Methyl iodide → methyl 5-bromo-2,3-dimethyl-2H-indazole-4-carboxylate

To a solution of diisopropylamine (1.38 mL, 9.73 mmol) in tetrahydrofuran (25 mL) was added 1.6M butyllithium/hexane solution (5.62 mL, 8.99 mmol) at −78° C., and the mixture was stirred for 30 min. A solution of methyl 5-bromo-2-methyl-2H-indazole-4-carboxylate (2.00 g, 7.49 mmol) in tetrahydrofuran (50 mL) was added and, after stirring for 30 min, iodomethane (933 μL, 15.0 mmol) was added. After stirring for 30 min, the reaction solution was diluted with saturated aqueous ammonium chloride solution. The solvent was evaporated under reduced pressure. The residue was diluted with ethyl acetate, washed with water and 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=20/80→50/50) to give the title compound (1.10 g, yield 52%).

1. stirringafter stirring for 30 min
2. stirringAfter stirring for 30 min
3. customThe solvent was evaporated under reduced pressure
4. additionThe residue was diluted with ethyl acetate
5. washwashed with water and saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. customThe solvent was evaporated under reduced pressure
8. customthe residue was purified by silica gel column chromatography (ethyl acetate/hexane=20/80→50/50)

ORD record

ord-dde0cccedc594f0e87d90ba13ced49a7

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08247429B2