Patent ID: 7776868

Claim:
A compound of Formula I: wherein R 1 is hydrogen, optionally substituted C 1-6 alkyl, optionally substituted C 2-10 alkenyl, or optionally substituted C 2-6 alkynyl; R 2 is hydrogen, optionally substituted C 1-4 alkyl, —X—O—P(O)(OR) 2 , or —X—O—R 7 , in which X is C 1-4 alkylene, R is hydrogen or C 1-6 alkyl, and R 7 is C 1-6 alkyl; R 3 is hydrogen, optionally substituted C 1-4 alkyl, or a 5 or 6 membered optionally substituted monocyclic heterocycle containing 1, 2, 3, or 4 heteroatoms independently selected from oxygen, sulfur and nitrogen; R 4 and R 5 are independently methyl or hydrogen; and R 6 is optionally substituted phenyl, optionally substituted heteroaryl, optionally substituted heterocycle, or optionally substituted cycloalkyl, or a pharmaceutically acceptable salt thereof.