Question

Which is the major product of the sulphonation of chlorobenzene?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Sulphonation of benzene is an aromatic electrophilic reaction. It occurs by the replacement of H-atom by sulphonic acid group in the benzene ring.
In the sulphonation of benzene, the electrophilic species is $S{O}_3$.
Since, $C{l}^{-}$ group attached to benzene is ortho and para directing, so it forms $o-$ and $p-$ chloronitrobenzene as products in electrophilic substitution reaction of chlorobenzene.
Considering ortho and para product, para is the major because here the $Cl$ and $S{O}_{3}H$ groups are separated by long distance. This reduce the steric repulsion between the group.
Ortho product have repulsion between the $Cl$ and $S{O}_{3}H$ so it less stable.
Thus, para product is the major product. Hence correct option is a.