Question

Replacement of $Cl$ of chlorobenzene to give phenol requires drastic conditions, but $Cl$ of $2,4$-dinitrochlorobenzene is readily replaced. This is because :

• A. $-N{O}_2$ group makes the ring electron rich at ortho and para positions.
• B. $-N{O}_2$ group withdraws electrons from meta position.
• C. $-N{O}_2$ donate electrons at meta position.
• D. $-N{O}_2$ withdraws electrons from ortho and para positions.

Answer 1

The correct option is D $-N{O}_2$ withdraws electrons from ortho and para positions.

$N{O}_2$ group shows $-M$ effect due to which electrons are withdrawn from ortho and para position which makes the benzene ring more prone to electrophilic substitution reaction and hence replacement of $Cl$ can be done easily.