Patent ID: 7638631

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R 1 represents heteroaryl, wherein said heteroaryl group of R 1 may be optionally substituted by one or more substituents which may be the same or different, and which are selected from the group consisting of halogen, hydroxy, cyano, nitro, oxo, haloC 1-6 alkyl, polyhaloC 1-6 alkyl, haloC 1-6 alkoxy, polyhaloC 1-6 alkoxy, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylthio, C 1-6 alkoxyC 1-6 alkyl, C 3-7 cycloalkylC 1-6 alkoxy, C 1-6 alkylsulfonyl, C 1-6 alkylsulfinyl, C 1-6 alkylsulfonyloxy, C 1-6 alkylsulfonylC 1-6 alkyl, C 1-6 alkylsulfonamidoC 1-6 alkyl, C 1-6 alkylamidoC 1-6 alkyl, phenyl, phenylsulfonyl, phenylsulfonyloxy, phenyloxy, phenylsulfonamido, phenylcarboxamido, phenoyl, or a group —COR 15 , —COOR 15 , —NR 15 R 16 , —CONR 15 R 16 , —NR 15 COR 16 , —NR 15 SO 2 R 16 or —SO 2 NR 15 R 16 , wherein R 15 and R 16 independently represent hydrogen, C 1-6 alkyl, haloC 1-6 alkyl, polyhaloC 1-6 alkyl or C 3-6 cycloalkyl or together form a heterocyclic ring; R 2 represents C 1-8 alkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 3-6 cycloalkyl, C 5-6 cycloalkenyl or —C 1-4 alkyl-C 3-6 cycloalkyl; wherein said C 3-6 cycloalkyl groups of R 2 may be optionally substituted by one or more substituents which may be the same or different, and which are selected from the group consisting of halogen, C 1-4 alkyl or polyhaloC 1-6 alkyl groups; each R 3 and R 4 group independently represents C 1-4 alkyl; m and n both represent 0.