Dissolve 1-benzyl-piperidine-4-carboxamidine dihydrochloride (2 g; 1.00 equiv; 6.89 mmoles) in dimethylformamide (90 mL). Add powdered potassium carbonate (4 equiv; 27.56 mmoles; 3.8095 g) and warm to ˜45° C. Add 3-chloro-4-fluoro-phenacyl bromide (2.00 equiv; 13.782 mmoles; 3.5366 g) in 8 mL with DMF dropwise over 40 minutes. Dilute with 50 mL ethyl acetate, stir 5 min and filter. Evaporate and partition with ethyl acetate/sat. sodium bicarbonate, wash organic layer with water, then saturated aqueous sodium chloride. Dry with MgSO4, filter and evaporate to red foam. Purify over flash silica gel with 0-10% MeOH/ACN. Pool fractions to give 1.9772 g (5.346 mmol, 78%) 1-Benzyl-4-[5-(3-chloro-4-fluoro-phenyl)-1H-imidazol-2-yl]-piperidine.
