N-L-ALPHA-ASPARTIL-L-PHENYLENIN (ASPARTAME) 1-METHYL ESTER PREPARATION OF THE ALPHA ISOMER FOR THE ISOMER BETA IN A REACTION FOR THE PREPARATION OF THE N-L-

摘要

An improved coupling step of an alpha -APM manufacturing process is disclosed. The solvents in the coupling step are adjusted in one of two ways to improve the alpha - to beta - isomer ratio of the product of the coupling step, alpha , beta protected L-aspartyl-L-phenylalanine or lower alkyl ester thereof. In one manner, the solvent may comprise an increased concentration of a carboxylic acid such as acetic acid alone. In the other manner, one or more additional solvents along with a carboxylic acid such as acetic acid in conventionally known concentrations are used.