Ethyl Acetate → N-(Trifluoroacetyl)-L-Asp-L-Phe-OMe

Participants

Reaction Steps

In 84.4 g of ethyl acetate 21.1 g (0.1 mole) of N-trifluoroacetyl-L-aspartic anhydride was suspended, and 9.2 g (0.11 mole) of sodium acetate was added at -5 - 0° C. with stirring, and 21.6 g (0.1 mole) of L-phenylalanine methyl ester hydrochloride was added at the same temperature. The mixture was reacted for 3 hours with stirring at the same temperature and concentrated under reduced pressure. Thereafter 63.3 g of acetic acid was added and stirred for an hour at 15°-20° C. Precipitated crystals were filtered, washed and dried. Crystals of N-trifluoroacetyl-α-L-aspartyl-L-phenylalanine methyl ester were obtained in a yield of 30.6 g (78.5% yield on L-phenylalanine methyl ester hydrochloride). The crystals obtained were analyzed by high performance liquid chromatography to give a ratio of α-isomer:β-isomer of 99.0:1.0.

Provenance & Evidence