Q. In a reaction of aniline a coloured product C was obtained. C₆H₅NH₂ (A) —(NaNO₂, HCl)→ B —(C₆H₅N(CH₃)₂, cold)→ C The structure of C would be
A) C₆H₅–N=N–C₆H₄–N(CH₃)₂ (para)
B) C₆H₅–N=N–CH₂–N(CH₃)–C₆H₅
C) 2-CH₃C₆H₄–N=N–C₆H₄-2-CH₃
D) C₆H₅–NH–NH–C₆H₄–N(CH₃)₂ (para)
Explanation
[Solution from source] Diazotisation of aniline gives benzenediazonium chloride, the intermediate B. In the cold it couples with N,N-dimethylaniline at the activated para position, giving the coloured azo dye p-(dimethylamino)azobenzene. The –NH–NH– (hydrazo) compound has no N=N chromophore, so it would not be the coloured coupling product. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.