Patent ID: 7838520

Claim:
A histone deacetylase inhibitor of formula (3): or a pharmaceutically acceptable salt thereof, wherein Ar 3 is arylene or heteroarylene, either of which is optionally substituted; Cy 3 is optionally substituted, heteroaryl which is optionally fused to one or two aryl or heteroaryl rings, or to one or two saturated or partially unsaturated cycloalkyl or heterocyclic rings, each of which rings is optionally substituted; provided that when Cy 3 has —C(O)—, —C(S)—, —S(O)—, or —S(O) 2 — in the ring, then Cy 3 is not additionally substituted with a group comprising an aryl or heteroaryl ring; and X 2 is selected from the group consisting of a chemical bond, L 3 and W 1 -L 3 , wherein W 1 , at each occurrence, is S, O, or N(R 9 ), where R 9 is selected from the group consisting of hydrogen, alkyl, aryl, and aralkyl; and L 3 is C 1 -C 4 alkylene, C 2 -C 4 alkenylene, or C 2 -C 4 alkynylene; provided that X 2 does not comprise a —C(O)— or —C(S)— group; and further provided that when Cy 3 is pyridine, then X 2 is L 3 or W 1 -L 3 .