반응 #8596

반응 방정식

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

수율 65.2%

용매

toluene

반응 조건

후처리

1. 1
   온도the resulting solution was heated
2. 2
   온도at reflux for 4 hours
3. 3
   기타quenched by the dropwise addition of saturated aqueous sodium bicarbonate
4. 4
   추출The reaction was extracted with ethyl acetate
5. 5
   세척the ethyl acetate phase washed with brine
6. 6
   건조dried (magnesium sulfate)
7. 7
   여과filtered
8. 8
   농축concentrated
9. 9
   기타The residue was purified by recrystallization from ethyl acetate-hexanes

실험 절차

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).

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