Hydrochloric Acid → 1-Carbobenzoxy-4-piperidinecarboxylic Acid

Participants

Reaction Steps

A diethyl ether (50 ml) solution of benzyl chloroformate (36 g, 0.21 mols) was dropwise added to an aqueous solution (200 ml) of isonipecotic acid (25 g, 0.19 mols) and sodium hydrogencarbonate (49 g, 0.58 mols) with stirring at room temperature. After the addition, this was further stirred at room temperature for 15 hours. The reaction mixture was acidified with concentrated hydrochloric acid added thereto, and then extracted with ethyl acetate. The extract was washed with brine, then dried with anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was crystallized from isopropyl ether/hexane, and taken out through filtration. A colorless crystal of N-benzyloxycarbonylisonipecotic acid (36 g, 71%) was obtained.

Provenance & Evidence