Hinsberg reagent (benzene sulfonyl chloride) reacts with primary amines to form sulfonamides, which are soluble in alkaline solutions. Secondary amines, like methylamine, also form sulfonamides, but these are not soluble in alkaline solutions. Tertiary amines and aniline do not react with Hinsberg reagent.
- Option (A) Aniline: Reacts with Hinsberg reagent.
- Option (B) N,N-Dimethyl aniline: Does not react.
- Option (C) Methyl amine: Reacts with Hinsberg reagent.
- Option (D) C₆H₅NH C₆H₅: Does not react.
Thus, the correct answer is A and C only.