反应详情

温度

0 °C

Phosphorus(V) oxybromide (921 mg, 3.43 mmol) was slowly added to a suspension of 2-(2,6-dichlorophenyl)-7-methyl-2H-pyrazolo[4,3-c]pyridine-5-oxide (404 mg, 1.37 mmol) in DCE (9.0 mL) at 0° C., under an atmosphere of nitrogen. The reaction mixture was stirred at 0° C. for 30 minutes and then at room temperature overnight. The orange suspension was poured onto saturated aqueous sodium carbonate solution and was stirred for 10 minutes. This was extracted with DCM and the organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (0-30% ethyl acetate in cyclohexane) to afford the title compound as a white solid (185 mg, 38% yield). 1H NMR (300 MHz, DMSO-d6): δ 9.20 (s, 1H), 7.90-7.89 (m, 1H), 7.84-7.80 (m, 2H), 7.76-7.72 (m, 1H), 2.45 (d, J=1.2 Hz, 3H).

1. customat room temperature
2. customovernight
3. stirringwas stirred for 10 minutes
4. extractionThis was extracted with DCM
5. washthe organic layer was washed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by silica gel flash chromatography (0-30% ethyl acetate in cyclohexane)