Question

In the following reaction sequence, identify compound \( (R) \).

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

In the Kolbe-Schmitt reaction, phenoxide ions react with carbon dioxide to form a carboxylated product.

Answer 1

The Correct Option is A

To solve this problem, we need to analyze the chemical reaction sequence step-by-step and identify the structure of compound \( (R) \).

The given sequence involves three main steps:

1. Starting with phenol, reacting with NaOH.
2. Reaction of the product with CO₂.
3. Acidification with H⁺.

Step 1: Reaction of phenol with NaOH.

Phenol reacts with NaOH to form sodium phenoxide:

C_6H_5OH + NaOH \rightarrow C_6H_5ONa + H_2O

Step 2: Reaction with CO₂.

Sodium phenoxide reacts with CO₂ in the Kolbe-Schmitt reaction to form sodium salicylate:

C_6H_5ONa + CO_2 \rightarrow C_6H_4(OH)COONa

Step 3: Acidification with H⁺.

Sodium salicylate is then treated with H⁺ to form salicylic acid:

C_6H_4(OH)COONa + H^+ \rightarrow C_6H_4(OH)COOH

Thus, the compound \( (R) \) is salicylic acid, which corresponds to option 1.

Conclusion: The correct answer is option 1. The reactions convert phenol into salicylic acid, demonstrating a typical example of the Kolbe-Schmitt reaction.