How will you distinguish between primary, secondary, and tertiary aliphatic amines using Hinsberg's reagent?

Q: How will you distinguish between primary, secondary, and tertiary aliphatic amines using Hinsberg's reagent?

Hinsberg's reagent (benzene sulphonyl chloride, $C6H5SO2Cl$) is used to distinguish between primary, secondary, and tertiary amines through the following tests: Primary Amine: When a primary amine reacts with Hinsberg's reagent, it forms N-alkylbenzenesulphonamide. This sulphonamide contains a strongly acidic hydrogen atom attached to the nitrogen atom due to the electron-withdrawing sulphonyl group. Therefore, it is soluble in aqueous alkali (like $NaOH$) to form a clear solution. Secondary Amine: When a secondary amine reacts with Hinsberg's reagent, it forms N,N-dialkylbenzenesulphonamide. This product does not contain any hydrogen atom attached to the nitrogen atom. As a result, it is insoluble in aqueous alkali ($NaOH$). Tertiary Amine: Tertiary amines do not react with Hinsberg's reagent at all because they lack a replaceable hydrogen atom on the nitrogen atom. Thus, the tertiary amine remains insoluble in the reaction mixture and does not dissolve upon adding alkali.

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Hinsberg's reagent (benzene sulphonyl chloride, $C_6H_5SO_2Cl$) is used to distinguish between primary, secondary, and tertiary amines through the following tests:

Primary Amine: When a primary amine reacts with Hinsberg's reagent, it forms N-alkylbenzenesulphonamide. This sulphonamide contains a strongly acidic hydrogen atom attached to the nitrogen atom due to the electron-withdrawing sulphonyl group. Therefore, it is soluble in aqueous alkali (like $NaOH$) to form a clear solution.
Secondary Amine: When a secondary amine reacts with Hinsberg's reagent, it forms N,N-dialkylbenzenesulphonamide. This product does not contain any hydrogen atom attached to the nitrogen atom. As a result, it is insoluble in aqueous alkali ($NaOH$).
Tertiary Amine: Tertiary amines do not react with Hinsberg's reagent at all because they lack a replaceable hydrogen atom on the nitrogen atom. Thus, the tertiary amine remains insoluble in the reaction mixture and does not dissolve upon adding alkali.

MP Board · Class 12 · Chemistry · AminesHow will you distinguish between primary, secondary, and tertiary aliphatic amines using Hinsberg's reagent?