Oxidative cyclisations of o-substituted anilines and benzoic acids with manganese dioxide
Abstract
In a neutral medium, oxidation by manganese dioxide of N-o-aminophenyl-, N-o-aminobenzyl-, and N-o-carboxyphenyl-amines gave benzimidazoles, quinazolones, and benzoxazinones, respectively. Similarly, o-alkylbenzoic acids yielded phthalides. Reaction mechanisms and spectral data of various products are discussed.