(N/A) Acylation: Aliphatic and aromatic primary and secondary amines react with acid chlorides,anhydrides,and esters via a nucleophilic substitution reaction. This process is known as acylation,and the resulting products are called amides.
The reaction is typically performed in the presence of a base stronger than the amine,such as pyridine. The base acts to remove the $HCl$ formed during the reaction,which shifts the equilibrium to the right,favoring the formation of the amide product.
$1.$ Acylation of Ethanamine: Ethanamine reacts with acetyl chloride in the presence of pyridine to form $N$-ethylethanamide.
$C_2H_5NH_2 + CH_3COCl \xrightarrow{\text{Pyridine}} C_2H_5NHCOCH_3 + HCl$
$2.$ Acylation of Aniline (Benzenamine): Aniline reacts with ethanoic anhydride in the presence of pyridine to form $N$-phenylethanamide (acetanilide).
$C_6H_5NH_2 + (CH_3CO)_2O \xrightarrow{\text{Pyridine}} C_6H_5NHCOCH_3 + CH_3COOH$