SELECTIVE N-ACETYLISATION OF AMINO ACIDS BY CONVERSION WITH KETENES IN AQUEOUS SOLUTION

摘要

: A process for the N-acetylisation of amino acids by reaction with ketenes in aqueous solutions. The process of the invention comprises dissolving the amino acid in an approximately equimolar quantity of aqueous alkali liquor to provide a solution having a concentration between 5 and 40 weight percent amino acid, and passing into the solution an approximately equimolar quantity of ketene gas until the pH value of the solution has fallen to the pH value of a corresponding aqueous solution of the pure N-acetyl-amino acid-alkali salt. The resulting solution of N-acetyl-amino acid-alkali salt can be used directly for enzymatic asymmetric hydrolysis for the purpose of producing pure optical isomers of amino acids.