Citric Acid → 2-Fluoro-5-methoxybenzeneethanol

Beteiligte Stoffe

Reaktionsschritte

To a mixed solution of 2-fluoro-5-methoxybenzaldehyde (0.8 ml) in tetrahydrofuran (4 ml) and dimethylsulfoxide (4 ml), 1.97 g of trimethylsulfonium iodide and 308 mg of sodium hydride were added under ice-cooling, and the reaction solution was stirred at room temperature for 2 hours. To the reaction solution was added a saturated aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate. The combined organic layers were washed with a saturated saline solution and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue obtained was purified by silica gel column chromatography (eluent: hexane/ethyl acetate (98:2-50:50)) to afford a crude product as a colorless oil. To a solution of the crude product in tetrahydrofuran (2 ml), 200 mg of Sodium cyanoborohydride and 0.4 ml of trifluoroborane-diethylether complex were added under ice-cooling, and the reaction solution was stirred at room temperature for 2 hours. To the reaction solution was added 10% aqueous citric acid, and the mixture was extracted with chloroform and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue obtained was purified by silica gel column chromatography (eluent: hexane/ethyl acetate (95:5-30/70)) to afford the title compound as a colorless oil.

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