Question:

Consider the following reactions,

The compound [P] is :

Show Hint

Azo-dye formation needs a primary aromatic amine; tribromination with bromine water needs three free positions ortho/para to \(\mathrm{NH_2}\).
Updated On: Nov 5, 2026
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Scheme: [P] with \(\mathrm{NaNO_2/HCl}\), 0-5 \(^\circ\)C then \(\beta\)-naphthol/NaOH gives a coloured azo dye, so [P] is a primary aromatic amine (diazotisation + coupling). The N-methyl amine (option 3) is secondary and would give an N-nitroso compound instead, so it is out.
[P] + \(\mathrm{Br_2/H_2O}\) gives \(\mathrm{C_7H_6NBr_3}\). The parent \(\mathrm{C_7H_9N}\) (toluidine) has lost 3 H and gained 3 Br, i.e. 3 ring positions are substituted. \(\mathrm{NH_2}\) activates only its two ortho and one para positions.
o-Toluidine (option 1): free activated positions are only C4 and C6, so only 2 Br. p-Toluidine (option 4): free activated positions are C2 and C6, so only 2 Br.
m-Toluidine (option 2): positions 2, 4 and 6 are all free and activated, so 2,4,6-tribromo-3-methylaniline \(\mathrm{C_7H_6NBr_3}\) forms.
Hence [P] = m-toluidine.
Answer: (2) m-toluidine (3-methylaniline)
Was this answer helpful?
0
0