Combine (1H-benzimidazol-2-yl)(1-benzylpiperidin-4-yl)amine (0.5 g, 1.6 mmol) and tetrahydrofuran (10 mL). Cool to −78° C. Add dropwise, a solution of potassium bis(trimethylsilyl)amide (3.6 mL, 0.5 M in toluene, 1.8 mmol). After 30 minutes, add 2-chloroethyl ethyl ether (0.2 g, 1.8 mmol). Warm to ambient temperature and heat to reflux. After 4 hours, add 2-chloroethyl ethyl ether (0.2 g, 1.8 mmol) and tetrabutylammonium bromide (0.1 g). After 12 hours, cool to ambient temperature and add water. Separate the organic layer and extract the aqueous layer with dichloromethane. Dry the combined organic layers over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with 2% triethylamine/10% methanol/ethyl acetate to give (1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)(1-benzylpiperidin-4-yl)amine: Rf=0.55 (2% triethylamine/10% methanol/ethyl acetate).
