7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one → 7-bromo-4-fluoro-2-methoxy-9-methyl-9H-xanthen-9-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one (22 g, 68.1 mmol) was dissolved in 300 ml of THF and cooled to −30° C. in a dry ice ACN bath. Methylmagnesium chloride (34.0 mL, 102 mmol) (3M in THF) was added to the slurry maintaining temperature less than −15° C. The solution was allowed to warm to RT (undissolved solids went into solution), then quenched with saturated NH4Cl (250 mL). The aqueous layer was extracted with EtOAc (3×200 mL) and the combined organic layers were washed with brine and dried over anhydrous sodium sulfate, filtered and concentrated to afford 7-bromo-4-fluoro-2-methoxy-9-methyl-9H-xanthen-9-ol as a brown liquid that was used without further purification.

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