However, aryl halides having electron withdrawing groups( like – NO 2,-
SO 3 H, etc.) at ortho and para positions undergo nucleophilic substitution reaction easily.
Presence of electron withdrawing group(-NO 2) increases the reactivity.
Electrophilic Substitution Reactions
Halogens are deactivating but O, p-directing. Thus, chlorination, nitration, sulphonation and Friedel Craft’ s reaction give a mixture of o- and P- chloro substituted derivatives.
Halogenation