Ammonium Chloride → 4-(difluoromethyl)phenyl 4-fluoro-1-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl) indol-3-yl methanol

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Reaction Steps

To a mixture of magnesium turnings (71 mg) in tetrahydrofuran (2 ml) was added dropwise a solution of 1-bromo-4-difluoromethylbenzene (587 mg) in tetrahydrofuran (1.5 ml) under being stirred vigorously. The mixture was warmed with a dryer, and thereto was added 1,2-dibromoethane (4 drops). The resultant mixture was vigorously stirred at room temperature till a disappearance of magnesium turnings, and then dropwise added to a solution of the above 4-fluoro-1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)indole-3-carboxaldehyde (350 mg) in tetrahydrofuran (4 ml) over 10 minutes at −78° C. under argon atmosphere. The mixture was stirred at same temperature for 1 hour, and thereto was added a saturated aqueous ammonium chloride solution (20 ml). The resultant mixture was extracted with ethyl acetate (50 ml) 3 times, and the combined organic layer was dried over magnesium sulfate. The insoluble materials were filtered off, and the filtrate was evaporated under reduced pressure to give crude 4-(difluoromethyl)phenyl 4-fluoro-1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)indol-3-yl methanol, which was used in the subsequent step without further purification.

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