Reaktion #9291

Reaktionsgleichung

sodium nitrite

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

ethanol

water

→

title compound

Ausbeute 70.3%

7-Bromo-2-methoxypyrazolo[1,5-a]pyridine-3-amine

Ausbeute 70.3%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.ADDITIONwas added
3. 3
   Temperaturthe mixture was heated
4. 4
   workup.STIRRINGstirred at 60° C. for 30 minutes
5. 5
   FiltrationThe insoluble residue was filtered out
6. 6
   workup.ADDITIONwater was added
7. 7
   Extraktionextraction
8. 8
   WaschenAfter washing the organic layer with brine
9. 9
   Trocknendrying it over anhydrous magnesium sulfate
10. 10
    Filtrationfiltering it
11. 11
    Einengenthe solvent was concentrated under reduced pressure
12. 12
    Sonstigethe residue was purified by silica gel column chromatography

Vorschrift

After dissolving 7-bromo-2-methoxypyrazolo[1,5-a]pyridine (1 g) in acetic acid (10 mL), an aqueous solution (5 mL) containing sodium nitrite (334 mg) was added and the mixture was stirred at room temperature for 20 minutes. After adding ethanol (60 mL) and water (30 mL) to the reaction mixture, zinc powder (1 g) was added and the mixture was heated and stirred at 60° C. for 30 minutes. The insoluble residue was filtered out, water was added, and extraction was performed with ethyl acetate. After washing the organic layer with brine, drying it over anhydrous magnesium sulfate and filtering it, the solvent was concentrated under reduced pressure, the residue was purified by silica gel column chromatography, and the title compound (750 mg) was obtained from the n-hexane:ethyl acetate (3:1) fraction as brown crystals.

Quelle