COMEDK 2025 Morning Solved Paper

Concept:The conversion uses nitration, bromination, reduction, diazotization, and hydrolysis in a specific order to place the hydroxyl group at the meta position relative to bromine.Explanation:Step 1: Nitrate benzene using conc. $\mathrm{HNO}_3 / \mathrm{H}_2 \mathrm{SO}_4$ (reagent ii) to form nitrobenzene. The $-\mathrm{NO}_2$ group is meta-directing.Step 2: Brominate nitrobenzene with $\mathrm{Br}_2 / \mathrm{Fe}$ (reagent v). The $-\mathrm{NO}_2$ directs bromine to the meta position, giving 3‑bromonitrobenzene.Step 3: Reduce the nitro group to an amino group using $\mathrm{Fe} / \mathrm{HCl}$ (reagent iv). This yields 3‑bromoaniline.Step 4: Diazotize 3‑bromoaniline with $\mathrm{NaNO}_2 / \mathrm{HCl}$ at $0^{\circ} \mathrm{C}$ (reagent i) to form the diazonium salt.Step 5: Hydrolyze the diazonium salt with $\mathrm{H}_2 \mathrm{O}$ at $283 \mathrm{~K}$ (reagent iii) to replace the diazonium group with $-\mathrm{OH}$, producing 3‑bromophenol.Answer:The correct sequence is ii → v → iv → i → iii, which corresponds to option B.