Question

An organic compound $‘A^{\prime }\left(C_3{H}_{9}N\right)$ reacts with benzene-sulphonyl chloride to give a solid insoluble in alkali. The structure of $‘A^{\prime }$ is :

• A. $C{H}_{3}NH{C}_2{H}_5$
• B. $(C{H}_3{)}_{3}N$
• C. $C{H}_{3}C{H}_{2}C{H}_{2}N{H}_2$
• D. Insufficient data to predict

Answer 1

The correct option is A $C{H}_{3}NH{C}_2{H}_5$

Primary amines when react with Hinsberg reagent (benzene sulphonyl chloride) formed a product which is soluble in alkali. Whereas secondary amine performing same reaction gives a product which is insoluble in alkali. Tertiary amines do not react with Hinsberg reagent. Hence this test is used to distinguish between $1^o,2^o$ and $3^o$ amines.
Compound (A) gives alkali insoluble product with this reagent and is $2^o$ amine.