Efficient Microwave-Assisted Synthesis of Ionic Esterified Amino Acids

In this work, an efficient microwave-assisted methodology for the esterification of unprotected α-amino acids is described. Ionic esterified amino acids were synthesized in satisfactory yields in a facile one-pot solventless protocol from unprotected amino acids and alcohols under acid catalysis (MsOH or p-TsOH) to afford the pure products after a simple work-up procedure. This procedure can also be extended to the preparation of long and short chain alkyl and benzyl esters.