反応 #8596

反応方程式

Boron trifluoride

7-chloro-2-(4-methoxyphenyl)pyrazolo[1,5-α]pyridine

acetic anhydride

→

1-[7-(chloro)-2-(4-methoxyphenyl)pyrazolo[1,5-α]pyridin-3-yl]ethanone

収率 65.2%

溶媒

toluene

反応条件

後処理

1. 1
   温度the resulting solution was heated
2. 2
   温度at reflux for 4 hours
3. 3
   その他quenched by the dropwise addition of saturated aqueous sodium bicarbonate
4. 4
   抽出The reaction was extracted with ethyl acetate
5. 5
   洗浄the ethyl acetate phase washed with brine
6. 6
   乾燥dried (magnesium sulfate)
7. 7
   ろ過filtered
8. 8
   濃縮concentrated
9. 9
   その他The residue was purified by recrystallization from ethyl acetate-hexanes

実験手順

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).

出典