Tetrahydrofuran → HCID 67243118, compound

Temperature

-30 °C

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, filtered and concentrated to provide 7-bromo-3-methoxy-5-methyl-5H-chromeno[2,3-b]pyridin-5-ol as a yellow solid.

1. customdid not rise above −35° C
2. customAfter 1 hour the reaction, which
3. customwas quenched with 50 mL of ethyl acetate
4. customThe solution was then carefully quenched with 800 mL of 50% ammonium chloride
5. additionThe mixture was poured into a separatory funnel
6. additioncontaining ethyl acetate (100 mL)
7. customThe layers were separated
8. washthe organics were washed with brined,
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. extractionThe aqueous layer was extracted with ethyl acetate (3×500 mL)
13. washThe combined organic layers were washed with water
14. dry with materialbrine, dried over sodium sulfate
15. filtrationfiltered
16. washThis organic solution was washed with brined,
17. dry with materialdried over sodium sulfate
18. filtrationfiltered
19. concentrationconcentrated

ORD record

ord-0e98076437024e4e8c6f28e85b7a23ca

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08426447B2