Gabriel phthalimide synthesis is preferred for the preparation of aliphatic primary amines.

Question

Give a plausible explanation for each of the
following statements :

Gabriel phthalimide synthesis is preferred for the preparation of aliphatic primary amines.

Answer 1

In aromatic amines, 

Tthe lone pair of electrons on the N-atom is delocalized over the benzene ring. 

As a result electron density on the nitrogen atom decreases. 

Whereas in aliphatic primary amines, due to +1 effect of alkyl group, electron density on nitrogen atom increases. 

As the pKh value of aliphatic amines is more than that of aromatic amines, aromatic amines are less basic than primary aliphatic amines. 

Hence,

Gabriel phthalimide synthesis is preferred for the preparation of aliphatic amines.