Question

Choose the correct answer among the alternatives given :

Chlorobenzene can be converted into phenol by heating in aqueous sodium hydroxide solution at a temperature of 623 K and a pressure of 300 atm. However, the rate of reaction can be increased by the presence of certain groups in the benzene ring.

What will be the order of reactivity of following compounds towards the above substitution reaction?

• A. iii > ii > i
• B. ii > iii > i
• C. i > ii > iii
• D. i > iii > ii

Answer 1

The correct option is A iii > ii > i

We know that $-N{O}_2$ is an electron withdrawing group. $-N{O}_2$ attached to the ring reduces the electron density.

Greater the electron deficiency in the ring greater is the reactivity towards nucleophilic substitution.
Hence the order of reactivity is as shown.
Option A is correct.