反应详情

Phosphorous oxychloride (0.6 mL, 6.4 mmol) was added to N,N-dimethylformamide (10 mL) and the resulting mixture stirred at room temperature for 10 minutes. 5-Chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine (1.0 g, 4.1 mmol) was added and the reaction mixture was stirred at room temperature for 12 hours. The reaction mixture was poured into ice-water and neutralized to pH 7 with aqueous ammonium hydroxide. The resulting slurry was extracted with dichloromethane. The combined organics were washed with brine, dried (magnesium sulfate), filtered and concentrated to give, after recrystallization from acetonitrile, 5-chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde (0.95 g, 85%) as a white solid. 1H NMR (CDCl3): δ 10.07 (s, 1H), 8.49 (d, 1H), 8.44 (d, 1H), 7.78 (q, 2H), 7.22 (t, 2H), 7.07 (dd, 1H). MS m/z 275 (M+1).

1. stirringthe reaction mixture was stirred at room temperature for 12 hours
2. extractionThe resulting slurry was extracted with dichloromethane
3. washThe combined organics were washed with brine
4. dry with materialdried (magnesium sulfate)
5. filtrationfiltered
6. concentrationconcentrated
7. customto give
8. customafter recrystallization from acetonitrile, 5-chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde (0.95 g, 85%) as a white solid