Dimethylformamide → 5-Bromo-2-chloro-3-nitropyridine

HRID 1182937Notes

Reaction equation

HRID 1182937 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([N+:9]([O-:11])=[O:10])[C:5](=O)[NH:6][CH:7]=1.CN(C=O)C.O=P(Cl)(Cl)[Cl:19]>>[Br:1][C:2]1[CH:3]=[C:4]([N+:9]([O-:11])=[O:10])[C:5]([Cl:19])=[N:6][CH:7]=1

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 851475-Bromo-3-nitro-2-pyridone

Product 1

HCID 70194125-Bromo-2-chloro-3-nitropyridineYield 85%

Procedure

To a solution of 5-bromo-3-nitropyridin-2(1H)-one (4.62 g, 21.10 mmol) in POCl3 (46.2 ml) was added DMF (4.62 ml, 59.7 mmol) at room temperature. The mixture was refluxed for 2 hours, and then cooled to room temperature and concentrated in vacuo. The residue was treated with saturated aq. NaHCO3 and extracted with EtOAc. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by column chromatography on SiO2 (Hex:EtOAc=3:1) to give 5-bromo-2-chloro-3-nitropyridine (4.24 g, 85%) as a yellow solid. 1H-NMR (CDCl3, Varian 400 MHz) δ 8.37 (1H, d, J=2.4 Hz), 8.70 (1H, d, J=2.0 Hz).

Workup

  1. temperatureThe mixture was refluxed for 2 hours
  2. concentrationconcentrated in vacuo
  3. additionThe residue was treated with saturated aq. NaHCO3
  4. extractionextracted with EtOAc
  5. washThe combined organic layers were washed with brine
  6. dry with materialdried over anhydrous Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customThe residue was purified by column chromatography on SiO2 (Hex:EtOAc=3:1)

Sources & evidence

ORD record
ord-7aef2fae972d42489df6241190dcf7cb
Source dataset
uspto-grants-2014_03
Patent number
US08664230B2

Reaction notes

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