Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

Options

A. `H_(2)("excess")//Pt`
B. `LiAlH_(6)` in ether
C. Fe and HCl
D. Sn and HCl

Explanation

To determine which reagent would not be a good choice for reducing an aryl nitro compound to an amine, we can analyze the given options step by step.

### Step-by-Step Solution:

1. **Identify the Aryl Nitro Compound**:
- Let's consider nitrobenzene as our example of an aryl nitro compound. The structure of nitrobenzene is C6H5NO2, where the nitro group (-NO2) is attached to a benzene ring.

2. **Evaluate the First Reagent (H2 with Pt)**:
- When nitrobenzene is treated with hydrogen gas (H2) in the presence of a platinum catalyst (Pt), the nitro group is reduced to an amine group (-NH2), resulting in aniline (C6H5NH2).
- **Conclusion**: This is a good choice for reduction.

3. **Evaluate the Second Reagent (Fe and HCl)**:
- The combination of iron (Fe) and hydrochloric acid (HCl) is another common method for reducing nitro compounds. This reaction also converts nitrobenzene to aniline.
- **Conclusion**: This is also a good choice for reduction.

4. **Evaluate the Third Reagent (Sn and HCl)**:
- Tin (Sn) in the presence of hydrochloric acid (HCl) similarly reduces nitrobenzene to aniline.
- **Conclusion**: This is a good choice for reduction as well.

5. **Evaluate the Fourth Reagent (LiAlH4 in Ether)**:
- Lithium aluminum hydride (LiAlH4) is a very strong reducing agent. However, it does not effectively reduce aryl nitro compounds like nitrobenzene to amines. Instead, it can lead to side reactions or no reaction at all when applied to such compounds.
- **Conclusion**: This is not a good choice for reduction.

6. **Final Answer**:
- The reagent that would not be a good choice for reducing an aryl nitro compound to an amine is **Lithium Aluminum Hydride (LiAlH4) in Ether**.