Patent ID: 6225493
Filing Date: 2001-05-01
Classification: C07K

Abstract:
A process of purifying N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester comprising the steps of:providing a mixture of (i) the .alpha.- and .beta.-isomers of N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester and (ii) an organic solvent;contacting the mixture with aqueous metal ion, whereby the .beta.-isomer of N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester chelates the metal ion to form a metal complex; andpartitioning the metal complex from the .alpha.-isomer of N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester.