How will you distinguish between primary secondary and tertiary amines with nitrous acid?
Then, how will you distinguish between primary secondary and tertiary amines?
The Hinsberg test, which can distinguish primary, secondary, and tertiary amines, is based upon sulfonamide formation. In the Hinsberg test, an amine is reacted with benzene sulfonyl chloride. If a product forms, the amine is either a primary or secondary amine, because tertiary amines do not form stable sulfonamides.
Likewise, how can primary secondary and tertiary amines be distinguished with the help of nitrous acid?
The reaction between nitrous acid and amines were used in past as a way of distinguishing primary, secondary and tertiary amines. In every reaction, the amine is acidified with hydrochloric acid adding a solution of sodium nitrite. The nitrite and the acid form nitrous acid which reacts with the amine.
Reaction of Amines with Nitrous Acid. Nitrous acid (HNO2 or HONO) reacts with aliphatic amines in a fashion that provides a useful test for distinguishing primary, secondary and tertiary amines. This happens with 3º-amines, and the salts are usually soluble in water.