Question

Conversion of benzene diazonium chloride to chlorobenzene in presence of CuCl / HCl is known as

• A. Sandmeyer reaction
• B. Mendius reaction
• C. Gattermann reaction
• D. Hofmann degradation

Hint:

To avoid getting confused between the Sandmeyer and Gattermann reactions, remember that Sandmeyer uses copper Salts ($\text{Cu}_2\text{Cl}_2$ or CuCl), while Gattermann relies purely on metallic copper powder (Cu).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The problem describes a conversion of an aromatic diazonium salt to an aryl chloride using a copper(I) catalyst and asks for the reaction's name.

Step 2: Key Formula or Approach:
This transformation is a classic method for introducing halogens into aromatic rings via the replacement of the diazonium group.

Step 3: Detailed Explanation:
Treating benzenediazonium chloride with cuprous chloride (CuCl) in HCl liberates nitrogen gas and yields chlorobenzene. This specific substitution process mediated by copper(I) salts is historically known as the Sandmeyer reaction.

Step 4: Final Answer:
The described reaction is the Sandmeyer reaction, matching option (A).