Water → 7-bromo-3-chloro-1-fluoro-5-methyl-5H-chromeno[2,3-c]pyridin-5-ol

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Reaction Conditions

Reaction Steps

A suspension of 7-bromo-3-chloro-1-fluoro-5H-chromeno[2,3-c]pyridin-5-one (35 g, 107 mmol) in dry THF (210 mL) under nitrogen atmosphere was cooled to 0° C. and a solution of methylmagnesium bromide (3.0M solution in diethyl ether; 107 mL, 320 mmol) in dry THF (70 mL) was added over 10 minutes via an addition funnel. After complete addition a saturated aqueous solution of NH4Cl (125 mL) was added slowly to the stirring reaction mixture, keeping the internal temperature below 30° C. Water was added and the mixture was extracted twice with EtOAc. The combined organic layers were dried over sodium sulfate before concentrating under reduced pressure to afford 7-bromo-3-chloro-1-fluoro-5-methyl-5H-chromeno[2,3-c]pyridin-5-ol (34.33 g, 100 mmol).

Provenance & Evidence