Question

The nitration will mainly take place at position:

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is D 4

Carbon (1) is at para position to alkyl group.
Carbon (2) is at ortho position to amine group
Carbon (3) is at para position to amide group
Carbon (4) is at para position to amine group

Alkyl group is less donating compare to amine and amide because it shows only +H group whereas amine and amide shows +R effect. Since +R effect is prior they have more electron donating capability.

Comparing amine and amide, amine is more electron donating than amide because lone pair of electron on amide involve in cross conjugation with carbonyl group so it is not readily available for donation.
Hence, amine is more electron donating.

Carbon (2) and carbon (4) are ortho and para position to amine group. Here carbon at para position undergoes nitration because nitration at ortho position some steric hindrance is there to the incoming group and also the $-I$ effect of $N$ is least at para position.
Therefore, nitration occurs at (4) position