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

A solution of 2-ethylpyrazolo[1,5-a]pyridine (5.0 g, 34.2 mmol) in tetrahydrofuran (50 mL) was cooled to below −70° C. under a nitrogen stream, and then a solution of n-butyllithium in hexane (32.5 mL, 1.58M solution, 51.4 mmol) was added dropwise at below −60° C. After stirring for 1 hour, bromopentafluorobenzene (9.3 g, 37.7 mmol) was added dropwise to the reaction mixture at below −60° C. The reaction mixture was stirred for 2 hours at below −70° C., and then water (50 mL) was added to the reaction mixture and the temperature was raised to room temperature. Ethyl acetate (50 mL) and water (50 mL) were added thereto, and extraction was performed with ethyl acetate. The organic extract was washed twice with 5% brine (50 mL) and dried over anhydrous magnesium sulfate, and then the solvent was evaporated under reduced pressure to afford 6.9 g of the title compound.

1. stirringThe reaction mixture was stirred for 2 hours at below −70° C.
2. extractionextraction
3. extractionThe organic extract
4. washwas washed twice with 5% brine (50 mL)
5. dry with materialdried over anhydrous magnesium sulfate
6. customthe solvent was evaporated under reduced pressure

ORD record

ord-85f2e64085df471a913f882860bc6893

Source dataset

uspto-grants-2008_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07323569B2