Copper-Catalyzed Oxidation Of 2-Arylmethyl Benzimidazoles

Benzimidazole derivatives is an important five-membered nitrogen-containing heterocyclic compound. Its considerable stock in nature and widespread, and its use is also more diverse. Benzimidazoles exhibit wide ranges of biological activity such as anticancer, phosphodiesterase inhibitory activity, histamine or N- methyl -D- aspartate receptor antagonist activity, proton pump inhibitory activity, antihypertensive and antivirus. Currently, many medicines made from benzimidazole skeleton structure has been widely used clinically to treat a variety of diseases such as gastric ulcer drug omeprazole and lansoprazole and so on. In addition, benzimidazoles can be ueed as a excellent organic ligands in coordination chemistry, catalysis and molecular recognition and other fields as well. Based on this, synthesis, modification and application of functional benzimidazole and its derivatives has drawed the interest of the researchers from all over the world.In summary, a copper-catalyzed oxidation reaction has happened on 2- benzyl benzimidazoles with O2 in the air as a oxidant. Thesis includes the following components:First, o-phenylenediamine and acid has been mixed in the ethylene glycol to form 2-benzyl benzimidazoles, which has been tested in the novelty search to show whether it has been synthesised or not.Then,we use the substances we have just made to be oxidated.with the 02 in the air as a oxidant and copper salt as a catalyst.The 2-arylmethylidene-1H-benzo[d]imidazoles was characterized by 1H-NMR and 13C-NMR. After that, we discussed the condition of the reaction by the method of orthogonal test. The best condition of this reaction is:using DMF as solvent, Cu(OAc)2 as catalyst and NaOH as alkali.the mixture is heated to 120℃ and kept for 24 hours. In this condition, the yield of 2-arylmethylidene-1H-benzo[d]imidazole is more than 50%. At last, the universality of the moethod has been tested, and the possible mechanism has been dicussed.