Question

Which one of the following is most reactive towards electrophilic attack ?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

The group showing electron-donating effect (such as $-N{H}_2,-OH$ ) should stabilise the intermediate ions, i.e. makes the ring more reactive towards electrophilic substitution than benzene and are called activating group while electron withdrawing group (such as $-Cl,N{O}_2$ ) increases the positive charge on ring. thus deactivates the ring. Hence, phenol is more readily attacked by an electrophile.