METHOD OF PURIFYING .ALPHA.-L-ASPARTYL-L-PHENYLALANINE METHYL ESTER

摘要

Mixtures containing .alpha.-L-aspartyl-L-phenylalanine methyl ester and 3-benzyl-6-carboxymethyl-2,5-dioxopiperazine are brought into contact with hydrochloric acid in an aqueous solvent to precipitate .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride and 3-benzyl-6-carboxymethyl-2,5-dioxopiperazine, which are then separated from each other by classification. The method of the invention permits efficient purification of .alpha.-L-aspartyl-L-phenylalanine methyl ester.