Water → N-(Benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester

Beteiligte Stoffe

Reaktionsschritte

In 100.4 g of acetic acid, 25.1 g (0.1 mole) of N-benzyloxycarbonyl-L-aspartic anhydride was suspended and 22.7 g (0.1 mole) of L-phenylalanine methyl ester sulfate was added with stirring at 5°-10° C. Successively 17.6 g (0.21 mole) of sodium acetate was added at the same temperature. The reaction was carried out for 4 hours with stirring at the same temperature. Thereafter 87.1 g of water was added to the reaction mixture to adjust the concentration of organic carboxylic acid to 53.5% by weight. After cooling to 0°-5° C., precipitated crystals were filtered, washed and dried. Crystals of N-benzyloxycarbonyl-α-L-aspartyl-L-phenylalanine methyl ester were obtained. The yield was 31.2 g (73.1% yield on L-phenylalanine methyl ester sulfate).

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