Only aliphatic primary (1∘) amines (amines having the formula R−NH2 where R≠C6H5 ) are synthesised by Gabriel's phthalimide synthesis. The structures of the given compounds are as follows. (a) C2H5NH2 ethanamine. (1∘ amine) (b) CH3NHCH3‌‌ N-methylmethanamine ‌‌2∘ amine).