Patent ID: 8367687

Claim:
A compound of formula I: or a pharmaceutically acceptable salt, wherein R 1 is C 3-14 -cycloalkyl, C 6-14 aryl, a 3-14 membered cycloheteroalkyl group, C 1-6 alkylC 6-14 aryl, or C 1-6 alkylC 3-14 cycloalkyl, which may be unsubstituted or substituted with one or more of C 1-6 -alkyl or C 6-14 -aryl; R 2 is H, C 1-6 -alkyl, C 2-6 -alkenyl, C 2-6 -alkynyl, hydroxyl, or halo; R 3 and R 4 are independently H, C 1-6 -alkyl, or C 3-14 -cycloalkyl; and X is N or CR 12 where R 11 and R 12 are independently H, halogen, or C 1-6 -alkyl.