Rearrangements of Benziminazole N-Oxide

Abstract

" Oxbenzimidazole " has been shown to deoxygenate readily with phosphorus trichloride, giving benziminazole. Rearrangement with cold acetic anhydride and with benzoyl chloride gives monoacetyl- and monobenzoylbenziminazolones respectively. A N-acetyl structure for the monoacetyl compound has been established by examination of infrared spectra and by synthesis. These reactions confirm the N-oxide structure for " oxbenzimidazole ".