Why cannot be aromatic primary amines prepared by Gabriel pthalimide synthesis ?

Explanation

The key step in the Gabriel phthalimide synthesis is a `S_(N)2` reaction in which the nucleophile, phthalimide anion displaces the halide ion from alkyl halide to form N-alkylphthalimide. This upon subsequent acid or alkaline hydrolysis gives the corresponding aliphatic primary amine.


Since aryl halides do not undergo nucleophilic substitution reactions easily, therefore, arylamines, i.e., aromatic primary amines cannot be prepared by Gabriel phthalimide reactions.