Ethyl Acetate → 7-Bromo-2-ethyl-3-nitropyrazolo[1,5-a]pyridine

HRID 1181861Notes

Reaction equation

HRID 1181861 reaction equation
[Br:1][C:2]1[N:7]2[N:8]=[C:9]([CH2:11][CH3:12])[CH:10]=[C:6]2[CH:5]=[CH:4][CH:3]=1.F[B-](F)(F)F.[O:18]=[N+:19]=[O:20].C(OCC)(=O)C>C(#N)C>[Br:1][C:2]1[N:7]2[N:8]=[C:9]([CH2:11][CH3:12])[C:10]([N+:19]([O-:20])=[O:18])=[C:6]2[CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 11073463Nitronium tetrafluoroborateHCID 219845107-Bromo-2-ethylpyrazolo[1,5-a]pyridine

Product 1

HCID 219844817-Bromo-2-ethyl-3-nitropyrazolo[1,5-a]pyridineYield 50.8%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

After dissolving 7-bromo-2-ethylpyrazolo[1,5-a]pyridine (1.1 g) in acetonitrile (20 mL), nitronium tetrafluoroborate (1.3 g) was added while stirring on ice, and stirring was continued for 30 minutes. The reaction mixture was added to ice water, extraction was performed with ethyl acetate and the extract was washed with water and brine. After drying over anhydrous magnesium sulfate and filtration, the solvent was concentrated under reduced pressure, the residue was purified by silica gel column chromatography, and the title compound (670 mg) was obtained from the n-hexane:ethyl acetate (10:1) fraction as yellow crystals.

Workup

  1. additionwas added
  2. stirringstirring
  3. washthe extract was washed with water and brine
  4. dry with materialAfter drying over anhydrous magnesium sulfate and filtration
  5. concentrationthe solvent was concentrated under reduced pressure
  6. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-cacdbe8ed7f64283a8fe1d7f61b18cf7
Source dataset
uspto-grants-2007_10
Patent number
US07285666B2

Reaction notes

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