Synthesis and Transformations of 4-Hydroxy-2-methylquinoline-6-carbohydrazide

Abstract

A substituted quinoline-6-carbohydrazide was synthesized by the reaction of ethyl 4-hydroxy-2-methylquinoline-6-carboxylate with hydrazine hydrate. The quinoline-6-carbohydrazide was reacted with phenyl isothiocyanate to obtain the corresponding phenylhydrazinecarbotioamide. The intramolecular cyclization of the latter in alkaline and acidic media gave quinolyl-substituted triazole and thiadiazole. The reaction of the quinoline-6-carbohydrazide with carbon disulfide in an alkaline media yielded a quinolyl-substituted 1,3,4-oxadiazole, and the reactions of the same reagent with substituted benzaldehydes gave N′-(substituted benzylidene)quinoline-6-carbohydrazides.