Advances in the synthesis of benzimidazol-2-ones

Known methods for the synthesis of benzimidazol-2-ones are considered and integrated. Approaches based on transformations of aniline derivatives, $\mathrm{N},\mathrm{N}'$-disubstituted ureas and halobenzenes are analyzed. Methods involving rearrangements of heterocyclic compounds, such as benzodiazepinones, benzodiazepinediones, quinoxalinones and tetrazolones, as well as fused and spirocyclic systems incorporating a benzimidazole moiety, are presented. A separate section is devoted to rearrangements of anthranilic acid derivatives giving benzimidazol-2-ones. The mechanisms of formation of these compounds are discussed; the attention is focused on rearrangements of quinoxalinones giving rise to bis-heterocyclic systems.
The bibliography includes 181 references.