Patent ID: 8450344

Claim:
A compound of formula (I): or any optical isomer, diastereomer, enantiomer, tautomer, or physiologically acceptable salt thereof; wherein R 1 and R 2 are, independently, hydrogen, C 1 -C 4 alkyl, C 2 -C 4 alkenyl, C 2 -C 4 alkynyl, C 1 -C 4 carbonyl, C 1 -C 4 carbonylamino, C 1 -C 4 alkoxy, C 1 -C 4 sulfonyl, C 1 -C 4 sulfonylamino, C 1 -C 4 thioalkyl or C 1 -C 4 carboxyl; or R 1 and R 2 combine to form a heterocycloalkyl ring of at least 5 and at most 8 member atoms, or R 1 and R 3 combine to form a heterocycloalkyl ring of at least 5 and at most 8 member atoms; wherein one of R 3 and R 4 is an aryl group, a heteroaryl group, a cycloalkyl group, a heterocycloalkyl group, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, or C 2 -C 8 alkynyl, and the other of R 3 and R 4 is hydrogen or C 1 -C 4 alkyl, the stereocenters being either ‘R’ or ‘S’ in configuration independently; and wherein X 1 and X 2 are, independently, hydrogen, hydroxyl, halogen, C 1 -C 4 alkyl, C 2 -C 4 alkenyl, C 2 -C 4 alkynyl, amino, nitro, cyano, C 1 -C 4 carbonyl, C 1 -C 4 carbonylamino, C 1 -C 4 alkoxy, C 1 -C 4 sulfonyl, C 1 -C 4 sulfonylamino, C 1 -C 4 thioalkyl or C 1 -C 4 carboxyl.