JEE Main · 2025 · 22 Jan 2025 · Shift 2 · Compounds Containing Nitrogen

Each compound is matched to the reagent that carries out its specific reduction to an amine.

(A) A primary amide, $\mathrm{R}-\mathrm{CO}-\mathrm{N}{\mathrm{H}}_2$, is reduced straight to the primary amine $\mathrm{R}-\mathrm{C}{\mathrm{H}}_2-\mathrm{N}{\mathrm{H}}_2$ by $\mathrm{LiAl}{\mathrm{H}}_4$ followed by aqueous workup — the strong hydride reduces the carbonyl all the way to $-\mathrm{C}{\mathrm{H}}_2-$ without touching the C–N bond. Match: (A)–(III).

(B) Nitrobenzene is reduced to aniline by $Sn/HCl$ (or $Fe/HCl$), the classical dissolving-metal reduction of an aromatic nitro group. Match: (B)–(IV).

(C) A nitrile, $\mathrm{R}-\mathrm{C}\equiv \mathrm{N}$, is hydrogenated over a nickel catalyst to give the primary amine: $\mathrm{R}-\mathrm{C}\equiv \mathrm{N}\stackrel{{\mathrm{H}}_2/Ni}{\to }\mathrm{R}-\mathrm{C}{\mathrm{H}}_2-\mathrm{N}{\mathrm{H}}_2$. Match: (C)–(II).

(D) An N-substituted phthalimide undergoes hydrolytic cleavage of the imide ring by aqueous $\mathrm{NaOH}$, releasing the primary amine $\mathrm{R}-\mathrm{N}{\mathrm{H}}_2$ along with sodium phthalate — the basis of the Gabriel synthesis. Match: (D)–(I).

The correct matching is (A)–(III), (B)–(IV), (C)–(II), (D)–(I).