Dichloromethane → Hydrochloric Acid

Participants

Reaction Steps

A solution of 4-(4-hydroxy-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.5 g, 5.4 mmol) in dry tetrahydrofuran (5 mL) is added to suspension of sodium hydride (431 mg, 60% in oil, 10.8 mmol) in dry tetrahydrofuran (35 mL). After 15 minutes reaction time, a solution of 1-bromomethyl-4-trifluoromethyl-benzene (1.9 g, 8.1 mmol) in tetrahydrofuran (5 mL) is added. The reaction is stirred for 16 hours at room temperature, is filtered and concentrated under vacuum. The residue obtained is diluted in ethyl acetate (40 mL) and the organic layer is washed with water (3×20 mL), is dried over magnesium sulfate, filtered and concentrated under vacuum. The residue obtained is dissolved in a 1 to 1 mixture of dichloromethane and trifluoroacetic acid (30 mL), and stirred for 30 minutes. The mixture is then concentrated under vacuum, and co-evaporated in dichloromethane (30 mL). The resulting residue is diluted in diethylether (5 mL) and a molar solution of hydrochloric acid in diethylether is added (10 mL). The precipitate formed is filtered, washed with diethylether (10 mL) and dried under vacuum. The desired product is isolated as hydrochloride as a colorless solid in the presence of traces of solvent.

Provenance & Evidence