Phosphorus tribromide → 2,5-Dibromo-3-fluoropyridine

97.6 g (508.0 mmol) of 5-bromo-3-fluoro-2-hydroxypyridine are stirred at 150° C. for 6 hours in 500 ml of phosphorus tribromide. The mixture is subsequently poured into ice water, stirred for 2 hours and extracted three times with dichloromethane, and the organic phase is washed with sodium hydrogencarbonate solution until neutral, dried over sodium sulfate and evaporated to dryness. Chromatographic purification (silica gel/dichloromethane) gives 76.53 g of 2,5-dibromo-3-fluoropyridine. ##STR22##

1. extractionextracted three times with dichloromethane
2. washthe organic phase is washed with sodium hydrogencarbonate solution until neutral,
3. dry with materialdried over sodium sulfate
4. customevaporated to dryness
5. customChromatographic purification (silica gel/dichloromethane)

ORD record

ord-10ddbb917b9245f2a0679a4960596aba

Source dataset

uspto-grants-1995_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05445763