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

Participants

Reaction Steps

77.11 g (354.4 mmol) of 5-bromo-2-hydroxy-3-nitropyridine are heated at 120° C. for 3 hours together with 101.61 g (354.4 mmol) of phosphorus oxytribromide and 33.7 ml (354.4 mmol) of phosphorus tribromide. The reaction mixture is subsequently poured carefully, in small portions, into ice water, stirred for 1 hour and extracted three times with dichloromethane. The organic phase is washed twice with water, dried over sodium sulfate, filtered and freed from the solvent. Chromatographic purification (silica gel/dichloromethane) gives 43.05 g of 2,5-dibromo-3-nitropyridine. ##STR11##

Provenance & Evidence