Potassium Hydroxide → 5-(difluoromethoxy)-3-iodo-1-methyl-1H-indazole

Diethyl bromodifluoromethylphosphonate (9 g, 10.9 mmol) was added in one portion to a cooled (dry ice-acetone bath) solution of 3-iodo-1-methyl-1H-indazol-5-ol (3 g, 37.8 mmol) and KOH (15 g, 267 mmol) in CH3CN (50 mL) and H2O (50 mL) with stirring, the reaction mixture was warmed to room temperature and stirred for 0.5 h, the mixture was diluted with EtOAc (50 mL), The organic layer was washed with H2O (50 mL), brine (100 mL), dried over Na2SO4 and concentrated under reduced pressure, the residue was purified by column chromatography (silica gel, 200-300 mesh, eluting with petroleum ether/EtOAc=3:1) to give 5-(difluoromethoxy)-3-iodo-1-methyl-1H-indazole (1.85 g, 53%) as a white solid. LCMS: (M+H)+=325; 1H NMR (300 MHz, CDCl3), δ 7.36-7.33 (m, 1H), 7.28-7.23 (m, 1H), 7.19 (s, 1H), 6.53 (t, 1H, J=73.5 Hz), 4.09 (s, 3H).

1. stirringstirred for 0.5 h
2. washThe organic layer was washed with H2O (50 mL), brine (100 mL)
3. dry with materialdried over Na2SO4
4. concentrationconcentrated under reduced pressure
5. customthe residue was purified by column chromatography (silica gel, 200-300 mesh, eluting with petroleum ether/EtOAc=3:1)

ORD record

ord-0b6f2c2e918a4c72aca5771957abe10a

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658646B2