Carbon Dioxide → Salicylic Acid

Participants

Reaction Steps

In a pressure reaction vessel were charged 100 g of sodium phenolate, 40 g of phenol and 400 g of 1-phenyl-1-(2,3-dimethylphenyl)-ethane, and a reaction was allowed to proceed at 170° C. and at a carbon dioxide pressure of 10 kg/cm2 (G) for 2 hours, with stirring. The reaction mixture was cooled and charged into 500 ml of water, followed by separation into the reaction medium layer and the water layer at 90° C. The water layer was extracted with 50 g of xylene, and the phenol was recovered with an aqueous sodium 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 94.3 g of salicylic acid, with neither p-hydroxybenzoic acid nor isophthalic acid being detected as an isomer. The yield based on sodium phenolate was 90.2%, and the recovered phenol was 57 g, with the selectivity being 98.5%.

Provenance & Evidence