Acetic Anhydride → 33605-76-4

Participants

Reaction Steps

In 28.6 g of acetic acid, 16.1 g (0.1 mole) of N-formyl L-aspartic acid was suspended and 10.2 g (0.1 mole) of acetic anhydride was added. The mixture was warmed to 50°-55° C. and stirred for 5 hours at the same temperature. After finishing the reaction, the resulting mixture was cooled to 15°-20° C. and then 9.2 g (0.11 mole) of sodium acetate and 20.5 g (0.095 mole) of L-phenylalanine methyl ester hydrochloride were successively added at the same temperature. The reaction was carried out for 4 hours with stirring at the same temperature. The reaction mixture was then concentrated and 57.2 g of water was added and cooled to 10°-15° C. Precipitated crystals were filtered, washed and dried. Crystals of N-formyl-α-L-aspartyl-L-phenylalanine methyl ester thus obtained were 28.2 g. The crystals were analyzed by high performance liquid chromatography to give a ratio of α-isomer:β-isomer of 81.0:19.0. The crystals were purified with a conventional method to give high purity crystals of N-formyl-α-L-aspartyl-L-phenylalanine methyl ester. The yield was 20.8 g (68.0% yield on L-phenylalanine methyl ester hydrochloride).

Provenance & Evidence