NEET 2023, Chemistry Q29: Preparation of Amines

(i) Nitriles ($\text{R-C}\equiv \text{N}$) reduce to ${\text{R-CH}}_2-{\text{NH}}_2$ — primary amine.

(ii) Isocyanides ($\text{R-N}\equiv \text{C}$) reduce to ${\text{R-NH-CH}}_3$ — secondary amine. This is the exception.

(iii) Amides reduce to primary amines: ${\text{CH}}_3{\text{CONH}}_2\to {\text{CH}}_3{\text{CH}}_2{\text{NH}}_2$.

(iv) Hofmann bromamide reaction gives ${\text{CH}}_3{\text{NH}}_2$ (one carbon shorter, still a 1° amine).