Hydrogen Peroxide → 3,5-Dibromopyridine 1-oxide

3,5-Dibromopyridine (30.5 g, 0.12 mol) was dissolved in dichloromethane (80 mL) and methlytrioxorhenium (150 mg, 0.603 mmol) was added 30% hydrogen peroxide (27 mL) was added slowly over 5 minutes and the mixture was stirred at ambient temperature for 3 hours. An additional 40 mL of hydrogen peroxide was added and the reaction was stirred 16 hours. Manganese dioxide (100 mg) was added and the suspension was stirred 40 minutes. The mixture was extracted with dichloromethane, dried over sodium sulfate, filtered, and concentrated under reduced pressure. Ethyl acetate was added and the suspension was refluxed for 30 minutes until solids dissolved and then the mixture was allowed to cool to ambient temperature and aged 48 hours. 3,5-dibromopyridine 1-oxide (25.09 g, 82% yield) was collected by vacuum filtration as pale yellow needles. 1H NMR (CDCl3) δ 8.27 (s, 2 H), 7.56 (s, 1 H).

1. additionwas added slowly over 5 minutes
2. stirringthe reaction was stirred 16 hours
3. stirringthe suspension was stirred 40 minutes
4. extractionThe mixture was extracted with dichloromethane
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. additionEthyl acetate was added
9. temperaturethe suspension was refluxed for 30 minutes until solids
10. dissolutiondissolved
11. temperatureto cool to ambient temperature and aged 48 hours

ORD record

ord-6fca58b854354abaa79dcb0346ffcc67

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08691991B2