Patent ID: 8101640

Claim:
A compound having the formula XIII: or a stereoisomer, pharmaceutically acceptable salt, ester, or prodrug thereof, wherein R 4 is selected from the group consisting of (1) H, (2) substituted or unsubstituted C i -C 6 -alkyl, (3) C 1 -C 6 -alkyl substituted with aryl, (4) C 1 -C 6 -alkyl substituted with heterocyclyl, and (5) C 1 -C 6 -alkyl substituted with heteroaryl; A is H or —CH(CH 3 )OH; R 1 is H or substituted or unsubstituted C 1-6 -alkyl; R 2 is selected from the group consisting of (1) H, (2) substituted or unsubstituted C 1 -C 6 -alkyl, (3) substituted or unsubstituted aryl, (4) substituted or unsubstituted heterocyclyl, (5) substituted or unsubstituted heteroaryl, (6) C 1 -C 6 -alkyl substituted with aryl, (7) C 1 -C 6 -alkyl substituted with heterocyclyl, (8) C 1 -C 6 -alkyl substituted with heteroaryl, or R 1 and R 2 together with the N atom to which they are attached can form a substituted or unsubstituted heterocyclic ring, having from 3 to 10 ring atoms, wherein 1-2 ring atoms of the heterocyclic ring system are selected from N, O and S.