(i) Aniline does not undergo Friedel – Crafts reaction.

In the presence of AlCl 3, the Friedel–Crafts reaction is carried out. However, we already know that AlCl 3 is acidic, whereas aniline is not. Aniline is a very basic substance. As a result, aniline is reacted with AlCl 3 to generate a salt ( this has been shown in the equation given below ).

Because of the positive charge on the benzene ring, the electrophilic substitution is deactivated.

N – atom, N – nucleus, N – nucleus As a result, aniline is immune to the Friedel–Crafts reaction.

(ii) Diazonium salts of aromatic amines are more stable than those of aliphatic amines

Resonance is undergone by the diazonium ion, which is depicted in the figure given below.

The stability of the diazonium ion is accounted for by this resonance. Thus, the stability of diazonium salts of aromatic amines is higher than that of aliphatic amines.

(iii) Gabriel phthalimide synthesis is preferred for synthesizing primary amines

Because only 1 ° amine is generated, the Gabriel phthalimide synthesis is chosen.

There are no 2° or 3° amines produced in this synthesis. As a result, a pure 1° amine could be created. As a result, Gabriel phthalimide synthesis is used for primary amine synthesis.