Hydrogen Peroxide → 2,6-Dibromopyridine N-Oxide

Temperature

100 °C

To an ice-cold solution of 2,6-dibromopyridine (50 g, 0.21 mol) in trifluoroacetic acid (250 mL) was added 30% H2O2 solution (70 mL) drop wise over 1 h. The reaction mixture was washed, heated to 100° C. for 16 h then cooled to rt, poured into 1.50 L of water and the precipitate filtered. The solid thus obtained (10 g) was the starting material (2,6-dibromopyridine). The filtrate was extracted with dichloromethane (3×1 L) and the combined organic layer was washed with 0.50 M K2CO3 solution (3×500 mL). The organic layer was then dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The residue was treated with hexane then filtered to obtain the desired product as an off white solid (38.50 g, 72% and 90% yield based on the recovery of the starting material).

1. washThe reaction mixture was washed
2. temperaturethen cooled to rt
3. additionpoured into 1.50 L of water
4. filtrationthe precipitate filtered
5. customThe solid thus obtained (10 g)
6. extractionThe filtrate was extracted with dichloromethane (3×1 L)
7. washthe combined organic layer was washed with 0.50 M K2CO3 solution (3×500 mL)
8. dry with materialThe organic layer was then dried over anhydrous Na2SO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. additionThe residue was treated with hexane
12. filtrationthen filtered

ORD record

ord-e7a0c0e89ace4ea9a347fd585b123598

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181234B2