Abstract The synthesis of a series of substituted 2-(piperazin-1-yl) benzothiazole/ benzoxazole coupled with 1, 3, 4-oxadiazole-2-thiol pharmacophore (8a–t) is described using a three carbon spacer (Jones and Helm, Drugs 69: 1903–1910, 2009). The structures of the compounds were confirmed by NMR and mass spectral data. All the synthesized compounds have been evaluated for their cytotoxicity towards five human cancer cell lines ...