Q. The order of decreasing reactivity towards an electrophilic reagent, for the following
(i) Benzene
(ii) Toluene
(iii) Chlorobenzene
(iv) Phenol
would be

 4197  227 AIPMTAIPMT 2007Organic Chemistry – Some Basic Principles and Techniques Report Error

Solution:

The order of decreasing reactivity towards electrophilic reagent is
or Anisole > toluene > benzene > chlroro benzene.When electron releasing groups such as amino and methoxy groups are present, they increase the electron density on benzene ring and increases the rate of electrophilic aromatic substitution reaction. When electron withdrawing chloro group is present, it decreases the electron density on benzene ring and decreases the rate of electrophilic aromatic substitution reaction.