Primary amines can be prepared by Gabriel Phthalimide synthesis but only aliphatic primary amines, aromatic primary amines cannot be prepared by this technique. When phthalimide is heated with ethanolic KOH, potassium salt of phthalimide is formed which on heating with alkyl halide followed by alkaline hydrolysis produces the corresponding primary amine. Aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide, hence the formation of aromatic primary amines do not occur.