Identify the major product formed in the following sequence of reactions:

Solution

Chemistry ma’am · 4 steps

Bromine water puts three Br on aniline, then H₃PO₂ swaps the amino group for a plain H.

1. Step 1, bromination. -NH₂ strongly activates the ring, so bromine water does not stop at one Br. It fills both ortho positions and the para position at once, giving 2,4,6-tribromoaniline as a white precipitate.
2. Step 2, diazotisation. NaNO₂ with HCl at 0 to 5 °C turns the -NH₂ into -N₂⁺Cl⁻. The three Br atoms stay where they are.

   ArN₂⁺Cl⁻ + H₃PO₂ + H₂O → ArH + N₂ + H₃PO₃ + HCl

3. Step 3, deamination. Hypophosphorous acid replaces the diazonium group with H, and N₂ gas leaves. The carbon that held -NH₂ now carries only H.
4. So. The Br atoms that were at 2, 4 and 6 now sit meta to one another, so the product is 1,3,5-tribromobenzene, option (c).

The idea to keep. Use -NH₂ as a temporary guide: let it direct groups ortho and para, then diazotise and remove it with H₃PO₂. This gives meta patterns that direct substitution cannot.

Answer from the NTA final answer key. Solution by PrepWiser.