An alkyl isocyanide is prepared by -

Options

A. Heating an amide with `P_(2)O_(5)`
B. Reacting an alcohol with `NH_(3)`
C. The action of AgCN on alkyl halide
D. The action of KCN on alkyl halide

Answer

To prepare an alkyl isocyanide, we can follow these steps based on the information provided in the video transcript:

### Step-by-Step Solution:

1. **Understanding the Structure of Isocyanide**:
- An alkyl isocyanide is represented as R-N≡C, where R is an alkyl group. The isocyanide functional group consists of a nitrogen atom bonded to a carbon atom, which is in turn triple-bonded to another nitrogen atom.

2. **Identifying the Reagents**:
- To prepare alkyl isocyanide, we can use the reagent silver cyanide (AgCN). This reagent contains a cyanide ion (CN⁻) that acts as a nucleophile.

3. **Reaction Mechanism**:
- When an alkyl halide (R-X) reacts with AgCN, the cyanide ion (CN⁻) attacks the alkyl halide.
- In this reaction, the nucleophilic part of CN⁻ is the nitrogen atom. Due to the covalent nature of AgCN, the nitrogen atom is more likely to donate its electron pair and form a bond with the alkyl group.

4. **Formation of Isocyanide**:
- As a result of the nucleophilic attack, the product formed is R-N≡C, which is the alkyl isocyanide. This reaction is significant because it specifically leads to the formation of isocyanide rather than other cyanide derivatives.

5. **Conclusion**:
- Therefore, the preparation of alkyl isocyanide can be achieved by reacting an alkyl halide with silver cyanide (AgCN).

### Final Answer:
An alkyl isocyanide is prepared by reacting an alkyl halide with silver cyanide (AgCN).

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