N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide (EDC, 331 mg, 2.18 mmol) is added to a solution of 4-bromo-N-1-isopropylbenzene-1,2-diamine (180 mg, 0.786 mmol) and methyl 4-isothiocyanatobenzoate (140 mg, 0.725 mmol) in tetrahydrofuran was added. The reaction was heated to reflux for 2 hr and cooled to room temperature. The mixture was diluted with ethyl acetate and washed with 1 N HCl and saturated sodium bicarbonate solution. The organic layer was concentrated and purified by Biotage column chromatography to give methyl 4-(5-bromo-1-isopropyl-1H-benzo[d]imidazol-2-ylamino)benzoate (202 mg)
