Acetic Anhydride → N-(Trifluoroacetyl)-L-Asp-L-Phe-OMe

Participants

Reaction Steps

In 63.3 g of acetic acid, 22.9 g (0.1 mole) of N-trifluoroacetyl-L-aspartic acid was suspended and 10.2 g (0.1 mole) of acetic anhydride was added. The mixture was warmed to 55°-60° C. and stirred for 6 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 2 hours with stirring at the same temperature. Precipitated crystals were filtered, washed and dried. Crystals of N-trifluoroacetyl-α-L-aspartyl-L-phenylalanine methyl ester were obtained in the yield of 29.3 g (79.0% yield on L-phenylalanine methyl ester hydrochloride). The crystals thus obtained were analyzed by high performance liquid chromatography to find α-isomer alone.

Provenance & Evidence