Tetrahydrofuran → HCID 67243118, compound

Participants

Reaction Conditions

Reaction Steps

To a slurry of 7-bromo-3-methoxy-5H-chromeno[2,3-b]pyridin-5-one (23 g, 75 mmol) in THF (751 mL, 75 mmol) at −40° C. was added methylmagnesium chloride, 3.0 M solution in THF (88 mL, 263 mmol) over 2 minutes such that the temperature did not rise above −35° C. The resulting red slurry was maintained at −30° C. After 1 hour the reaction, which was now homogeneous, was quenched with 50 mL of ethyl acetate. The solution was then carefully quenched with 800 mL of 50% ammonium chloride. The mixture was poured into a separatory funnel containing ethyl acetate (100 mL). The layers were separated and the organics were washed with brined, dried over sodium sulfate, filtered and concentrated. The aqueous layer was extracted with ethyl acetate (3×500 mL). The combined organic layers were washed with water and then brine, dried over sodium sulfate, filtered, and combined with the above derived oil. This organic solution was washed with brined, dried over sodium sulfate, fitlered and concentrated to provide 7-bromo-3-methoxy-5-methyl-5H-chromeno[2,3-b]pyridin-5-ol as a yellow solid.

Provenance & Evidence