Patent ID: 7842836

Claim:
A compound of formula I or a pharmaceutically acceptable salt thereof wherein B is H, C 1 -C 4 alkyl, or C 2 -C 6 alkenyl; wherein said C 1 -C 4 alkyl is optionally substituted with one or two hydroxy groups; A and A′ are each independently H, C 1 -C 4 alkyl, or C 2 -C 6 alkenyl; wherein each C 1 -C 4 alkyl is independently optionally substituted with one or two hydroxy groups; or A and A′ together with the carbon atom to which they are attached, form a cyclopropyl, cyclobutyl, or cyclopentyl group, optionally substituted with at least one methyl, hydroxy, or halogen; R 1 is H or F; R 2 is Br or I; R 0 is OR 3 ; wherein R 3 is H, C 1 -C 4 alkyl or phenyl; wherein each C 1 -C 4 alkyl or phenyl group is independently optionally substituted with at least one halogen, hydroxy, azido, cyano, cyanomethyl, nitro, phenyl, difluoromethyl, trifluoromethyl, methoxy, or C 1 -C 4 alkoxy.