The increasing order of reactivity of substituted benz0yl chlorides towards nucleophilic substitution
Electronic effects govern in the order
Resonance/Mesomeric &gt; Hyperconjugation &gt; inductive
+M or +R dominate over inductive. That's because +M involves π electrons which are more reactive than the sigma electrons. + I operates through sigma electrons. So therefore +M effect has priority over +I.
Therefore the order of reactivity towards nucleophilic substitution is 4&gt;1&gt;2&gt;3