Question

4. Bonus mechanism problem:. Provide a detailed, step by step mechanism for the following reaction. Explain the unexpected regiochemistry. 1) HNO3 H2SO4 2) NaOH NO2

Answer 1

Generally electron donating groups are ortho, para director and electron withdrawing groups are meta director.

Aromatic Nitration reaction:

Nitration mixture have sulphuric acid and nitric acid.

The given amino benzene protonate in the presence of acid before nitration reaction happens.

Actually amine is ortho, para directing group. But after protonation which become electron deficient and meta-directing group.

This is the reason why the nitration on amino benzene give meta-product.