Question

How can you convert phenyl magnesium bromide to benzoic acid?

Hint:

- The reaction of a Grignard reagent with carbon dioxide and subsequent acid hydrolysis forms a carboxylic acid. - This reaction is known as the Grignard reaction for carboxylation.

Answer 1

Phenyl magnesium bromide (C\(_6\)H\(_5\)MgBr) can be converted to benzoic acid by reacting it with carbon dioxide (CO\(_2\)) followed by hydrolysis. The reaction steps are: \[ \text{C}_6\text{H}_5\text{MgBr} + \text{CO}_2 \, (\text{dry ether}) \rightarrow \text{C}_6\text{H}_5\text{COOMgBr} \] Then, hydrolyze the intermediate with water and acid: \[ \text{C}_6\text{H}_5\text{COOMgBr} + \text{H}_2\text{O}/\text{H}^+ \rightarrow \text{C}_6\text{H}_5\text{COOH} \] This converts the Grignard reagent into benzoic acid.