Hydrogen Bromide → 4-Bromo-2,3-dimethylpyridine 1-oxide

Temperature

100 °C

A mixture of 2,3-dimethyl-4-nitropyridine N-oxide (5 g, 29.7 mmol) and hydrogen bromide (30% wt in acetic acid, 100 mL) was heated for 48 hours at 100° C. The mixture was then filtered, washing through with 2 M sodium hydroxide and the filtrate was extracted with dichloromethane (×3). The combined organic solutions were washed with brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel, eluting with ethyl acetate:pentane, 50:50, to afford the title product as a pale yellow solid.

1. filtrationThe mixture was then filtered
2. washwashing through with 2 M sodium hydroxide
3. extractionthe filtrate was extracted with dichloromethane (×3)
4. washThe combined organic solutions were washed with brine
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated in vacuo
7. customThe residue was purified by column chromatography on silica gel
8. washeluting with ethyl acetate

ORD record

ord-e333fe47a0704b768d3872fda216bcda

Source dataset

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07291640B2