28177-48-2

colorless crystalline low melting solid

2,6-Difluorophenol undergoes oxidative polymerization in the presence of the Fe-N,N?-bis(salicylidene)ethylenediamine (salen) complex (catalyst) and hydrogen peroxide (oxidizing agent) to give poly(2,6-difluoro-1,4-phenylene oxide). It is also used as pharmaceutical intermediates.

General procedure for the synthesis of 2,6-difluorophenol from 2,6-difluoroanisole: 2,6-difluoroanisole (4.00 mL, 33.9 mmol) was dissolved in acetonitrile (50 mL), and trimethylchlorosilane (8.80 mL, 102 mmol) and sodium iodide (15.0 g, 100 mmol) were added sequentially. The reaction mixture was heated to 100 °C for 5 hours. After completion of the reaction, it was cooled to room temperature and the solvent was removed by evaporation under reduced pressure. Water (40 mL) was added to the residue and extracted with dichloromethane (30 mL x 3). The organic phases were combined and washed sequentially with water (40 mL) and saturated brine (40 mL), and then dried over anhydrous sodium sulfate. After filtration, the solvent was removed by evaporation under reduced pressure to obtain the crude product. The crude product was purified by column chromatography (eluent: petroleum ether/ethyl acetate, v/v = 6/1) to afford the yellow oily product 2,6-difluorophenol (2.2 g, 50% yield).

[1] Patent: CN105384687, 2016, A. Location in patent: Paragraph 0479; 0480; 0481; 0482
[2] Journal of the American Chemical Society, 1959, vol. 81, p. 94,95, 97