6-Aminohexanoic Acid → 6-(((Phenylmethoxy)carbonyl)amino)hexanoic acid

Participants

Reaction Steps

The first step was to protect 6-aminocaproic acid using benzyl chloroformate to give N-benzyloxycarbonyl-6-aminocaproic acid. This first step was carried out as follows. A solution of 6-aminocaproic acid (32.8 g, 0.25M) in 75 mL of H2O and 42 mL of 6N NaOH was cooled in a salt-ice bath to below 10° C. With stirring, benzyl chloroformate, 46.9 g, 0.275M) and 2N NaOH (138 mL) were alternatively added in small portions over 90 min. After the addition was complete, the solution was brought to room temperature, and stirring was continued for an additional 1 hr. The product was precipitated by lowering the pH to 2 with concentrated HCL, and H2O was added as required to keep the suspension stirring. The white precipitate was filtered, then resuspended and triturated with 1 liter of water. The solid was filtered, washed with water, compressed and then washed with hexane. The solid was then thoroughly dried in a vacuum desiccator to yield 55 grams (83% yield) of N-benzyloxycarbonyl-6-aminocaproic acid.

Provenance & Evidence