Patent ID: 8754117

Claim:
A compound having a structure of formula (I) or a pharmaceutically acceptable salt, solvate, enantiomer, diastereomer, racemic mixture, enantiomerically enriched mixture, or enantiomerically pure form thereof: wherein R 1 is selected from H, C 1 -C 3 substituted or unsubstituted alkyl and C 1 -C 3 substituted or unsubstituted heteroalkyl; R 2 and R 2a are independently selected from H, C 1 -C 3 substituted or unsubstituted alkyl, C 1 -C 3 substituted or unsubstituted heteroalkyl, and OR 3 R 3 is selected from H, C 1 -C 3 substituted or unsubstituted alkyl and C 1 -C 3 substituted or unsubstituted heteroalkyl; R 5 is selected from H, C 1 -C 3 substituted or unsubstituted alkyl, C 1 -C 3 substituted or unsubstituted heteroalkyl, and OR 6 R 6 is selected from H, C 1 -C 3 substituted or unsubstituted alkyl and C 1 -C 3 substituted or unsubstituted heteroalkyl is selected from: Ar is selected from wherein X 1 and X 2 are independently selected from H and halogen with the proviso that at least one of X 1 and X 2 is halogen.