Oxonium, trimethyl-, tetrafluoroborate(1-) (1:1) → methyl 5-bromo-6-fluoro-2-methyl-2H-indazole-4-carboxylate

To a solution of methyl 5-bromo-6-fluoro-1H-indazole-4-carboxylate (700 mg, 2.56 mmol) in ethyl acetate (26 mL) was added trimethyloxonium tetrafluoroborate (569 mg, 3.85 mmol) at room temperature, and the mixture was stirred for 2.5 hr. The reaction solution was diluted with saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→50/50) to give the title compound (570 mg, yield 78%).

1. extractionthe mixture was extracted with ethyl acetate
2. washThe extract was washed with saturated brine
3. dry with materialdried over anhydrous sodium sulfate
4. customThe solvent was evaporated under reduced pressure
5. customthe residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→50/50)

ORD record

ord-7fddd5c934924e0f83d9aff864c9eec4

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08247429B2