Methyl L-phenylalaninate hydrochloride → N-formyl-beta-L-aspartyl-L-phenylalanine methyl ester

Participants

Reaction Steps

In 179.4 g of methylenechloride, 14.3 g (0.1 mole) of N-formyl-L-aspartic anhydride was suspended, and 9.2 g (0.11 mole) of sodium acetate was added at 20°-25° C. with stirring, and 21.6 g (0.1 mole) of L-phenylalanine methyl ester hydrochloride was added at the same temperature during 30 minutes. The mixture was reacted for 5 hours with stirring at the same temperature. Precipitated crystals were filtered, washed and dried. Crystals of a mixture of N-formyl-α-L-aspartyl-L-phenylalanine methyl ester, and N-formyl-β-L-aspartyl-L-phenylalanine methyl ester were obtained in a yield of 30.0 g. The crystals obtained were analyzed by high performance liquid chromatography to give a ratio of α-isomer:β-isomer of 75.0:25.0. The crystals were purified by a conventional method to obtain pure crystals of N-formyl-α-L-aspartyl-L-phenylalanine methyl ester. The yield was 16.1 g (50% yield on L-phenylalanine methyl ester hydrochloride).

Provenance & Evidence