<p></p> <p>The synthesis of five N,N″-substituted thiocarbamides, namely N-(naphthyl)-N″-(pentoxycarbonyl) thiocarbamide <b>(H<sub>2</sub>L1</b>), N-(2-Chloro-4-nitrophenyl)-N″-(pentoxycarbonyl) thiocarbamide(<b>H<sub>2</sub>L2</b>), N-(2-methoxy-4-nitrophenyl)-N″-(pentoxycarbonyl) thiocarbamide (H<sub>2</sub>L3), N-(3-nitrophenyl)-N″-(pentoxycarbonyl) thiocarbamide (<b>H<sub>2</sub>L4</b>) and N-(naphthyl)-N″-(2, 2, 2-trichloroethoxycarbonyl) thiocarbamide (<b>H<sub>2</sub>L5</b>) was performed by the reaction of pentoxycarbonyl chloroformate with naphthyl amine, 2-chloro-4-nitroaniline, 2-methoxy-4-nitroaniline, 3-nitroaniline, respectively, for the first four and by the reaction of 2, 2, 2-trichloroethoxycarbonyl chloroformate with naphthyl amine for the last compound. These compounds were fully characterized by using various spectroscopic (FT-IR, <sup>1</sup>H and <sup>13</sup>C NMR) and single crystal X-ray studies of <b>H<sub>2</sub>L1</b> and <b>H<sub>2</sub>L5</b>. In the crystal structure of both the compounds the (C˭S) and (C˭O) groups are trans to each other across the C−N bond. The crystal packing of <b>H<sub>2</sub>L1</b> shows that the molecules form centrosymmetric dimers connected by N2−H····S hydrogen bonds. In <b>H<sub>2</sub>L5</b> an offset face-to-face π–π stacking is observed between two naphthalene rings of two molecules. <i>In vitro</i> cytotoxicity of synthesized compounds was evaluated using five human carcinoma cell lines 2008, C13* (cervical carcinoma), A2780, A2780/CP and IGROV-1 (ovarian carcinoma). The IC<sub>50</sub> values of compounds <b>H<sub>2</sub>L2 ─ H<sub>2</sub>L4</b> demonstrated them to be very promising anticancer agents.</p
