Ethanol → 3-Bromo-5-ethoxypyridine

Under a nitrogen atmosphere, sodium (4.60 g, 200 mmol) was added to absolute ethanol (100 mL) at 0-5° C., and the stirring mixture was allowed to warm to ambient temperature over 18 h. To the resulting solution was added 3,5-dibromopyridine (31.5 g, 133 mmol), followed by DMF (100 mL). The mixture was heated at 70° C. for 48 h. The brown mixture was cooled, poured into water (600 mL), and extracted with ether (3×500 mL). The combined ether extracts were dried (Na2SO4), filtered, and concentrated by rotary evaporation. Purification by vacuum distillation afforded 22.85 g (85.0%) of an oil, bp 89-90° C. at 2.8 mm Hg (lit. bp 111° C. at 5 mm Hg, see K. Clarke, et al., J. Chem. Soc. 1885 (1960)).

1. temperatureThe mixture was heated at 70° C. for 48 h
2. temperatureThe brown mixture was cooled
3. extractionextracted with ether (3×500 mL)
4. dry with materialThe combined ether extracts were dried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated by rotary evaporation
7. customPurification
8. distillationby vacuum distillation

ORD record

ord-6ece41c08661436e98961363a5f653de

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07375110B2