Sodium hydride → 1-(4-(4-Trifluoromethyl-benzyloxy)-phenyl)-piperazine

A solution of 4-(4-hydroxy-phenyl)-piperazine-1-carboxylic acid tent-butyl ester (1.5 g, 5.4 mmol) in dry tetrahydrofuran (5 mL) was added to a suspension of sodium hydride (431 mg, 60% in oil, 10.8 mmol) in dry tetrahydrofuran (35 mL). After 15 min, a solution of 1-bromomethyl-4-trifluoromethyl-benzene (1.9 g, 8.1 mmol) in tetrahydrofuran (5 mL) was added. The mixture was stirred for 16 hr at room temperature, filtered, and concentrated under vacuum. The resulting residue was diluted in ethyl acetate (40 mL), and the organic layer was washed with water (3×20 mL), dried over magnesium sulfate, filtered, and concentrated under vacuum. The resulting residue was dissolved in a 1:1 mixture of dichloromethane and trifluoroacetic acid (30 mL). The mixture was then stirred for 30 min. Afterward, the mixture was concentrated under vacuum, taken up in dichloromethane (30 mL), and evaporated to dryness. The resulting residue was diluted in diethylether (5 mL) and then combined with a molar solution of HCl in diethylether (10 mL, 1M). A precipitate formed, which was filtered, washed with diethylether (10 mL), and dried under vacuum. The desired product was isolated as a hydrochloride salt with traces of solvent.