Question

Show how each of the following compounds can be converted to benzoic acid.
i. Ethyl benzene     ii. Acetophenone
iii. Bromobenzene   iv. Phenylethene (Styrene)

Answer 1

i. Oxidation of ethyl benzene with alkaline KMnO₄ followed by acid hydrolysis gives benzoic acid.

ii. Oxidation of acetophenone with alkaline KMnO₄ followed by acid hydrolysis gives benzoic acid.

iii. Bromobenzene reacts with magnesium to form Grignard reagent which attacks carbon dioxide to form an intermediate which on acid hydrolysis gives benzoic acid.

iv. Oxidation of phenyl ethene with alkaline KMnO₄ followed by acid hydrolysis gives benzoic acid.