A simple and greener approach for the amide bond formation employing FeCl3 as a catalyst

Catalytic use of FeCl3 in the presence of glacial AcOH for the direct amidation of acid with amine in toluene has been described in this paper. The protocol worked well for the less nucleophilic aniline and its variants which gave the best results under the present reaction conditions. Amidation of bromoacetic acid and sterically hindered amino acid also proceed effectively to yield the corresponding amides. The protocol is catalytic and circumvents the use of stoichiometric amounts of reagents. The reaction led to water soluble by-products and thus makes the product isolation easier.