Question

Which of the following amines undergoes acylation reaction?

• A. Ethyldimethylamine
• B. N-Methylaniline
• C. N,N-Dimethylmethanamine
• D. N,N-Dimethylaniline

Answer 1

Answer: (B)

N-Methylaniline

Answer 2

For an amine to undergo acylation (i.e., form an amide by reaction with an acyl chloride or acid anhydride), it must have at least one N–H bond. This is essential as the hydrogen is abstracted during the formation of the amide.

• Ethyldimethylamine: A tertiary aliphatic amine with no N–H bond → Does not undergo acylation.
• N-Methylaniline: A secondary aromatic amine with one N–H bond → Undergoes acylation.
• N,N-Dimethylmethanamine: A tertiary aliphatic amine with no N–H bond → Does not undergo acylation.
• N,N-Dimethylaniline: A tertiary aromatic amine with no N–H bond → Does not undergo acylation.

Only N-Methylaniline possesses an N–H bond and can undergo acylation.