Eight 5-substituted-1,3,4-oxadiazole-2-ones were synthesized using substituted benzoic hydrazides as starting materials and triphosgene as cyclization reagent at ambient temperature with high purity and good yields.Their structures were characterized by IR,MS,1H NMR and elemental analysis.The salient features of this method included the simple reaction set-ups,safety,short reaction time and high yields of products.
