NOVEL HETEROPENTALENES. SYNTHESIS OF HETEROPENTALENES FROM TETRAHYDROIMIDAZO -(1,2,4)-THIADIAZOLES AND CONVERSION OF CERTAIN HETEROPENTALENES TO BENZOTHIAZOLE DERIVATIVES

Article abstract of DOI:10.1016/S0040-4020(01)88906-7

Oxidation of 1-phenylcarbamoylimidazolidine-2-thione gives 2,3,5,6-tetrahydro-2-phenylimidazo<1,2-d>-(1,2,4)-thiadiazole-3-one which undergoes addition reactions with heterocumulenes leading to various heteropentalenes.Oxidation of 1-phenylthiocarbamoylimidazolidine-2-thione yields 1-(benzothiazol-2-yl)-imidazolidine-2-thione, also obtained by acid catalysed decomposition of 3,4-ethano-2,3,4,5-tetrahydro-2,5-bisphenylimino-1,6,6aS^IV-trithia-3,4-diazapentalene.A similar acid catalysed decomposition to a benzothiazole occurs with 2,3,4,5-tetrahydro-1,6-diphenyl-3,4-propano-6aS^IV-thia-1,3,4,6-tetraazapentalene-2,5-dithione.