JEE Main · 2023 · 08 Apr 2023 · Shift 1 · Compounds Containing Nitrogen

Benzenediazonium chloride reacts either by coupling or by loss of nitrogen, depending on the reagent. With aniline (reagent A) it couples at the para position to give the azo compound ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{N}=\mathrm{N}{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{N}{\mathrm{H}}_2$, which is product III. With $\mathrm{HB}{\mathrm{F}}_4$ followed by heating (B), the Balz–Schiemann reaction replaces the diazonium group by fluorine to give fluorobenzene, product I. With $Cu/HCl$ (C), the Gattermann reaction gives chlorobenzene, product IV. With $CuCN/KCN$ (D), the Sandmeyer reaction gives benzonitrile, product II. The matching is A–III, B–I, C–IV, D–II.