The action of sodium sulphide on 1,3,4-oxadiazolium salts

Abstract

N-Aryl-1,3,4-oxadiazolium salts react with sodium sulphide to yield N′-acyl-N-aryl-N-thioacylhydrazines, which cyclise in the presence of acetic anhydride and perchloric acid to give 1,3,4-thiadiazolium perchlorates, the original oxadiazolium salts, or a mixture of the two, depending on the nature of the substituents. Oxadiazolo[3,2-a]-pyridinium salts similarly yield 1-acylaminopyridine-2-thiones, two of which have been converted into 1,3,4-thiadiazolo[3,2-a]pyridinium perchlorates.