Patent ID: 6875868

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt: in which: A is a group of formula (b): R 1 represents a C 3 -C 7 carbocyclic, C 1 -C 8 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl group, the latter four groups being optionally substituted by one or more substituent groups independently selected from halogen atoms, —OR 4 , —NR 5 R 6 , —CONR 5 R 6 , —COOR 7 , —NR 8 COR 9 , —SR 10 , —SO 2 R 10 , —SO 2 NR 5 R 6 , —NR 8 SO 2 R 10 , an aryl or heteroaryl group both of which can be optionally substituted by one or more substituents independently selected from halogen atoms, cyano, nitro, —OR 4 , —NR 5 R 6 , —CONR 5 R 6 , —COOR 7 , —NR 8 COR 10 , —SR 10 , —SO 2 R 10 , —SO 2 NR 5 R 6 , —NR 8 SO 2 R 10 , C 1 -C 6 alkyl or trifluoromethyl groups; wherein aryl is selected from the group consisting of phenyl and naphthyl, and heteroaryl is selected from the group consisting of pyridine, pyrimidine, thiazole, oxazole, pyrazole, imidazole, and furan one of R 2 and R 3 is hydrogen and the other is C 3 -C 4 alkyl substituted by one or more hydroxy groups; R 4 represents hydrogen, C 1 -C 6 alkyl or a phenyl group the latter two of which may be optionally substituted by one or more substituent groups independently selected from halogen atoms, phenyl, —OR 11 and —NR 12 R 13 ; R 5 and R 6 independently represent a hydrogen atom or a C 1 -C 6 alkyl or phenyl group the latter two of which may be optionally substituted by one or more substituent groups independently selected from halogen atoms, phenyl, —OR 14 and —NR 15 R 16 , —CONR 15 R 16 , —NR 15 COR 16 , —SO 2 NR 15 R 16 , NR 15 SO 2 R 16 or R 5 and R 6 together with the nitrogen atom to which they are attached form a 4- to 7-membered saturated heterocyclic ring system optionally comprising a further heteroatom selected from oxygen and nitrogen atoms, which ring system may be optionally substituted by one or more substituent groups independently selected from phenyl, —OR 14 , —COOR 14 , —NR 15 R 16 , —CONR 15 R 16 , —NR 15 COR 16 , —SO 2 NR 15 R 16 , NR 15 SO 2 R 16 or C 1 -C 6 alkyl, itself optionally substituted by one or more substituents independently selected from halogen atoms and —NR 15 R 16 and —OR 17 groups; R 10 represents a C 1 -C 6 alkyl or a phenyl group, each of which may be optionally substituted by one or more substituent groups independently selected from halogen atoms, phenyl, —OR 17 and —NR 15 R 16 ; Z is CR 20 where R 20 represents H; and each of R 7 , R 8 , R 9 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 independently represent a hydrogen atom, C 1 -C 6 , alkyl, or a phenyl group.