JEE Main · 2023 · 30 Jan 2023 · Shift 1 · Compounds Containing Nitrogen

Benzyl isocyanide is ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2-\mathrm{NC}$, bound to the molecule through nitrogen. Treating benzyl bromide with silver cyanide gives mainly the isocyanide, because the silver-cyanide bond steers attack through nitrogen. Benzylamine, a primary amine, warmed with chloroform and alcoholic potassium hydroxide undergoes the carbylamine reaction, which delivers the same benzyl isocyanide. The secondary amine ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{C}{\mathrm{H}}_2\mathrm{NHC}{\mathrm{H}}_3$ cannot give a carbylamine reaction, and benzyl tosylate with potassium cyanide gives the ordinary nitrile rather than the isocyanide. The routes that yield benzyl isocyanide are the reaction of benzyl bromide with silver cyanide and the carbylamine reaction of benzylamine.