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

Participants

Reaction Conditions

Reaction Steps

Piperidine-4-carboxylic acid (64.8 g, 0.5 mol) in H2O (50 mL) was treated with NaOH (44.0 g, 1.1 mol). The reaction mixture was cooled to 0° C. and treated with CbzCl (93.8 g, 0.55 mol). The reaction mixture was stirred at ambient temperature for 4 hours and the mixture was extracted with Et2O (3 150 mL). The aqueous phase was acidified with 6 N HCl (140 mL) and extracted with EtOAc (3 200 mL). The solution was dried over MgSO4, filtered, and concentrated to afford crude piperidine-1,4-dicarboxylic acid monobenzyl ester (120 g), which was used without further purification: MS (ESI) m/z 262 [M−H]+.

Provenance & Evidence