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