Simple and mild procedures for synthesis of benzimidazole derivatives using heterogeneous catalyst systems

TsOH/graphite and N,N-dimethylaniline/graphite were found to be catalyst systems for condensation reaction of o-phenylendiamine with different aldehydes to form benzimidazole derivatives under mild and simple conditions. The graphite was easily recovered by a simple extraction and could be reused without decrease of activity in the presence of fresh TsOH and N,N-dimethylaniline.