Question

The Hinsberg's method is used to detect

• A. primary amines
• B. secondary amines
• C. tertiary amines
• D. All of the above.

Answer 1

The correct option is D All of the above.

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.
If the product is soluble in alkali, it is formed by primary amines whereas product formed by secondary amine is not soluble in alkali.
Hence, (d) is the correct option.