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

Participants

Reaction Steps

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%).

Provenance & Evidence