Reaction of isothiocyanates with thiourea and amidinothioureas: Formation of S-(N-substituted thiocarbamyl)isothioureas and 1-Alkyl(or aryl)-4-imino(or arylimino)-6-iminohexahydro-1,3,5-triazine-2-thiones

Abstract

Alkyl and aryl isothiocyanates react with thiourea in the presence of alkali to yield S-(N-substituted thiocarbamyl)isothioureas. The products are identified by their chemical and mass spectral characteristics.These compounds yield 5-imino-2-alkyl(or ary1)imino-1,3,4-dithiazolidine salts when oxidized in acid medium. The parent compounds are regenerated from these dithiazolidines on reduction with hydrogen sulphide.  Condensation of isothiocyanates with amidinothiourea and aryl amidinothioureas on the other hand yields 1-alkyl(or aryl)-4,6-diiminohexahydro-1,3,5-triazine-2-thiones and 1-alkyl(or ary1)-4-arylimino-6-iminohexahydro-1,3,5-triazine-2-thione respectively.Plausible mechanisms for these reactions are discussed.