Carbon Dioxide → 3-Hydroxy-2-naphthoic acid

Participants

Reaction Conditions

Reaction Steps

In a pressure reaction vessel were charged 166 g of sodium 2-naphtholate, 72 g of 2-naphthol and 498 g of hydrogenated triphenyl, and a reaction was allowed to proceed at 260° C. and at a carbon dioxide pressure of 5 kg/cm2 (G) for 3 hours, with stirring. The reaction mixture was charged into 800 ml of water, and the resulting mixture was adjusted to a pH 5.5 with sulfuric acid, followed by separation into the reaction medium layer and the water layer at 85° C. The 2-naphthol was recovered with an aqueous sodium hydroxide solution from the reaction medium layer. After recovery of 2-naphthol, the water layer was adjusted to a pH 2.0 with sulfuric acid at the same temperature, cooled to 40° C. and subjected to filtration to give 89.3 g of 2-hydroxynaphthalene-3-carboxylic acid. The product was found to contain only 0.1% of 2-hydroxynaphthalene-6-carboxylic acid, with no trace of 2-hydroxynaphthalene- 1-carboxylic acid. The yield based on sodium 2-naphtholate was 47.5%, with the selectivity being 99.3%.

Provenance & Evidence