2-(1,2,4-Oxadiazol-5-yl)anilines Based on Amidoximes and Isatoic Anhydrides: Synthesis and Structure Features

An efficient one-pot method was developed for the synthesis of 2-(1,2,4-oxadiazol-5-yl)anilines via the reaction of amidoximes with isatoic anhydrides in a NaOH–DMSO medium at ambient temperature. The method allows to obtain structurally diverse substituted anilines bearing the 1,2,4-oxadiazole motif in moderate to excellent yields without the utilization of protective groups. The reaction scope includes aryl, hetaryl, and cycloalkyl amidoxime and isatoic anhydrides with different substituents in the aromatic ring as well as at the amide N atom. Structures of two anilines were studied by single crystal X-ray diffraction method and intramolecular hydrogen bonding between N atom of oxadiazole moiety and NH 2 group was revealed.