Patent ID: 8440684

Claim:
A compound having Formula I, its enantiomers, diastereoisomers, hydrates, solvates, crystal forms, tautomers or a pharmaceutically acceptable salt thereof, wherein: X is O or S; R 1 is substituted or unsubstituted —C 1-6 alkyl, substituted or unsubstituted —C 2-6 alkenyl, substituted or unsubstituted —C 2-6 alkynyl, substituted or unsubstituted C 3-8 cycloalkyl, substituted or unsubstituted C 3-8 cycloalkenyl, substituted or unsubstituted heterocycle or substituted or unsubstituted aryl; R 2 is H, halogen, substituted or unsubstituted —C 1-6 alkyl, substituted or unsubstituted —C 2-6 alkenyl, substituted or unsubstituted —C 2-6 alkynyl, substituted or unsubstituted C 3-8 cycloalkyl, substituted or unsubstituted C 3-8 cycloalkenyl, substituted or unsubstituted heterocycle or substituted or unsubstituted aryl; R 3 is H, substituted or unsubstituted —C 1-6 alkyl, substituted or unsubstituted —C 2-6 alkenyl, or substituted or unsubstituted —C 2-6 alkynyl; and R 4 is H, substituted or unsubstituted C 1-6 alkyl or substituted or unsubstituted C 3-8 cycloalkyl, substituted or unsubstituted C 3-8 cycloalkenyl, substituted or unsubstituted heterocycle or substituted or unsubstituted aryl.