Reacción #9277

Ecuación de reacción

water

n-butyllithiumhexane

2-ethylpyrazolo[1,5-a]pyridine

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

→

title compound

Rendimiento 73.1%

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

Rendimiento 73.1%

Disolventes

tetrahydrofuran

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

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

Procedimiento

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.

Fuente