Question

Explain the following observations:
(i)Electrophilic substitution in case of aromatic amines takes place more readily than benzene .
(ii)Aryl cyanides cannot be formed by the reaction of aryl halides and sodium cyanide.
(iii)Tertiary amines do not undergo acylation .

Answer 1

1. Electrophilic substitution is more easier in aromatic amines as compared to benzene due to the increased nucleophilicity of the aromatic amine due to +R effect of NH₂.

2. Aryl chlorides are in resonance, they show +R effect and the lone pair of X group forms double bond with C so, removal of X is not possible.

3. Tertiary amines do not have a proton on N to get substituted by the acyl group. Thus, they do not undergo acylation.