Isoxazole compounds as inhibitors of heat shock proteins

1. A method of inhibiting Heat Shock Protein 90 (HSP90) activity in mammals comprising administering to the mammal an amount of a compound of formula (A) or (B) or a salt, N-oxide, hydrate or solvate thereof, or a prodrug thereof effective to inhibit HSP90 activity:

wherein

R 1 is a group of formula (IB)

wherein in any compatible combination

R represents one or more optional substituents,

Alk 1 and Alk 2 are optionally substituted divalent C 1 -C 6 alkylene or C 2 -C 6 alkenylene radicals,

p, r and s are independently 0 or 1,

Z is —O—, —S—, —(C═O )—, —(C═S)—, —SO 2 —, —C(═O )O—, —C(═O )NR A —,

—C(═S)NR A —, —SO 2 NR A —, —NR A C(═O)—, —NR A SO 2 — or NR A — wherein R A is hydrogen or C 1 -C 6 alkyl, and

Q is hydrogen or an optionally substituted carbocyclic or heterocyclic radical;

R 2 is (i) a group of formula (IA):

—Ar 1 -(Alk 1 ) p -(Z) r -(Alk 2 ) s -Q  (IA)

wherein in any compatible combination

Ar 1 is an optionally substituted aryl or heteroaryl radical, and

Alk 1 , Alk 2 , p, r, s, Z, R A and Q are as defined in relation to R 1 ;

(ii) a carboxamide radical; or

(iii) a non aromatic carbocyclic or heterocyclic ring wherein a ring carbon is optionally substituted, and/or a ring nitrogen is optionally substituted by a group of formula —(Alk 1 ) p -(Z) r -(Alk 2 ) s -Q wherein Q, Alk 1 , Alk 2 , Z, p, r and s are as defined above in relation to group (IA); and

R 3 is hydrogen, optionally substituted cycloalkyl, cycloalkenyl, C 1 -C 6 alkyl, C 1 -C 6 alkenyl, or C 1 -C 6 alkynyl; or a carboxyl, carboxamide, or carboxyl ester group.

2. The method as claimed in claim 1 wherein the compound has formula (ID) or the formula B regioisomer thereof,

wherein each R independently represents an optional substituent and R 3 represents a carboxamide group.

3. The method as claimed in claim 1 wherein the compound has formula (IE) or the formula B regioisomer thereof,

wherein R 3 represents a carboxamide group; R 9 represents —CH 2 NR 10 R 11 or —NR 10 R 11 wherein the substituted amino group —NR 10 R 11 is a solubilising group; and R 8 represents an optional substituent.

4. The method as claimed in claim 1 wherein the compound is selected from:

5-(2,4-Dihydroxy-5-isopropyl-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-isopropyl-phenyl)-4-(4-piperidin-1-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

4-(4-Diethylaminomethyl-phenyl)-5-(2,4-dihydroxy-5-isopropyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy- 5-isopropyl-phenyl)-4- [4-(4-methyl-piperazin- 1 -ylmethyl)-phenyl]- isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5 -isopropyl-phenyl)-4-(4-ethylaminomethyl-phenyl)-isoxazole-3 -carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-isopropyl-phenyl)-4-[4-(isopropylamino-methyl)-phenyl]-isoxazole-3-carboxylic acid ethylamide

4-(4-Cyclohexylaminomethyl-phenyl)-5-(2,4-dihydroxy-5 -isopropyl-phenyl)-isoxazole-3 -carboxylic acid ethylamide

4-[4-(tert-Butylamino-methyl)-phenyl]-5-(2,4-dihydroxy-5-isopropyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-isopropyl-phenyl)-4-{4-[(2-methoxy-ethylamino)-methyl]-phenyll}-isoxazole-3-carboxylic acid ethylamide

5 -(2,4-Dihydroxy-5-isopropyl-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3 -carboxylic acid isopropylamide

5-(2,4-Dihydroxy-5-isopropyl-phenyl)-4-[4-(4-methyl-piperazin-1-ylmethyl)-phenyl]-isoxazole-3-carboxylic acid isopropylamide

5-(5-tert-Butyl-2,4-dihydroxy-phenyl)-4-[4-(4-methyl-piperazin-1-ylmethyl)-phenyl]-isoxazole-3-carboxylic acid ethylamide

5-(5-tert-Butyl-2,4-dihydroxy-phenyl)-4-(4-piperidin-1-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-isobutyl-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-isobutyl-phenyl)-4-(4-piperidin-1-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(5-tert-Butyl-2,4-dihydroxy-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(5-tert-Butyl-2,4-dihydroxy-phenyl)-4-(4-diethylaminomethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

3-(5-Chloro-2,4-dihydroxy-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazo1e-5-carboxylic acid ethylamide

4-(4-Diethylaminomethyl-phenyl)-5-(4,6-dihydroxy-2′-methyl-biphenyl-3-yl)-isoxazole-3-carboxylic acid ethylamide

4-(4-Diethylaminomethyl-phenyl)-5-(4′-fluoro-4,6-dihydroxy-biphenyl-3-yl)-isoxazole-3-carboxylic acid ethylamide

4-(4-Diethylaminomethyl-phenyl)-5-(4,6-dihydroxy-biphenyl-3-yl)-isoxazole-3-carboxylic acid ethylamide

5-(2′-Fluoro-4,6-dihydroxy-biphenyl-3-yl)-4-(4-pyrrolidin-1-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(4,6-Dihydroxy-biphenyl-3-yl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(2,4-Dihydroxy-5-phenethyl-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(5-Chloro-2,4-dihydroxy-phenyl)-4-(4-piperidin-1-ylmethyl-phenyl)-isoxazole-3-carboxylic acid isopropylamide

4-(4-Diethylaminomethyl-phenyl)-5-(5-ethyl-2,4-dihydroxy-phenyl)-isoxazole-3-carboxylic acid ethylamide

5-(5-Ethyl-2,4-dihydroxy-phenyl)-4-[4-(4-methyl-piperazin-1-ylmethyl)-phenyl]-isoxazole-3-carboxylic acid ethylamide

5 -(5-Ethyl-2,4-dihydroxy-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3 -carboxylic acid ethylamide

5 -(5 -Chloro-2,4-dihydroxy-phenyl)-4-(4-diethylaminomethyl-phenyl)-isoxazole-3 -carboxylic acid ethylamide

5-(5-Chloro-2,4-dihydroxy-phenyl)-4-[4-(4-methyl-piperazin-1-ylmethyl)-phenyl]-isoxazole-3-carboxylic acid ethylamide

5-(5 -Chloro-2,4-dihydroxy-phenyl)-4-(4-morpholin-4-ylmethyl-phenyl)-isoxazole-3 -carboxylic acid ethylamide

and salts, hydrates, solvates and prodrugs thereof.

5. The method as claimed in claim 1 wherein the radical Ar 1 present in R 1 has formula (1B)

wherein Alk 1 , Alk 2 , p, r, s, Z and Q are as defined in claim 1 , and R represents one or more optional substituents.

6. The method as claimed in claim 5 wherein that the ring carbon atom adjacent the hydroxyl group in radical (IB) is unsubstituted.

7. The method as claimed in claim 1 wherein, in R 1 , each of p, r, and s is 0, and Q is hydrogen.

8. The method as claimed in claim 7 wherein R 1 is optionally substituted phenyl.

9. The method as claimed in claim 7 wherein R 1 is 2-hydroxyphenyl, optionally further substituted by one or more of hydroxy, methyl, ethyl, methoxy, ethoxy , chloro, or bromo.

10. The method as claimed in claim 7 wherein R 1 is 2,4-dihydroxyphenyl, substituted in the 5-position by a small lipophilic substituent.

11. The method as claimed in claim 10 wherein the small lipophilic substituent methyl, ethyl, isopropyl, isobutyl, tert-butyl, chloro, or bromo.

12. The method as claimed in claim 10 wherein the hydroxyl groups in R 1 are protected by groups which are cleaved in the body to release the hydroxyl groups.

13. The method as claimed in claim 12 wherein the protecting groups are methylcarbonyloxy, or isopropylamino-carbonyloxy.

14. The method as claimed in claim 1 wherein, in R 1 , p, r and s are each 0, and Q is an optionally substituted carbocyclic or heterocyclic ring.

15. The method as claimed in claim 14 wherein Q is an optionally substituted phenyl or pyridyl ring.

16. The method as claimed in claim 1 wherein, in R 1 , p and/or s are each 1 and r is 0.

17. The method as claimed in claim 1 wherein, in R 1 , each of p, r, and s is 1.

18. The method as claimed in claim 1 wherein, in R 1 , p and s are each 0 and r is 1.

19. The method as claimed in claim 1 wherein R 2 is a group of formula (1A).

20. The method as claimed in claim 19 wherein R 2 is optionally substituted 2-, 3-, or 4-pyridyl, 2- or 3-furanyl, 2- or 3-thienyl, or thiazolyl.

21. The method as claimed in claim 20 wherein optional substituents present in R 2 are selected from methoxy, ethoxy, methylenedioxy, ethylenedioxy, fluoro, chloro, bromo, and trifluoromethyl.

22. The method as claimed in claim 19 wherein R 2 is phenyl substituted in the 4 position by methoxy, ethoxy, fluoro, chloro, bromo, piperazinyl, N-methylpiperazinyl, or piperidinyl.

23. The method as claimed in claim 1 wherein R 2 has the partial structure:

wherein the substituted amino group —NR 10 R 11 is a solubilising group.

24. The method as claimed in claim 23 wherein the solubilising group is selected from morpholinyl, piperidinyl, piperazinyl, pyrrolidinyl, ethylamino, isopropylamino, diethylamine, cyclohexylamino, cyclopentylamino, methoxyethylamino, piperidin-4-yl, N -acetylpiperazinyl, methylsulfonylamino, thiomorpholinyl, thiomorpholinyldioxide, 4-hydroxyethylpiperidinyl, and 4-hydroxypiperidinyl.

25. The method as claimed in claim 1 wherein R 2 is a carboxamide group of formula —CONR B (Alk) n R A wherein

Alk is a divalent alkylene, alkenylene or alkynylene radical, and the Alk radical may be optionally substituted,

n is 0 or 1,

R B is hydrogen or a C 1 -C 6 alkyl or C 2 -C 6 alkenyl group,

R A is hydroxy or optionally substituted carbocyclic; or heterocyclyl, in which heterocyclic rings may be substituted,

or R A and R B taken together with the nitrogen to which they are attached form an N-heterocyclic ring which may optionally contain one or more additional hetero atoms selected from 0, S and N, and which may optionally be substituted on one or more ring C or N atoms.

26. The method as claimed in claim 1 wherein R 3 is hydrogen, methyl, ethyl, n- or iso-propyl, trifluoromethyl, hydroxyethyl, methylsulfonaminomethyl, or a carboxamide group —CONR B (Alk) n R A as defined in claim 25 .

27. The method as claimed in claim 1 wherein R 3 is ethylaminocarbonyl or isopropylaminocarbonyl.

28. The method as claimed in claim 1 wherein the compound has formula (ID) or the formula B regioisomer thereof,

wherein each R independently represents an optional substituent and R 3 represents a carboxamide group.

29. The method as claimed in claim 1 wherein the compound has formula (IE) or the formula B regioisomer thereof,

wherein R 3 represents a carboxamide group; R 9 represents —CH 2 NR 10 R 11 or N R 10 R 11 wherein the substituted amino group —NR 10 R 11 is a solubilising group; and R 8 represents an optional substituent.