Question

Although chlorine is an electron withdrawing group, yet it is ortho-, para- directing in electrophilic aromatic substitution reactions .Its answer is given in NCERT but it doesn't make any sense to me. Please explain it in detail !

Answer 1

• Being a very electronegative element chlorine withdraws electrons through – I effect and donate electrons(have lone pair) through resonance(+R).

• As we know resonance is dominating over inductive but in case of halogens inductive is dominating over resonance so, chlorine is slightly electron withdrawing via inductive but it act as o, p directing group bcoz of presence of lone pair.

• One of the lone pair of electrons of chlorine can conjugate to the ring and direct the electrophile to the ortho and para positions of the ring.

hope it helps..