Previously, we reported a click-chemistry based approach to the synthesis of a novel class of histonedeacetylase (HDAC) inhibitors [1]. The lead compound NSC746457 was found to be as potent as SAHA (Vorinostat). Further optimization of NSC746457 by using the HDAC2-TSA crystal structure is described herein. Docking of NSC746457 into HDAC2 binding domain suggested that the hydrophobic residue Phe210 flanking