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How will you bring about the following conversion?
Aniline to bromobenzene
Answer
Answer
Official answer keyEquations: $\mathrm{C_{6}H_{5}NH_{2}} + \mathrm{NaNO_{2}} + 2\mathrm{HCl} \xrightarrow{\text{273-278}\text{ }\text{K}} \mathrm{C_{6}H_{5}N_{2}Cl} + \mathrm{NaCl} + 2\mathrm{H_{2}O}$ $\mathrm{C_{6}H_{5}N_{2}Cl} + \mathrm{HBr} \xrightarrow{\mathrm{Cu_{2}Br_{2}}\text{ }\text{(Sandmeyer}\text{ }\text{reaction)}} \mathrm{C_{6}H_{5}Br} + \mathrm{N_{2}} + \mathrm{HCl}$
Aniline is diazotised and the diazonium chloride is warmed with $\mathrm{Cu_2Br_2/HBr}$ to give bromobenzene.
From ISC 2027 Specimen Chemistry Paper 1, question 18(ii).