Hydrochloric Acid → 4'-Ethoxy-2,3,2',3'-tetrafluorobiphenyl-4-ol

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Reaction Steps

In a reactor under nitrogen atmosphere, 20.0 g of compound (a2)17.2 g of 4-bromo-2,3-difluorophenol (a3), 30.6 g of sodium carbonate, 0.54 g of palladium on carbon catalyst (Pd/C) were dissolved in 120 mL of 2-propanol (IPA). After stirring by refluxing for 10 hours, the reaction mixture was cooled to room temperature, and injected into a mixture of 500 ml of 1N hydrochloric acid and 300 ml of toluene which was cooled into 0° C. The mixture was separated into organic layer and aqueous layer and the organic layer was extracted. The resulting organic layer was washed with saturated chloride aqueous solution and dried over anhydrous magnesium sulfate, and the solvent was concentrated under reduced pressure to provide the residue. The resulting residue was purified by recrystallization from heptan, dried to provide 13.2 g of 4′-ethoxy-2,3,2′,3′-tetrafluorobiphenyl-4-ol (a4) as a white solid.

Provenance & Evidence