The oxidation products of 1-Alkyl-3-arylthioureas: A chemical and spectral study

Abstract

The oxidation of 1-alkyl-3-arylthioureas with hydrogen peroxide in acidic aqueous ethanol yields 2,4-dialkyl-3,5-bis(arylimino)-1,2,4- thiadiazoles and N,N?-dialkyl-N?-aryl-N-benzothiazolylguanidines as the final products. The former were found to rearrange into the latter in acidic solutions. The formation of amidinothioureas as the precursors of thiadiazoles is established by their isolation from solutions which were partly oxidized. The reduction of the thiadiazole afforded an amidino-thiourea which was different from the one obtained by partial oxidation of thiourea. The reaction of benzenesulphonyl chloride on these thioureas also yielded amidinothioureas. The N.M.R. and mass spectra of the products obtained by the oxidation of these thioureas are also discussed briefly.