Gabriel synthesis proceeds through nucleophilic substitution of alkyl halides by potassium phthalimide and is effective for primary aliphatic amines. Aryl halides such as chlorobenzene do not undergo this SN2 pathway due to partial double bond character of the C-X bond and sp2 carbon, so aromatic amines like aniline are not formed by this route. Ethylamine, n-propylamine, and benzylamine can be prepared because their corresponding halides are suitable substrates.