Hydrogen Peroxide → 6-Bromo-5-chloropyridin-3-ol

To crude 2-bromo-3-chloro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (Preparation 238, 8.27 g, 26.0 mmol) was added methanol (100 mL), and the stirred solution cooled in an ice bath. To the solution was added hydrogen peroxide solution (35% in water, 4.25 mL, 43.8 mmol) over 5 minutes. The solution was allowed to warm slowly to room temperature for 18 hours. The reaction was quenched by addition of 1M aqueous sodium thiosulfate solution (500 mL), with rapid stirring for 15 minutes. The organics were removed in vacuo, and brine (100 mL) was added. The aqueous phase was extracted into ethyl acetate (3×100 mL). The combined organic phases were dried over magnesium sulfate, filtered and the solvent removed to leave an off white solid. The solid was triturated in 4:1 heptene:ethyl acetate and filtered to afford the title compound as a white solid (2.20 g, 41%).

1. temperaturethe stirred solution cooled in an ice bath
2. customThe reaction was quenched by addition of 1M aqueous sodium thiosulfate solution (500 mL)
3. customThe organics were removed in vacuo, and brine (100 mL)
4. additionwas added
5. extractionThe aqueous phase was extracted into ethyl acetate (3×100 mL)
6. dry with materialThe combined organic phases were dried over magnesium sulfate
7. filtrationfiltered
8. customthe solvent removed
9. customto leave an off white solid
10. customThe solid was triturated in 4:1 heptene
11. filtrationethyl acetate and filtered

ORD record

ord-980490b3b09049dd962fe858026573d9

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08592629B2