Chlorobenzene can be prepared by reacting aniline with

Options

A. `HCl " and " Cu_(2)Cl_(2)`
B. chlorine in presence of U.V. light
C. chlorine in presence of anhydrous `AlCl_(3)`
D. nitrous acid followed by heating with `Cu_(2)Cl_(2)`

Answer

To prepare chlorobenzene from aniline, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The question states that we need to prepare chlorobenzene from aniline. Aniline is an aromatic amine with the formula C6H5NH2.

2. **Choose the Suitable Reagent**: To convert aniline (C6H5NH2) to chlorobenzene (C6H5Cl), we need to use a reagent that can introduce a chlorine atom into the aromatic ring. One effective method is to use nitrous acid (HNO2) to form a diazonium salt.

3. **Formation of Diazonium Salt**:
- Aniline reacts with nitrous acid (which can be generated in situ from sodium nitrite (NaNO2) and hydrochloric acid (HCl)) to form benzenediazonium chloride (C6H5N2Cl).
- The reaction can be represented as:
\[ C6H5NH2 + HNO2 \rightarrow C6H5N2Cl + H2O \]

4. **Substitution Reaction**:
- The benzenediazonium chloride can then undergo a substitution reaction with a chlorine source, such as phosphorus pentachloride (PCl5) or carbon tetrachloride (CCl4), to yield chlorobenzene.
- The reaction can be represented as:
\[ C6H5N2Cl + CuCl \rightarrow C6H5Cl + N2 + CuCl2 \]

5. **Final Product**: The final product of this reaction is chlorobenzene (C6H5Cl).

### Conclusion:
Thus, chlorobenzene can be prepared by reacting aniline with nitrous acid followed by a reaction with a chlorine source.