Question

Which of the following tests can distinguish primary, secondary and tertiary amines?

• A. Azo-dye test
• B. Hinsberg reagent
• C. Carbylamine test
• D. Acetyl chloride

Answer 1

The correct option is B Hinsberg reagent

Treatment of an amine with benzenesulfonyl chloride in aqueous sodium hydroxide is useful for determining whether an unknown amine is primary, secondary or tertiary.

Primary amines - dissolves in base and precipitates from acid is a positive test.

Secondary amines - precipitates from base and no change from acid is a positive test.

Tertiary amines - precipitates from base and dissolves in acid is a positive test.