Methyl iodide → 3-bromo-5-chloro-1-methyl-1H-indazole

Temperature

0 °C

3-bromo-5-chloro-1H-indazole (7.5 g, 32.4 mmol) was dissolved in anhydrous DMF (60 mL) then cooled to 0° C. With vigorous stirring, cesium carbonate (13.36 g, 41 mmol) was added in one portion followed by dropwise addition of iodomethane (2.55 mL, 41 mmol). The reaction was then stirred at 0° C. for 1 hour. The reaction was diluted with distilled water (80 mL), and extracted with EtOAc (3×60 mL). The organic extracts were washed with brine (2×), dried over Na2SO4, and purified by column chromatography (gradient 0 to 15% EtOAc/hexanes) to afford the product. 1H NMR (400 MHz, CDCl3) δ 7.58 (d, J=1.8 Hz, 1H), 7.38 (dd, J=8.9, 1.9 Hz, 1H), 7.30 (d, J=8.9 Hz, 1H), 4.04 (s, 3H).

1. extractionextracted with EtOAc (3×60 mL)
2. washThe organic extracts were washed with brine (2×)
3. dry with materialdried over Na2SO4
4. custompurified by column chromatography (gradient 0 to 15% EtOAc/hexanes)
5. customto afford the product

ORD record

ord-d2005f8c92cd4571907dab176ff3d38a

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08987250B2