Hydrochloric Acid → 1-Carbobenzoxy-4-piperidinecarboxylic Acid

Participants

Reaction Steps

To a stirred solution of piperidine-4-carboxylic acid (5.0 g, 38.7 mmol) and NaOH (1.86 g, 46.5 mmol) in H2O (15 ml) was added dropwise a 50% solution of benzyl chloroformate in toluene (13.6 mL, 40.6 mmol) over a period of half an hour at 0° C. The reaction mixture was stirred at room temperature for 6 hours. The progress of the reaction was monitored by TLC. After completion, the reaction mixture was acidified with dil. HCl (pH 3) and extracted with ethyl acetate (3×100 ml). The combined organic phases were dried over sodium sulfate and concentrated. The crude product was purified by flash column chromatography (silica gel, elution with 30% ethyl acetate/n-hexanes) to afford piperidine-1,4-dicarboxylic acid monobenzyl ester (VI) (6.5 g, 64%) as a pale yellow oil.

Provenance & Evidence