Process for producing an addition compound of a dipeptide ester and an

Abstract

A process for producing an addition compound of N-benzyloxycarbonyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester and phenylalanine methyl ester. Benzyloxycarbonylation of the amino group of L-aspartic acid by benzyloxycarbonylchloride in the presence of a base and esterification of phenylalanine containing its L-body by methanol in the presence of an acid are carried out and both the reaction solutions are admixed after residual methanol is removed from the esterification reaction solution. A proteolytic enzyme is added to the resulting mixture solution after it is adjusted to have a pH, value, at which no substantial deactivation of the enzyme occurs. The reaction of N-benzyloxycarbonyl-L-aspartic acid and phenylalanine methyl ester is carried out in the solution at a pH, at which the proteolytic enzyme exerts the enzymatic activity to deposit the addition compound which is then recovered.