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

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.

1. stirringstirring
2. waitwas continued for 30 minutes
3. extractionto the reaction mixture, extraction
4. extractionthe organic extract
5. washwas washed with water and brine
6. extractionThe obtained organic extract
7. dry with materialwas dried over anhydrous magnesium sulfate
8. filtrationfiltered
9. customthe solvent was evaporated under reduced pressure
10. customthe residue was purified by silica gel column chromatography

ORD-Eintrag

ord-a846a0dc936f4d218d91c63c6b3c0bc5

Quelldatensatz

uspto-grants-2007_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07176216B2