Research on 1, 2, 4-triazoles

The stability of sulfides and sulfones of 1-aryltetrazoles and 4-aryl-1, 2, 4-triazoles depends on the acceptor character of the heterocyclic ring. Unlike tetrazole sulfides, triazole sulfides do not undergo hydrolysis, Tetrazole sulfones are more readily hydrolyzed than triazole ones. When an electron-donor substituent is introduced into the p-position of the phenyl ring, the rate of hydrolysis is cut. Neither triazole nor tetrazole sulfides and sulfones, not arylated at a nitrogen atom, are hydrolyzed by alkali, because of a partial decrease in positive charge at the carbon atom of the sulfoazomethine group through formation of an anion with a sextet of -electrons in the ring. Hydrolysis of sulfides and sulfones can conveniently be used to prepared 1-aryltetrazolinones-5 and 4-aryl-1, 2, 4-triazolinones-3.For Part V see 8].