Question

A student tried to synthesis 4-nitro-$N, N$-dimethylaniline from $N, N$-dimethylaniline via electrophilic aromatic substitution using nitric acid $\left(HNO_3\right)$ and sulphuric acid $\left(H_2SO_4\right)$. To his surprise, the major product he obtained was 3-nitro-N, N-dimethylaniline. Why the designed reaction failed to provide the desired product, 4-nitro-$N, N$-dimethylaniline?

• A. The amine group is meta directing.
• B. Protonation at amine group makes it meta directing.
• C. The amine group is strong electron withdrawing group by -I effect.
• D. Steric inhibition to resonance is responsible for the above result

Answer 1

Answer: (B)

This is because of the protonation of amine group which makes it meta directing.