Benzothiazoline derivatives. II. Preparation of N‐substituted derivatives of 2‐benzothiazolinethione by thiation of the 2‐oxo analogs

Abstract

AbstractThuiation of the benzoate and acetate esters of 3‐(2‐hydroxyethyl)‐2‐benzothiazolinone (Ig) gave the corresponding thiones. The benzoate was then deblocked to yield 3‐(2‐hydroxyethyl)‐2‐benzothiazolinethione (Ik), a compound not accessible by direct addition or substitution. Attempts to introduce a chlorine (or bromine) atom in place of the hydroxy 1 group in the latter compound or its S‐isomer, 2‐(2‐hydroxyethylthio)benzothiazole (11a), gave 2,3‐dihydrothiazolo‐[2,3‐b ] benzothiazolium chloride (or bromide) (IIIa or b). The latter compound undergoes dihydrothiazolo ring opening when treated with sodium hydroxide or sodium sulfide to give bis[2‐(2‐benzolhiazolinon‐,3‐yl)ethyl]disulfide (IVc) or bis[2‐(2‐benzothiazolinethion‐3‐yl)ethyl] disulfide (lVb),respectively. 2‐Benzothiazolinethione reacted with ethylenimine and with N‐phenylethylenimine to give S‐substituted derivatives. Addition to vinyl n‐butyl ether gave the expected N‐substituted derivative, which was found to undergo removal of the butyoxyethyl group when subjected to conventional conditions for ether cleavage.