Reaktion #9280

Reaktionsgleichung

ethyl acetate

7-bromo-2-ethylpyrazolo[1,5-a]pyridine

nitronium tetrafluoroborate

→

title compound

Ausbeute 50.8%

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

Ausbeute 50.8%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGstirring
3. 3
   Waschenthe extract was washed with water and brine
4. 4
   TrocknenAfter drying over anhydrous magnesium sulfate and filtration
5. 5
   Einengenthe solvent was concentrated under reduced pressure
6. 6
   Sonstigethe residue was purified by silica gel column chromatography

Vorschrift

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.

Quelle