A compound represented by formula I: or a pharmaceutically acceptable salt thereof wherein: ring A represents a heteroaryl group containing two six membered rings and one or two nitrogen atoms; each R 1 represents H or is selected from the group consisting of halo, CN, OH, NO 2, CO 2 R a, NR a R b, S 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 2 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 each R 3 represents H or is selected from the group consisting of halo, CN, OH, NO 2, CO 2 R a, NR a R b, S 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, NR a R b, and C 1-6 alkoxy; or 3 R 3 groups are as described above and 1 R 3 represents a 5-6 membered heteroaryl ring containing 0-1 oxygen or sulfur atom and 1-4 nitrogen atoms, said heteroaryl group being optionally substituted with 1-2 halo, C 1-3 alkyl, C 2-3 alkenyl or C 1-3 alkoxy groups, the alkyl and alkenyl portions of, C 1-3 alkyl, C 2-3 alkenyl and C 1-3 alkoxy being optionally substituted with 1-3 halo atoms up to perhalo; and further optionally substituted with 1 group selected from OH, oxo and C 1-6 alkoxy, said heteroaryl ring being further optionally substituted with a member selected from the group consisting of CN, OH, NO 2, CO 2 R a, NR a R b and S p R a. ring A represents a heteroaryl group containing two six membered rings and one or two nitrogen atoms; each R 1 represents H or is selected from the group consisting of halo, CN, OH, NO 2, CO 2 R a, NR a R b, S 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 2 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 each R 3 represents H or is selected from the group consisting of halo, CN, OH, NO 2, CO 2 R a, NR a R b, S 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, NR a R b, and C 1-6 alkoxy; or 3 R 3 groups are as described above and 1 R 3 represents a 5-6 membered heteroaryl ring containing 0-1 oxygen or sulfur atom and 1-4 nitrogen atoms, said heteroaryl group being optionally substituted with 1-2 halo, C 1-3 alkyl, C 2-3 alkenyl or C 1-3 alkoxy groups, the alkyl and alkenyl portions of, C 1-3 alkyl, C 2-3 alkenyl and C 1-3 alkoxy being optionally substituted with 1-3 halo atoms up to perhalo; and further optionally substituted with 1 group selected from OH, oxo and C 1-6 alkoxy, said heteroaryl ring being further optionally substituted with a member selected from the group consisting of CN, OH, NO 2, CO 2 R a, NR a R b and S p R a.