Aniline does not undergo Friedel-Crafts reaction because
(A) It forms salt with the Lewis acid catalyst, AlCl3.
(B) Nitrogen of aniline acquires negative charge.
(C) Nitrogen of aniline acquires positive charge.
(D) Nitrogen acts as a strong deactivating group in the further reaction.
Choose the correct answer from the options given below :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A), (C) and (D) only
The Friedel–Crafts reaction needs anhydrous \( \ce{AlCl3} \), a Lewis acid, as the catalyst, and aniline is a Lewis base:
\( \displaystyle \ce{C6H5NH2 + AlCl3 -> C6H5NH2^+-AlCl3^-} \)
(A) It forms salt with the Lewis acid catalyst, \( \ce{AlCl3} \). — Correct. This is the reason the catalyst is used up and the reaction fails.
(B) Nitrogen of aniline acquires negative charge. — Incorrect. Nitrogen gives its lone pair to aluminium, so it becomes positively charged; the negative charge is on aluminium.
(C) Nitrogen of aniline acquires positive charge. — Correct. It has donated its lone pair to \( \ce{AlCl3} \).
(D) Nitrogen acts as a strong deactivating group in the further reaction. — Correct. The positively charged nitrogen pulls electrons out of the ring, so the ring no longer attacks the electrophile.
NCERT (2026-27 edition):
Electrophilic Substitution – …
