Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Steps

4-Oxo-piperidine-1-carboxylic acid tert-butyl ester (500 mg; 2.51 mmol), 3-trifluoromethyl-phenylamine (404 mg; 2.51 mmol) and sodium triacetoxyborohydride (1.59 g; 7.53 mmol) are suspended in dichloroethane (25 mL). After 1 day reaction time at room temperature, the mixture is diluted with dichloromethane (100 mL) and the organic layer is washed with aq. sat ammonium chloride (2×50 mL) and water (3×50 mL), is then dried over magnesium sulfate and is concentrated under reduced pressure. The residue obtained is triturated with cold diethylether (10 mL) until precipitation is observed. The precipitate is filtered and dried under vacuum. The crude product is dissolved in dichloromethane (5 mL) and trifluoroacetic acid (5 mL) is added dropwise under vigorous stirring. After 30 minutes reaction time, the mixture is concentrated under reduced pressure and co-evaporated with dichloromethane (2×10 mL). The residue obtained is then dissolved in diethylether (5 mL) and a molar solution of hydrochloric acid in diethylether (5 mL) is added. The precipitate formed is filtered and dried under high vacuum to afford the desired product as hydrochloride (289 mg; 1.03 mmol).

Provenance & Evidence