Question

Which of the following reactions uses diazonium salt ?

• A. Sandmeyer reaction
• B. Mendius reaction
• C. Hofmann rearrangement reaction
• D. carbylamine reaction

Hint:

Sandmeyer converts aryl diazonium salt to aryl halide using CuX.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
A diazonium salt \(\text{ArN}_2^+\text{X}^-\) is made by diazotisation of a primary aromatic amine. It is a useful intermediate.

Step 2: Detailed Explanation:
In the Sandmeyer reaction, the diazonium group is replaced by \(-\text{Cl}\), \(-\text{Br}\) or \(-\text{CN}\) using \(\text{CuCl}\), \(\text{CuBr}\) or \(\text{CuCN}\). So it uses a diazonium salt.
Mendius reaction reduces nitriles to primary amines. Hofmann rearrangement (bromamide) converts an amide to an amine with one fewer carbon. The carbylamine reaction converts a primary amine and chloroform into an isocyanide. None of these involve a diazonium salt.

Step 3: Final Answer:
Sandmeyer reaction, option (A).

Final Answer:
The Sandmeyer reaction replaces the diazonium group. \[ \boxed{\text{(A) }\text{Sandmeyer reaction}} \]