m/z 444 [MH]+, RT 3.04min.
Method C
A 12-L, round-bottom flask was equipped with an overhead, mechanical stirrer, a temperature probe with a J-KEM temperature controller, a condenser and a nitrogen inlet adapter. The flask was charged with picolinic acid (0.180 kg, 1.46 mol), MIBK (4.0 L), 1 ,1 '-carbonyldiimidazole (0.23 kg, 1.42 mol,) and more MIBK (0.66 L). The mixture was stirred and warmed to 50 0C over approximately 1 hour, and the temperature overshot to 56 0C. The solids dissolved during the heat up to 50 0C and carbon dioxide was generated. After 1 hour at 50 0C, (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7- tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (0.467 kg, 1.31 mol) was added to the reaction. The mixture was then warmed to 90 0C over 1 hour. HPLC analysis of the reaction after heating at 90 0C for 5.5 hours indicated that the reaction was complete. The heat was turned off, and 1.0 N hydrochloric acid solution (2.33 L) was added. The temperature dropped to 61 0C. After stirring overnight, the product precipitated and was filtered. The filtercake was washed with water (1 x 2.23 L, 1 x 2.43 L) and heptanes (1.40 L). The wet cake was dried in a vacuum oven at 50 0C for 22 hours to give 396 g of product (68%) HPLC analysis 97.7% (AUC) tR = 18.6 min.
Method D
Formation of 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1,2,4-oxadiazol-3-y I] butyl}-3,7- dihydro-1H-purine-2,6-dione Form 1
The reaction vessel was charged with 3-Butyl-8-chloro-1-{4-[5-(2-pyridinyl)-1 ,2,4- oxadiazol-3-yl]butyl}-3,7-dihydro-1/-/-purine-2,6-dione (1wt), acetone (20vol) and water (O.θvol). The mixture was stirred and warmed to 50-60 0C and agitated for a minimum of 1 hour. A solution was formed which is clarified at this temperature by filtration through a 1 micron filter into a 2nd reaction vessel. The solution was cooled over approximately 3 hours to 33-38°C and seeded at this temperature with 3-Butyl-8- chloro-1 -{4-[5-(2-py rid iny I )- 1 ,2,4-oxadiazol-3-yl]butyl}-3,7-dihydro-1 H-purine-2,6-dione (Form 1 , 0.01 wt). The thin suspension was agitated at this temperature for a minimum of 1hour then cooled to 20-25°C and held at this temperature for a minimum of 12hours. The suspension thus formed was cooled to 13-17°C and held at this temperature for a minimum of 1 hour. The suspension was then sampled*, and the solid collected by filtration in the laboratory. The solid was dried and analysed by xrpd/DSC to check form. If the form is as required (Form 1) the batch is filtered, washed (2x3vol acetone) and dried in a vacuum oven at 50°C. The batch is offloaded once analysis shows solvent levels (acetone, water) to be at acceptable.
Expected yield (75-80%w/w).
If the form of the sample taken at * is shown to be other than pure Form 1 , then "the batch is reheated to 35-45°C and agitated at this temperature for a minimum of 1 hour. The thin suspension is then cooled to 20-250C and held at this temperature for a minimum of 12hours. The suspension thus formed is then cooled to 13-17°C and held at this temperature for a minimum of 1 hour. The suspension is then sampled, and the solid collected by filtration in the laboratory. The solid is dried and analysed by xrpd/DSC to check form. If the form is as required (Form 1) the batch is filtered, washed and dried as described previously. If the form is not pure Form 1 , then the cycle from " is repeated until a satisfactory result is obtained.
X-Rav Powder Diffraction (XRPD)
X-ray powder diffraction (XRPD) data are shown in Figures 1-3. The data were acquired on a PANalytical X'Pert Pro powder diffractometer, model PW3040/60, serial number DY1850 using an X'Celerator detector. The acquisition conditions were: radiation: Cu Ka, generator tension: 40 kV, generator current: 45 mA, start angle: 2.0°2θ, end angle: 40.0°2 θ, step size: 0.0167 °2 θ, time per step: 31.75 seconds. The samples were prepared by mounting a few milligrams of sample on a Si wafer (zero background) plates, resulting in a thin layer of powder.
Example 169: 3-Butyl-8-chloro-1 -(4-r5-(4-hvdroxyphenyl)-1 ,2,4-oxadiazol-3- yllbutyl)-3,7-dihvdro-1H-purine-2.6-dione
4-Hydroxybenzoic acid (35mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7- tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The mixture was purified by MDAP to give the title compound as a white solid (5mg, 4%). LC/MS: m/z 459 [MH]+, RT 3.24min.
Example 170 : 8-Chloro-1-r4-(5-phenyl-1,2.4-oxadiazol-3-yl)butyll-3-propyl-3.7- dihvdro-1 H-purine-2.6-dione
Benzoic acid (9mg, 0.074mmol) and CDI (13mg, 0.081 mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1 h. (1Z)-5-(8-Chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H- purin-1-yl)-Λ/-hydroxypentanimidamide (28mg, 0.081 mmol) was added and the mixture was stirred at 8O0C for 4h. The mixture was purified by MDAP to give the title compound as a white solid (0.6mg, 2%). LC/MS: m/z 429 [MH]+, RT 3.21 min.
1H NMR (MeOH-d4) δ: 0.93 (t, 3H1 J = 7.5Hz), 1.74 (m, 4H), 1.84 (m, 2H), 2.84 (t, 2H, J = 7Hz), 3.97 (t, 2H, J = 7.5Hz), 4.08 (t, 2H, J = 7Hz), 7.57 (dd, 2H, J = 7 & 7.5Hz), 7.65 (dd, 1 H, J = 7 & 7.5Hz), 8.08 (d, 2H, J = 7.5Hz).
Example 171 : 3-Butyl-8-chloro-1-(4-r5-f2-chloro-6-fluorophenyl)-1.2.4-oxadiazol-3- yllbutyl>-3.7-dihvdro-1AV-purine-2.6-dione
2-Chloro-6-fluorobenzoic acid (44mg, 0.25mmol) and CDI (45mg, 0.28mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) was added and the mixture was stirred at 9O0C for 16h. The mixture was purified by MDAP. The product fraction was combined and concentrated to give the title compound as a white solid (6.4mg, 5%). LC/MS: m/z 495 [MH]+, RT 3.58min.
Example 172: 3-Butyl-8-chloro-1-(4-r5-(5-hvdroxy-2-pyridinvn-1.2.4-oxadiazol-3- yllbutyl}-3.7-dihvdro-1H-purine-2,6-dione
δ-Hydroxy^-pyridinecarboxylic acid (24mg, 0.17mmol) and CDI (31 mg, 0.19mmol) were stirred in anhydrous DMSO (0.9ml) at rt for 1 h. (1Z)-5-(3-Butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/-hydroxypentanimidamide (68mg, 0.19mmol) was added and the mixture was stirred at 9O0C for 16h. The mixture was purified by MDAP and the product fractions concentrated to give the title compound as a white solid (19mg, 24%). LC/MS: m/z 459 [MH]+, RT 3.03min.
Example 173: 8-Chloro-3-pentyl-1-(4-r5-(3-thienyl)-1,2.4-oxadiazol-3- vnbutyl)-3.7-dihvdro-1H-purine-2.6-dione
A solution of (1Z)-5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/- hydroxypentanimidamide (50mg, 0.13mmol) in EtOH (1 ml) was treated with a 21%
solution of NaOEt in EtOH (55μl, 0.21 mmol) and ethyl 3-thiophenecarboxylate (18μl, 0.13mmol). The mixture was heated in the microwave at 15O0C for 10min. After cooling, the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous extracted again with EtOAc. The combined extracts were concentrated and purified by the MDAP. The title compound was obtained as an off-white solid (20mg, 32%). LC/MS: m/z 463 [MH]+, RT 3.6min.
Example 174 : 8-Chloro-3-pentyl-1-{4-r5-(2-thienyl)-1.2.4-oxadiazol-3-vnbutyl>-3.7- dihydro-1 H-purine-2,6-dione
2-Thiophenecarboxylic acid (14mg, O.Hmmol) was dissolved in NMP (0.9ml) and treated with CDI (18mg, O.Hmmol). After 1 h, (1Z)-5-(8-chloro-2,6-dioxo-3-pentyl- 2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/-hydroxypentanimidamide (50mg, 0.13mmol) was added and the mixture heated in the microwave at 15O0C for 15min. The solution was directly purified by MDAP to obtain the title compound which was then freeze dried from 1 ,4-dioxane to give the title compound as a white solid (19mg, 31%). LC/MS: m/z 463 [MH]+, RT 3.5min.
Example 175: 8-Chloro-3-pentyl-1-^H5-(1.3-thiazol-2-yl)-1.2.4-oxadiazol-3- yllbutyl}-3,7-dihydro-1H-purine-2,6-dione
A solution of (1Z)-5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/- hydroxypentanimidamide (50mg, 0.13mmol) in EtOH (1.5ml) was treated with a 21 % solution of NaOEt in EtOH (50μl, 0.13mmol) and ethyl 1 ,3-thiazole-2-carboxylate (18mg, 0.11mmol). The mixture was heated in the microwave at 17O0C for 10min. After cooling, the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated then concentrated and purified by the MDAP. The title compound was obtained as a white solid (13mg, 21%).
LC/MS: m/z 464 [MH]+, RT 3.3min.
1H NMR (DMSO-Cl6) δ: 0.83 (t, 3H, J = 7Hz), 1.21-1.32 (m, 4H), 1.60-1.77 (m, 6H), 2.84 (t, 2H, J = 7Hz), 3.91 (m, 4H), 8.23 (d, 1 H1 J = 3Hz), 8.27 (d, 1 H, J = 3Hz),14.4 (br s, 1 H).
Example 176: 3-butyl-8-chloro-1 -l4-r3-(2-pyridinyl)-1.2.4-oxadiazol-5-yllbutyl>-3.7- dihydro-1 H-purine-2.6-dione
a) Preparation of 3-butyl-8-chloro-1-{4-[3-(2-pyridinyl)-1 ,2,4-oxadiazol-5-yl]butyl}-3,7-
To a mixture of ethyl 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1- yl)pentanoate (120mg, 0.32mmol) and of N-hydroxy-2-pyridinecarboximidamide (50mg, 0.36mmol) in EtOH (2ml) was added a 21% (w/v) solution of sodium ethoxide in EtOH (0.225ml, 0.62mmol) and then heated in a sealed vial in a microwave oven at 14O0C for 10min. The cooled mixture was evaporated to dryness and the residue partitioned between chloroform (5ml) and saturated aqueous ammonium chloride (5ml). The organic phase was evaporated to dryness and the crude product subjected to purification by MDAP. Product containing fractions were combined and evaporated to dryness. The product was triturated to a solid in a small amount of diethyl ether then dried to reveal the title compound as a white solid (44mg, 31%). LC/MS: m/z 444 [MH]+, RT 3.03min. 1H NMR (CDCI3) δ: 0.96 (t, 3H, J = 7.3Hz), 1.40 (m, 2H), 1 ,74 (m, 2H), 1.88 (m, 2H), 1.99 (m, 2H), 3.07 (t, 2H, J = 7.5Hz), 4.09 (t, 2H, J = 7.5Hz), 4.17 (t, 2H, J = 7.0Hz), 7.43 (m, 1 H), 7.64 (m, 1 H), 8.10 (m, 1 H), 8.79 (m, 1 H).
b) Preparation of N-hydroxy-2-pyridinecarboximidamide
To a mixture of 2-pyridinecarbonitrile (3g, 29mmol) and potassium carbonate (4.1g, 30mmol)in EtOH (30ml) was added water (15ml) and, cautiously, hydroxylamine hydrochloride (2.9g, 42mmol) and then heated at reflux for 6h, cooled and evaporated
to dryness. The residue was treated with water (100ml) and the suspended solid product filtered off, washed with water and dried to yield the title compound as a white solid (2.28g, 57%).
1H NMR (DMSO-d6) δ: 5.85 (br s, 2H), 7.40 (m, 1 H), 7.79 (m, 1 H), 7.86 (m, 1 H), 8.55 (m, 1 H), 9.92 (S, 1 H)
Example 177: 3-Butyl-8-chloro-1-r4-(3-phenyl-1.2.4-oxadiazol-5-v0butyll-3.7- dihydro-1 H-purine-2.6-dione
Method A a) 3-Butyl-8-chloro-1 -[4-(3-phenyl-1 ,2,4-oxadiazol-5-yl)butyl]-3,7-dihydro-1 H-purine- 2,6-dione
Ethyl 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate (74mg, 0.2mmol) and benzamidoxime (30mg, 0.22mmol) were suspended in dry EtOH (1ml) and ethanolic sodium ethoxide (21% by wt., 0.111ml, 0.3mmol) was added. The mixture was gently warmed until solids were dissolved and then heated in the microwave reactor at 14O0C for 10min. The mixture was then partitioned between EtOAc and 2M HCI and the organic phase dried (Na2SO4) and evaporated. MDAP afforded the pure title compound (40.7mg). LC/MS: m/z 443 [MH]+, RT 3.67min. 1H NMR (DMSO-d6) δ: 0.89 (t, 3H, J = 7Hz), 1.22-1.34 (m, 2H), 1.57-1.75 (m, 4H), 1.75-1.86 (m, 2H), 3.05 (t, 2H, J = 7 Hz), 3.88-3.98 (m, 4H), 7.52-7.63 (m, 3H), 7.95-8.0 (m, 2H). dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1-yl)pentanoate
To 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5g, 5.31 mmol) in dry DMF (25ml) was added Cs2CO3 (1.905g, 5.84mmol), followed by ethyl 5- bromovalerate (1.46g, 6.99mmol). The mixture was heated at 550C for 18h then allowed to cool. It was degassed by repeatedly evacuating and readmitting nitrogen,
then morpholine (3.70ml, 42.5mmol) and tetrakis(triphenylphosphine)palladium(0) (1.Og, 0.865mmol) were added and the mixture stirred for 5h. EtOAc (75ml), 2M HCI (40ml) and water (20ml) were added and the organic phase was separated, washed with brine (3 x 25ml), filtered to remove some insoluble yellow solid, dried (Na2SO4) and evaporated. The residue (2.5g) was purified by aminopropyl SPE (2Og), loading in THF-MeOH (1 :1 ), washing with MeOH and eluting the product with DCM-MeOH (1 :1) containing 5% added AcOH to afford the title compound (1.53g). LC/MS:, m/z 371 MH+, RT 3.18min
Method B a) 3-Butyl-8-chloro-1 -[4-(3-phenyl-1 ,2,4-oxadiazol-5-yl)butyl]-3,7-dihydro-1 H-purine- 2,6-dione
CDI (0.98g, 6.1 mmol) was added to a solution of 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7- tetrahydro-1H-purin-1-yl)pentanoic acid (1.89g, 5.5mmol) in DMF (15ml) and stirred under nitrogen for 1.5h. Benzamidoxime (0.91 g, 6.1mmol) was added and the mixture stirred at 1100C overnight. The reaction mixture was partitioned between EtOAc and 2M HCI. The organic layer was separated, washed with brine, dried (MgSO4) and evaporated. The crude product was crystallised from methanol and then further purified using the Companion™ system and a gradient elution from cyclohexane to EtOAc. Product containing fractions were combined and evaporated to give the title compound as a white solid (850mg). LC/MS: m/z 443 [MH]+, RT 3.52min.
1H NMR (MeOH-d4) δ: 0.94 (t, 3H, J = 7.5Hz), 1.31-1.41 (m, 2H), 1.65-1.73 (m, 2H), 1.75-1.83 (m, 2H), 1.87-1.96 (m, 2H), 3.04 (t, 2H, J = 7.5Hz), 4.01 (t, 2H, J = 7.5Hz),
4.06 (t, 2H, J = 7Hz), 7.46-7.55 (m, 3H), 7.98-8.02 (m, 2H). oxo-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanoic acid
A mixture of ethyl 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1- yOpentanoate (2.8g, 7.55mmol), LiOH (542mg, 22.7mmol), water (2.5ml) and methanol (50ml) was stirred at rt for for 6Oh. The mixture was portioned between water and EtOAc and the pH of the aqueous phase adjusted to pH 4-5. The organic layer was separated, washed with brine, dried (MgSO
4) and evaporated to give the title compound as a white solid (2.18g). LC/MS: m/z 343 [MH]
+, RT 2.69min.
Example 178 : 8-Chloro-3-pentyl-1-f4-(3-phenyl-1.2,4-oxadiazol-5-yl)butvn-3.7- dihydro-1 H-purine-2,6-dione
A mixture of methyl 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purin-1- yl)pentanoate (50mg, 0.13mmol), benzamidine oxime (20mg, 0.15mmol) and a 21% solution of NaOEt in EtOH (76μl, 0.20mmol) in EtOH (1.5ml) was heated in the microwave at 14O0C for 10min. After cooling the reaction was partitioned between 2M
HCI (aq) and EtOAc. The organic layer was separated, dried (MgSO4) and concentrated. Purification by the MDAP gave the title compound as a white solid
(25mg, 41%).
LC/MS: m/z 457 [MH]+, RT 3.7min.
1H NMR (DMSO-d6) δ: 0.82 (t, 3H1 J = 7 Hz), 1.25 (m, 4H)1 1.66 (m, 4H), 1.79 (m, 2H)1
3.04 (t, 2H, J = 7Hz), 3.92 (4H,m), 7.57 (m, 3H), 7.97 (m, 2H), 14.5 (br s, 1 H).
Example 179: 3-Butyl-8-chloro-1 -{4-f3-(3-hydroxyphenyl)-1 ,2,4-oxadiazol-5- yllbutyl>-3.7-dihydro-1H-purine-2.6-dione
A mixture of ethyl 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1- yl)pentanoate (50mg, 0.13mmol), Λ/,3-dihydroxybenzenecarboximidamide (25mg, 0.16mmol), 21% solution of NaOEt in EtOH (55μl, 0.15mmol) and EtOH (1.5ml) was heated in the microwave at 18O0C for 10min. Another aliquot of 21% solution of NaOEt in EtOH (55μl, 0.21 mmol) was added and the mixture heated in the microwave at
1750C for 30min. After cooling the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, concentrated and purified by the MDAP. The title compound was obtained as an off-white solid (20mg, 32%). LC/MS: m/z 459 [MH]+, RT 3.3min.
Example 180 : 8-Chloro-1-{4-r3-(4-hvdroxyphenv0-1.2.4-oxadiazol-5-vπbutyl)-3- pentyl-3.7-dihydro-1H-purine-2.6-dione
A solution of 5-(8-chloro-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1/-/-purin-1-yl)pentanoic acid (50mg, 0.14mmol) in DMF (2ml) was treated with CDI (23mg, 0.14mmol) and stirred at rt for 30min. Λ/,4-dihydroxybenzenecarboximidamide (26mg, 0.17mmol) was added and the mixture heated in the microwave at 12O0C for 15min. After cooling the reaction was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, concentrated and purified by the MDAP. The title compound was obtained as an off-white solid (17mg, 26%). LC/MS: m/z 473 [MH]+,RT 3.5min.
Example 181 : 3-Butyl-8-chloro-1-r4-(5-phenyl-2AV-tetrazol-2-yl)butyll-3.7-dihvdro- 1 H-purine-2,6-dione
A mixture of 4-[3-butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H- purin-1-yl]butyl methanesulfonate (50mg, 0.12mmol), Cs2CO3 (45mg, 0.14mmol) and
DMF (3ml) was treated with 5-phenyl-1H-tetrazole (20mg, 0.14mmol) and stirred for
6Oh at 5O0C. After cooling, the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (20mg, 0.017mmol) was added and the mixture degassed once more. Morpholine (150μl, 1.7mmol) was added and the mixture was stirred under nitrogen for 18h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The
combined extracts were concentrated, giving a yellow residue. MeOH was added and then passed down an NH2-propyl column with the product eluting with 2%
AcOH/MeOH. Further purification by MDAP gave the title compound as an off-white solid (15mg, 29%).
LC/MS: m/z 443 [MH]+, RT 3.4min.
1H NMR (DMSO-de) δ: 0.86 (t, 3H, J = 7Hz), 1.26 (m, 2H), 1.59 (m, 4H), 1.97 (m, 2H),
3.90 (m, 4H), 4.76 (t, 2H, J = 7Hz), 7.54 (m, 3H), 8.02 (m, 2H), 14.4 (br s, 1 H).
Example 182 : 3-Butyl-8-chloro-1-r4-(5-oxo-4-phenyl-4,5-dihvdro-1 H-tetrazol-1- yl)butvn-3,7-dihydro-1H-purine-2.6-dione
A mixture of 4-[3-butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1/-/- purin-1-yl]butyl methanesulfonate (50mg, 0.12mmol), Cs2CO3 (45mg, 0.14mmol) and
DMF (3ml) was treated with 1-phenyl-1 ,2-dihydro-5H-tetrazol-5-one (23mg, 0.14mmol) and stirred for 6Oh at 5O0C. After cooling, the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (20mg, 0.017mmol) was added and the mixture degassed once more. Morpholine (150μl, 1.7mmol) was added and the mixture was stirred under nitrogen for 18h, then partitioned between 2M HCI (aq) and
EtOAc. The organic layer was separated and the aqueous layer extracted again with
EtOAc. The combined extracts were concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl column with the product eluting with 2%
AcOH/MeOH. Further purification by MDAP gave the title compound as an off-white solid (27mg, 51%). NB. ca. 10% O-alkylated material present.
LC/MS: m/z 459 [MH]+, RT 3.1min.
1H NMR (DMSO-d6) δ: 0.88 (t, 3H, J = 7Hz), 1.28 (m, 2H), 1.62 (m, 4H), 1.79 (m, 2H), 3.91 (m, 4H), 4.03 (m, 2H), 7.44 (m, 1 H), 7.57 (m, 2H), 7.85 (m, 2H), 14.5 (br s, 1H).
Example 183 : 3-Butyl-8-chloro-1-r4-(4-methyl-2.5-dioxo-3-phenyl-1- imidazolidinyl)butyll-3.7-dihydro-1W-purine-2,6-dione
a)3-Butyl-8-chloro-1-[4-(4-methyl-2,5-dioxo-3-phenyl-1-imidazolidinyl)butyl]-3,7- dihydro-1H-purine-2,6-dione
A mixture of 4-[3-butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1/-/- purin-1-yl]butyl methanesulfonate (88mg, 0.20mmol), Cs2CO3 (80mg, 0.24mmol) and DMF (2ml) was treated with 5-methyl-1-phenyl-2,4-imidazolidinedione (46mg, 0.24mmol) and stirred for 18h at 7O0C. After cooling, the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (25mg, 0.022mmol) was added and the mixture degassed once more. Morpholine (174μl_, 2.0mmol) was added and the mixture was stirred under nitrogen for 5h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The combined extracts were concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl SPE with the product eluting with 2% AcOH/MeOH. Further purification by MDAP gave the title compound as a solid (70mg, 71%). LC/MS: m/z 487 [MH]+, RT 3.2min.
b) 4-[3-Butyl-8-chloro-2,6-dioxo-7-(2-propen-1 -yl)-2,3,6,7-tetrahydro-1 H-purin-1 -yl]butyl methanesulfonate
A solution of 3-butyl-8-chloro-1-(4-hydroxybutyl)-7-(2-propen-1-yl)-3,7-dihydro-1/-/- purine-2,6-dione (1.3Og, 3.66mmol) in DCM (10ml) was treated with triethylamine (0.77ml, 5.50mmol) followed by portionwise addition of methanesulfonic anhydride (702mg, 4.03mmol). CARE, effervescence. The reaction mixture was stirred at rt for 10min then partitioned between sat. NaHCO3 (aq) solution and DCM. The organic layer was separated and washed with 1 M HCI (aq) and then brine. It was dried (MgSO4) and concentrated, giving the title compound as a viscous oil (1.6Og, quant.). LC/MS: m/z 433 [MH]+, RT 3.3min.
c) 3-Butyl-8-chloro-1 -(4-hydroxybutyl)-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6- dione
A stirred solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (5.Og, 17.7mmol) in DMF (100ml) was treated with Cs
2CO
3 (6.3g, 19.5mmol) and 4- bromo-1-butanol (3.0ml, 21.2mmol). The mixture was heated at 5O
0C for 5h then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated, giving a yellow solid. Purification by silica SPE (EtOAc/cyclohexane mixtures as the eluent) and then by the Companion™ system (IPA/DCM mixtures as the eluent) gave the title compound as a colourless oil (1.35g, 21%). LC/MS: m/z 355 [MH]
+, RT 2.9min.
Example 184 : S-Chloro-i^-rø-fcvclopentylsulfonvOphenyllbutyll-S-pentyl-aj- dihydro-1 H-purine-2.6-dione
8-Chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (100mg, 0.34mmol) was dissolved in DMF (1 ml) and sequentially treated with 4-[4-
(cyclopentylsulfonyl)phenyl]-1-butanol (105mg, 0.37mmol), PPh3 (404μl of a 1 M solution in DMF) and DBAD (404μl of a 1 M solution in DMF). After stirring for 24h under nitrogen, the mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (39mg, 0.034mmol) was added and the mixture degassed once more. Morpholine (297μl, 3.4mmol) was added and the mixture was stirred under nitrogen for 63h, then partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl SPE with the product eluting with 2% AcOH/MeOH. The product was further purified by MDAP giving the title compound as a beige solid (5mg, 3%).
LC/MS: m/z 521 [MH]+, RT 3.7min.
Example 185 : 8-Chloro-W4-r4-(methyloxy)phenyl1butyl}-3-pentyl-3.7-dihvdro- 1 H-purine-2.6-dione
A solution of 4-(4-bromobutyl)phenyl methyl ether (88mg, 0.36mmol) in DMF (3ml) was reacted with 8-chloro-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione (90mg, 0.30mmol) and Cs2CO3 (109mg, 0.33mmol) for 5h at 5O0C. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (35mg, 0.030mmol) was added and the mixture degassed once more. Morpholine (0.26ml, 3.0mmol) was added and the mixture was stirred under nitrogen for 3h. Another aliquot of Pd(PPh3J4 (35mg, 0.030mmol) was added and left for a further 3h. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated and the aqueous layer extracted again with EtOAc. The combined extracts were concentrated, giving a yellow residue. MeOH was added and then passed down an aminopropyl SPE with the product eluting with 3% AcOH/MeOH. The product was further purified by MDAP giving the title compound as a solid (2mg, 1.5%). LC/MS: m/z 419 [MH]+, RT 3.7min. 1H NMR; (MeOH-d4) δ: 0.90 (t, 3H, J = 7Hz), 1.28-1.40 (m, 4H), 1.57-1.75 (m, 6H), 2.57 (t, 2H, J = 7Hz), 3.73 (s, 3H), 3.97-4.02 (4H, m), 6.77 (m, 2H), 7.06 (m, 2H).
Example 186: 8-Chloro-3-pentyl-1 -(3-r3-(methyloxy)phenyllpropyl>-3.7-dihvdro- 1 H-purine-2,6-dione
a) 8-Chloro-3-pentyl-1-{3-[3-(methyloxy)phenyl]propyl}-3,7-dihydro-1 H-purine-2,6- dione
8-Chloro-3-pentyl-1-{3-[3-(methyloxy)phenyl]propyl}-7-(2-propen-1-yl)-3,7-dihydro-1 H- purine-2,6-dione (2.94g) was dissolved in anhydrous THF (40ml). The solution was
degassed using a nitrogen/vacuum purge 6 times. Tetrakis(triphenylphosphine) palladium (0.66g) was added followed by morpholine (5ml). After stirring for 18hr, the reaction mixture was diluted with EtOAc and was washed with 1 N HCI and brine (x2), dried (MgSO4) and evaporated in vacuo. This crude material was purified on an aminopropyl SPE (7Og) eluting with MeOH then MeOH containing 3% AcOH to give the title compound as a pale yellow solid (1.56g). LC/MS: m/z 405 [MH]+, RT 3.51 min.
b) 8-Chloro-3-pentyl-1 -{3-[3-(methyloxy)phenyl]propyl}-7-(2-propen-1 -yl)-3,7-dihydro- 1H-purine-2,6-dione
8-Chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (1.76g, 5.94mmol) and 3-[3-(methyloxy)phenyl]-1-propanol (1.0Og, 6.04mmol) were dissolved in anhydrous THF (50ml) under an atmosphere of nitrogen. After 5min triphenylphosphine (1.87g, 7.12mmol) was added. After a further 5min di-tert-butyl azodicarboxylate (1.64g, 7.1mmol) was added. The solution was stirred for 2Oh at rt. The cloudy solution was concentrated in vacuo and purified on a 5Og Silica Il SPE (IST) using a Biotage FlashMaster™ Personal, eluting with cyclohexane /EtOAc 5:1 the appropriate fractions were concentrated in vacuo to give the title compound as a pale cream oil containing minor impurities(2.94g).
LC/MS:, m/z 445 [MH]+, RT 3.88min.
Example 187 : 8-Chloro-1-f3-(3-hydroxyphenyl)propyn-3-pentyl-3,7-dihvdro-1tf- purine-2.6-dione
To a suspension of 8-chloro-3-pentyl-1-{3-[3-(methyloxy)phenyl]propyl}-3,7-dihydro-1 H- purine-2,6-dione (1.52g, 3.86mmol) in anhydrous DCM (40ml) at -730C was slowly added 1 N borontribromide in DCM (4.6ml). The reaction mixture was stirred at -7O0C for 2hours and then at rt for 96h. The reaction mixture was cooled in ice, and water (6.8ml) was added slowly. The reaction mixture was then diluted with EtOAc and water, and the organic phase was washed with saturated, sodium hydrogen carbonate (x3) and brine then dried (MgSO4) and evaporated in vacuo. A portion of this crude material
(90mg) was purified by MDAP to give the title compound after freeze drying as a white solid (40mg).
LC/MS:, m/z 391 [MH]+, RT 3.43min.
1H NMR (DMSO-de) δ: 0.85 (t, 3H, J = 7Hz); 1.27 (m, 4H); 1.63 (m, 2H); 1.80 (m, 2H);
2.50 (m, 2H); 3.89 (m, 4H); 6.57 (m, 3H); 7.02 (t, 1 H, J = 8Hz); 9.22 (s, 1 H); 14.39 (s,
1 H)
Example 188: 3-butyl-8-chloro-1 -{ 4-r3-(4-hvdroxyphenyl)-1.2.4-oxadiazol-5- yllbutyl)-3.7-dihvdro-1H-purine-2,6-dione
A stirred solution of 5-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1- yl)pentanoic acid (100mg, 0.29mmol) in DMF (4ml) was treated with CDI (52mg, 0.32mmol). After 1h, Λ/,4-dihydroxybenzenecarboximidamide was added and the mixture heated at 1000C for 6h. On cooling, the reaction mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. Purification by MDAP afforded the title compound as a pale grey solid (72mg). LC/MS: m/z 459 [MH]+, RT 3.27min.
The following compounds (Table 10) were prepared using a method analogous to that for Example 177, using the appropriate amidoxime.
Table 10
Example 192: S-Butyl-δ-chloro-i-O-rS-d-phenylcvclopentvD-i ,2.4-oxadiazol-5- vnpropyl>-3,7-dihvdro-1H-purine-2,6-dione
Ethyl 4-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)butanoate (53mg, 0.15mmol), /V-hydroxy-i-phenylcyclopentanecarboximidamide (34mg, 0.165mmol) and sodium methoxide (20mg, 0.37mmol) in dry MeOH (0.75ml) were heated at 14O
0C in the microwave reactor for 10min. The mixture was then partitioned between ethyl acetate and 2M HCI, the organic phase evaporated and the product purified by MDAP to give the title compound as a solid (29.1mg). LC/MS: m/z 497 [MH]
+, RT 3.76min.
The following compounds (Table 11) were prepared using a method analogous to that for Example 192, using the appropriate amidoxime [with the exception that for Examples 210, 211 and 212 EtOH was used as reaction solvent; for Examples 210, 211 and 212 the reactions were worked up by adding 2M HCI until neutral and evaporating the solvent; for Example 206 the scale was 32mg of starting ethyl ester; Example 208 the scale was 42mg of starting ethyl ester].
Table 11
Example 210: 3-Butyl-8-chloro-1-r3-(3-{r4-(methyloxy)phenyllmethylM,2.4-
Prepared using a method analogous to that used for Example 93, except an additional final purification step using HPLC was employed. Yield Θ.Omg. LC/MS: m/z 473 [MH]+, RT 3.27min.
The following compounds (Table 12) were prepared using a method analogous to that for Example 96, using the appropriate amidoxime [with the exception that for Example 211 the scale was 0.12mmol instead of 0.15mmol; for Example 216 the crude product was stirred in EtOH (0.75ml) with 2M NaOH (0.5ml) overnight prior to the usual EtOAc/HCI workup and MDAP; Example 218 was isolated as an impurity from the preparation of Example 219 and was separated from it by HPLC; for Examples 221, 222 and 223 the pH during aqueous workup was adjusted to approximately 5 prior to extraction; additionally Example 223 was further purified by silica SPE (2g, DCM- MeOH 40:1then 20:1 ) after MDAP].
Table 12
The following compounds (Table 13) were prepared using a method analogous to that for Example 114, using the appropriate amidoxime [with the exception that Example 226 was conducted on half the scale of Example 114 and during workup the aqueous phase was neutralised prior to extraction; Example 227 was conducted on half the scale of Example 114 and the crude product stirred with 2M NaOH (0.5ml) in EtOH (1 ml) for 5h prior to workup and MDAP; for Example 232 0.185ml (O.δmmol) of 21 % NaOEt was used].
Example 237: 3-Butyl-8-chloro-1 -(3-(3-r(2-oxo-2.3-dihydro-1 H-benzimidazol-5- yl)methyll-1.2,4-oxadiazol-5-yl>propyl)-3,7-dihvdro-1H-purine-2,6-dione
Synthesised by a method analogous to that for Example 126 with the exception that a further 2 equivalents of 21 % sodium ethoxide (0.11ml) was used, the extra heating time was 20min. and the product was isolated by filtration followed by trituration with hot MeOH. Yield 14.5mg. LC/MS: m/z 499 [MH]+, RT 2.78min.
The following compounds (Table 14) were prepared by a method analogous to that for Example 18 [with the exception that Examples 238-243 were all synthesised on a scale starting from 50mg of 8-chloro-3-pentyl-7-(2-propen-1-yl)-1-[3-(1H-pyrazol-4- yl)propyl]-3,7-dihydro-1H-purine-2,6-dione; Examples 241 , 243, 245, 246 and 247 were additionally purified by MDAP following aminopropyl SPE; Example 242 was additionally purified by recrystallisation from MeOH following aminopropyl SPE; for Example 248, 128mg (1.2mmol) of sodium carbonate was used; during workup the aqueous phase was adjusted to pH6 prior to extraction; and the product was purified by MDAP then by further HPLC; for Example 241 solids which precipitated during workup were combined with the EtOAc extracts prior to SPE].
Table 14
Example 249: 8-Chloro-1 -(3-f 1 -r(4-chlorophenyl)methvn-1 H-pyrazol-4-yl>propyl)- 3-pentyl-3.7-dihydro-1H-purine-2,6-dione
3-pentyl-7-(2-propen-1 -yl)-1 -[3-(1 H-pyrazol- 4-yl)propyl]-3,7-dihydro-1 H-purine-2,6-dione (50mg, 0.123mmol) in dry DMF (1.5ml) was stirred with sodium carbonate (75mg, 0.708mmol) and 4-chlorobenzyl bromide (150mg, 0.73mmol) at 4O
0C for 18h. The mixture was partitioned between EtOAc and water, the organic phase washed with brine, dried and evaporated. The product was purified by normal phase chromatography on silica (Companion System, EtOAc - cyclohexane gradient) giving an oil (44mg). This was stirred in degassed, dry DMF (1ml) with tetrakis(triphenylphosphine)palladium(0) (19mg) and morpholine (0.072ml) under nitrogen for 6h. The mixture was partitioned between EtOAc and 2M HCI and the organic phase evaporated and purified by the usual aminopropyl SPE procedure. Yield 21.0mg. LC/MS: m/z 489 [MH
+], RT 3.59min.
The following compounds (Table 15) were prepared by a method analogous to that for Example 23 [with the exception that for Example 250 a second portion of Pd(PPh3J4 was added after 5h, stirring was continued overnight, and final purification was achieved by HPLC; for Example 252 required additional purification by MDAP; Example 257 required additional purification by recrystallisation from MeOH; Example 258 required additional purification by trituration with MeOH].
Example 259: 8-Chloro-3-pentyl-1 -F3-(1 -pentyl-1 H-pyrazol-4-vπpropyn-3,7- dihydro-1 H-purine-2,6-dione
8-Chloro-3-pentyl-7-(2-propen-1-yl)-1-[3-(1H-pyrazol-4-yl)propyl]-3,7-dihydro-1/-/- purine-2,6-dione (61 mg, 0.15mmol) and sodium carbonate (32mg, 0.3mmol) in dry DMF (1.5ml) was heated with 1-iodopentane (238mg, 1.2mmol) in the microwave reactor at 1200C for 25min. After cooling the mixture was degassed and stirred with tetrakis(thphenylphosphine)palladium(0) (40mg, 0.0346mmol) and morpholine (0.2ml) for 7h. A further 20mg of Pd(PPh3J4 was then added and stirring continued overnight. The mixture was stirred with EtOAc and 2M HCI for 1h and the organic phase separated and evaporated. The product was purified by aminopropyl SPE (5g) washing with MeOH-THF (1 :1 ), then MeOH, and eluting the product with DCM-MeOH (1 :1 ) containing 5% added AcOH to give the title compound (25mg). LC/MS: m/z 435 [MH]+, RT 3.65min.
The following compounds (Table 16) were prepared by a method analogous to that for Example 259 [with the exception that the compounds were purified by MDAP and for Example 261 the total heating time in the microwave reactor was 50min].
Table 16
Example 264: 8-Chloro-3-pentyl-1 -f3-M -(2-phenylethyl)-1 A/-pyrazol-4-yll propyl}- 3,7-dihvdro-1 H-purine-2.6-dione
8-Chloro-3-pentyl-7-(2-propen-1 -yl)-1 -[3-(1 H-pyrazol-4-yl)propyl]-3,7-dihydro-1 H- purine-2,6-dione (81 mg, 0.2mmol), sodium carbonate (42mg, 0.4mmol) and (2- iodoethyl)benzene (0.174ml, 1.2mmol) were heated together in dry DMF (1ml) under microwave irradiation at 12O0C for 25min. Tetrakis(triphenylphosphine)palladium(0) (46mg, 0.04mmol) and morpholine (0.174ml) were added and the mixture stirred for 6h. Further quantities (46mg and 0.174ml) of these reagents were added and stirring continued for a further 6Oh. Workup and purification as for the examples in Table 16 gave the title compound (15.5mg). LC/MS: m/z 469 [MH]+, RT 3.60min.
Example 265 : 8-Chloro-3-pentyl-1-(3-{1-r2-(1-pyrrolidinyl)ethyll-1H<>yrazol-4-
8-Chloro-3-pentyl-7-(2-propen-1-yl)-1-[3-(1/-/-pyrazol-4-yl)propyl]-3,7-dihydro-1/-/- purine-2,6-dione (61 mg, 0.15mmol), sodium carbonate (159mg, 1.5mmol) and 1-(2- chloroethyl)pyrrolidine hydrochloride (127mg, 0.75mmol) were heated together in dry DMF (2ml) at 8O
0C for 65h. Tetrabutylammonium iodide (55mg, 0.15mmol) was added and heating continued for another 18h. A further quantity of 1-(2-chloroethyl)pyrrolidine hydrochloride (127mg, 0.75mmol) was added and the mixture heated by microwaves at 12O
0C, then a 3
rd aliquot of 1-(2-chloroethyl)pyrrolidine hydrochloride (100mg) was added, with a further 25min at 12O
0C in the microwave. The mixture was partitioned between water and EtOAc, the organic phase separated, washed with brine and evaporated. This material was partitioned between EtOAc and 2M HCI. The separated aqueous phase was basified to pH9, saturated with NaCI and extracted with EtOAc (x2). The extracts were evaporated and the residue (28mg) stirred in dry degassed DMF (1.5ml) with tetrakis(triphenylphosphine)palladium(0) (50mg) and morpholine (0.2ml) for 6h. The mixture was partitioned between EtOAc and 2M HCI, the aqueous phase filtered, extracted twice with EtOAc and evaporated to dryness. The residue was purified by the aminopropyl SPE procedure, followed by MDAP to yield the title compound (1.9mg). LC/MS: m/z 462 [MH]
+, RT 2.46min.
Example 266 : 8-Chloro-1-(3-m(5-chloro-2-thienyl)methyl1-1H-pyrazol-4-
To 8-chloro-3-pentyl-7-(2-propen-1-yl)-1-[3-(1/-/-pyrazol-4-yl)propyl]-3,7-dihydro-1H- purine-2,6-dione (61 mg, 0.15mmol) in dry THF (1 ml) at -780C, under nitrogen, was added potassium t-butoxide (1 M in THF, 0.15ml), followed by 2-chloro-5- (chloromethyl)thiophene (25mg, 0.15mmol). Stirring was continued at -780C for 15min, then at room temperature for 1h and finally at 6O0C for 18h. The solution was degassed and morpholine (0.13ml) and tetrakis(triphenylphosphine)palladium(0) (35mg) added and stirring continued for 6h. Further quantities (0.2ml morpholine, 50mg Pd(PPh3J4) were added and stirring continued overnight. Worked up by partition between EtOAc and 2M HCI, the organic phase evaporated and purified by the standard aminopropyl SPE procedure followed by MDAP yielding title compound as a white solid (5.1 mg). LC/MS: m/z 495 [MH]+, RT 3.68min.
Example 267 : 8-Chloro-3-pentyl-1-r3-(1H-pyrazol-4-yl)propyn-3.7-dihvdro-1/y- purine-2,6-dione acetate
8-Chloro-3-pentyl-7-(2-propen-1-yl)-1-[3-(1/-/-pyrazol-4-yl)propyl]-3,7-dihydro-1/-/- purine-2,6-dione (50mg, 0.124mmol) in dry degassed THF (1.5ml) was stirred with tetrakis(triphenylphosphine)palladium(0) (29mg, 0.025mmol) and morpholine (0.108ml) under nitrogen for 5h. The mixture was partitioned between EtOAc and 0.5M citric acid and the organic phase separated. Two further EtOAc extractions were performed and the combined organics were evaporated and the product purified by aminopropyl SPE (2g), loading and washing with THF-MeOH (1 :1 ) then washing with MeOH and eluting with DCM-MeOH (1 :1) containing 5% AcOH. Yield 28.3mg. LC/MS: m/z 365 [MH]+, RT 2.89min.
Example 268 : 8-Chloro-3-hexyl-1-(2-hvdroxyethyl)-3,7-dihydro-1H-purine-2,6- dione
1 -(2-hydroxyethyl)-3,7-dihydro-1 H-purine-2,6-dione
8-Chloro-3-hexyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (1 OOmg,
0.322mmol), cesium carbonate (126mg, 0.387mmol) and 2-chloroethanol (29.8mg, 0.37mmol) in dry DMF (3ml) were heated together under nitrogen at 550C for 42h. The cooled mixture was degassed thoroughly and stirred with tetrakis(triphenylphosphine)palladium(0) (74mg) and morpholine (0.28ml) for 5h. The reaction was worked up by partition between EtOAc and 2M HCI, the organic phase being separated and evaporated. The residue was loaded onto an aminopropyl SPE cartridge (5g) in THF-MeOH (1 :1), washed with the same solvent, then with neat MeOH, and the product eluted with DCM-MeOH (1 :1 ) containing AcOH (2.5% rising to 5%). The product thus obtained was further purified by MDAP to afford the title compound (38mg). LC/MS: m/z 315 [MH]+, RT 2.79min.
b) 8-Chloro-3-hexyl-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione
To 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (226mg, 1 mmol) and sodium carbonate (117mg, 1.1mmol) in dry DMF (7ml) was added 1-iodohexane (223mg, 1.05mmol). The mixture was stirred and heated at 5O0C for 2 days. After cooling, the mixture was partitioned between EtOAc and water, the organic phase washed with brine, dried over Na2SO4 and evaporated. The crude product was recrystallised from EtOAc-cyclohexane (1 :2). Yield 146mg. LC/MS: m/z 311 [MH]+, RT 3.12min.
The following compounds (Table 17) were prepared by a method analogous to that for Example 268, except for Example 270 the scale was reduced to 75mg (0.243mmol) of the precursor 8-chloro-3-(3-cyclopropylpropyl)-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine- 2,6-dione.
Table 17
The intermediates were prepared according to the method of Example 268b, except that 8-chloro-3-(3-cyclopropylpropyl)-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione was purified by silica SPE (5g) eluting with EtOAc-cyclohexane (2:3).
Example 271 : 3-Butyl-8-chloro-1-(3-r5-(phenylmethyl)-1,3,4-oxadiazol-2-
To 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (99mg, 0.35mmol) in dry DMF (2ml) was added cesium carbonate (137mg, 0.42mmol) followed by a solution in dry DMF (1 ml) of 2-(3-chloropropyl)-5-(phenylmethyl)-1 ,3,4-oxadiazole (99mg, 0.42mmol). The mixture was stirred under nitrogen and heated at 55
0C for 2.5h then stirred at room temperature overnight. The mixture was degassed by repeatedly evacuating and admitting nitrogen and then tetrakis(triphenylphosphine)palladium(0) (81 mg, 0.07mmol) and morpholine (0.305ml, 3.5mmol) were added and stirring was continued for 5h EtOAc and 2M HCI were added and the mixture stirred for 20min then filtered. The organic phase was separated and evaporated, and the product was purified by aminopropyl SPE (5g) washing with THF-MeOH (1 :1 ) then with MeOH and eluting the acidic product with DCM-MeOH (1 :1 ) containing 5% added AcOH. The product thus obtained was purified further by MDAP to yield the title compound (92mg). LC/MS: m/z 443 [MH]
+, RT 3.18min.
The following compounds (Table 18) were prepared by a method analogous to that for Example 271, with the exception that Example 279 was further purified by HPLC.
Table 18
Synthesis of chloropropyl 1 ,3,4-oxadiazole intermediates from Table 18:
2-[(2-chloro-4-fluorophenyl)methyl]-5-(3-chloropropyl)-1 ,3,4-oxadiazole 2-(3-chloropropyl)-5-[(2,4-difluorophenyl)methyl]-1 ,3,4-oxadiazole 2-(3-chloropropyl)-5-(phenylmethyl)-1 ,3,4-oxadiazole
Diacyl hydrazines (500mg, synthesis below) were stirred in dry toluene (4ml) and phosphorus oxychloride (4ml) was added. The mixtures were heated at 9O0C for 2h then allowed to cool and the solvents evaporated. The residues were dissolved in dry toluene, evaporated and then partitioned between EtOAc and aqueous NaHCO3. The organic phases were washed with brine, dried over Na2SO4 and evaporated to give the required oxadiazoles as colourless oils. These were not purified further but reacted directly with the xanthines as above.
-(phenylacetyl)butanohydrazide
To 4-chlorobutyryl chloride (1.12ml, lOmmol) in dry DCM (10ml) was added, dropwise, over 40min, a mixture of phenylacetic hydrazide (1.5g, lOmmol) and DIPEA (1.77ml, 10.2mmol) in dry DCM (40ml) at room temperature. A dense white precipitate formed. After a further 20min. 2M HCI (30ml) was added and the title compound (white solid) was filtered off, washed with water and dried (2.24g). LC/MS: m/z 255 [MH]+, RT 2.20min.
-chloro-4-fluorophenyl)acetyl]butanohydrazide
(i) A solution of 2-chloro-4-fluorophenylacetyl chloride (lOmmol) in dry DCM (15ml) was added over 20min to a mixture of t-butyl carbazate (1.32g, lOmmol) and DIPEA (1.77ml, 10.2mmol) in dry DCM (20ml). After stirring for a further 2h, the mixture was washed with 1 M HCI then with aqueous NaHCO3. A white solid precipitated at this point, which was filtered off, washed with water and DCM then dried to yield 1 ,1- dimethylethyl 2-[(2-chloro-4-fluorophenyl)acetyl]hydrazinecarboxylate (1.94g).
(ii) This compound (1.92g, 6.34mmol) was suspended in dioxan (2ml) and 4M HCI in dioxan (5ml) was added. A dense white precipitate formed. After 1 h the mixture was partitioned between EtOAc and saturated aqueous NaHCO3 and the organic phase washed with brine, dried (Na2SO4) and evaporated giving 2-(2-chloro-4- fluorophenyl)acetohydrazide as a white solid (1.07g).
(iii) A mixture of 2-(2-chloro-4-fluorophenyl)acetohydrazide (909mg, 4.5mmol) and DIPEA (0.817ml, 4.7mmol) in dry DCM (65ml) was added over 20min to 4-chlorobutyryl chloride (0.505ml, 4.5mmol) in dry DCM (5ml). After 1.5h, 2M HCI was added and the precipitated 4-chloro-/V-[(2-chloro-4-fluorophenyl)acetyl]butanohydrazide was filtered off, washed with water and dried (1.24g). LC/MS: m/z 307 [MH]+, RT 2.61 min.
ropyl)-5-[(2,4-difluorophenyl)methyl]-1 ,3,4-oxadiazole
(i) A solution of 2,4-difluorophenylacetyl chloride (lOmmol) in dry DCM (15ml) was added over 10min. to a mixture of t-butyl carbazate (1.32g, lOmmol) and DIPEA (1.77ml, 10.2mmol) in dry DCM (20ml). After stirring for 1.5h the mixture was washed with 1 M HCI then with aqueous NaHCO
3. The organic phase was evaporated to afford 1 ,1-dimethylethyl 2-[(2,4-difluorophenyl)acetyl]hydrazinecarboxylate as a white solid.
(ii) 1 ,1-dimethylethyl 2-[(2,4-difluorophenyl)acetyl]hydrazinecarboxylate (lOmmol) in dioxan (5ml) was stirred with 4M HCI in dioxan (8ml) for 1.5h. The mixture was partitioned between EtOAc and saturated aqueous NaHCO3 and the organic phase washed with brine, dried (Na2SO4) and evaporated. Reaction was incomplete so the residue was stirred again with 4M HCI in dioxan (1OmI) for 2.5h. Workup as previously gave 2-(2,4-difluorophenyl)acetohydrazide as a solid (570mg).
(iii) A mixture of 2-(2,4-difluorophenyl)acetohydrazide (570mg, 3.06mmol) and DIPEA (0.553ml, 3.2mmol) in dry DCM (30ml) was added to 4-chlorobutyryl chloride (0.343ml, 3.06mmol) in dry DCM (5ml) over 15min. An immediate white precipitate formed. After stirring for 1 h, 2M HCI (20ml) was added and the solid 2-(3-chloropropyl)-5-[(2,4- difluorophenyl)methyl]-1 ,3,4-oxadiazole was filtered off, washed with water and dried (726mg). LC/MS: m/z 291 [MH]+, RT 2.45min.
Example 280 : 3-Butyl-8-chloro-1-r4-(3-phenyl-5-isoxazolyl)butyll-3,7-dihvdro-1tf- purine-2,6-dione
5-isoxazolyl)butyl]-3,7-dihydro-1 H-purine-2,6-dione
3-Butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100mg,
0.354mmol) and 4-(3-phenyl-5-isoxazolyl)-1-butanol (77mg, 0.355mmol) were dissolved in dry THF (4ml) under nitrogen. A solution of dibenzyl azodicarboxylate (94%, 224mg, 0.708mmol) in dry THF (2ml) was added. The mixture was cooled to O0C and a solution of triphenylphosphine (185mg, 0.708mmol) in dry THF (1 ml) was added. The mixture was stirred for 20min at O0C then at room temperature overnight. The mixture was degassed then stirred with morpholine (0.308ml) and tetrakis(triphenylphosphine)palladium(0) (82mg) for 4.5h. A further 60mg of tetrakis(triphenylphosphine)palladium(0) was added and stirring continued overnight. The reaction was worked up by partition between EtOAc and 2M HCI1 the organic phase evaporated and purified by aminopropyl SPE (5g) washing with THF-MeOH
(1 :1), MeOH and eluting with DCM-MeOH (1 :1 ) containing 5% AcOH. Further purification by MDAP afforded the title compound (56mg). LC/MS: m/z 442 [MH]+, RT 3.59min.
b) 4-(3-Phenyl-5-isoxazolyl)-1-butanol
To Λ/-hydroxybenzenecarboximidoyl chloride (622mg, 4mmol) in dry DCM (6ml) was added 5-hexyn-1-ol (431 mg, 4.4mmol). The mixture was cooled to O0C under nitrogen as triethylamine (0.612ml, 4.4mmol) was added dropwise over 10min. Stirred for a further 20min at O0C then at room temperature overnight. The mixture was washed with water and the organic phase evaporated. The product was purified by silica SPE (2Og) eluting with EtOAc-cyclohexane (1 :2, then 3:1 ) to give a white waxy solid (443mg). LC/MS: m/z 218 [MH]+, RT 2.74min.
Example 281 : 3-Butyl-8-chloro-1-l3-r3-(phenylmethyl)-5-isoxazolyllpropyl)-3.7- dihydro-1 H-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -{3-[3-(phenylmethyl)-5-isoxazolyl]propyl}-3,7-dihydro-1 H-purine- 2,6-dione
Prepared analogously to 3-butyl-8-chloro-1-[4-(3-phenyl-5-isoxazolyl)butyl]-3,7-dihydro- 1/-/-purine-2,6-dione (Example 280) using half the molar quantities, starting from 3- butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (50mg, 0.177mmol) and 3-[3-(phenylmethyl)-5-isoxazolyl]-1-propanol (38.4mg, 0.177mmol). Yield 24.2mg, LC/MS: m/z 442 [MH]+, RT 3.43min.
b) 3-[3-(Phenylmethyl)-5-isoxazolyl]-1 -propanol
Synthesised as with 4-(3-phenyl-5-isoxazolyl)-1-butanol, using Λ/-hydroxy-2- phenylethanimidoyl chloride (253mg, 1.5mmol) and 4-pentyn-1-ol (139mg, 1.65mmol). Yield 61 mg of pale yellow oil. LC/MS: m/z 218 [MH]+, RT 2.62min.
Example 282: 3-Butyl-8-chloro-1 -{3-f(3-phenyl-1 ,2.4-oxadiazol-5-yl)thio1propyl>- 3.7-dihvdro-1 H-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -{3-[(3-phenyl-1 ,2,4-oxadiazol-5-yl)thio]propyl}-3,7-dihydro-1 H-
Prepared by the method of 3-butyl-8-chloro-1-[4-(3-phenyl-5-isoxazolyl)butyl]-3,7- dihydro-1/-/-purine-2,6-dione starting from 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7- dihydro-1/-/-purine-2,6-dione (100mg, 0.354mmol) and 3-[(3-phenyl-1 ,2,4-oxadiazol-5- yl)thio]-1-propanol (83.5mg, 0.354mmol) except that a 2nd aliquot of 250mg of tetrakis(triphenylphosphine)palladium(0) was added during the deprotection step. Yield 19.6mg LC/MS: m/z 461 [MH]+, RT 3.75min.
b) 3-[(3-phenyl-1 ,2,4-oxadiazol-5-yl)thio]-1 -propanol
To 3-phenyl-1 ,2,4-oxadiazole-5(2H)-thione (178mg, 1 mmol) in dry THF (3ml) was added DIPEA (0.174ml, 1 mmol) and 3-bromo-1 -propanol (139mg, 1mmol). Stirring was continued for 65h then the mixture was partitioned between EtOAc and water. The organic phase was washed with brine, dried (Na2SO4) and evaporated to give title compound as an oil (235mg). LC/MS: m/z 237 [MH]+, RT 2.94min.
Example 283: 3-Butyl-8-chloro-1 -f2-r(3-phenyl-1 ,2,4-oxadiazol-5-yl)thio1ethyl)-3,7- dihvdro-1 H-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -{2-[(3-phenyl-1 ,2,4-oxadiazol-5-yl)thio]ethyl}-3,7-dihydro-1 H-
Prepared by a method analogous to that used for Example 270 (3-Butyl-8-chloro-1-[4- (3-phenyl-5-isoxazolyl)butyl]-3,7-dihydro-1H-purine-2,6-dione) starting from 3-butyl-8- chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (141 mg, 0.5mmol) and 2-[(3-
phenyl-1 ,2,4-oxadiazol-5-yl)thio]ethanol (111mg, 0.5mmol). A single portion of tetrakis(triphenylphosphine)palladium(0) (232mg) was used in the deprotection step, however, stirring being continued for 6h. Purification by aminopropyl SPE followed by MDAP afforded the title compound as a white solid (33.1mg). LC/MS: m/z 447 [MH]
+, RT 3.67 min.
b) 2-[(3-phenyl-1 ,2,4-oxadiazol-5-yl)thio]ethanol
The title compound was obtained in a similar manner to 3-[(3-phenyl-1 ,2,4-oxadiazol-5- yl)thio]-1-propanol, from 2-bromoethanol, after a reaction time of 24h and purification by silica SPE (ethyl acetate-cyclohexane 1 :1 ). Yield 176mg. LC/MS: m/z 223 [MH]+, RT 2.98 min.
Example 284: 3-Butyl-8-chloro-1 -(2-ff3-(phenylmethyl)-1 ,2,4-oxadiazol-5- yllamino)ethyl)-3,7-dihydro-1H-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -(2-{[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]amino}ethyl)-3,7- dihydro-1 /-/-purine-2,6-dione
3-Butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (64.4mg,
0.228mol), 2-{[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]amino}ethanol (50mg, 0.228mmol) and dibenzyl azodicarboxylate (136mg, 0.456mmol) were stirred in dry THF (3ml) at O0C as triphenylphosphine (119mg, 0.456mmol) in dry THF (1 ml) was added dropwise. The mixture was stirred at O0C for 10min. then at room temperature for 2 overnight periods. It was thoroughly degassed and stirred with morpholine (0.2ml) and tetrakis(triphenylphosphine)palladium(0) (53mg, 0.046mmol) for 5h. A further 53mg of the catalyst was then added and stirring continued overnight. The reaction was worked up by partition between EtOAc and 2M HCI, the organic phase evaporated and purified by aminopropyl SPE (5g) washing with THF-MeOH (1 :1 ), MeOH and eluting with DCM- MeOH (1 :1 ) containing 5% AcOH. Further purification by MDAP afforded the title compound (11.8mg). LC/MS: m/z 444 [MH]+, RT 3.12min.
b) 2-{[3-(Phenylmethyl)-1 ,2,4-oxadiazol-5-yl]amino}ethanol
3-(Phenylmethyl)-5-(trichloromethyl)-1 ,2,4-oxadiazole (140mg, 0.505mmol) in dry DMF (2ml) was stirred with ethanolamine (0.25ml) for 1.5h. The mixture was partitioned between EtOAc and water, the organic phase washed with water, brine, dried (Na2SO4) and evaporated to give a white waxy solid (87mg). LC/MS: m/z 220 [MH]+, RT 2.22min.
Example 285 : 3-Butyl-8-chloro-1-(2-ir3-(phenylmethyl)-1.2,4-oxadiazol-5- yllthio)ethyl)-3,7-dihvdro-1AY-purine-2,6-dione
a) 3-Butyl-8-chloro-1 -(2-{[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]thio}ethyl)-3,7-dihydro- 1 H-purine-2,6-dione
3-Butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (150mg, 0.531 mmol) and 2-{[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]thio}ethanol (125mg,
0.530mmol) in dry THF (4ml) were cooled to O0C and dibenzyl azodicarboxylate (94%,
336mg, 1.06mmol) in dry THF (2ml) was added followed by triphenylphosphine
(278mg, 1.06mmol). The mixture was stirred at O0C for 15min. then at room temperature for 2 overnight periods. Morpholine (1g) and tetrakis(triphenylphosphine)palladium(0) (250mg, 0.216mmol) were added to the degassed solution, and after 5h a further 100mg of Pd(PPh3J4 was added and stirring continued for 3 overnight periods. The reaction was worked up by partition between
EtOAc and 2M HCI, the organic phase evaporated and purified by aminopropyl SPE
(5g) washing with THF-MeOH (1 :1 ), MeOH and eluting with DCM-MeOH (1 :1 ) containing 5% AcOH. Further purification by MDAP afforded the title compound afforded title compound (26mg).
LC/MS: m/z 461 [MH]+, RT 3.47min.
b) 2-{[3-(Phenylmethyl)-1 ,2,4-oxadiazol-5-yl]thio}ethanol
To 3-(phenylmethyl)-1 ,2,4-oxadiazole-5(2H)-thione (384mg, 2mmol) in dry THF (5ml) was added DIPEA (0.348ml, 2mmol) and 2-bromoethanol (250mg, 2mmol). The mixture was stirred at room temperature overnight and then partitioned between EtOAc and 1M HCI. The organic phase was washed with brine, dried, evaporated and purified
by silica SPE (1Og) eluting with EtOAc-cyclohexane (1 :2) to give title compound (315mg) as a colourless oil. LC/MS: m/z 237 [MH]+, RT 2.74min.
Example 286: 3-Butyl-8-chloro-1 -{ P-P-phenylpropylH ,2.4-oxadiazol-5- yllmethyl}-3.7-dihvdro-1A7-purine-2.6-dione
a) 3-Butyl-8-chloro-1 -{[3-(3-phenylpropyl)-1 ,2,4-oxadiazol-5-yl]methyl}-3,7-dihydro-1 H- purine-2,6-dione
Ethyl (3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 /-/-purin-1 -yl)acetate (66mg,
0.2mmol) and (1Z)-Λ/-hydroxy-4-phenylbutanimidamide (39mg, 0.22mmol) were stirred in dry ethanol (1ml) with ethanolic sodium ethoxide (21%wt. solution, 0.111 ml, 0.3mmol) and heated under microwave irradiation at 140 C for 10 min. The cooled mixture was partitioned between ethyl acetate and 2M hydrochloric acid, the organic phase separated and evaporated. The product was purified by MDAP to give the title compound as a solid (31.5mg). LC/MS: m/z 443 [MH]+, RT 3.56 min.
b) Ethyl (3-butyl-8-chloro-2,6-dioxo-2,3,6l7-tetrahydro-1 H-purin-1 -yl)acetate
3-Butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (1.5g, 5.31 mmol) and cesium carbonate (1.903g, 5.84mmol) were stirred together in dry DMF (25ml). Ethyl bromoacetate (0.648ml, 5.84mmol) was added and the mixture was stirred at 55 C overnight. The cooled mixture was degassed using nitrogen and stirred with tetrakis(triphenylphosphine)palladium(0) (1g) and morpholine (3.73ml) for 4.5h. The mixture was partitioned between ethyl acetate (80ml) and 2M HCI (50ml). The organic phase was washed with 3 x 80ml brine, filtered, dried over Na2SO4 and evaporated. The product was purified by aminopropyl SPE (2Og), washing with THF-MeOH (1 :1),
then neat MeOH and eluting the product with DCM-MeOH (1 :1) containing acetic acid (2.5% rising to 5%), which gave pure title compound (1.16g). LC/MS: m/z 329 [MH]+, RT 2.87min.
Example 287: 3-Butyl-8-chloro-1 -fr3-(2-phenylethyl)-1 ,2,4-oxadiazol-5-yllmethyl>- 3.7-dihvdro-1 H-purine-2,6-dione
Synthesised by a method analogous to that for Example 286, starting from (1Z)-Λ/- hydroxy-3-phenylpropanimidamide. Yield 22.6mg. LC/MS: m/z 429 [MH]+, RT 3.43 min.
Example 288: 3-Butyl-8-chloro-142-r3-(2-phenylethyl)-1 ,2,4-oxadiazol-5-yllethyl>- 3,7-dihydro-1 H-purine-2.6-dione
Synthesised by a method analogous to that for Example 286, starting from (1Z)-Λ/- hydroxy-3-phenylpropanimidamide and ethyl 3-(3-butyl-8-chloro-2,6-dioxo-2,3,6,7- tetrahydro-1/-/-purin-1-yl)propanoate. Yield 23.3mg.
LC/MS: m/z 443 [MH]+, RT 3.40 min.
Example 289: Ethyl 3-(3-butyl-8-chloro-2,6-dioxo-2,3.6,7-tetrahydro-1H-purin-1- vDpropanoate o o
O
Synthesised as for ethyl (3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1- yl)acetate starting from ethyl 3-bromopropanoate (0.749ml, 5.84mmol), except that,
after the initial overnight heating period, further ethyl 3-bromopropanoate (1.5ml) was added, heating was resumed for a further 4h, then a further portion of cesium carbonate (1.903g), followed 2h later by a third portion of ethyl 3-bromopropanoate (1.5ml) were added. Heating at 55 C was then continued for a second overnight period before workup and deprotection as above. Yield 0.404g. LC/MS: m/z 343 [MH]+, RT 2.90min.
The following compounds (Table 19) were prepared by a method analogous to that for Example 3, with any modification noted in the method A-F.
Table 19
Method A: Analogous to that for Example 3
Method B: Similar to Method A, except material was purified using autopreparative HPLC after purification by aminopropyl SPE.
Method C: Similar to Method A, except material was purified by washing with water after purification by aminopropyl SPE.
Method D: Similar to Method A, except material was purified by MDAP after purification by aminopropyl SPE.
Method E: Similar to Method A, except material was purified by SCX SPE after initial purification using aminopropyl SPE.
Method F: Similar to Method A, except material was purified using preparative HPLC using a Zorbax Phenyl column.
Example 321 : 8-Chloro-1 -r3-tethyloxytethyll-3-(2.2.2-trifluoroethvn-3.7-dihvdro- 1 AY-purine-2,6-dione
a) 8-Chloro-1 -[3-(ethyloxy)ethyl]-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1 H-purine-2,6- dione
To a greenhouse tube equipped with a stirrer was added caesium carbonate (85mg, 0.26mmol), followed by a solution of 8-chloro-7-(2-propen-1-yl)-3-(2,2,2-trifluoroethyl)- 3,7-dihydro-1H-purine-2,6-dione (69mg, 0.22mmol) in dry DMF (1 ml) and then a solution of 1-bromo-3-(ethyloxy)ethane (60mg, 0.39mmol) in dry DMF (1 ml). The mixture was heated to 8O0C for 5h under nitrogen, then allowed to cool to room temperature for 16h. The reaction mixture was concentrated using a vacuum centrifuge. THF (2.5ml) was added to the mixture, followed by Pd(PPh3)4 (30mg, 0.026mmol) and morpholine (19OuL, 2.2mmol) and the mixture stirred at rt under nitrogen for 72h. The mixture was partitioned between 2N HCI (2ml) and chloroform (4ml), the organic layer separated using a hydrophobic frit, and the aqueous layer extracted with chloroform (2x4ml). Combined organic layers were concentrated under reduced pressure then loaded in 1 :1 DCM/MeOH onto an aminopropyl SPE (5g), washing with 1 :1 DCM/MeOH and eluting with 20% to 80% acetic acid in 1 :1 DCM/MeOH. Solvent was removed under reduced pressure to afford the title compound as a solid (70mg, 93%).
1H NMR (MeOD) δ: 1.11 (t, 3H, J = 7Hz), 3.51 (q, 2H, J = 7Hz), 3.64 (t, 2H1 J = 6Hz), 4.18 (t, 2H, J = 6Hz), 4.73 (q, 2H, J = 9Hz). LC/MS: m/z 341 [MH]+, RT 2.72min.
b) 8-Chloro-7-(2-propen-1 -yl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1 H-purine-2,6-dione
8-Chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (1.5g, 6.62mmol) in dry DMF (50ml) was stirred with sodium carbonate (980mg, 9.25mmol) and 1 ,1 ,1-trifluoro- 2-iodoethane (1.2g, 5.71 mmol) at room temperature for 18h under nitrogen. The mixture was heated at 5O0C for 6h then cooled to rt and stirred for a further 10h. The mixture was heated at 12O0C for 4h, further 1 ,1 ,1-trifluoro-2-iodoethane (426mg, 2.03mmol) added, and the reaction mixture heated at 12O0C for a further 3h. The reaction mixture was concentrated under reduced pressure. A further amount of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (3.8g, 16.8mmol) in dry DMF (125ml) was stirred with sodium carbonate (2.5g, 23.1 mmol)
and 1 ,1 ,1-trifluoro-2-iodoethane (4.1g, 19.5mmol) and the reaction mixture heated at 12O0C for 16h under nitrogen. This reaction mixture was combined with the previous crude material and concentrated under reduced pressure. The residue was triturated with DCM, the mixture filtered, and the filtrate concentrated under reduced pressure then dissolved in DCM (20ml). 10ml of this material was purified by silica chromatography using a 100g Silica column, eluting the title compound with a suitable gradient of ethyl acetate/cyclohexane. The remaining 10ml was purified using a Silica RediSep cartridge (13Og) on a Companion, eluting the title compound with a suitable gradient of ethyl acetate/cyclohexane. Fractions containing the title compound from both purification modes were combined and concentrated under reduced pressure to give the title compound as a white solid (1.6g, 22% overall yield). LC/MS: m/z 309 [MH]+, RT 2.59min.
Example 322: 8-Chloro-1 -r3-(2.6-dichlorophenyl)propyn-3-pentyl-3.7-dihydro-1 H- purine-2.6-dione. sodium salt
To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (40mg, 0.14mmol) in dry DMF (0.25ml) was added caesium carbonate (49mg, 0.15mmol) followed by a solution of 2-(3-bromopropyl)-1 ,3-dichlorobenzene (54mg, 0.20mmol) in dry DMF (0.25ml). The mixtures were stirred at 6O0C for 16h, then Pd(PPh3J4 (16mg, 0.014mmol) added, followed by morpholine (118uL, 1.4mmol) and the mixtures stirred for a further 16h. Solvent was removed using a vacuum centrifuge and the sample dissolved in DMSO (0.25ml) then loaded onto a C18 SPE (5g). 2N NaOH (0.5ml) was added and a suitable gradient of ammonia/water/MeCN used to elute the product. The title compound was isolated as a solid (52mg, 83%).
1H NMR (DMSO-d6) δ: 0.84 (t, 3H, J = 7Hz)1 1.18 - 1.36 (m, 4H), 1.55 - 1.69 (m, 2H), 1.69 - 1.85 (m, 2H), 2.78 - 2.89 (m, 2H), 3.85 (t, 2H, J = 7Hz), 3.95 (t, 2H, J = 7Hz), 7.23 (dd, 1 H, J = 9 and 7Hz), 7.41 (d, 2H, J = 7Hz). LC/MS: m/z 445 [MH]+, RT 4.05min.
The following compounds (Table 20) were prepared using a method analogous to that for the Example 322, from the corresponding alkyl halides:
Table 20
Method A: Analogous to that for Example 3
Method B: Similar to Method A, except after concentration by vacuum centrifuge, material was partitioned between 2M HCI and DCM, the aqueous layer isolated then purified using C18 SPE in the manner described in Method A.
Method C: Similar to Method A, except after concentration by vacuum centrifuge, material was partitioned between 2M HCI and DCM, and the product was isolated from the organic layer after autopreparative HPLC.
Method D: Similar to Method A, except product was isolated using aminopropyl SPE.
Method E: Similar to Method A, except material was further purified on a phenyl HPLC using a suitable gradient of water/MeOH/MeCN/TFA, then autopreparative HPLC, using a suitable gradient of water/acetonitrile.
The following compounds (Table 21) were prepared using a method analogous to that for Example 142, from the corresponding acids and (1Z)-4-(3-butyl-8-chloro-2,6-dioxo- 2,3,6,7-tetrahydro-1 H-purin-1 -yl)-Λ/-hydroxybutanimidamide.
Table 21
Example 353: 3-Butyl-8-chloro-1 -(2-{r4-(2-thienyl)phenvnoxy>ethyl)-3,7-dihvdro- 1 H-purine-2.6-dione
A microwave vial containing a magnetic stirrer bar was charged with 2-thienylboronic acid (16mg, 0.125mmol), 1-{2-[(4-bromophenyl)oxy]ethyl}-3-butyl-8-chloro-3,7-dihydro- 1 H-purine-2,6-dione (50mg, 0.113mmol), aqueous sodium carbonate (1 ml, 1 M solution) and dimethoxyethane (1 ml). This mixture was degassed with nitrogen and then Pd(PPh3J2CI2 (4mg, 5.6x10-6mol) was added. The reaction mixture was capped and heated at 1400C in a microwave for 15min (pressure reached 7bar). The crude reaction mixture was acidified with HCI (2M, 1.5ml), washed with chloroform (2x1 ml) and the phases separated. The combined organics were evaporated and the crude product purified by MDAP to afford the title compound (10mg). LC/MS: m/z 445 [MH]+, RT 3.76min
Example 354: 3-Butyl-8-chloro-1 -(2-{r4-(4-methyl-2-thienyl)phenvHoxy}ethyl)-3,7-
A microwave vial containing a magnetic stirrer bar was charged with (4-methyl-2- thienyl)boronic acid (18mg, 0.125mmol), 1-{2-[(4-bromophenyl)oxy]ethyl}-3-butyl-8- chloro-3,7-dihydro-1 H-purine-2,6-dione (50mg, 0.1 13mmol), aqueous sodium carbonate (1 ml, 1 M solution) and dimethoxyethane (1ml). This mixture was degassed with nitrogen and then Pd(PPh3J2CI2 (4mg, 0.0056mmol) was added. The reaction mixture was capped and heated at 1400C in a microwave for 15min (pressure reached 7bar). The crude reaction mixture was acidified with HCI (2M, 1.5ml), washed with chloroform (2x1 ml) and the phases separated. The combined organics were evaporated and the crude product purified by MDAP to afford the title compound (17mg). LC/MS: m/z 459 [MH]+, RT 3.9min
Example 355: 1 -{2-r(4-Bromophenyl)oxy1ethyl)-3-butyl-8-chloro-3.7-dihvdro-1 H- purine-2.6-dione
nyl)oxy]ethyl}-3-butyl-8-chloro-3,7-dihydro-1H-purine-2,6-dione
1 -{2-[(4-Bromophenyl)oxy]ethyl}-3-butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H- purine-2,6-dione (2.3g, 4.8mmol) was stirred in a mixture of nitrogen degassed DCM (40ml) and AcOH (4ml). Tetrakis(triphenylphosphine)palladium (1.1g, 0.896mmol) and phenylsilane (5.9ml, 48mmol) were added and the mixture stirred at rt for 2h. This was then evaporated and the residue triturated with a mixture of diethyletheπcyclohexane (1 :2) to afford the title compound (1.02g, 49%) as a white solid. LC/MS: m/z 441/443 [MH]+, RT 3.6min
b) 1 -{2-[(4-bromophenyl)oxy]ethyl}-3-butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H- purine-2,6-dione
3-Butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (2.8g, 9.8mmol) in dry DMF (50ml) was added Cs2CO3 (6.4g, 19.6mmol) followed by 2-bromoethyl 4- bromophenyl ether (3.6g, 13mmol). The mixture was heated at 800C for 17h and then allowed to cool. The reaction mixture was evaporated and the crude product partitioned between EtOAc and HCI (2N). The organic phase was separated and washed with brine, dried (MgSO4) and evaporated to give the crude product. This was purified by silica SPE (5Og), eluting with cyclohexaneiethylacetate (10:1 to 1 :1 ) to afford the title compound as a cream coloured solid (2.9g, 62%). LC/MS: m/z 381/483 [MH]+, RT 3.87min.
Example 356: 1 ,1 '-(1.4-Butanediyl)bis(3-butyl-8-chloro-3.7-dihvdro-1 /Y-purine-2,6- dione)
) I.I^M-ButanediyObisβ-butyl-δ-chloro-SJ-dihydro-IH-purine^.β-dione)
1 , 1 '-(1 ,4-Butanediyl)bis[3-butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6- dione] (24mg, 0.039mmol) was stirred in a mixture of nitrogen degassed DCM (2ml) and AcOH (0.2ml). Tetrakis(triphenylphosphine)palladium (38mg, 0.033mmol) and phenylsilane (42uL, 0.39mmol) were added and the mixture stirred at rt for 2h. This was then evaporated and the crude product purified by reverse phase chromatography (5-95% gradient, H2O: CH3CN) to afford the title compound (2mg). LC/MS: m/z 539 [MH]+, RT 3.33min
b) 1 ,r-(1 ,4-Butanediyl)bis[3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6- dione]
3-Butyl-8-chloro-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (60mg, 0.212mmol) in dry DMF (1ml) was added Cs2CO3 (207mg, 0.636mol) followed by 1 ,4-diiodobutane (16uL, 0.106mmol). The mixture was heated at 800C for 17h and then allowed to cool. The reaction mixture was partitioned between DCM and HCI (2M). The organic phase was separated and washed with brine, dried (MgSO4) and evaporated to give the crude product. This was purified by MDAP to afford the title compound as a cream coloured solid (24mg). LC/MS: m/z 619 [MH]+, RT 3.95min.
The following compounds (Table 22) were prepared using a method analogous to that for Example 356.
Table 22
Example 359: 8-Chloro-1 -r2-(ethyloxy)ethyll-3-(4.4,4-trifluorobutyl)-3.7-dihydro- 1 H-purine-2,6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1 H-purine- 2,6-dione (84mg, 0.25mmol) in DMF (1 ml) was treated with caesium carbonate (163mg, O.δmmol) and 1-bromo-2-(ethyloxy)ethane (42mg, 0.275mmol). The mixture was heated at 8O0C for 4h and then cooled.
The reaction mixture was degassed with nitrogen and then treated with morpholine (22OuL) and tetrakis(triphenylphosphine)palladium (29mg, 0.025mmol) and stirred for 4h. The reaction mixture was partitioned between chloroform and HCI (2M). The organic phase was separated and evaporated. The crude product was loaded on to an aminopropyl SPE. The non acidic impurities were eluted with a mixture of DCM and MeOH and the desired product eluted with 10%AcOH in DCM. Evaporation afforded the title compound (77mg). LC/MS: m/z 369 [MH]+, RT 1.96min.
Example 360: 8-Chloro-3-propyl-1 -(4-r3-(2-pyridinyl)-1 ,2,4-oxadiazol-5-yllbutyl>- 3.7-dihvdro-1 H-purine-2.6-dione
a) 8-Chloro-3-propyl-1 -{4-[3-(2-pyridinyl)-1 ,2,4-oxadiazol-5-yl]butyl}-3,7-dihydro-1 H- purine-2,6-dione
A solution of 8-chloro-7-(2-propen-1-yl)-1-{4-[3-(2-pyridinyl)-1 ,2,4-oxadiazol-5-yl]butyl}- 3,7-dihydro-1/-/-purine-2,6-dione (40mg, 0.09mmol) in DMF (3ml) was treated with potassium carbonate (15mg, O.Ummol) and 1-iodopropane (19mg, O.U mmol). The mixture was heated at 4O0C for 3h then at 7O0C for a further 3h. The mixture was cooled and degassed by the successive application of vacuum and nitrogen gas. The mixture was then treated with a solution of tetrakis(triphenylphosphine)palladium(0) (10mg, 0.009mmol) and morpholine (0.1ml, 1.2mmol) and then stirred overnight. The mixture was evaporated and partitioned between chloroform (2ml) and water (2ml). The aqueous phase was extracted with further chloroform (2ml) and the combined organics evaporated and the residue dissolved in methanol (2ml). The solution was applied to a 1g aminopropyl SPE and eluted with methanol and then with 5% acetic acid in methanol. Product-containing fractions were pooled and evaporated and the product further purified by MDAP to reveal 8-chloro-3-propyl-1-{4-[3-(2-pyridinyl)-1 ,2,4- oxadiazol-5-yl]butyl}-3,7-dihydro-1 /-/-purine-2,6-dione (1.4mg) as a white solid. LC/MS: m/z 430 [MH]+, RT 2.84min.
b) 8-Chloro-7-(2-propen-1 -yl)-1 -{4-[3-(2-py rid i ny I )- 1 ,2,4-oxadiazol-5-yl]butyl}-3,7- dihydro-1 H-purine-2,6-dione
A suspension of Λ/-hydroxy-2-pyridinecarboximidamide (1.15g, 8.4mmol) in anhydrous THF (20ml) was treated with sodium methoxide (0.38g, 7.0mmol) and the mixture stirred for 5min. The mixture was treated with ethyl 5-[8-chloro-2,6-dioxo-7-(2-propen- 1-yl)-2,3,6,7-tetrahydro-1H-purin-1-yl]pentanoate (2g, 5.6mmol) and the stirred for about 5min until all the material had dissolved. The mixture was then sealed and heated in a microwave at 12O0C for 15min then cooled and partitioned between ethyl acetate (100ml) and saturated aqueous sodium bicarbonate (50ml). The aqueous phase was extracted with further ethyl acetate (50ml) and the combined organics dried (MgSO4), filtered and evaporated. The product was purified by flash chromatography using a gradient elution from 1 :9 ethyl acetate/cyclohexane to ethyl acetate to reveal 8-
chloro-7-(2-propen-1 -yl)-1 -{4-[3-(2-pyridinyl)-1 ,2,4-oxadiazol-5-yl]butyl}-3,7-dihydro-1 H- purine-2,6-dione (1.49g) as a white solid. LC/MS: m/z 428 [MH]+, RT 2.70min.
Similarly prepared was 8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5- yl}propyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione using ethyl 4-[8-chloro- 2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purin-1-yl]butanoate. LC/MS: m/z 463 [MH]+, RT 3.09min.
c) Ethyl 5-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1/-/-purin-1- yl]pentanoate
A solution of 8-chloro-7-(2-propen-1-yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7- dihydro-1H-purine-2,6-dione (10g, 28mmol) in DMF (10ml) was treated with potassium carbonate (4.8g, 35mmol) and ethyl 5-bromopentanoate (6.5g, 31 mmol) and then heated to 7O0C for 3h, cooled and evaporated. The residue was partitioned between ethyl acetate (100ml) and water (50ml). The organic phase was dried (MgSO4), filtered and evaporated and the crude intermediate dissolved in dichloromethane (90ml), treated with trifluoroacetic acid (17ml) and the mixture stirred at ambient temperature overnight. Toluene (50ml) was added and the mixture evaporated to dryness. The product was purified by flash chromatography using a gradient elution from cyclohexane to ethyl acetate to reveal 8.65g of ethyl 5-[8-chloro-2,6-dioxo-7-(2-propen- 1-yl)-2,3,6,7-tetrahydro-1H-purin-1-yl]pentanoate as a white solid. LC/MS: m/z 355 [MH]+, RT 2.75min.
Similarly prepared was ethyl 4-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro- 1 H-purin-1 -yl]butanoate. LC/MS: m/z 341 [MH]+, RT 2.61 min.
d) 8-Chloro-7-(2-propen-1 -yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7-dihydro-1 H- purine-2,6-dione
To a solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (5g, 22.1 mmol) in DMF (80ml) was added 2-2-(trimethylsilyl)ethoxymethyl chloride (4.3ml, 24.2mmol) and sodium carbonate ( 2.6g, 24.2mmol). After stirring at room temperature overnight further 2-2-(trimethylsilyl)ethoxymethyl chloride (4.3ml, 24.2mmol) and sodium carbonate (1.3g, 12.1 mmol) were added and stirring continued for 2h. The reaction mixture was then partitioned between 5% LiCI aq and ethyl acetate. The organic extract was separated, washed with brine, dried (MgSO4) and concentrated. Purification by Biotage™ chromatogratphy using a silica cartridge eluting 1 :4-1 :2 ethyl acetate/cyclohexane afforded the title compound (3.14g, 40%). m/z 374 [MNH4 +]
The following compounds (Table 23) were prepared by a method analogous to that for Example 360, from 8-chloro-7-(2-propen-1-yl)-1-{4-[3-(2-pyridinyl)-1 ,2,4-oxadiazol-5- yl]butyl}-3,7-dihydro-1 /-/-purine-2,6-dione and the appropriate alkylating agent.
Table 23
The following compounds (Table 24) were prepared by a method analogous to that for Example 360, from 8-chloro-1-(3-{3-[(2,4-difluorophenyl)methyl]-1 ,2,4-oxadiazol-5-
yl}propyl)-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione and the appropriate alkylating agent.
Table 24
Example 398: 1 -r3-(3-Bromophenyl)propyn-8-chloro-3-pentyl-3,7-dihydro-1 H- purine-2,6-dione
A solution of 3-(3-bromophenyl)-propan-1-ol (1.627g, 7.56mmol) in THF (65ml) was treated with 8-chloro-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H-purine-2,6-dione (2.04g, 6.87mmol) under nitrogen. PPh
3 (2.164g, 8.25mmol) was added to the stirred mixture after 2min and after a further 6min DBAD (1.9g, 8.25mmol) was added in one portion. The mixture was stirred for 2.5h and then left to react for 16h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh
3)
4 (794mg, 0.69mmol) was added and the mixture degassed once more. Morpholine (6ml, 68.8mmol) was added and the mixture was stirred under nitrogen for 6h. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO
4) and concentrated. The residue was taken up into MeOH and purified by passing down an aminopropyl SPE, the product eluted with 2- 5% AcOH/MeOH. The title compound was obtained as an off-white solid (2.48g, 79%). LC/MS: m/z 455, 453 [MH]
+, RT 3.85min.
Example 399: 8-Chloro-1 -(2-r(3-hvdroxyphenyl)oxylethyl)-3-pentyl-3,7-dihvdro- 1H-purine-2,6-dione and Example 400: 8-chloro-1-(2-U3-((2-f(3- hvdroxyphenyl)oxy1ethyl)oxy)phenvnoxy>ethyl)-3-pentyl-3,7-dihvdro-1H-purine- 2,6-dione
A solution of 2-(2-hydroxyethyl)-resorcinol (1.156g, 7.5mmol) in THF (60ml) was treated with 8-chloro-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 /-/-purine-2,6-dione (2.016g, 6.79mmol) under nitrogen. PPh3 (2.138g, 8.15mmol) was added to the stirred mixture after 4min and after a further 8min DBAD (1.88g, 8.16mmol) was added in one portion. The mixture was stirred for 1 h 50min and then left to react for 16h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3J4 (785mg, 0.68mmol) was added and the mixture degassed once more. Morpholine (5.9ml, 67.7mmol) was added and the mixture was stirred under nitrogen for 4.5h. The mixture was partitioned between 2M HCI (aq) and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and concentrated. The residue was taken up into MeOH and purified by passing it down an aminopropyl SPE, the product gradient elution with 2-5% AcOH/MeOH. The fractions containing product were evaporated to give a pale yellow foam (2.39g) and a pale yellow gum (213mg). The foam was dissolved in dichloromethane (50ml) and passed through a hydrophobic frit. The solution was evaporated and dried in vacuo to give 8-chloro-1-{2-[(3-
hydroxyphenyl)oxy]ethyl}-3-pentyl-3,7-dihydro-1 H-purine-2,6-dione as a white solid (1.919g, containing 15% 8-chloro-1-(2-{[3-({2-[(3- hydroxyphenyl)oxy]ethyl}oxy)phenyl]oxy}ethyl)-3-pentyl-3,7-dihydro-1 H-purine-2,6- dione).
The gum was purified by MDAP to give 8-chloro-1-{2-[(3-hydroxyphenyl)oxy]ethyl}-3- pentyl-3,7-dihydro-1/-/-purine-2,6-dione as a white solid (126mg). LC/MS: m/z 393 [MH]+, RT 3.23min as well as 8-chloro-1 -(2-{[3-({2-[(3-hydroxyphenyl)oxy]ethyl}oxy)phenyl]oxy}ethyl)-3-pentyl-3,7- dihydro-1H-purine-2,6-dione as a pale yellow solid (38mg). LC/MS: m/z 529 [MH]+, RT 3.62min.
The following compounds (Table 25) were prepared using a method analogous to that for 8-chloro-1-{2-[(3-hydroxyphenyl)oxy]ethyl}-3-pentyl-3,7-dihydro-1 H-purine-2,6-dione above, from the corresponding alcohol.
Table 25
Example 403: 8-Chloro-1 -O-O-rO-chlorophenvDoxyiphenyllpropyD-a-pentyl-SJ- dihydro-1 /y-purinβ-2,6-dione
1-[3-(3-Bromophenyl)propyl]-8-chloro-3-pentyl-3,7-dihydro-1 /-/-purine-2,6-dione (100mg, 0.22mmol) was dissolved in dioxan (0.75ml). Copper (1 ) iodide (9mg, 0.05mmol), N,N-dimethylglycine hydrochloride (9mg, O.Oδmmol), cesium carbonate (215mg, 0.66mmol) and 3-chlorophenol (52mg, 0.4mmol) were added to the solution. The mixture was heated under microwave irradiation at 2000C for 10min, followed by another 10min at 2000C after which the cooled mixture was filtered and the residue washed with EtOAc and MeOH. The filtrate and washings were combined and evaporated under reduced pressure to leave a red/brown solid. The solid was partitioned between DCM and water. The phases were separated by hydrophobic frit and the organic evaporated under reduced pressure to leave a solid. The solid was purified by MDAP to give the title compound as a yellow solid/ gum (27mg, 24%). LC/MS: m/z 501 [MH]+, RT 4.25min.
Example 404: 8-Chloro-3-pentyl-1 -f 3-r3-(phenyloxy)phenyllpropyl}-3,7-dihydro- 1 H-purine-2,6-dione
1-[3-(3-Bromophenyl)propyl]-8-chloro-3-pentyl-3,7-dihydro-1/-/-purine-2,6-dione (100mg, 0.22mmol), copper (1 ) iodide (4mg, 0.02mmol), N,N-dimethylglycine hydrochloride (9mg, O.OΘmmol) cesium carbonate (144mg, 0.44mmol) and phenol
(31 mg, 0.33mmol) were placed in dioxan (0.44ml). Then the mixture was heated in the microwave at 15O0C for 3.3min, then further quantities of cesium carbonate (72mg,
0.22mmol), copper (1) iodide (6mg, 0.03mmol) and dioxan (0.44ml) were added to the mixture and heated in the microwave at 17O0C for 10min, followed by another 10min at
2000C. The cooled mixture was filtered and the residue washed with EtOAc. The filtrate
and washings were combined and evaporated under reduced pressure to leave a dark brown gum. The gum was purified by MDAP to give the title compound as a pale cream solid (44mg, 42%). LC/MS: m/z 467 [MH]+, RT 4.14min.
Example 405: 8-Chloro-1 -rS-O'-chloro-S-biphenylvDpropyn-S-pentyl-SJ-dihvdro- 1 /V-purine-2,6-dione
A mixture of 1-[3-(3-bromophenyl)propyl]-8-chloro-3-pentyl-3,7-dihydro-1H-purine-2,6- dione (100mg, 0.22mmol) and 3-chlorophenyl boronic acid (35mg, 0.22mmol) was stirred in isopropanol (0.35ml). A solution of sodium carbonate (70mg, 0.66mmol) in water (0.35ml) was added to the mixture followed by 10% palladium on carbon (6mg, Degussa type E101 NE/W). The mixture was heated in the microwave at 16O
0C for 10min, then filtered (glass fibre filter) and the residues washed with IPA. The filtrate and washings were combined and evaporated under reduced pressure to leave a gum. The gum was partitioned between DCM and water. The organic phase was separated and the aqueous phase extracted with EtOAc. The combined organic phases were dried (MgSO
4) and concentrated to leave a foam. The foam was purified by MDAP to give the title compound as a colourless gum (40mg, 37%). LC/MS: m/z 485 [MH]
+, RT 4.27min.
The following compounds (Table 26) were prepared using a method analogous to that for 8-chloro-1 -[3-(3'-chloro-3-biphenylyl)propyl]-3-pentyl-3,7-dihydro-1 H-purine-2,6- dione (Example 405) above, from the corresponding boronic acid, except that the 2- chorophenyl analogue was heated in the microwave at 16O0C for 10min twice while in the work up 1M hydrochloric acid was used instead of water. Also the EtOAc extraction was omitted.
Table 26
Example 408: 3-Butyl-8-chloro-1 -(3-phenylpropyD-3.7-dihydro-1 H-purine-2.6- dione
a) 3-Butyl-8-chloro-1 -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione
3-Butyl-1-(3-phenylpropyl)-3,7-dihydro-1 /-/-purine-2,6-dione (100mg, 0.31 mmol) and
NCS (41 mg, 0.31 mmol) were suspended in MeCN (5ml) and heated at 1200C under microwave irradiation for 10min. The reaction mixture was concentrated under reduced pressure and the title compound isolated using HPLC.
1H NMR (CDCI3) δ: 0.96 (3H, t), 1.37-1.43 (2H, m), 1.70-1.78 (2H, m), 2.00-2.09 (2H, m), 2.73 (2H, t), 4.08 (2H, t), 4.14 (2H, t), 7.13-7.26 (5H, m), 12.6 (1 H, br.s).
LC/MS: m/z 361 [MH]+.
b) 3-Butyl-1-(3-phenylpropyl)-3,7-dihydro-1H-purine-2,6-dione
3-Butyl-7-(phenylmethyl)-1 -(3-phenylpropyl)-3,7-dihydro-1 /-/-purine-2,6-dione (0.6g, 1.44mmol) was dissolved in acetic acid (35ml), 20% palladium hydroxide on carbon (0.366g) was added, and the mixture was shaken under hydrogen (at 50psi) overnight. The catalyst was removed by filtration through Celite® and washed with acetic acid. The filtrate was concentrated under reduced pressure and the title compound isolated using HPLC (0.385g, 82%). LC/MS: m/z 327 [MH]+.
c) 3-Butyl-7-(phenylmethyl)-1 -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione
7-Benzyl-3-butyl-3,7-dihydro-1/-/-purine-2,6-dione (0.5g, 1.68mmol) and potassium carbonate (0.347g, 2.5mmol) were suspended in DMF (20ml), (3-bromopropyl)benzene (390mg, 1.96mmol) was added. The reaction mixture was stirred at ambient temperature overnight. The reaction mixture was evaporated to dryness and the residue was partitioned between water and ethyl acetate. The organic layer was washed with water, followed by brine, dried over anhydrous sodium sulphate and concentrated under reduced pressure to yield the title compound. 1H NMR (CDCI3) δ: 0.95 (3H, t), 1.34-1.43 (2H, m), 1.68-1.76 (2H, m), 1.98-2.07 (2H, m), 2.71 (2H, t), 4.05-4.10 (4H, m), 5.49 (2H, s), 7.19-7.24 (5H, m), 7.33-7.38 (5H, m), 7.52 (1 H, s). LC/MS: m/z 417 [MH]+.
d) 7-Benzyl-3-butyl-3,7-dihydro-1 H-purine-2,6-dione
7-Benzyl-3,7-dihydro-1 H-purine-2,6-dione (17.14g, 70.8mmol) [Synthetic Communications, 20(16), 2459-2467, 1990] and potassium carbonate (11.43g, 82.8mmol) were suspended in DMF (400ml) at 40
0C. After stirring for thirty minutes, butyl iodide (8.76ml, 77.0mmol) was added, and the mixture was stirred at 40
0C overnight. 50% Aqueous acetic acid (60ml) was added, and the solution was concentrated under reduced pressure. The residue was suspended in water (500ml), and the products were extracted into chloroform. The organics were collected, concentrated, and product was isolated using flash chromatography eluting with 1% methanol in dichloromethane (9.49g, 45%).
1H NMR (CDCI
3) δ: 0.95 (3H, t), 1.34-1.41 (2H, m), 1.70-1.78 (2H, m), 4.05 (2H, t), 5.46 (2H, s), 7.31-7.40 (5H, m), 7.56 (1H, s), 8.21 (1 H, br.s). LC/MS: m/z 299 [MH]
+.
Example 409: 3-Butyl-8-chloro-1 -r2-(phenyloxy)ethyll-3J-dihydro-1 H-purine-2.6- dione
a) 3-Butyl-8-chloro-1 -[2-(phenyloxy)ethyl]-3,7-dihydro-1 /-/-purine-2,6-dione
The title compound was prepared using the procedure for 3-butyl-8-chloro-1 -(3- phenylpropyl)-3,7-dihydro-1/-/-purine-2,6-dione, from 3-butyl-1-[2-(phenyloxy)ethyl]-3,7- dihydro-1/-/-purine-2,6-dione and NCS.
1H NMR (CDCI3) δ: 0.95 (3H, t), 1.36-1.45 (2H, m), 1.71-1.79 (2H, m), 4.11 (2H1 1), 4.29
(2H, t), 4.54 (2H, t), 6.87-6.94 (3H, m), 7.21-7.27 (2H, m), 13.10 (1 H, br.s).
LC/MS: m/z 363 [MH]+.
b) 3-Butyl-1 -[2-(phenyloxy)ethyl]-3,7-dihydro-1 H-purine-2,6-dione
The title compound was prepared using the procedure outlined for 3-butyl-1-(3- phenylpropyl)-3,7-dihydro-1 /-/-purine-2,6-dione, from 3-butyl-7-(phenylmethyl)-1 -[2- (phenyloxy)ethyl]-3,7-dihydro-1 /-/-purine-2,6-dione.
LC/MS: m/z 329 [MH]+.
c) 3-Butyl-7-(phenylmethyl)-1-[2-(phenyloxy)ethyl]-3,7-dihydro-1/-/-purine-2,6-dione
The title compound was prepared using the procedure outlined for 3-butyl-7- (phenylmethyl)-i -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione, from 7-benzyl-3- butyl-3,7-dihydro-1/-/-purine-2,6-dione and 2-bromoethyl phenyl ether.
1H NMR (CDCI
3) δ: 0.95 (3H, t), 1.35-1.44 (2H, m), 1.69-1.78 (2H, m), 4.07-4.11 (2H, m), 4.26 (2H, t), 4.434 (2H, t), 5.49 (2H, s), 6.87-7.38 (10H, m), 7.55 (1 H, s). LC/MS: m/z 419 [MH]
+.
Example 410: 8-Chloro-3-methyl-1-(3-phenylpropyl)-3,7-dihvdro-1H-purine-2,6- dione
a) 8-Chloro-3-methyl-1 -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione
The title compound was prepared using the procedure outlined for 3-butyl-8-chloro-1- (3-phenylpropyl)-3,7-dihydro-1 /-/-purine-2,6-dione, from 3-methyl-1 -(3-phenylpropyl)- 3,7-dihydro-1/-/-purine-2,6-dione and NCS. 1H NMR (CDCI3) δ: 2.01-2.12 (2H, m), 2.74 (2H, t), 3.57 (3H, S)1 4.14 (2H, t), 6.99-7.24 (5H, m), 12.5 (1 H, br.s). LC/MS: m/z 319 [MH]+.
b) 3-Methyl-1 -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione
The title compound was prepared using the procedure outlined for 3-butyl-1-(3- phenylpropyl)-3,7-dihydro-1 /-/-purine-2,6-dione, from 3-methyl-7-(phenylmethyl)-1 -(3- phenylpropyl)-3,7-dihydro-1H-purine-2,6-dione. LC/MS: m/z 285 [MH]+.
c) 3-Methyl-7-(phenylmethyl)-1 -(3-phenylpropyl)-3,7-dihydro-1 H-purine-2,6-dione
The title compound was prepared using the procedure outlined for 3-butyl-7- (phenylmethyl)-1-(3-phenylpropyl)-3,7-dihydro-1H-purine-2,6-dione, from 3-methyl-7- (phenylmethyl)-3,7-dihydro-1 H-purine-2,6-dione and (3-bromopropyl)benzene. LC/MS: m/z 375 [MH]+.
d) 3-Methyl-7-(phenylmethyl)-3,7-dihydro-1 H-purine-2,6-dione
The title compound was prepared using the procedure described for 7-benzyl-3-butyl- 3,7-dihydro-1/-/-purine-2,6-dione using methyl iodide (0.28ml, 4.46mmol). Purification was achieved by trituration. The product was isolated as a solid, insoluble in chloroform and water (0.334g, 57%). 1H NMR (DMSO-d6) δ: 3.34 (3H, s), 5.44 (2H, s), 7.26-7.37 (5H, m), 8.21 (1 H, s), 11.13 (1 H, s). LC/MS: m/z 257 [MH]+.
Example 411 : 8-Chloro-3-pentyl-1 -(M -(phenylmethvD-1 H-indol-5-yllmethylϊ-3.7- dihvdro-1 H-purine-2.6-dione
a) 8-Chloro-3-pentyl-1 -{[1 -(phenylmethyl)-i /-/-indol-5-yl]methyl}-3,7-dihydro-1 H-purine- 2,6-dione
8-Chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione (156mg, 0.5mmol) was dissolved in anhydrous THF (5ml) under nitrogen and [1-(phenylmethyl)-1H-indol-5-yl]methanol (138mg, 0.58mmol) was added. After several minutes triphenylphosphine (168mg, 0.63mmol) was added followed 5-10min later by DBAD (155mg, 0.67mmol) and the solution stirred for 18h. The mixture was degassed by applying a vacuum and then nitrogen was introduced. Pd(PPh3)4 (63mg, 0.054mmol) was added and the mixture degassed once more. Morpholine (0.461 ml, 5.3mmol) was added and the mixture was stirred under nitrogen for 24h. A further quantity of Pd(PPh3)4 (58mg, 0.05mmol) was added and the mixture was stirred under nitrogen for 96h. The mixture was diluted with EtOAc and washed with 2M HCI (5ml) then brine (15ml), dried (MgSO4) and concentrated. The crude material was purified by an aminopropyl SPE (eluent MeOH to wash through the impurities, then with 3-4% AcOH/MeOH). The product fractions were combined and concentrated to give the title compound as a white solid (43mg, 17%). LC/MS: m/z 476 [MH]+, RT 3.78min.
b) [1 -(Phenylmethyl)-I H-indol-5-yl]methanol
Methyl 1-(phenylmethyl)-1 /-/-indole-5-carboxylate (1.17g, 4.4mmol) was dissolved in anhydrous THF under nitrogen and cooled to -50C. 1M Lithium aluminiumhydride in diethylether (4.0ml) was added slowly. The cooling bath was removed and the reaction mixture was left overnight at room temperature. The reaction was quenched by the sequential addition of water (0.15ml), 15% NaOH (0.15ml) followed by water (0.45ml) then ethyl acetate and sodium sulphate were added and the mixture stirred for 0.5h. The insoluble material was filtered and washed well with ethyl acetate. The filtrate was concentrated in vacuo to give the title compound as a cream solid which darkened on standing (1.04g, 100%). LC/MS: m/z 238 [MH]+, RT 3.03min.
The following alcohols were prepared by reduction of the corresponding methyl ester in a similar manner:
lmethyl)-I /-/-indol-4-yl]methanol
LC/MS: m/z 238 [MH]+, RT 3.03min.
[2-(Phenylmethyl)-1 ,3-benzoxazol-4-yl]methanol
LC/MS: m/z 240 [MH]+, RT 2.02min.
(phenylmethyl)-1/-/-indole-5-carboxylate
Methyl 1 /-/-indole-5-carboxylate (1.0g, 5.7mmol) was dissolved in anhydrous DMF under nitrogen and cooled to 20C. Sodium hydride (0.25g, 6.3mmol, 60% in paraffin) was added. After 0.5h benzyl bromide (0.75ml, Θ.Ommol) was added and the reaction mixture stirred for 4hr at room temperature, then left overnight. The reaction mixture was poured into water (50ml) and ethyl acetate (10ml). The aqueous phase was extracted further with ethyl acetate (50ml). The combined organic phases were washed with dil. ammonia then brine, dried (MgSO4) and concentrated in vacuo. The crude product was purified on a 5Og Si SPE (gradient elution cyclohexane/ethyl acetate 8% to 16%). The relevant fractions were concentrated in vacuo to give the title compound as a white solid (1.17g, 77%) LC/MS: m/z 266 [MH]+, RT 3.60min.
phenylmethyl)-1/-/-indole-4-carboxylate was prepared in a similar manner
LC/MS: m/z 266 [MH]+, RT 3.58min.
Methyl 2-(phenylmethyl)-1 ,3-benzoxazole-5-carboxylate
Trimethylbenzylorthoformate (1.34g, 6.8mmol) was dissolved in methanol (2ml) and methyl-3-amino-hydoxybenzoate (0.56g, 3.35mmol) was added followed by cone, hydrochloric acid (9.1 ml). The mixture was stirred at reflux for 4.75h, allowed to cool and evaporated in vacuo. The residue was partitioned between diethyl ether (10ml) and 2M NaOH solution (5ml). The organic phase was washed with water (5ml) and the combined aqueous phases were back extracted with ether (10ml). The combined organic phases were dried (MgSO4) and concentrated in vacuo to leave an orange oil (1.37g). The crude product was purified on silica (4Og SPE, gradient elution cyclohexane/ethyl acetate 0-100%) to give the title compound as a white solid (0.72g, 80%). LC/MS: m/z 268 [MH]+, RT 3.27min.
3-[3-(Phenylmethyl)phenyl]-1-propanol
3-[3-(phenylcarbonyl)phenyl]propanoic acid (491 mg, 1.96mmol) was dissolved in anhydrous THF under nitrogen and cooled to O0C. 1M LiAIH4 in ether (2.13ml) was added slowly and the reaction mixture was stirred at room temperature for 2Oh. The reaction was cooled in ice and tetrahydrofuran (5ml) and 1 M LiAIH4 in ether solution (2.2ml) added. The reaction mixture was heated at reflux for 7hr then left at room temperature for 3 days. The reaction was quenched with sequentially, water (0.16ml), 15% NaOH (0.16ml) and water (0.47ml) then diluted with ethyl acetate and dried with sodium sulphate. The insoluble material was filtered and thoroughly washed with ethyl acetate. The filtrate was concentrated in vacuo to give 3-{3- [hydroxy(phenyl)methyl]phenyl}-1-propanol as a white opaque oil (0.42g, 90%) LC/MS: m/z 243 [MH]+, RT 2.71 min.
The above material (200mg, 0.82mmol) was dissolved in anhydrous dichloromethane (5ml) and triethylsilane (0.53ml, 3.2mmol) followed by trifluoroacetic acid (0.36ml, 4.1 mmol) were added. The reaction mixture was stirred for 1 h then washed with saturated sodium hydrogen carbonate solution. The organic phase was filtered through a hydrophobic frit and concentrated in vacuo. The crude product was purified over silica (4g SPE, gradient elution cyclohexane/ethyl acetate 0-30%) to give the title compound as a colourless oil (68mg, 37%). LC/MS: m/z 227 [MH]+, RT 3.25min.
The following compounds (Table 27) were prepared using a method analogous to that for 8-chloro-3-pentyl-1 -{[1 -(phenylmethyl)-i /-/-indol-5-yl]methyl}-3,7-dihydro-1 H-purine- 2,6-dione from the corresponding alcohols as described above.
Table 27
Example 415: 8-Chloro-1 -(2-hvdroxy-6-phenylhexyl)-3-pentyl-3,7-dihydro-1 H- purine-2,6-dione
a) 8-Chloro-1 -(2-hydroxy-6-phenylhexyl)-3-pentyl-3,7-dihydro-1 H-purine-2,6-dione
A solution of 8-chloro-1-(2-hydroxy-6-phenylhexyl)-3-pentyl-7-(2-propen-1-yl)-3,7- dihydro-1/-/-purine-2,6-dione (0.084g, 0.18mmol) and Pd(PPh
3J
4 (0.042g, 0.035mmol) in THF (5ml) was degassed (sequential evacuation followed by addition of nitrogen x 3) then morpholine (0.25ml, 2.8mmol) added and the mixture stirred overnight. The solution was loaded onto an aminopropyl SPE (5g) and eluted with MeOH to remove by-products then with 5%AcOH/MeOH to isolate the title compound, after concentration, as an oil (0.022g, 29%). LC/MS: m/z 433 [MH]
+
b) 8-Chloro-1 -(2-hydroxy-6-phenylhexyl)-3-pentyl-7-(2-propen-1 -yl)-3,7-dihydro-1 H- purine-2,6-dione
To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (0.107g, 0.36mmol) and 1-chloro-6-phenyl-2-hexanol (0.107g, O.δmmol) in DMF (5ml) was added cesium carbonate (0.24g, 0.74mmol) and the mixture heated at 6O0C for 3h, whereupon a further 80mg of cesium carbonate was added and heating continued at 1000C for 18h. The solution was allowed to cool, concentrated and the residues purified by chromatography over silica (2Og SPE, eluting with first with DCM then DCM/10%ether) to yield the title compound as a yellow oil (0.085mg, 53%). LC/MS: m/z 473 [MH]+
Example 416: 8-Chloro-1 -{4-r2-oxo-3-(phenylmethyl)-1 -pyrrolidinyllbutyll-3- pentyl-3.7-dihvdro-1H-purine-2,6-dione
a) 8-Chloro-1-{4-[2-oxo-3-(phenylmethyl)-1-pyrrolidinyl]butyl}-3-pentyl-3,7-dihydro-1H- purine-2,6-dione
A solution of 8-chloro-1-{4-[2-oxo-3-(phenylmethyl)-1-pyrrolidinyl]butyl}-3-pentyl-7-(2- propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (0.35g, 0.67mmol), Pd(PPh
3)
4 (0.082g, 0.07mmol) and morpholine (0.6ml, 6.7mmol) in THF (10ml) was degassed (sequential evacuation followed by addition of nitrogen x 3) then stirred for 4h. The solution was then loaded onto an aminopropyl SPE (5g) and eluted first with MeOH then 5%AcOH/MeOH to provide the title compound containing a small impurity. Further purification over silica (1Og SPE, gradient elution ether/ethyl acetate 1 :0 to 0:1) provided the title compound as a clear oil (0.1Og, 31%). LC/MS: m/z 486 [MH]
+
b) 8-Chloro-1-{4-[2-oxo-3-(phenylmethyl)-1-pyrrolidinyl]butyl}-3-pentyl-7-(2-propen-1- yl)-3,7-dihydro-1H-purine-2,6-dione
Prepared as with 8-chloro-1-(2-hydroxy-6-phenylhexyl)-3-pentyl-7-(2-propen-1-yl)-3,7- dihydro-1 H-purine-2,6-dione using 1-(4-bromobutyl)-3-(phenylmethyl)-2-pyrrolidinone as the alkylating agent, potassium carbonate as base and heating at 5O0C for 18h. Yield 86%. LC/MS: m/z 526 [MH]+
c) 1-(4-bromobutyl)-3-(phenylmethyl)-2-pyrrolidinone
To a solution of 3-(phenylmethyl)-2-pyrrolidinone (0.23g, 1.3mmol) and 1 ,4- dibromobutane (0.57g, 4.2mmol) in DMF (5ml) was added sodium t-butoxide (0.151g, 1.6mmol) and the solution stirred for 18h. The solution was concentrated and the residues chromatographed over silica (2Og SPE, eluting first with cyclohexane then with DCM) to provide the title compound as a colourless oil containing a trace of DMF (0.25g, 61%). LC/MS: m/z 31 1 [MH]+
Example 417: 8-Chloro-1-f4-r2-oxo-1-(phenylmethyl)-3-pyrrolidinyllbutyl)-3- pentyl-3.7-dihydro-1H-purine-2,6-dione
a) 8-Chloro-1 -{4-[2-oxo-1 -(phenylmethyl)-3-pyrrolidinyl]butyl}-3-pentyl-3,7-dihydro-1 H- purine-2,6-dione
To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (0.086g, 0.29mmol) and 3-(4-bromobutyl)-1-(phenylmethyl)-2-pyrrolidinone (0.17g, 0.55mmol, 1 :1 mixture with 2-(phenylmethyl)-2-azaspiro[4.4]nonan-1-one) in THF (5ml) was added potassium carbonate (0.08g, 0.58mmol) and the mixture heated and stirred at 5O0C for 18h. The solution was allowed to cool then degassed (sequential evacuation followed by addition of nitrogen x 3) and Pd(PPh3)4 (0.09g, 0.077mmol) followed by morpholine (0.2ml, 2.2mmol) added and the solution stirred at ambient temperature for 18h. The solution was separated between ethyl acetate and dil HCI and the organics washed with brine, dried and concentrated. Purification of the residues using an aminopropyl SPE (5g) eluting first with MeOH then 5%AcOH/MeOH yielded the title compound as a yellow oil which crystallised on standing under ether (0.031 g, 22%).
LC/MS: m/z 486 [MH]+
b) 3-(4-Bromobutyl)-1 -(phenylmethyl)-2-pyrrolidinone
To a solution of 1-(phenylmethyl)-2-pyrrolidinone (0.47g, 2.7mmol) in THF (10ml) at - 78
0C was added lithium hexamethyldisilylazine (2.8ml, 2.7mmol, 1 M solution) over 5min. After 15min 1 ,4-dibromobutane (0.32ml, 2.7mmol) was added and the solution allowed to attain ambient temperature over 2h then stirred for a further 18h. The solution was separated between ethyl acetate and water and the organics isolated, dried and concentrated. Chromatography over silica (2Og SPE) eluting with cyclohexane then DCM and finally ether provided a clear oil which was a 1 :1 mixture of the title compound and 2-(phenylmethyl)-2-azaspiro[4.4]nonan-1-one (0.17g). This was used in the next step without further purification. LC/MS: m/z 310, 312 [MH]
+
Example 418: 8-Chloro-1-(5-{5-r(3.4-dichlorophβnyl)methvπ-2H-tetrazol-2- yl)pentyl)-3-pentyl-3J-dihvdro-1H-purine-2,6-dione
To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1 /-/-purine-2,6-dione (0.18g, 0.61 mmol) in THF (5ml) was added 5-{5-[(3,4-dichlorophenyl)methyl]-2H- tetrazol-2-yl}-1-pentanol (0.191g, 0.61 mmol; prepared in similar fashion to Example 35), triphenylphosphine (0.36g, 1.3mmol) and finally dibenzylazodicarboxylate (0.4Og1 1.3mmol). The solution was stirred for 18h after which Pd(PPh3J4 (0.16g, 0.137mmol) followed by morpholine (0.75ml, 8.3mmol) was added and the solution stirred at ambient temperature for 6h. The solution was loaded onto an aminopropyl SPE (5g) and eluted with MeOH then 5%AcOH/MeOH to yield the title compound containing minor impurities. Further chromatography (silica SPE, 2Og) eluting with ether yielded the title compound as a white solid (0.061 g, 18%). LC/MS: m/z 553 [MH]+
Example 419: 8-Chloro-3-pentyl-1 -f 5-r3-(phenylmethyl)-1 ,2,4-oxadiazol-5- ylipentyl>-3,7-dihvdro-1H-purine-2.6-dione
To a solution of 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (0.093g, 0.3mmol) in THF (5ml) was added 5-[3-(phenylmethyl)-1 ,2,4-oxadiazol-5-yl]-1- pentanol (0.077g, 0.3mmol; prepared in similar fashion to Example 87b), triphenylphosphine (0.17g, 0.6mmol) and finally dibenzylazodicarboxylate (0.2Og, 0.6mmol). The solution was stirred for 18h, degassed, after which Pd(PPh3J4 (O.Oδg, 0.07mmol) followed by morpholine (0.35ml, 3.9mmol) was added and the solution stirred at ambient temperature for 6h. The solution was loaded onto an aminopropyl
SPE (5g) and eluted with MeOH then 5%AcOH/MeOH to yield the title compound as a cream solid (0.051 g, 34%). LC/MS: m/z 485 [MH]+
Example 420: S-Chloro-i-O-fS-f^chlorophenvD-i/Y-pyrazol-S-vnpropyD-S-pentyl-
Prepared as with 8-chloro-1-(5-{5-[(3,4-dichlorophenyl)methyl]-2H-tetrazol-2-yl}pentyl)- 3-pentyl-3,7-dihydro-1 H-purine-2,6-dione using 3-[5-(4-chlorophenyl)-1 H-pyrazol-3-yl]- 1-propanol. The final product material was washed with ether to yield the title compound as a cream solid (30%). LC/MS: m/z 475 [MH]+
Example 421 : 3-Butyl-8-chloro-1 -{4-r5-(1 -methyl-1 H-1.2.3-triazol-4-yl)-1.2.4- oxadiazol-3-yllbutyl}-3,7-dihvdro-1H-purine-2,6-dione
A solution of the 1-methyl-1/-/-1 ,2,3-triazole-4-carboxylic acid (18mg, 0.14mmol) in DMF (0.5ml) was treated with CDI (23mg, 0.14mmol) at rt for 1 h. A solution of (1Z)-5-
(S-butyl-δ-chloro^.θ-dioxo^ΛΘJ-tetrahydro-IH-purin-i-yO-N- hydroxypentanimidamide (50mg, 0.14mmol) in DMSO (0.4ml) was added to the mixture then heated to 1000C for 18h. The reaction mixture was purified by MDAP to give the title compound as a white solid (18mg). LC/MS: m/z 448 [MH]+, RT 2.86min.
The following compounds (Table 28) were prepared using a method analogous to that for Example 421, using the appropriate carboxylic acid.
Table 28
Example 465 : 1-{4-ri.3-Benzoxazol-2-yl(methyl)amino1butyl)-8-chloro-3-ethyl- 3.7-dihvdro-1 H-purine-2.6-dione
A solution of 2-chloro-1 ,3-benzoxazole (0.46g, 3mmol) in THF (20ml) was treated with 1-methylpyrrolidine (0.26g, 3mmol) and the reaction mixture heated at reflux for 6h, then cooled and evaporated to dryness. Purification by flash chromatography [Isco Companion, 12g Redisep cartridge, gradient elution from cyclohexane to cyclohexane/diethyl ether (3:2)] revealed 0.52g (73% yield) of Λ/-(4-chlorobutyl)-Λ/- methyl-1 ,3-benzoxazol-2-amine as a colourless oil. LC/MS: m/z 239 [MH]+, RT 3.12min.
A solution of 8-chloro-3-ethyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (0.112g, 0.44mmol) in DMF (10ml) was treated with potassium carbonate (O.Oδg,
0.6mmol) and Λ/-(4-chlorobutyl)-Λ/-methyl-1 ,3-benzoxazol-2-amine (0.12g, O.δmmol).
The reaction mixture was heated at 750C for 18h and then cooled to ambient temperature. The mixture was degassed by the repeated application of vacuum followed by backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (0.03g, 0.026mmol) and morpholine (0.5ml,
5.7mmol). Stirred for 4h under a nitrogen atmosphere at ambient temperature after which time the mixture was evaporated to dryness and the residue partitioned between
chloroform (40ml) and saturated aqueous ammonium chloride (40ml). The organic phase was evaporated to dryness and the residue dissolved in methanol (5ml) and added to a 5g aminopropyl SPE cartridge which was subsequently washed with methanol and the product eluted with a 5% solution of acetic acid in methanol. Combined product-containing fractions were evaporated to dryness and the product purified by MDAP to give the title compound as a white solid (0.043g, 23%). LC/MS: m/z 417 [MH]+, RT 2.91 min.
The following compounds (Table 29) were prepared by a method analogous to that for Example 465.
Table 29
Example 468 : 3-Butyl-8-chloro-1 -f5-(1 ,3-dioxo-1.3-dihydro-2H-isoindol-2- yl)pentvn-3,7-dihydro-1H-purine-2.6-dione
A solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (0.5g, 1.8mmol) in DMF (20ml) was treated with potassium carbonate (0.3g, 2.1mmol) and 1 ,5-dibromopentane (1.2ml, 8.9mmol) and then heated at 5O0C for 2h. The mixture was cooled and evaporated to dryness. The residue was partitioned between ethyl acetate
(30ml) and saturated aqueous sodium bicarbonate (30ml). The aqueous phase was extracted with a further ethyl acetate (30ml) and the combined organics dried over magnesium sulfate, filtered and evaporated to dryness. The product was purified by flash chromatography [Isco Companion, 40g Redisep carteidge, gradient elution from cyclohehane to cyclohexane/ethyl acetate (1 :1)] to reveal 0.663g (87%) of 1-(5- bromopentyl)-3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione as a colourless oil. LC/MS: m/z 431/433 [MH]+, RT 3.76min.
To a solution of 1-(5-bromopentyl)-3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H- purine-2,6-dione (0.642g, 1.5mmol) in DMF (10ml) was added potassium phthalimide (0.303g, 1.6mmol) and the mixture heated at 5O0C for 2h then cooled. The mixture was degassed by the repeated application of vacuum followed by backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (0.173g, 0.15mmol) and morpholine (1.3ml, 15mmol). The mixture was allowed to stand at ambient temperature under a blanket of nitrogen for 18h after which time the mixture was evaporated and the residue partitioned between chloroform (30ml) and saturated aqueous ammonium chloride (30ml). The aqueous phase was extracted with a further chloroform (30ml) and the combined organics dried over magnesium sulfate, filtered and evaporated. The residue was dissolved in methanol (5ml) and added to a 10g aminopropyl SPE cartridge which was subsequently washed with methanol and the product eluted with a 5% solution of acetic acid in methanol. Product-containing fractions were evaporated and then purification by MDAP to give N-[5-(3-butyl-8-chloro- 2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1-yl)pentyl]-2-(4-morpholinylcarbonyl)benzamide as a white solid (0.137g, LC/MS: m/z 545 [MH]+, RT 2.77min) and the title compound as a white solid (0.239g, 35%).
LC/MS: m/z 458 [MH]+, RT 3.33min.
Example 469 : 8-Chloro-1^4-r3-(2,4-difluorophenyl)-1.2.4-oxadiazol-5-yllbutyl}-3- ethyl-3.7-dihvdro-1H-purine-2,6-dione
a) 8-Chloro-1 -{4-[3-(2,4-difluorophenyl)-1 ,2,4-oxadiazol-5-yl]butyl}-3-ethyl-3,7-dihydro- 1 H-purine-2,6-dione
A solution of 5-(8-chloro-3-ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)pentanoic acid (0.05g, 0.16mmol) in DMSO (1ml) was treated with CDI (0.029g, 0.18mmol) and the mixture stirred at room temperature for 1 h. Subsequently, the mixture was treated with 2,4-difluorobenzamidoxime (0.03g, 0.18mmol) and then heated to 12O
0C for 30 min. The product was purified from the crude mixture using MDAP. Product-containing fractions were evaporated using a stream of nitrogen and the resulting colourless gum triturated in ether and dried to reveal the title compound as a white solid (50mg, 70%). LC/MS: m/z 451 [MH]
+, RT 2.23min.
b) 5-(8-chloro-3-ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoic acid
A solution of ethyl 5-(8-chloro-3-ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 - yl)pentanoate (2.3g, 6.7mmol) in methanol (75ml) was treated with water (3ml) and lithium hydroxide (0.481 g, 20.1 mmol) and the mixture stirred at 4O0C for 17h. The mixture was evaporated to dryness and the residue treated with 50ml of ethyl acetate and 50ml of water. The 2 phases were separated and the aqueous phase adjusted to pH5 using 2M aqueous hydrochloric acid. The precipitated product was filtered off and dried to yield 5-(8-chloro-3-ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)pentanoic acid as a white solid (1.99g, 95%). LC/MS: m/z 315 [MH]+, RT 2.34min.
c) Ethyl 5-(8-chloro-3-ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanoate
A solution of 8-chloro-7-(2-propen-1-yl)-3-ethyl-3,7-dihydro-1H-purine-2,6-dione (3g, 11.8mmol) in DMF (40ml) was treated with potassium carbonate (1.9g, 14.1mmol) and ethyl 5-bromopentanoate (2.24ml, 14.1mmol) and the mixture heated in a nitrogen atmosphere at 7O0C for 5h and then cooled. The mixture was degassed by the repeated application of vacuum followed by backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (1.36g, 1.1mmol) and morpholine (10.3ml, 1 18mmol). The mixture was stirred in a nitrogen atmosphere for 4h and then evaporated to dryness. The residue was partitioned between 100ml of ethyl acetate and 100ml of water. The aqueous phase was re-extracted with 100ml of ethyl acetate
and the combined organics dried over magnesium sulfate, filtered and evaporated. The residue was triturated in diethyl ether, filtered and dried to reveal ethyl 5-(8-chloro-3- ethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanoate compound as a white solid (2.3g, 57%). LC/MS: m/z 343 [MH]+, RT 2.73min.
The following compounds (Table 30) were prepared by a method analogous to that for Example 469.
Table 30
The following compounds (Table 31) were prepared using a method analogous to that for Example 158, using the appropriate acid.
Table 31
The following compounds (Table 32) were prepared using a method analogous to that for Example 36, using the appropriate tetrazole and 3-[3-alkyl-8-chloro-2,6-dioxo-7-(2- propen-1-yl)-2,3,6,7-tetrahydro-1H-purin-1-yl]propyl methanesulfonate. MDAP was employed to further purify those compounds insufficiently pure following normal phase chromatography.
Table 32
Example 597 : 1-r5-(1.3-Benzoxazol-2-yl)pentvn-8-chloro-3-ethyl-3.7-dihvdro-1H- purine-2,6-dione
-8-chloro-3-ethyl-3,7-dihydro-1/-/-purine-2,6-dione
a) A solution of S-ethyl-S-chloro^-^-propen-i-yO-S^-dihydro-I H-purine^.θ-dione (0.095g, 0.37mmol) in DMF (10ml) was treated with potassium carbonate (0.0615g, 0.45mmol) and 2-(5-chloropentyl)-1 ,3-benzoxazole (0.091 g, 0.41 mmol) and the mixture heated at 7O
0C for 4.5h. The mixture was cooled and degassed by the repeated application of vacuum to the reaction mixture and subsequent backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (0.043g, 0.037mmol) and morpholine (0.32ml, 3.7mmol) and the mixture stirred for 4h in a nitrogen atmosphere. The mixture was evaporated to dryness and the residue partitioned between 25ml of ethyl acetate and 25ml of brine. The aqueous phase was re-extracted with 25ml of ethyl acetate and the combined organics dried over magnesium sulfate, filtered and evaporated. The residue was dissolved in 5ml of methanol and added to a 5g aminopropyl SPE which was subsequently washed with methanol and the product eluted with a 5% solution of acetic acid in methanol. Product- containing fractions were pooled and evaporated to reveal a colourless gum which was triturated with diethyl ether and dried to give the title compound as a white solid (0.0538g, 36%). LC/MS: m/z 402 [MH]
+, RT 3.06min
b) 2-(5-Chloropentyl)-1 ,3-benzoxazole
6-Chloro-Λ/-(2-hydroxyphenyl)hexanamide (0.95g, 3.9mmol) was treated with toluene (20ml) and 4-toluenesulfonic acid monohydrate (0.05g, 0.26mmol) and the mixture heated in the microwave at 16O0C for 1h then cooled and evaporated. The residue was partition between 25ml of ethyl acetate and 25ml of saturates aqueous sodium bicarbonate. The aqueous phase was extracted twice more with 25ml ethyl acetate and the combined organics dried over magnesium sulfate, filtered and evaporated to dryness. The product was then purified by flash chromatography (gradient elution: cyclohexane to cyclohexane/ethyl acetate 1 :1 ) to give 2-(5-chloropentyl)-1 ,3- benzoxazole as a colourless oil which solidified upon standing (0.47g, 53%). LC/MS: m/z 224 [MH]+, RT 3.32min
c) 6-chloro-Λ/-(2-hydroxyphenyl)hexanamide
2-Aminophenol (0.5g, 4.6mmol) was stirred in ethyl acetate (15ml) and treated dropwise with 6-chlorohexanoyl chloride (0.664ml, 5.5mmol) and then dropwise with triethylamine (0.95ml, 6.9mmol). After 1 h the mixture was washed with 2 x 25ml of
saturated aqueous sodium bicarbonate and the organic phase dried over magnesium sulfate, filterd and evaporated to dryness to give 6-chloro-Λ/-(2- hydroxyphenyl)hexanamide as a pale brown solid (0.05g, 86%). LC/MS: m/z 242 [MH]+, RT 2.95min.
The following compounds (Table 33) were prepared using a method analogous to that for Example 597.
Table 33
Example 601 : 1-r5-(1,3-Benzothiazol-2-yl)pentvn-3-butyl-8-chloro-3.7-dihvdro- 1 H-purine-2.6-dione
a) 1 -[5-(1 ,3-Benzothiazol-2-yl)pentyl]-3-butyl-8-chloro-3,7-dihydro-1 H-purine-2,6-dione
A solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1 H-purine-2,6-dione (0.053g, 0.19mmol) in DMF (5ml) was treated with potassium carbonate (0.026g, 0.19mmol) and 2-(5-chloropentyl)-1 ,3-benzothiazole (0.0498g, 0.21 mmol) and the mixture heated at 6O0C for 3 days. The mixture was cooled and degassed by the repeated application of vacuum to the reaction mixture and subsequent backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (0.0294g, 0.025mmol) and morpholine (0.164ml, 1.9mmol) and the mixture stirred for 18 hours in a nitrogen atmosphere. The mixture was evaporated to dryness and the residue partitioned between 25ml of ethyl acetate and 25ml of saturated aqueous sodium bicarbonate. The organic phase was dried over magnesium sulfate, filtered and evaporated. The residue was dissolved in 5ml of methanol and added to a 5g aminopropyl SPE which was subsequently washed with methanol and the product eluted with a 5% solution of acetic acid in methanol. Product-containing fractions were pooled and evaporated and the residue subjected to purification by MDAP to give the title compound as a white solid (0.0101 g, 12%). LC/MS: m/z 446 [MH]+, RT 3.55min.
b) 2-(5-Chloropentyl)-1 ,3-benzothiazole
An ice-cooled solution of 2-aminothiophenol (0.376ml, 3.54mmol) in anhydrous THF (5ml) was treated with diisopropylethylamine (0.62ml, 3.54mmol) followed by 6- chlorohexanoyl chloride (0.36ml, 2.95mmol). The mixture was stirred at ambient temperature for 2h then heated at reflux for 19h and then cooled and diluted with DCM (10ml). The solution was washed with 10ml of 2M aqueous hydrochloric acid, 10ml of 2M aqueous sodium hydroxide and 10ml of brine; dried over magnesium sulfate, filtered and evaporated to reveal 0.4122g of a pale yellow oil. The product was purified by flash chromatography using a gradient elution from cyclohexane to cylcohexane/ethyl acetate (7:3) to give 2-(5-chloropentyl)-1 ,3-benzothiazole as a colourless oil (0.0541 g, 6%). LC/MS: m/z 240 [MH]+, RT 3.48min.
Example 602 : 3-Butyl-8-chloro-1-{3-r4-(phenylmethyl)-1-piperazinvnpropyl>-3.7- dihydro-1 H-purine-2,6-dione
A solution of 3-[3-butyl-8-chloro-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1/-/- purin-1-yl]propyl methanesulfonate (0.08g, 0.19mmol) in DMF (5ml) was treated with potassium carbonate (O.Oδg, 0.6mmol) and 1-benzylpiperazine (0.04g, 0.23mmol) and then heated at 7O0C for 2h. The mixture was cooled, evaporated to dryness and partitioned between 10ml of DCM and 10ml of water. The organic phase was evaporated to dryness and the residue dissolved in anhydrous THF (5ml). The solution was cautiously degassed by the repeated application of vacuum to the reaction mixture and subsequent backfilling with nitrogen gas and then treated with tetrakis(triphenylphosphine)palladium(0) (0.01Og, 0.009mmol) and morpholine (0.200ml, 2.3mmol) and the mixture stirred for 2h in a nitrogen atmosphere. The mixture was evaporated and the residue taken up in 5ml of methanol and added to a 2g aminopropyl SPE cartridge which was then washed with methanol and the product eluted using a 3% solution of acetic acid in methanol. Product-containing fractions were pooled and evaporated to dryness. The product was then purified by flash chromatography using a gradient elution from DCM /2% Acetic acid to DCM /20% MeOH /2% Acetic acid and the final product freeze-dried from 1 ,4-dioxan to give the title compound as a white solid (0.021 g, 24%). LC/MS: m/z 459 [MH]+, RT 2.37min.
The following compounds (Table 34) were prepared by the appropriate general methodology described above.
Table 34
Example 837: 3-Butyl-8-chloro-1 -f4-r5-(2-fluoro-4-hvdroxyphenyl)-1 ,2,4-oxadiazol- 3-yllbutyl)-3,7-dihvdro-1H-purine-2,6-dione a) 3-Butyl-8-chloro-1 -{4-[5-(2-fluoro-4-hydroxyphenyl)-1 ,2,4-oxadiazol-3-yl]butyl}-3,7- dihydro-1 H-purine-2,6-dione
CDl (45mg, 0.28mmol) in anhydrous DMSO (0.5ml) was added to 2-fluoro-4- hydroxybenzoic acid (40mg, 0.25mmol) and stirred at rt for 2h. 5-(3-Butyl-8-chloro-2,6- dioxo-2F3,6,7-tetrahydro-1H-purin-1-yl)-Λ/-hydroxypentanimidamide (100mg, 0.28mmol) in DMSO (0.4ml) was added and the resulting mixture heated at 9O0C for 18h. Purification by MDAP afforded the title compound as a solid (38mg, 28%). LC/MS: m/z 477 [MH]+, RT 3.39min.
1H NMR (DMSO-d6) δ: 0.87 (t, 3H, J = 7Hz), 1.27 (m, 2H), 1.56-1.78 (m, 6H), 2.77 (t, 2H, J = 7Hz), 3.90 (m, 4H), 6.80 (m, 2H), 7.91 (t, 1 H, J = 9Hz), 11.01 (s, 1 H), 14.45 (br s, 1 H).
b) 5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1/-/-purin-1-yl)-Λ/- hydroxypentanimidamide
5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)pentanenitrile (8.5g, 26mmol) was dissolved in EtOH (100ml). Hydroxylamine (50% in water; 2.6ml, 39mmol) was added and the mixture heated at 8O0C for 48h under nitrogen. The reaction mixture was concentrated in vacuo, the resultant solid washed with methanol and dried to give the title compound as a solid (5.9g, 47%). LC/MS: m/z 357 [MH]+, RT 2.17min.
c) 5-(3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1 H-purin-1 -yl)pentanenitrile
5-Bromopentanenitrile (4.54ml, 39mmol) and cesium carbonate (12.7g) were added to a solution of 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1/-/-purine-2,6-dione (10g, 35mmol) in DMF (100ml) and the mixture stirred under nitrogen at 4O0C overnight and allowed to cool.
The mixture was then degassed by the repeated successive application of a vacuum and then nitrogen pressure. The mixture was then treated with tetrakis(triphenylphosphine)palladium(0) (2.86g, 2.5mmol) and morpholine (30.8ml,
350mmol). The mixture was stirred in a nitrogen atmosphere for 3h and then partitioned between EtOAc and 2M aqueous hydrochloric acid. The aqueous layer was separated and extracted with EtOAc (x2). The combined organic phases were concentrated in vacuo to give a solid that was washed with ether, filtered and dried.
The filtrate was concentrated and purified on an aminopropyl column eluting with
MeOH followed by 3% AcOH/MeOH. The product-containing fractions were combined and concentrated to give a solid, which was combined with the filtered product. The title compound was obtained as a solid (10.5g, 93%). LC/MS: m/z 324 [MH]+, RT 2.75min.
The following compounds (Table 35) were prepared using a method analogous to that for Example 837, using the appropriate carboxylic acid.
All publications, including but not limited to patents and patent applications, cited in this specification are herein incorporated by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein as though fully set forth.