Oxidative Debenzylation and Cyclisation of I,5-Disubstituted 2-S-Benzyliso-4-thiobiurets: Formation of 3,5-Disubstituted Imino-1,2,4-dithiazolidines or/and the Related N-2-Benzothiazolyl-N'-substituted-S-benzylisothiocarbamides and 1,2,4-Thiadiazolines

Bromine and iodine in hot concentrated solutions in chloroform or benzene have been found to effect debenzylation of the 1,5-dieryl- and 1.alkyl-5-aryl.2-S-benzylime4-thiobiurete, followed by ring closure to the related 3,5-disubstituted imino.1,2,4-dithiazolidince. Depending on the reaction conditions, smaller or larger quantities of the related N-2-benzothiszoly1,N'-substituted-R-benzylisothiocarbamides are produced simultaneously. When the substituents in positions 1,5 in the starting isodithiobiuret are an aryl and alkyl group respectively, the related 3.5-disubstituted imino-1,2.4-dithiazolidine is the sole product. Similarly, when both 1.5-positions are substituted by alkyl groups, the related dithiazolidinen or the 1,2,4-thiadiszol­ines are the main products