What is the Difference Between Aniline and Benzylamine?

The main difference between aniline and benzylamine lies in the attachment of the amine group to the benzene ring. Aniline, also known as benzeneamine or phenylamine, has the chemical formula C6H5NH2 and belongs to the class of aromatic amines. In aniline, the amine group is directly attached to the benzene ring.

On the other hand, benzylamine, also known as 1-phenylmethanamine, is a colorless water-soluble liquid. In benzylamine, the amine group is attached to the benzene ring indirectly through a -CH2- group. This difference in the attachment of the amine group results in different chemical and physical properties for the two compounds.

A chemical test that can be used to distinguish between aniline and benzylamine is their reaction with nitrous acid, which is generated in situ from sodium nitrite and mineral acid. When nitrous acid reacts with benzylamine, an unstable diazonium salt is produced, along with an alcohol byproduct and the release of N2 gas. In contrast, when nitrous acid reacts with aniline at a very low temperature, a stable diazonium salt is produced without the evolution of nitrogen gas.

Comparative Table: Aniline vs Benzylamine

The main difference between aniline and benzylamine is the structure of their molecules. Aniline has a benzene ring attached directly to an amino group, while benzylamine consists of a benzyl group attached to an amino group. Here is a table summarizing their differences:

Both compounds are soluble in organic solvents such as ethanol, methanol, and acetone. Aniline and benzylamine can be distinguished by their reactions with nitrous acid. Benzylamine reacts with nitrous acid to form an unstable diazonium salt, which gives alcohol with the evolution of nitrogen gas. On the other hand, aniline reacts with HNO2 at a low temperature to form a stable diazonium salt, and nitrogen gas is not evolved.