The yield of chlorobenzene obtained by reaction of phenols with `PCl_(5)` is less due to formation of

Options

A. `o-` Chlorophenol
B. `p- Chlorophenol
C. Phosphorous oxychloride
D. Triphenyl phosphate

Explanation

To solve the question regarding the yield of chlorobenzene obtained from the reaction of phenol with PCl5, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reaction**:
When phenol reacts with phosphorus pentachloride (PCl5), the expected reaction would typically yield chlorobenzene, along with by-products such as POCl3 (phosphoryl chloride) and HCl (hydrochloric acid).

2. **Identify the Competing Reaction**:
However, the yield of chlorobenzene is less due to the formation of another compound, which is triphenyl phosphate. This occurs because phenol can react with POCl3, which is formed as a by-product in the reaction.

3. **Formation of Triphenyl Phosphate**:
The reaction can be represented as follows:
- Phenol (C6H5OH) reacts with POCl3, where three moles of phenol can react with one mole of POCl3.
- This leads to the formation of triphenyl phosphate (C6H5)3PO4.

4. **Reaction Mechanism**:
- Each chlorine atom in POCl3 can be replaced by a phenol molecule, resulting in the formation of triphenyl phosphate.
- The structure of triphenyl phosphate can be depicted as having three phenyl groups attached to a phosphate group.

5. **Conclusion**:
Since the majority of phenol reacts to form triphenyl phosphate instead of chlorobenzene, the yield of chlorobenzene is significantly reduced. The side products of this reaction include hydrochloric acid (HCl).

### Final Answer:
The yield of chlorobenzene obtained by the reaction of phenols with PCl5 is less due to the formation of **triphenyl phosphate**.

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