Patent ID: 7687534

Claim:
A compound represented by formula I: or a pharmaceutically acceptable salt thereof wherein: ring A represents a phenyl or naphthyl group; each R 1 and R 2 represents H or is selected from the group consisting of halo, CN, OH, NO 2 , CO 2 R a , NR a R b , S(O) p R a , C 1-10 alkyl, C 2-10 alkenyl or C 1-10 alkoxy, the alkyl and alkenyl portions of, C 1-10 alkyl, C 2-10 alkenyl and C 1-10 alkoxy being optionally substituted with 1-5 halo atoms up to perhalo; and further optionally substituted with 1 group selected from OH, oxo and C 1-6 alkoxy; p represents 0, 1 or 2; each R a and R b independently represents H or C 1-4 alkyl optionally substituted with 1-5 halo atoms up to perhalo; and further optionally substituted with 1 group selected from OH, oxo and C 1-6 alkoxy; R 3 represents C 1-6 alkyl or C 2-6 alkenyl, each optionally substituted with 1-5 halo atoms up to perhalo, and further optionally substituted with 1 group selected from OH, oxo and C 1-6 alkoxy, and R 4 represents H or C 1-4 alkyl optionally substituted with 1-3 halo atoms up to perhalo and 1 phenyl ring.