Patent ID: 7750042

Claim:
A compound represented by the following structural formula: or a pharmaceutically acceptable salt thereof, wherein: Y is a covalent bond or a substituted or unsubstituted straight chained hydrocarbyl group; R 1 is an aliphatic group, a substituted aliphatic group, a non-aromatic heterocyclic ring, or a substituted non-aromatic heterocyclic ring; R 2 is —H, an aliphatic group, a substituted aliphatic group, a non-aromatic heterocyclic ring, a substituted non-aromatic heterocyclic ring, an aryl group or a substituted aryl group; R 3 and R 4 are independently an aliphatic group, a substituted aliphatic group, a non-aromatic heterocyclic ring, a substituted non-aromatic heterocyclic ring, an aryl group or a substituted aryl group, or R 1 and R 3 taken together with the carbon and nitrogen atoms to which they are bonded, and/or R 2 and R 4 taken together with the carbon and nitrogen atoms to which they are bonded, form a non-aromatic heterocyclic ring optionally fused to an aromatic ring; R 5 -R 6 are independently —H, an aliphatic group, a substituted aliphatic group, an aryl group or a substituted aryl group; and Z is ═O or ═S; provided that when Y is —CH 2 , R 3 and R 4 are both phenyl and R 5 -R 6 are all —H, then R 1 and R 2 are not both methyl.