反应详情

温度

100 °C

An autoclave was charged with 498 g of light oil (boiling at 250°-350° C.) and 166 g of sodium β-naphtholate, and with stirring, 72 g of β-naphthol was added. The mixture was reacted with carbon dioxide under a pressure of 5 kg/cm2.G at a reaction temperature of 270° C. for 4 hours. The reaction mixture was added to 830 ml of water, and heated at 100° C. for 30 minutes to decompose a 2-hydroxynaphthalene-1-carboxylic acid salt. The mixture was then separated into a light oil layer and an aqueous layer at 85° C. From the light oil layer, β-naphthol was extracted as an aqueous solution of sodium β-naphtholate by using an aqueous solution of sodium hydroxide. The pH of the aqueous layer was adjusted to 5.5 with hydrochloric acid, and the tarry layer that sedimented was separated at 85° C., and β-naphthol was recovered from the tarry layer by vacuum distillation. Water (500 ml) was added to the aqueous layer, and the mixture was extracted with 650 ml of toluene at 80° C. From the toluene layer, β-napthol was extracted as an aqueous solution of sodium β-naphtholate by using an aqueous solution of sodium hydroxide. The pH of the aqueous layer was adjusted to 2.0 with hydrochloric acid, and the mixture was cooled to 40° C., followed by filtration. Thus, 79.9 g of 2-hydroxynaphthalene-3-carboxylic acid (melting range 220°-221° C.; purity 99.6%; β-naphthol content 0.03%) was obtained.

1. customThe mixture was then separated into a light oil layer
2. customat 85° C
3. extractionFrom the light oil layer, β-naphthol was extracted as an aqueous solution of sodium β-naphtholate
4. customthe tarry layer that sedimented was separated at 85° C.
5. distillationβ-naphthol was recovered from the tarry layer by vacuum distillation
6. additionWater (500 ml) was added to the aqueous layer
7. extractionthe mixture was extracted with 650 ml of toluene at 80° C
8. extractionFrom the toluene layer, β-napthol was extracted as an aqueous solution of sodium β-naphtholate
9. temperaturethe mixture was cooled to 40° C.
10. filtrationfollowed by filtration