Reaktion #435008

Reaktionsgleichung

water

n-butyllithium

2-ethylpyrazolo[1,5-a]pyridine

1,2-dibromo-1,1,2,2-tetrachloroethane

→

title compound

Ausbeute 73.1%

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

Ausbeute 73.1%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 30 minutes
3. 3
   Extraktionto the reaction mixture, extraction
4. 4
   Extraktionthe organic extract
5. 5
   Waschenwas washed with water and brine
6. 6
   ExtraktionThe obtained organic extract
7. 7
   Trocknenwas dried over anhydrous magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigethe solvent was evaporated under reduced pressure
10. 10
    Sonstigethe residue was purified by silica gel column chromatography

Vorschrift

To a solution of 2-ethylpyrazolo[1,5-a]pyridine (80 mg) dissolved in tetrahydrofuran (1 mL) was added n-butyllithium (1.6M hexane solution: 0.58 mL) dropwise at −78° C. under a nitrogen stream, and the reaction mixture was further stirred for 30 minutes at the same temperature. A solution of 1,2-dibromo-1,1,2,2-tetrachloroethane (196 mg) in tetrahydrofuran (0.5 mL) was added dropwise to the reaction mixture, and stirring was continued for 30 minutes. After raising the temperature to room temperature and adding water to the reaction mixture, extraction was performed with ethyl acetate and the organic extract was washed with water and brine. The obtained organic extract was dried over anhydrous magnesium sulfate and filtered, the solvent was evaporated under reduced pressure, the residue was purified by silica gel column chromatography and the title compound (90 mg) was obtained as a light brown oil from the n-hexane:ethyl acetate (20:1) fraction.

Quelle