2-bromo-3,5-difluoro-7-methoxy-9H-xanthen-9-one → 2-bromo-3,5-difluoro-7-methoxy-9-methyl-9H-xanthen-9-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-bromo-3,5-difluoro-7-methoxy-9H-xanthen-9-one (40 g, 117 mmol) and THF (300 mL) was cooled to 0° C. and treated with methylmagnesium chloride (58.6 mL, 176 mmol) (3M in THF). After stirring at this temperature for 20 minutes, the reaction was quenched by the addition of sataturated NH4Cl (500 mL). Brine was added and the mixture was extracted with EtOAc (3×100 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo to afford crude 2-bromo-3,5-difluoro-7-methoxy-9-methyl-9H-xanthen-9-ol as a brown solid that was carried on without further purification. MS m/z=339.0 [M+1−H2O].

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