Aniline dissolved in dilute HCl is reacted with sodium nitrite at 0∘C. This solution was added dropwise to a solution containing equimolar mixture of aniline and phenol in dil. HCl . The structure of the major product is:
(A)(see structure)
(B)(see structure)
(C)(see structure)✓ Correct
(D)(see structure)
Answer: (C)
Solution
Aniline with sodium nitrite in cold dilute HCl becomes benzenediazonium chloride. When this is run into a mixture of aniline and phenol that is still in dilute HCl, the medium decides the partner: coupling with phenol needs a mildly alkaline solution so that the reactive phenoxide can form, whereas coupling with an amine proceeds in just such a mildly acidic medium. In acid, therefore, the diazonium ion couples at the para position of aniline, and the major product is p-aminoazobenzene.
JEE Main · 2019 · 09 Apr 2019 · Shift 1 · Single correct option
