Phosphorus trichloride → N-acetoacetyl-L-aspartyl-L-phenylalanine methyl ester

Participants

Reaction Steps

Crude disodium N-acetoacetylaspartate, 28.51 parts, was stirred with 200 parts by volume of ethyl acetate and 11.7 parts by volume of acetic acid at 0°-5° C. under argon while 4.37 parts by volume of phosphorous trichloride was added dropwise. The resulting mixture was allowed to warm to ambient temperatures while stirring for 20 hours. To the resulting solution which contains N-acetoacetyl-L-aspartic anhydride was added dropwise over a 2 hour period 122 parts by volume of 0.9M L-phenylalanine methyl ester in dioxane. After continued stirring for 20 hours, the solvent was evaporated under vacuum at 35°-40° C. Toluene, 200 parts by volume, was added to the residue and the evaporation was repeated, giving crude N-acetoacetyl-L-aspartyl-L-phenylalanine methyl ester as a semi-solid yellow residue.

Provenance & Evidence