Question

Why aniline does not give friedel craft reaction?

Answer 1

Aniline doesn't undergo friedel craft reaction since the reagent AlCl3, being e- deficient acts as lewis base and attacks on the lone pair of nitrogen present in aniline to form an insoluble complex which precipitates out and the reaction doesn't proceed.

Answer 2

the friedel-crafts reaction is carried out in the presence of lewis acid such as agcl3. aniline being basic  in nature react with agcl3 and form salt . due to the positive charge on nitrogen electrophillic subsitution reaction on benzene ring deactivated. hence aniline does not under go friedel craft reaction.