Efficient amide formation from arylamines and esters promoted by AlCl/EtN: an experimental and computational investigation.

Efficient and selective preparation of amides from arylamines and esters has been achieved with an AlCl/EtN pair under mild conditions. A large number of arylamines were successfully acylated to the corresponding amides in high yields and short reaction times. For instance, a 94% yield of p-bromoacetanilide was obtained from p-bromoaniline and ethyl acetate in 10 min at room temperature. In addition, a computational study on the N-acylation of amines was performed using density functional theory. It was found that the energy barrier for N-acylation of aniline is 10 kcal/mol higher than that of methylamine. In the presence of AlCl, the activation energy for the N-acylation of aniline was reduced by 27.7 kcal/mol with the endothermic process becoming exothermic. Graphical Abstract: In this work, the efficient and selective preparation of amides from arylamines and esters has been performed successfully with an AlCl/EtN pair under mild conditions. A large number of arylamines were acylated to the corresponding amides with high yields and short reaction times. In addition, a computational study on the N-acylation of amines has been carried out using the density functional theory (DFT) method.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]