Preparation of N-acyl derivatives of amino acids from acyl chlorides and amino acids in the presence of cationic surfactants. A variation of the Schotten-Baumann method of benzoylation of amino acids

A very efficient method for the preparation of N-acylamino acids from the c orresponding acyl chloride and amino acid is described. Amino acids, potass ium carbonate, acyl chloride, and a catalytic amount of cationic surfactant s were mixed in tetrahydrofuran and refluxed without ever obtaining a dear reaction mixture. After hot filtration, the product was isolated from the h ot tetrahydrofuran solution in very high or almost quantitative yields.