Microwave-assisted synthesis of amide under solvent-free conditions

An efficient and environmentally friendly synthetic method for the synthesis of primary amides under microwave irradiation was described, in which the primary amine was directly reacted with acid without any catalytic agents. The reaction took place in 8-12 min, which was much shorter than the traditional synthetic methods, with almost quantitative yields. The influential factor of the reaction was discussed. The tautomerization between the carboxylic acid group and the H atom in alpha-carbon of L-amino acid was observed, presumably a dehydrated intermediate forming from this tautomerized isomer.