Fluorobenzene `(C_(6)H_(5)F)` can be synthesized in the laboratory .

Options

A. from aniline by diazotisation followed by heating the diazonium salt with `HBF_(4)`
B. by direct fluorination of benzene with `F_(2)` gas.
C. by reacting bromobenzene with NaF solution.
D. by heating phenol with HF and KF.

Answer

To synthesize fluorobenzene `(C6H5F)` in the laboratory, we can follow a specific method. Here’s a step-by-step breakdown of the process:

### Step 1: Diazotization of Aniline
1. **Start with Aniline**: The first step involves taking aniline `(C6H5NH2)`.
2. **Perform Diazotization**: Treat aniline with sodium nitrite `(NaNO2)` and hydrochloric acid `(HCl)` at a low temperature (0 to 5 degrees Celsius). This reaction will convert aniline into a diazonium salt, specifically benzenediazonium chloride `(C6H5N2Cl)`.

### Step 2: Formation of Fluorobenzene
3. **React with HBF4**: The next step involves heating the diazonium salt with tetrafluoroboric acid `(HBF4)`. This will facilitate the substitution of the diazonium group `(N2)` with a fluorine atom `(F)`, resulting in the formation of fluorobenzene `(C6H5F)`.

### Conclusion
The overall reaction can be summarized as:
- Start with Aniline → Diazotization → Benzenediazonium Chloride → Heating with HBF4 → Fluorobenzene

Thus, the correct method to synthesize fluorobenzene in the laboratory is through the diazotization of aniline followed by treatment with HBF4.

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