Systems with annulated thioxo azepinone moiety: an access through heterocyclic carbodithioate ring expansion

New 1-oxo-2-thioxo-1,2,4,5-tetrahydrobenz[d]azepine and 1-oxo-2-thioxo-1,2,4,5-tetrahydroazepino[4,5-b]indole derivatives were conveniently obtained by the novel recyclization reaction of (methylthio)carbonothioylsubstituted heterocyclic quaternary salts with expansion of the dihydropyridine ring.