A series of symmetrical and unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles were efficiently synthesized from the cyclodehydration of diacylhydrazines by using silica-supported dichlorophosphate as a recoverable cyclodehydrant in solvent-free medium under microwave irradiation. This protocol has advantages of no corrosion, no environmental pollution, accelerated rate, high yield and simple work-up procedure.
silica-supported dichlorophosphate; diacylhydrazine; 1,3,4-oxadiazole; microwave irradiation; solvent-free synthesis