Preparation of benzoic acid by clean oxidation of phenyl formaldehyde

Benzoic acid has been prepared through the oxidization of phenyl formaldehyde (10.1 mL) with hydrogen peroxide (30%, 11.5 mL) as oxidizing agent and amine hexadecane trimethyl P-W heteropoly acid (0.16 g) as catalyst; the influences of reaction temperature, content of catalyst, volume of hydrogen peroxide and reaction period on the yield of phenyl carboxylic acid have been investigated. Research results show that the yield of phenyl carboxylic acid reaches 75.5% if the reaction temperature is 90°C and the reaction period is 6 hours. Addition of carbon tetrachloride significantly decreases the yield of phenyl carboxylic acid; this proves that the reaction is of free group reaction.