Question

Choose the incorrect statement(s) from the following:

• A. N,N-Diethylbenzenesulphonamide is soluble in alkali.
• B. Hinsberg's reagent reacts with primary, secondary and tertiary amines.
• C. Diethylamine on treatment with carbon disulphide followed by excess of mercuric chloride will produce an isothiocyanate having pungent smell.
• D. Secondary amine on reaction with CS₂ will give dithiocarbamic acid which fail to react with mercuric chloride.

Answer 1

Answer: (A), (B), (C)

The correct options are
A N,N-Diethylbenzenesulphonamide is soluble in alkali.
B Hinsberg's reagent reacts with primary, secondary and tertiary amines.
C Diethylamine on treatment with carbon disulphide followed by excess of mercuric chloride will produce an isothiocyanate having pungent smell.

The hydrogen attached to the nitrogen of N-ethylbenzenesulphonamide is strongly acidic due to the presence of the strong electron withdrawing sulphonyl group, which makes the compound to be soluble in alkali. Due to the absence of such an acidic hydrogen, N,N-diethylbenzenesulphonamide is insoluble in alkali.
Benzenesulphonyl chloride, also known as Hinsberg's reagent, reacts with primary and secondary amines to form sulphonamides, but is inert towards tertiary amines.
Secondary amines produce dithiocarbamic acids which does not produce isothiocyanate on treatment with mercuric chloride, and thus it does not produce mustard oil smell.