Simple one-pot synthesis of thioureas from amines, carbon disulfide and oxidants in water

Abstract

The present study reports a new facile methodology for the synthesis of symmetrical and asymmetrical thioureas by a one-pot reaction of the required amine, carbon disulfide and an oxidant, i.e., hydrogen peroxide, ethylenediaminetetraacetic acid (EDTA)/sodium percarbonate system or air. The structures of the synthesized compounds were confirmed by IR, H-1- and C-13-NMR and MS methods. A reaction mechanism is proposed based on the isolation of reaction intermediate and the determination of their structure. The synthetic benefits of the presented methods are reflected in the operational simplicity, mild reaction conditions, short reaction times, solvent recycling, high purity and yield of the products, absence of dangerous by-products and technological applicability on an industrial scale. Considering the commercial importance of thioureas, it should be emphasized that implementation of the optimal synthesis of thiourea determined in this study for industrial production could provide a concurrent alternative to the existing technologies in use.