ACYLATION OF BENZIMIDAZOLE BY THE REGEL-BUECHEL METHOD. 2. DEACYLATION AND DISSOCIATION OF 1-METHYL-3-ACYL-2-(1'-METHYL-2'-BENZIMIDAZOLYL)-4-BENZIMIDAZOLINES

Article abstract of DOI:10.1007/BF00761985

With excess acyl halide 1-methyl-3-acyl-2-(1'-methyl-2'-benzimidazolyl)-4-benzimidazoline is converted to an unstable 1-methyl-3-acyl-2-(1'-methyl-3-acyl-4'-benzimidazolin-2'-yl)benzimidazolium chloride, which undergoes intramolecular redox cleavage with the formation of 1,1'-dimethyl-2,2'-dibenzimidazolyl and an aldehyde and dissociates at the C-C bond that connects the benzimidazolium and benzimidazoline fragments into a carbene yield and a 1-methyl-3-acylbenzimidazolium chloride.