Which one of following on reduction with lithium aluminium hydride yields a secondary amine ? .

Options

A. Methyl isocyanide
B. Acetamide
C. Methyl cyanide
D. Nitroethane

Explanation

To determine which compound yields a secondary amine upon reduction with lithium aluminium hydride (LiAlH4), we can follow these steps:

### Step 1: Identify the Compounds
We need to look at the given options (not provided in the question) and identify which one is an isocyanide. Isocyanides have the general structure R-N≡C, where R is an alkyl or aryl group.

### Step 2: Understand the Reduction Process
Lithium aluminium hydride (LiAlH4) is a strong reducing agent that provides four hydride ions (H-) for reduction reactions. When an isocyanide is reduced, it will undergo a transformation that typically results in the formation of a secondary amine.

### Step 3: Perform the Reduction Reaction
For an isocyanide like CH3N≡C (methyl isocyanide), the reduction process can be depicted as follows:

1. The four hydride ions from LiAlH4 will attack the isocyanide.
2. The triple bond between nitrogen and carbon will be converted into a single bond.
3. The nitrogen will then bond with two carbon atoms, resulting in a secondary amine.

The reaction can be summarized as:
- CH3N≡C + 4H (from LiAlH4) → (CH3)2NH (dimethylamine)

### Step 4: Identify the Product
The product formed from the reduction of the isocyanide is dimethylamine, which has the structure:
- CH3-NH-CH3

This structure indicates that the nitrogen atom is bonded to two methyl groups (CH3), confirming that it is a secondary amine.

### Conclusion
Therefore, the compound that yields a secondary amine upon reduction with lithium aluminium hydride is the isocyanide.

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