Question

Which reaction is used to prepare 2-hydroxy benzaldehyde from phenol?

• A. Reimer-Tiemann reaction
• B. Kolbe's reaction
• C. Williamson synthesis
• D. Etard's reaction

Hint:

Remember: Reimer-Tiemann reaction is used for formylation of phenol, while Kolbe's reaction is used for carboxylation of phenol.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Phenol can be functionalized at the ortho position using specific name reactions.
Step 2: Formula Application:
1. Reimer-Tiemann: $CHCl_3 + NaOH \to$ Salicylaldehyde (2-hydroxy benzaldehyde). 2. Kolbe's: $CO_2 + NaOH \to$ Salicylic acid (2-hydroxy benzoic acid).
Step 3: Explanation:
The Reimer-Tiemann reaction introduces an aldehyde group ($-CHO$) onto the phenol ring at the ortho position.
Step 4: Final Answer:
The reaction is the Reimer-Tiemann reaction.