Studies on Derivatives of Substituted Benzenesulf onyl Carbamic Acid.IV

Abstract

When N-substituted benzenesulfonyl-N'-alkyl thiourea is treated with water in the presence of selenium dioxide, the corresponding urea and red selenium are formed in a theoretical yield. Furthermore, upon treatment with methanol, amines, or butylmercaptan the thiourea gave the corresponding O-methylisourea, uanidines, or S-butylisothiourea in a good yield in one-step process.Since selenium dioxide is soluble in water as well as most of the organic solve-nts, the above mentioned reaction proceeds with ease at room temperature.The reaction between selenium dioxide and thiourea has not been reported in the literature to date. It is assumed that the reaction takes place through an inte-rmediate carbodiimide with subsequent attack by the nucleophillic reagent. A small IR absorption peak attributable to carbodiimide was noted at 2150 cm-1 in a chlor-oform solution of thiourea and selenium dioxide to support this assumption. Attempts to isolate the carbodiimide from such mixtures, however, failed.