Improved Convenient and Environmentally Benign Synthesis of Biological Active Benzimidazoles Using Activated Carbon and Molecular Oxygen

The reaction of 1,2-phenylenediamine with a variety of aromatic aldehydes in xylenes gave the corresponding benzimidazole derivatives in good to excellent yields (82-93%) in the presence of dry activated carbon and bubbling molecular oxygen.The present reaction involves the simple procedure, easy workup and environmentally benign materials such as molecular oxygen and reusable activated carbon.Benzimidazole derivatives have been used in human therapeutic areas as antiulcers, antihypertensives, antivirals, antifungals or anticancers and in veterinarian medicine as anthelmintic. 1They are regarded as