Hydrochloric Acid → 1-(3-Chlorophenyl)piperazin-2-one

Participants

Reaction Conditions

Reaction Steps

Through a solution of Boc-protected piperazinone from Step I (17.19 g, 55.4 mmol) in 500 mL of EtOAc at −78° C. was bubbled anhydrous HCl gas. The saturated solution was warmed to 0° C., and stirred for 12 hours. Nitrogen gas was bubbled through the reaction to remove excess HCl, and the mixture was warmed to room temperature. The solution was concentrated in vacuo to provide the hydrochloride as a white powder. This material was taken up in 300 mL of CH2Cl2 and treated with dilute aqueous NaHCO3 solution. The aqueous phase was extracted with CH2Cl2 (8×300 mL) until the analysis indicated complete extraction. The combined organic mixture was dried (Na2SO4), filtered, and concentrated in vacuo to provide the titled free amine as a pale brown oil.

Provenance & Evidence