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

HRID 1757349Notes

Reaction equation

HRID 1757349 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([N+:9]([O-:11])=[O:10])[C:5](O)=[N:6][CH:7]=1.P(Br)(Br)[Br:13]>>[Br:13][C:5]1[C:4]([N+:9]([O-:11])=[O:10])=[CH:3][C:2]([Br:1])=[CH:7][N:6]=1

Participants

3

Reactant 2

HCID 24614Phosphorus tribromideHCID 178418997HCID 178418997, compound

Product 1

HCID 2984702,5-Dibromo-3-nitropyridineYield 43.1%

Procedure

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##

Workup

  1. extractionextracted three times with dichloromethane
  2. washThe organic phase is washed twice with water
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. customChromatographic purification (silica gel/dichloromethane)

Sources & evidence

ORD record
ord-3bc0282e433e4935bac4d5633130af0f
Source dataset
uspto-grants-1995_08
Patent number
US05445763

Reaction notes

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