1,3-Dibromopropane → 4-(3-Bromopropoxy)-2-[(4-chlorophenoxy)methyl]-1-[3-[1-(t-butoxycarbonyl)piperidin-4-yl]propyl]benzimidazole

A solution of 1,3-dibromopropane (41.3 mg, 0.3 mmol, 1.5 eq) in anhydrous N,N-dimethylformamide (2 ml) was treated with a solution of 4-hydroxy-2-[(4-chlorophenoxy)methyl]-1-[3-[1-(t-butoxycarbonyl)piperidin-4-yl]propyl]benzimidazole (100 mg, 0.2 mmol, 1 eq) in anhydrous N,N-dimethylformamide (1 ml). The resulting mixture was stirred for twelve hours. The reaction was quenched by the addition of water (10 ml). The aqueous fraction was extracted with diethyl ether (3×10 ml). The organic fractions were combined, washed with water (3×10 ml), and brine (1×10 ml), and then dried over sodium sulfate. The solvents were removed in vacuo. The residue was subjected to column chromatography to yield the desired title product as a white crystalline product.