The best reagent for converting an alcohol into the corrosponding chloride is

Options

A. `PCI_(5)`
B. `PCI_(3)`
C. `HCI//ZnCI_(2)`
D. `SOCI_(2)`

Answer

To determine the best reagent for converting an alcohol into the corresponding chloride, we can analyze the options provided.

### Step-by-Step Solution:

1. **Identify the Reagents**: The options provided are PCl5, PCl3, HCl with ZnCl2, and SOCl2.

2. **Evaluate PCl5**:
- PCl5 has five chlorine atoms bonded to phosphorus.
- The steric hindrance caused by the bulky PCl5 makes it less effective for this conversion.
- **Conclusion**: PCl5 is not the best reagent.

3. **Evaluate PCl3**:
- PCl3 has three chlorine atoms attached to phosphorus.
- Similar to PCl5, it also suffers from steric hindrance due to the bulky nature of the reagent.
- **Conclusion**: PCl3 is not the best reagent.

4. **Evaluate HCl with ZnCl2 (Groove's Method)**:
- This method involves using HCl in the presence of ZnCl2 to convert alcohols into alkyl halides.
- However, this method can lead to the formation of carbocations and alkenes due to hyperconjugation, which is not desirable.
- **Conclusion**: Groove's method is not the best reagent.

5. **Evaluate SOCl2 (Thionyl Chloride)**:
- SOCl2 is used in the Darzen's process to convert alcohols into alkyl halides.
- The reaction produces SO2 and HCl as by-products, which are gases and readily evolve out of the reaction mixture.
- This minimizes side reactions and makes the process cleaner and more efficient.
- **Conclusion**: SOCl2 is the best reagent for converting alcohols into the corresponding chlorides.

### Final Answer:
The best reagent for converting an alcohol into the corresponding chloride is **SOCl2 (Thionyl Chloride)**.