Preparation and some reactions of 2,2-diaryl-2H-imidazole 1-oxides

Abstract

The acid-catalysed condensation of diphenylmethyleneamines with various α-hydroxyimino-ketones (1a–f) gave 2,2-diphenyl-2H-imidazole 1-oxides [(2a–f), and (8)]. These compounds react as nitrones with lithium aluminium hydride, methylmagnesium iodide, and dimethyl acetylenedicarboxylate. However, the reaction of 4-methyl-2,2-diphenyl- and 2,2,4-triphenyl-2H-imidazole 1 -oxides with sodium borohydride gave the corresponding 2H-imidazoles. Curtis rearrangement of 5-methyl-2,2-diphenyl-2H-imidazole-4-carbonyl azide 3-oxide (6) gave 7-methyl-5,5-diphenylimidazo[1,5-b][1,2,4]oxadiazol-2(5H)-one (14).