반응 #9277

반응 방정식

water

n-butyllithiumhexane

2-ethylpyrazolo[1,5-a]pyridine

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

→

title compound

수율 73.1%

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

수율 73.1%

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 30 minutes
3. 3
   추출extraction
4. 4
   세척the organic layer was washed with water and brine
5. 5
   건조After drying over anhydrous magnesium sulfate and filtration
6. 6
   농축the solvent was concentrated under reduced pressure
7. 7
   기타the residue was purified by silica gel column chromatography

실험 절차

After dissolving 2-ethylpyrazolo[1,5-a]pyridine (80 mg) in tetrahydrofuran (1 mL), an n-butyllithiumhexane solution (1.6 M; 0.58 mL) was added dropwise at −78° C. under a nitrogen stream, and the mixture was stirred for 30 minutes. A solution of 1,2-dibromo-1,1,2,2-tetrachloroethane (196 mg) in tetrahydrofuran (0.5 mL) was added to the reaction mixture, and stirring was continued for 30 minutes. The temperature was increased to room temperature, water was added, extraction was performed with ethyl acetate and the organic layer 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 (90 mg) was obtained from the n-hexane:ethyl acetate (20:1) fraction as a light brown oil.

출처