Question

Write the reaction involved in Kolbe’s reaction.

Hint:

Kolbe's reaction is the industrial method for preparing Salicylic acid, which is used to make Aspirin.

Answer 1

Step 1: Understanding the Concept:
Kolbe's reaction involves the electrophilic substitution of the phenoxide ion by carbon dioxide to form a hydroxy acid.
Step 2: Detailed Explanation:
Phenol is first converted to sodium phenoxide using NaOH.
Sodium phenoxide is then reacted with \( CO_2 \) at 400K and 4-7 atm pressure.
The intermediate sodium salicylate is acidified to give 2-hydroxybenzoic acid (Salicylic acid).
Chemical Equation:
\[ C_6H_5O^-Na^+ + CO_2 \xrightarrow{400K, 4-7 atm} \text{o-}HOC_6H_4COONa \xrightarrow{H^+} \text{o-}HOC_6H_4COOH \]
Step 3: Final Answer:
The product of Kolbe's reaction is salicylic acid.