Question

How is the following conversion carried out?

Chlorobenzene to benzoic acid

How will you convert chlorobenzene into benzoic acid?

Answer 1

Chlorobenzene (C₆H₅Cl) cannot be directly converted to benzoic acid under normal conditions due to the stability of the aryl–Cl bond. However, the conversion can be done through a multi-step process:

1. Convert Chlorobenzene to Benzonitrile (C₆H₅CN): This is done using cuprous cyanide (CuCN) in Sandmeyer’s reaction.
   \[\ce{C6H5Cl + CuCN ->[Heat][]C6H5CN + CuCl}\]
2. Hydrolysis of Benzonitrile to Benzoic Acid:
   \[\ce{C6H5CN + 2H2O ->[Dil{.}HCl/Heat][]C6H5COOH + NH3}\]