Boron trifluoride → 1-(7-Chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridin-3-yl)ethanone

HRID 896766

Reaktionsgleichung

Reaktionsgleichung von HRID 896766
[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:11]3[CH:16]=[CH:15][C:14]([F:17])=[CH:13][CH:12]=3)[CH:10]=[C:6]2[CH:5]=[CH:4][CH:3]=1.[C:18](OC(=O)C)(=[O:20])[CH3:19].B(F)(F)F>C1(C)C=CC=CC=1>[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:11]3[CH:16]=[CH:15][C:14]([F:17])=[CH:13][CH:12]=3)[C:10]([C:18](=[O:20])[CH3:19])=[C:6]2[CH:5]=[CH:4][CH:3]=1

Komponenten

5

Versuchsvorschrift

To a solution of 7-chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine (10.0 g, 40.5 mmol) in toluene (225 mL) at room temperature was added acetic anhydride (4.6 mL, 48.6 mmol). Boron trifluoride diethyletherate (5.6 mL, 44.6 mmol) was then added dropwise and the resultant solution was heated to reflux for 3.5 hours. The reaction mixture was cooled to room temperature and quenched by the dropwise addition of aqueous sodium bicarbonate. Ether was added and the organic layer was washed with brine. The aqueous layer was extracted with ether and the combined organics were dried over magnesium sulfate, filtered and concentrated. The residue was purified by recrystallization from ethyl acetate-hexanes to give 1-[7-chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridin-3-yl]ethanone (9.0 g, 77%) as redish needles. 1H NMR (CDCl3): δ 8.41 (d, 1 H), 7.59 (m, 2 H), 7.45 (dd, 1 H), 7.26-7.13 (m 3 H), 2.15 (s, 3 H); 19F NMR (CDCl3) δ −112.06; MS m/289 (M+1).

Aufarbeitung

  1. temperatureto reflux for 3.5 hours
  2. customquenched by the dropwise addition of aqueous sodium bicarbonate
  3. additionEther was added
  4. washthe organic layer was washed with brine
  5. extractionThe aqueous layer was extracted with ether
  6. dry with materialthe combined organics were dried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe residue was purified by recrystallization from ethyl acetate-hexanes

Quellen und Nachweise

ORD-Eintrag
ord-42d9002008bc4fb88124923bfafc7c1e
Quelldatensatz
uspto-grants-2005_07
Patentnummer
US06919352B2

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