Question

When benzene diazonium chloride is treated with Cu and HBr, bromobenzene, N2 and CuCl are obtained. This reaction is called

• A. Hoffmann reaction
• B. Gabriel reaction
• C. Sandmeyer reaction
• D. Gatterman reaction
• E. Hinsberg’s reaction

Hint:

Remember:
Cuprous salt (\(Cu_2X_2\)) = Sandmeyer.
Copper powder (Cu) = Gatterman.
The yield of the Sandmeyer reaction is generally better than the Gatterman reaction.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Aryl halides can be prepared from benzene diazonium salts through substitution reactions using copper-based catalysts.

Step 3: Detailed Explanation:
There are two similar-looking named reactions for this conversion:
1. Sandmeyer Reaction: Uses cuprous salts like \(Cu_2Cl_2\), \(Cu_2Br_2\), or \(Cu_2(CN)_2\) in the presence of the corresponding halogen acid.
2. Gatterman Reaction: This is a modification of the Sandmeyer reaction. Instead of using cuprous salts, it uses copper powder (Cu) in the presence of halogen acids like \(HCl\) or \(HBr\).
The question specifies the use of Cu and HBr, which identifies it as the Gatterman reaction.

Step 4: Final Answer:
The reaction described is the Gatterman reaction.