Carbon Dioxide → 4-Hydroxybenzoic Acid

Participants

Reaction Steps

In a pressure reaction vessel were charged 100 g of sodium phenolate, 35 g of phenol and 400 g of a mixture of hydrogenated triphenyls, and a reaction was allowed to proceed at 250° C. and at a carbon dioxide pressure of 7 kg/cm2 (G) for 20 minutes, with stirring The reaction mixture was cooled and charged into 200 ml of water, followed by separation into the reaction medium layer and the water layer at 60° C. The water layer was extracted with 50 g of xylene, and the phenol was recovered with an aqueous potassium hydroxide solution from the reaction medium and extraction medium layers. After recovery of phenol, the water layer was made acid with dilute sulfuric acid to give 80.8 g of p-hydroxybenzoic acid (having a purity of 100%), with neither salicylic acid nor isophthalic acid being detected as an isomer. The yield based on potassium phenolate was 77.3%, and the recovered phenol was 21.8 g, with the selectivity being 99.7%.

Provenance & Evidence