反应详情

To a solution of 7-chloro-2-(4-methoxyphenyl)pyrazolo[1,5-α]pyridine (18.7 g, 72.4 mmol) in toluene (300 mL) at room temperature was added acetic anhydride (8.2 mL, 86.9 mmol). Boron trifluoride diethyletherate (10.1 mL, 79.6 mmol) was then added dropwise and the resulting solution was heated at reflux for 4 hours. The reaction mixture was cooled to room temperature and quenched by the dropwise addition of saturated aqueous sodium bicarbonate. The reaction was extracted with ethyl acetate, and the ethyl acetate phase washed with brine, dried (magnesium sulfate), filtered and concentrated. The residue was purified by recrystallization from ethyl acetate-hexanes to give 1-[7-(chloro)-2-(4-methoxyphenyl)pyrazolo[1,5-α]pyridin-3-yl]ethanone (14.2 g, 65%) as reddish needles.1H NMR (CDCl3): δ 8.37 (dd, 1H), 7.49 (dd, 2H), 7.39 (dd, 1H), 7.10 (dd, 1H), 6.98 (dd, 2H), 3.84 (s, 3H), 2.13 (s, 3H); MS m/z 301 (M+1).

1. temperaturethe resulting solution was heated
2. temperatureat reflux for 4 hours
3. customquenched by the dropwise addition of saturated aqueous sodium bicarbonate
4. extractionThe reaction was extracted with ethyl acetate
5. washthe ethyl acetate phase washed with brine
6. dry with materialdried (magnesium sulfate)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by recrystallization from ethyl acetate-hexanes