PRODUCTION OF HIGHLY PURIFIED N-CARBONYLAMINO ACID ESTER

摘要

PROBLEM TO BE SOLVED: To produce the subject compound in a simple method suppressing generation of impurities as little as possible by reacting an amino acid ester with phosgene in an organic solvent containing an alcohol amount smaller than a specific value. SOLUTION: This compound (e.g. N-carbonyl-L-phenylalanine methyl ester) is obtained by reacting an amino acid ester with phosgene by using an amount of alcohol in the organic solvent as <=2.5 wt.% based on the amino acid ester in an organic solvent. The amino acid ester is obtained by subjecting an amino acid to esterification with an acid catalyst in an alcohol and is preferably an amino acid ester having an aromatic ring (e.g. a methyl ester body or ethyl ester body of phenyalanine or S-phenylcysteine). Preferably, a using amount of phosgene gas is 1-10 times of the amino acid ester and the reaction is performed at 30-200 deg.C.