The reaction of benzoyldicyandiamide [PhCO·NH·C(NH2):N·CN] with hydroxylamine hydrochloride, to give oxadiazoles

Abstract

When benzoyldicyandiamide is treated with hydroxylamine hydrochloride, the product is a mixture of 3-phenyl-5-ureido-1,2,4-oxadiazole (I)(major component) and 5-phenyl-3-ureido-1,2,4-oxadiazole (II). The infrared spectrum of the urea (I) is discussed. The urea (II) is degraded by alkali to 3-amino-5-phenyl-1,2,4-oxadiazole; further degradation gives benzoic acid. 5-Phenyl-3-ureido-1,2,4-oxadiazole has been prepared in good yield by the Curtius reaction from 3-ethoxycarbonyl-5-phenyl-1,2,4-oxadiazole.