Gabriel phthalimide synthesis is used to prepare 1∘ aliphatic or alicyclic amine. Hence, amine which can be synthesised by Gabriel phthalimide synthesis method contains α-carbon. Aniline (C6H5NH2) does not contain α−C cannot be prepared by Gabriel reaction. Rest amines all contain α−C in its respective position, hence they can easily give Gabriel phthalimide reaction.
∴ Three amins out of given four anions can be prepared by Gabriel synthesis.