JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Compounds Containing Nitrogen

Benzyl isocyanide, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\mathrm{NC}$, demands that nitrogen, not carbon, becomes bonded to the benzylic carbon. Benzyl bromide with silver cyanide gives this isocyanide, because the largely covalent $\mathrm{AgCN}$ lets nitrogen form the bond, so route A succeeds. Benzylamine, a primary amine, with chloroform and alkali undergoes the carbylamine reaction to yield benzyl isocyanide, so route B succeeds. Bromobenzene with $\mathrm{AgCN}$, and aniline by the carbylamine route, would both give phenyl isocyanide, with nitrogen joined directly to the ring, not benzyl isocyanide. Phenylethyl bromide with potassium cyanide gives a nitrile, with carbon attached and one carbon longer, not an isocyanide. Benzyl isocyanide is obtained from routes A and B.