Write short note on acetylation of amines.

Explanation

Acetylations : Introduction of acetyl group `(CH_(3)CO-)` into any molecular is known as acetylations. Primary and secondary amines react with acetyl chlorides or acetic anhydrides to form substituted amides. Tertiary amines do not react as there is no hydrogen atom on nitrogen. For example, with acetyl chloride.
`underset("Acetyl chloride Ethylamine"(1^(@)))(CH_(3)COCl+H+oversetoverset(H)(|)N-C_(2)H_(5))rarrunderset("N-Ethylacetamide")(CH_(3)COoversetoverset(H)(|)NC_(2)H_(5))+HCl`
`underset("Acetyl chloride")(CH_(3)CO)underset("Diethylamine"(2^(@)))(Cl+HN(C_(2)H_(5))_(2))rarrunderset("N, N-Diethylacetamide")(CH_(3)CON(C_(2)H_(5))_(2))+HCl`
Acetylation can also be carried out with anhydride.
`underset("Acetic anhydride")(CH_(3)C.O_.COCH_(3))+underset("Methylamine")(H+oversetoverset(H)(|)N-CH_(3))overset(CH_(3)COONa)rarrunderset("N-Methylacetamide")(CH_(3)CO.oversetoverset(H)(|)N-CH_(3))+underset("Acetic acid")(CH_(3)COOH)`
Acylation of aromatic amines is usually carried out in the presence of a catalyst e.g., acetylation with acetyl chloride is carried out in the presence of pyridine and acetylation with anhydride is carried out in the presence of conc. `H_(2)SO_(4)`.