Synthesis of unsymmetrically substituted 4H‐1,2,4‐triazoles

A general method was developed for the synthesis of unsymmetrically 3,5‐disubstituted 4H‐1,2,4‐tria‐zoles (Ph, H or Ph, CH3) with allyl or benzyl groups in the 4‐ring position. The reaction of the corresponding 3,5‐disubstituted 1,3,4‐oxadiazoles with allylamine or benzylamine gave the desired compounds. The oxadiazoles were prepared by heating at 100° N,N'‐diacylhydrazines with phosphorus pentoxide.