13.6 Describe a method for the identification of primary, secondary and tertiary amines. Also write chemical equations of the reactions involved.

<table border="1"><tbody><tr><td><p><strong>Primary amine</strong>: A primary (1°) amine is an amine that has the following general structural formula.</p><p>R= alkyl or aryl group</p><p><strong>Secondary amine</strong>: A secondary (2°) amine is an amine that has the following general structural formula.</p><p>R¹ and R²= alkyl or aryl group</p><p><strong>Tertiary amine: </strong>A tertiary amine is an amine that has the following structure</p><p>R¹, R² and R³ are alkyl or aryl groups</p><p><u>Identification of Primary, Secondary and Tertiary amines</u></p><p>Primary, secondary and tertiary amines can be identified by the following test:</p><p><strong>Hinsberg's test</strong>: This is an excellent test for the identification of primary, secondary and tertiary amines. In this test, the amine is shaken with benzenesulphonyl chloride ( Hinsberg's reagent) in the presence of an excess of aqueous KOH solution when</p><p><strong> (i)</strong> A primary amine gives a clear solution which on acidification gives an N-alkylbenzene sulphonamide which is soluble in</p><p>Due to the presence of strong electron withdrawing sulphonyl group in the sulphonamide, the H-atom attached to nitrogen can be easily released as a proton. So it is acidic and dissolves in alkali.</p><p><strong> (ii)</strong> A secondary amine reacts with Hinsberg's reagent to give a sulphonamide which is soluble in There is no H-atom attached to the N-atom in the sulphonamide Therefore it is not acidic and soluble in alkali.</p><p><strong> (iii)</strong> A Tertiary amine does not react with Hinsberg's reagent at all</p></td></tr></tbody></table>

0 Upvotes 0 Upvotes 0 Downvotes

• • Report Abuse
• Comment