The Gabriel synthesis of primary amines and all the missing structures are shown in the image attached.
What is the Gabriel synthesis of primary amines?
Primary amines are obtained from alkyl halides by the Gabriel synthesis. N-alkylphthalimide is created when phthalimide reacts with an alkyl halide in the presence of a base. The alkyl halide is attacked by the nucleophilic nitrogen of phthalimide, which is then hydrolyzed in an acidic environment to remove the phthalimide group and reveal the primary amine.
The synthesis of different primary amines is made possible by this process, which offers a gentle and selective method of amine alkylation without the need for harsh reaction conditions.