JEE Chemistry 2024 Question with Solution

Given: An alkyl halide is to be converted into an alkyl isocyanide.

Find: The reagent that gives alkyl isocyanide.

The solution explains that cyanide salts such as NaCN, NH$4$CN, and KCN generally form alkyl cyanides (nitriles) in nucleophilic substitution reactions, not alkyl isocyanides.

AgCN behaves differently because of its covalent character. In this case, the alkyl group attaches through nitrogen, leading to formation of alkyl isocyanide $\text{R-N}\equiv\text{C}$.

Conclusion: The correct reagent is AgCN. Therefore, the correct option is D.

Given: The product required is alkyl isocyanide.

Find: Which cyanide reagent gives isocyanide instead of nitrile.

Use the standard recall rule: KCN/NaCN usually give nitriles $\text{R-C}\equiv\text{N}$, whereas AgCN gives isocyanides $\text{R-N}\equiv\text{C}$ because of the covalent nature of AgCN.

Therefore, the correct option is D (AgCN).