Question

How do you convert the following? Acetophenone to Benzoic acid

Hint:

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

Answer 1

Concept: Acetophenone is a methyl ketone. Methyl ketones undergo
haloform reaction (iodoform reaction) when treated with halogen in alkaline medium, leading to cleavage and formation of carboxylate salt.
Step 1: Haloform reaction. \[ C_6H_5COCH_3 \xrightarrow{I_2/NaOH} C_6H_5COONa + CHI_3 \]
Step 2: Acidification. \[ C_6H_5COONa \xrightarrow{H^+} C_6H_5COOH \]
Final Conversion: \[ \text{Acetophenone} \xrightarrow{I_2/NaOH} \text{Sodium benzoate} \xrightarrow{H^+} \text{Benzoic acid} \]