Bromobenzene can be prepared from benzene diazonium chloride. Whenits is treated with

Options

A. `Cu/HBr`
B. `Br_(2), HBr`
C. `CuBr/HBr`
D. `Br_(2), CCI_(4)`

Answer

To prepare bromobenzene from benzene diazonium chloride, we can follow these steps:

### Step 1: Understanding the Reactants
Benzene diazonium chloride (C6H5N2Cl) is a compound that contains a diazonium group (N2+) attached to a benzene ring. This compound can be used in reactions to introduce different substituents onto the benzene ring.

**Hint:** Identify the functional groups in benzene diazonium chloride and their reactivity.

### Step 2: Choosing the Correct Reagent
To convert benzene diazonium chloride to bromobenzene, we need to use a reagent that can replace the diazonium group with a bromine atom. The common reagents for this transformation include copper(I) bromide (CuBr) in the presence of hydrobromic acid (HBr).

**Hint:** Look for reagents that are known to facilitate the substitution of the diazonium group.

### Step 3: The Reaction Mechanism
The reaction proceeds as follows:
1. The benzene diazonium chloride reacts with copper(I) bromide and hydrobromic acid.
2. The diazonium group (N2+) is replaced by a bromine atom (Br) to form bromobenzene (C6H5Br).

The overall reaction can be summarized as:
\[ \text{C}_6\text{H}_5\text{N}_2\text{Cl} + \text{CuBr} + \text{HBr} \rightarrow \text{C}_6\text{H}_5\text{Br} + \text{CuCl} + \text{N}_2 + \text{HCl} \]

**Hint:** Consider the role of each reagent in the reaction and what products are formed.

### Step 4: Conclusion
Thus, bromobenzene can be prepared from benzene diazonium chloride by treating it with copper(I) bromide and hydrobromic acid.

**Final Answer:** Bromobenzene can be prepared from benzene diazonium chloride when treated with copper(I) bromide and HBr.

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