One-Pot Synthesis of (arylmethylene)bis(naphthalene-2-yl-sulfane Catalyzed by PVPP-p-TSA

Replacing oxygen by sulfur in a functional group does not just correspond to a small step in the periodic table, but may well lead to another world of chemistry. The differences in chemical reactivity and stability can be explained by the change in atomic radii, in electronegativity, and in polarizability between oxygen and sulfur [1]. The protection of carbonyl groups as dithioacetals is a common and popular practice in organic chemistry [2]. The importance of thioacetals is due in part to their inherent stability under usual acidic or basic conditions and because of their behavior as masked acyl anions or methylene functions [3]. In this research, a convenient and an efficient method for the synthesis of (arylmethylene)bis(naphthalene-2-yl-sulfane) derivatives is described. The reaction proceeded via condensation of aldehydes with 2-thionaphthol in thepresence of polyvinylpolypyrrolidone-supported P-toluene sulfonic acid (PVPPp- TSA). These reactions were studied under different conditions. In terms of reaction time and yield, the optimum results were obtained for the synthesis of (arylmethylene)bis(naphthalene-2-yl-sulfane) derivatives in ethanol under reflux conditions. Clean methodologies, easy work-up procedure, high yield and simple preparation of the catalyst are some advantages of this work.