question_answer 15)

Describe a method for the identification of primary,secondary and tertiary amines. Also write chemical equations of thereactions involved. Give reaction with Hinsberg?s reagent (i.e., ) as it reacts differently with  and  amines.  

Answer:

Hinsberg's reagent (benzene sulphonylchloride with reacts with primary, secondary and tertiary amines in a differentmanner. This is used for the distinction of three types of amines, (i) Primary amineThe reaction of benzene sulphonyl chloride withprimary amine proudces N-alkyl benzene sulphonamide.Hydrogen attached to nitrogen in the product is acidic so it is soluble in alkali.   (ii) A secondary amine reacts with Hinsberg's reagent to fromN,N-dialkyl benzene sulphonamide which remains insoluble inalkali. (iii) A tertiary amine does not react with benzene sulphonyl chloride.