Question

Identify the compound that will react with Hinsberg’s reagent to give a solid which dissolves in alkali

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is A

Hinsberg's reagent is used to distinguish between primary, secondary, and tertiary amines. This reagent will react with different types of amines to either form a solid or not react at all.

Let's analyze the reactions of the types of amines with Hinsberg’s reagent:

• Primary Amines: They react with Hinsberg’s reagent (benzene sulfonyl chloride) to form a sulfonamide. The resulting sulfonamide is soluble in alkali due to the replacement of the acidic hydrogen in the sulphonamide, forming a water-soluble sodium salt.
• Secondary Amines: They also form sulfonamides, but these are not soluble in alkali as there is no replaceable hydrogen atom.
• Tertiary Amines: They do not react with Hinsberg’s reagent since they lack hydrogen atoms bonded to nitrogen.

The correct answer among the given options is the compound that will form a solid sulfonamide with Hinsberg's reagent and is soluble in alkali, which belongs to primary amines.

The structure indicates a primary amine. Hence, this compound will react with Hinsberg's reagent, form a sulfonamide, and dissolve in alkali.

Thus, the correct option is the first compound shown in the options.