The `-NO_(2)` group in an aromatic ring deactivates the ortho and para positions
Channel: Doubtnut
Date: 12/04/2020

The `-NO_(2)` group in an aromatic ring deactivates the ortho and para positions for an electrophilic attack. When `-NO_(2)` group is present at ortho or para positions of a leaving group (Nucleofuge) it activates the ring for nucleophilic attack. The reduction of `-NO_(2)` group by metal in acid causes its reduction to `-NH_(2)` group and then the ring becomes strongly activated for a electrophilic attack. The strong activation of `-NH_(2)` group is moderated by its acylation with `CH_(3)COCl` to `-NHAc` group. Deacylation is carried out by hydrolysis with `H_(3)O^(+)` or `OH^(-)`. The ring alkylation by using `RX//AlX_(3)` is not possible in presence of `-NO_(2)` or `-NH_(2)` group but is possible in presence of `-NHAc` group.