4-Piperidinecarboxylic acid → 1-Carbobenzoxy-4-piperidinecarboxylic Acid

Participants

Reaction Steps

A solution of isonipecotic acid (5.0 g, 38.72 mmol) in 10% aqueous sodium carbonate (100 mL) was cooled to 0° C. and treated with benzyl chloroformate (7.93 g, 46.75 mmol). The resulting biphasic mixture was allowed to warm to room temperature over 2 h, at which time it became homogeneous. The mixture was washed with ether (2×50 mL), then was acidified to pH~2 by addition of concentrated hydrochloric acid. The aqueous solution was extracted with ether (2×100 mL). The organic extracts were washed with brine (50 mL), combined, dried (Na2 SO4), filtered and evaporated to afford the product as a clear oil which slowly crystallized on standing (9.64 g, 36.6 mmol, 95%).

Provenance & Evidence