Question

What is the major product 'Z' in the following sequence?

• A. o- Hydroxy benzaldehyde
• B. p- Hydroxy benzaldehyde
• C. o- Hydroxy benzoic acid
• D. p- Hydroxy benzoic acid

Hint:

In the Reimer-Tiemann reaction, the hydroxyl group is introduced at the ortho position relative to the aldehyde group, forming o- Hydroxy benzaldehyde.

Answer 1

The Correct Option is A

Reimer-Tiemann Reaction with Phenol Analysis

Let's analyze the reaction step by step:

1. Reaction with NaOH: The compound oleum, which contains sulfuric acid, reacts with sodium hydroxide (\( \text{NaOH} \)). This typically leads to the formation of a phenoxide ion (\( \text{O}^- \)) in aromatic compounds.
2. Reaction with \( \text{CHCl}_3/\text{NaOH} \): The reaction of the phenoxide ion with chloroform (\( \text{CHCl}_3 \)) in the presence of \( \text{NaOH} \) follows the Reimer-Tiemann reaction, which introduces an aldehyde group at the ortho position relative to the existing substituent (in this case, the hydroxyl group).
3. Acidification (\( \text{H}^+ \)): After the reaction with \( \text{NaOH} \) and chloroform, the final acidic work-up yields o-Hydroxybenzaldehyde.

Conclusion:

Thus, the major product '\( \text{Z} \)' is o-Hydroxybenzaldehyde.