Q. 73 Aryl halides are extremely less reactive towards nucleophilic substitution.

Predict and explain the order of reactivity of the following compounds

towards nucleophilic substitution.


Aryl halides are less reactive towards nucleophilic substitution reaction. Presence of

electron withdrawing group at ortho and para position increases the stability of

intermediates and hence increases the reactivity of aryl halides towards nucleophilic

substitution reaction.

Now, more the number of EWG al ortho and para position, higher will be the reactivity of aryl

halide. Compound (lll) has three EWG so, it is most reactive and compound (|) has only one

EWG so. its least reactive, So, the order of reactivity is (i) <(l) <(iii)