| 摘要 |
N-Benzyloxycarbonyl aspartic acid substantially free of N-benzyloxycarbonyl aspartyl aspartic acid is prepared by introducing benzyl chloroformate gradually into an aqueous solution of the disodium salt of aspartic acid at temperatures of between 10 DEG C. and about 45 DEG C. while maintaining the pH of the aqueous solution at between 10.75 and 11.75. In a further embodiment, the mole ratio of unreacted benzyl chloroformate to the aspartic acid salt in the reaction medium is maintained preferably at no greater than 0.2. The resulting reaction mixture is acidified, e.g, with hydrochloric acid, to convert the reaction product to the free acid, which is separated from the reaction mixture, washed with water and dried to yield an essentially pure white granular product.
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