Patent ID: 7309712

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein: R 1 and R 3 independently represent H, C 1-6 alkyl, C 3-8 cycloalkyl, or halogen; R 2 represents C 1-6 alkyl, CF 3 or aryl; a represents 1 or 2; R 4 , R 5 , R 7 and R 8 independently represent H, C 1-6 alkyl, C 1-6 alkyloxy, CN or halogen, or R 4 and R 5 , or R 7 and R 8 , together with the ring to which they are attached form an aryl or heterocyclic fused ring system; X represents C or N; Y represents CH 2 or O; and R 6 represents H, CN or halo provided that, when X represents N, R 6 is absent.