The following reaction is known as
`C_(2) H_(5) OH + SOCI_(2)overset("Pyridine")rarr C_(2) H_(5) CI + SO_(2) + HCI`

Options

A. Kharasch effect
B. Williamson's sythesis
C. Darzen's procedure
D. Hunsdiecker reaction .

Explanation

To solve the question regarding the reaction:

\[ C_2H_5OH + SOCl_2 \xrightarrow{\text{Pyridine}} C_2H_5Cl + SO_2 + HCl \]

we need to identify the name of the reaction.

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- The reactants are Ethanol \((C_2H_5OH)\) and Thionyl Chloride \((SOCl_2)\).
- The products are Ethyl Chloride \((C_2H_5Cl)\), Sulfur Dioxide \((SO_2)\), and Hydrochloric Acid \((HCl)\).

2. **Understand the Reaction Type**:
- This reaction involves the conversion of an alcohol (ethanol) into an alkyl halide (ethyl chloride) through the substitution of the hydroxyl group \((OH)\) with a chlorine atom \((Cl)\).

3. **Recognize the Role of Thionyl Chloride**:
- Thionyl chloride is commonly used to convert alcohols into alkyl chlorides. The reaction proceeds via the formation of an intermediate that facilitates the substitution.

4. **Identify the Name of the Reaction**:
- This particular reaction is known as the **Darzens' procedure** (or Darzens' reaction), which is a method for converting alcohols into alkyl halides using thionyl chloride.

5. **Select the Correct Option**:
- From the options provided: Kharas effect, Williamson synthesis, Darzenne procedure, Hund's Dijkgraaf reaction, the correct answer is **Darzenne procedure**.

### Final Answer:
The following reaction is known as **Darzenne procedure**.

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