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Benzothiazoline derivatives. II. Preparation of N ‐substituted derivatives of 2‐benzothiazolinethione by thiation of the 2‐oxo analogs
Author(s) -
Sohar Paul,
Denny George H.,
Babson Robert D.
Publication year - 1969
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570060204
Subject(s) - chemistry , benzothiazole , bromine , ether , medicinal chemistry , bromide , sulfide , yield (engineering) , sodium hydroxide , sodium sulfide , chlorine , organic chemistry , metallurgy , materials science
Thuiation 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.