L-Aspartic Acid → N-(Benzyloxycarbonyl)aspartic acid

Participants

Reaction Steps

In most cases the Z-Asp dialkali metal salt was prepared in a 1 liter multi-necked flask equipped with a reflux condenser, two dropping funnels, a thermometer, a pH probe and a mechanical stirrer. L-Aspartic acid and water were charged into the flask and a 25% NaOH solution was added with stirring until the L-aspartic acid was fully dissolved. Benzyl chloroformate was added to the reaction mixture with sufficient sodium hydroxide solution to maintain the reaction mixture within the desired pH range. After the reaction was completed, each reaction mixture was separated into two equal portions and the Z-Asp was isolated under the conditions set forth in TABLE I. The temperatures of the crystallizations were controlled as shown in TABLE I. The product analyses are also set forth.

Provenance & Evidence