反应详情

A solution of methyl 2-(4-fluorophenyl)-pyrazolo[1,5-a]pyridine-3-carboxylate (5.0 g, 18.5 mmol) in 2N aqueous sodium hydroxide (50 ml) and methanol (30 mL) was-heated at reflux for about 3 hours. The mixture was filtered and the filtrate was washed with diethyl ether (20 mL) and then concentrated under reduced pressure to about half the original volume. Concentrated hydrochloric acid was added to adjust the pH to about 2 and the resulting solid was collected by filtration and washed with water and dried under vacuum to give the title compound as a white solid, 4.8 g (ca. 100%). 1H NMR (d6 DMSO) δ 12.43 (br s, 1h), 8.84 (d, 1H, J=6.9 Hz), 8.14 (d, 1H, J=9 Hz), 7.82 (m, 2H), 7.57 (t, 1H, J=8.1 Hz), 7.28 (t, 2H, J=9 Hz), 7.15 (td, 1H, J=6.9, 1.2 Hz). MS (+ve ion electrospray) 257 (100), (MH+).

1. temperatureat reflux for about 3 hours
2. filtrationThe mixture was filtered
3. washthe filtrate was washed with diethyl ether (20 mL)
4. concentrationconcentrated under reduced pressure to about half the original volume
5. additionConcentrated hydrochloric acid was added
6. filtrationthe resulting solid was collected by filtration
7. washwashed with water
8. customdried under vacuum