Question

Arrange the following compounds in their correct order of reactivity towards electrophilic substitution reaction.

• A. IV > III > II > I
• B. III > I > II > IV
• C. III > IV > II > I
• D. II > III > I > IV

Answer 1

The correct option is C III > IV > II > I

In aromatic substitution, benzene ring attacks on electrophile in electrophilic substitution. Thus benzene must have more electron density, which is possible if electron donating group is attached to it.

Electron donating group of benzene ring.

$\downarrow$

more electron density on benzene ring.

$\downarrow$

more reactive towards electrophilic substitution.

Thus, order of reactivity is $III>IV>II>I$, see the figure.