Dakin‐West Reaction

Abstract

The Dakin‐West reaction is the preparation of α‐acetamido alkyl methyl ketones via the intermediate of azlactone by the treatment of α‐amino acids with acetic anhydride in the presence of a base, such as pyridine. The study finds that high temperature is usually necessary for this reaction when pyridine is used as solvent; however, the addition of small amount of DMAP enables the reaction to occur at ambient temperatures with higher yield. Several mechanisms have been proposed for this reaction. This reaction has been modified to use DMAP and triethylamine with additional acetic acid and alanine to provide high yield. The benzoyl fluoride has also been used in this reaction. The reaction mechanism of N ‐acyl‐ N ‐alkyl α‐amino acids with trifluoroacetic anhydride is also summarized in the present study.