Hello,

Friedle-Crafts reaction is carried out in the presence of ALCL3 ( aluminium chloride) which is acidic in nature, while aniline is a strong base so thus aniline reacts with ALCL3 to form a salt. Due to the positive charge on the N-atom, electrophilic substitution in the benzene ring is deactivated hence, aniline does not undergo the Friedel-Crafts reaction.

Aniline does not under go Friedel-Crafts reaction due to the salt formation with aluminium chloride. due to this, the nitrogen of aniline acquires a positive charge and hence acts as a strong deactivating group for the further reaction.

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