Question

How do you convert the following? Acetophenone to Benzoic acid

Hint:

Methyl ketone + Haloform reaction → Carboxylic acid (one carbon less).

Answer 1

Step 1: Understanding the Reactants.
Acetophenone is an aromatic ketone with the structure \( \text{C}_6\text{H}_5\text{COCH}_3 \), while benzoic acid is an aromatic carboxylic acid with the structure \( \text{C}_6\text{H}_5\text{COOH} \). To convert acetophenone to benzoic acid, we need to oxidize the methyl group (\( \text{-CH}_3 \)) attached to the carbonyl group in acetophenone into a carboxyl group (\( \text{-COOH} \)).

Step 2: Oxidation Reaction.
To convert acetophenone to benzoic acid, we can use an oxidizing agent that will oxidize the methyl group (\( \text{CH}_3 \)) to a carboxyl group (\( \text{COOH} \)). One of the common methods is to use an oxidizing agent such as potassium permanganate (KMnO₄) or chromic acid (H₂CrO₄). These reagents will oxidize the methyl group into a carboxyl group, converting acetophenone into benzoic acid.

Step 3: Reaction with Potassium Permanganate (KMnO₄).
When acetophenone reacts with potassium permanganate under appropriate conditions, the permanganate ion (\( \text{MnO}_4^- \)) oxidizes the methyl group to a carboxyl group, resulting in the formation of benzoic acid.
The reaction can be written as: \[ \text{C}_6\text{H}_5\text{COCH}_3 + [O] \xrightarrow{\text{KMnO}_4} \text{C}_6\text{H}_5\text{COOH} \] Here, \( [O] \) represents the oxidizing agent, and the result is benzoic acid.

Step 4: Conclusion.
To convert acetophenone to benzoic acid, you can use potassium permanganate (KMnO₄) or chromic acid (H₂CrO₄) to oxidize the methyl group (\( \text{-CH}_3 \)) into a carboxyl group (\( \text{-COOH} \)), forming benzoic acid.