Dichloromethane → 3-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyloxy)-4-[(4-bromo-2-methyl-phenyl)methyl]-5-isopropyl-1H-pyrazole

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Reaction Steps

To a 1 L flask, add 4-[(4-bromo-2-methyl-phenyl)methyl]-5-isopropyl-1H-pyrazol-3-ol (24 g, 77.6 mmol), 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide (50.4 g, 116 mmol), benzyltributylammonium chloride (5 g, 15.5 mmol), dichloromethane (250 mL), potassium carbonate (32 g, 323 mmol), and water (120 mL). Stir the reaction mixture overnight at room temperature. Extract with dichloromethane (450 mL). Wash the extract with water (300 mL) and brine (500 mL). Dry the organic phase over sodium sulfate, filter, and concentrate under reduced pressure. Purify the resulting residue by flash chromatography (silica gel, gradient ethyl acetate/dichloromethane from 10-70% over 20 min, 330 g column) to provide the title compound (36.5 g, 57 mmol). MS (m/z): 638.5 (M+1), 636.5 (M−1).

Provenance & Evidence