Patent ID: 8097639

Claim:
A compound of formula I: wherein: R 1 is hydrogen or methyl; R 2 is selected from the group consisting of alkyl optionally substituted with 1-3 R 4 groups, aryl optionally substituted with 1-4 R 4 groups, cycloalkyl optionally substituted with 1-4 R 4 groups, heterocycloalkyl optionally substituted with 1-4 R 4 groups, and heteroaryl optionally substituted with 1-4 R 4 groups; X is O or NR 3 , where R 3 is hydrogen or alkyl; L 1 and L 2 are independently selected from the group consisting of a direct bond, methylene optionally substituted with 1-2 R 4 groups, (C 2 -C 12 )alkylene optionally substituted with 1-4 R 4 groups, (C 6 -C 12 )arylene optionally substituted with 1-4 R 4 groups, and (C 3 -C 12 )cycloalkylene optionally substituted with 1-4 R 4 groups; and each R 4 is independently selected from the group consisting of halo, nitro, cyano, oxo, aminoacyl, aminoacyloxy, carboxyl, carboxyl ester, carbonate ester, aminosulfonyl, (C 1 -C 10 )alkyl, (C 1 -C 10 )haloalkyl, (C 1 -C 10 )alkoxy, (C 6 -C 12 )aryl, (C 5 -C 12 )heteroaryl, (C 6 -C 12 )aryloxy, (C 3 -C 12 )cycloalkyl and (C 3 -C 12 )heterocycloalkyl.