TiCl4 Promoted synthesis of benzimidazole derivatives

Differently substituted benzimidazoles have been synthesised in very good yields in solvent-free conditions from o-phenylenediamine and aldehydes in the presence of TiCl 4 as a catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.