Complete the following reaction:
\[
\text{C}_6\text{H}_5\text{N}_2^+Cl^- \xrightarrow{\text{(i) HBF}_4} \xrightarrow{\text{(ii) NaNO}_2/\text{Cu}, \Delta} \quad ?
\]
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- The Balz-Schiemann reaction is used to introduce fluorine into the benzene ring.
- The Sandmeyer reaction is used to introduce nitro (-NO\(_2\)) and other functional groups.
The provided reaction sequence encompasses the Sandmeyer and Balz-Schiemann reactions, ultimately yielding fluorobenzene and nitrobenzene. Step 1: Balz-Schiemann Reaction (Fluorination) Initially, benzene diazonium chloride is reacted with HBF\(_4\) to produce benzene diazonium tetrafluoroborate. \[\text{C}_6\text{H}_5\text{N}_2^+Cl^- + HBF_4 \rightarrow \text{C}_6\text{H}_5\text{N}_2^+BF_4^-\]Upon heating, this intermediate decomposes to form fluorobenzene: \[\text{C}_6\text{H}_5\text{N}_2^+BF_4^- \xrightarrow{\Delta} \text{C}_6\text{H}_5F + N_2 + BF_3\]Step 2: Sandmeyer Reaction (Nitration) Subsequently, benzene diazonium chloride is treated with NaNO\(_2\)/Cu. This reagent system substitutes the diazonium group with a nitro (-NO\(_2\)) group, resulting in the formation of nitrobenzene. \[\text{C}_6\text{H}_5\text{N}_2^+Cl^- + NaNO_2/Cu, \Delta \rightarrow \text{C}_6\text{H}_5NO_2 + N_2\]
