Benzoic Acid → 4-Hydroxybenzoic Acid

Participants

Reaction Conditions

Reaction Steps

To a stainless steel autoclave containing 20.0 grams of acetonitrile is charged 122.0 grams (1.0 mole) of benzoic acid and 500 grams of water containing 200 grams (5.0 mole) of sodium hydroxide. Following this, 12.0 grams of a 30% aqueous hydrogen peroxide solution is added to the autoclave during a period of 20 minutes. During the addition of the aqueous hydrogen peroxide solution, the autoclave is maintained at a temperature of 50° C. and atmospheric pressure. At the end of the addition time, heating is discontinued, the autoclave is allowed to return to room temperature and the reaction product is transferred to a clean dry beaker. The product is acidified, extracted with ether and the ether layer is evaporated to produce a crude product. Fractional crystallization of the crude product in water and alcohol will yield essentially pure 2-hydroxybenzoic acid, 3-hydroxybenzoic acid and 4-hydroxybenzoic acid.

Provenance & Evidence