50 gm of [1H-Benzimidazole-2-n-propyl-4-methyl-6-(1′methyl benzimidazole-2′-yl)] was added to 200 ml dimethyl sulfoxide and 50 gm of potassium hydroxide. To this was added 60 gm of methyl-4-(bromomethyl)biphenyl-2-carboxylate at ambient temperature. The contents were stirred for 2 hours at 25-30° C., then heated to 40-50° C. and maintained for 2 hours. About 500 ml water was added to the reaction mixture at room temperature and acidified to pH 4 with acetic acid. The reaction mixture was filtered and washed with purified water, dried under reduced pressure at 50-60° C. to give 80 gm (88%) of the title product.
