A concise synthesis of substituted thiourea derivatives in aqueous medium.

An efficient method for the synthesis of symmetrical and unsymmetrical substituted thiourea derivatives by means of simple condensation between available building blocks such as amines and carbon disulfide in aqueous medium is presented. This protocol works smoothly with aliphatic primary amines to afford various di- and trisubstituted thiourea derivatives. The present method is also useful in synthesizing various substituted 2-mercapto imidazole heterocycles. This method proceeds through a xanthate (amino dithiol deivative) intermediate, unlike isothiocyanate as in an earlier known method.