Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Steps

A solution of piperidin-4-yl-carbamic acid tert-butyl ester (400 mg; 2.0 mmol), 5-fluoro-2-nitrobenzotrifluoride (418 g; 2.0 mmol) and potassium carbonate (1.11 g; 8.0 mmol) in dimethylsulfoxide (5 mL) is heated at 100° C. for 5 hours. The mixture is allowed to reach room temperature, is diluted with ethyl acetate (50 mL) and filtered. The filtrate is washed with aq. sat. sodium hydrogencarbonate (2×10 mL) and with water (10 mL). The organic layer is then dried over magnesium sulfate and evaporated under reduced pressure to afford the desired product (797 mg; 2.0 mmol). The [1-(4-Nitro-3-trifluoromethyl-phenyl)-piperidin-4-yl]-carbamic acid tert-butyl ester obtained (797 mg; 2.0 mmol) is dissolved in a 2 to 1 mixture of dichloromethane and trifluoroacetic acid (5 mL) and the resulting solution is stirred at room temperature for 1 hour. After concentration under reduced pressure, the residue obtained is co-evaporated with dichloromethane (2×10 mL), is then dissolved in diethylether (2 mL) and a molar solution of hydrochloric acid in diethylether (5 mL) is added. The precipitate formed is triturated in ethylacetate (5 mL), filtered and is dried under high vacuum to yield the desired product as hydrochloride (624 mg; 1.6 mmol).

Provenance & Evidence