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

Participants

Reaction Steps

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##

Provenance & Evidence