Conversion of N-(1-oximino-1-phenylpropyl-2)-α-phenylnitrone into imidazole N-oxide derivatives

Treatment of N-(1-anti-oximino-1-phenylpropyl-2)--phenylnitrone with benzoic anhydride in benzene leads to simultaneous formation of benzoyl derivatives both of the corresponding nitrone and of 1-hydroxymethyl-2, 4-diphenyl-3-imidazoline-3-oxide. Treatment of the latter with hydrogen chloride led to the isolation of 5-methyl-2, 4-diphenylimidazol-3-oxide. Its isomer 4-methyl-2, 5-diphenylimidazol-3-oxide is formed by the action of HCl on syn and anti isomers of N-(1-oximino-1-phenylpropyl-2)--phenylnitrone. IR and UV spectra are used to determine the structures of the compounds, which are confirmed by synthesis.