Sodium Sulfite → 2,3-Difluoro-6-methoxyphenol

Beteiligte Stoffe

Reaktionsschritte

To a solution of 2,3-difluoro-6-methoxybenzaldehyde (2.58 g) in methylene chloride (45 mL) was added 3-chloroperbenzoic acid (5.97 g) under ice-cooling, and the mixture was heated for reflux overnight. The reaction mixture was cooled in ice. To the mixture was added 10% aqueous sodium sulfite solution, and the resulting mixture was stirred for 20 minutes. The organic layer was separated and washed with water twice, a saturated aqueous sodium hydrogen carbonate solution, water and brine successively, and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the residue was dissolved in tetrahydrofuran (15 mL)-methanol (7.5 mL). To the solution was added sodium methoxide (28% methanol solution, 3.75 mL), and the mixture was stirred at room temperature for 1 hour. The reaction mixture was poured into 1 mol/L hydrochloric acid, and the resulting mixture was extracted with ethyl acetate. The extract was washed with brine and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: n-hexane−n-hexane/ethyl acetate=2/3) and column chromatography on aminopropylated silica gel (eluent: ethyl acetate/methanol=9/1−3/2) successively to give the title compound (1.7 g).

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