PREPARATION OF OPTICALLY ACTIVE NNACYLAMINO ACID

摘要

PURPOSE:To prepare the title optically active isomer, continuously, in high purity and yield, by crystallizing a super-saturated solution of N-acyl-DL-amino acid in the presence of crystals of the optically active isomer, under racemizing conditions. CONSTITUTION:A super-saturated solution of an N-acyl-DL-amino acid (e.g. N- aliphatic acylamino acid, N-aromatic acylamino acid, etc.) is seeded with the crystals of an optically active N-acylamino acid, and crystallized under racemizing conditions, e.g. in the presence of a racemizing catalyst (e.g. lower aliphatic carboxylic acid anhydride, aromatic carboxylic acid anhydride, etc.) at 30 deg.C to the boiling point of the solution.