Which of the following is used as a reductant in order to obtain an alkylamine from a nitroalkanes ?

Options

A. `Al_2 O_3`
B. `Sn + HCI`
C. `Na+C_2H_5 OH`
D. `Zn+Nh_4 Cl`

Answer

To solve the question of which reducing agent is used to convert nitroalkanes into alkylamines, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reaction**: We need to convert a nitroalkane (RNO2) into an alkylamine (RNH2). The nitro group (NO2) needs to be reduced to an amine group (NH2).

2. **Identify the Reducing Agents**: We need to consider the options provided and identify which ones are known to act as mild reducing agents suitable for this conversion.

3. **Evaluate the Options**:
- **Option A: Sn + HCl**: Tin (Sn) in the presence of hydrochloric acid (HCl) is a known mild reducing agent that can reduce nitro compounds to amines. This combination is commonly used in organic chemistry for such reductions.
- **Option B: Al2O3**: Aluminum oxide (Al2O3) is not a reducing agent; it is typically used as a catalyst or in the cleavage of carbon-halogen bonds.
- **Option C: Na + Ethanol**: Sodium in ethanol is a stronger reducing agent, typically used for reducing nitriles to primary amines, but it is not mild enough for nitroalkane reduction.
- **Option D: Zn + NH4Cl**: Zinc with ammonium chloride is used to reduce alcohols to alkanes, not suitable for the reduction of nitroalkanes to amines.

4. **Conclusion**: Based on the evaluation, the correct answer is **Option A: Sn + HCl**, as it effectively reduces nitroalkanes to alkylamines.

### Final Answer:
The correct answer is **Sn + HCl**.