反应详情

5-Cyclopropyl-2H-pyrazol-3-ylamine (2.9 g, 0.0235 mol) was suspended in AcOH (18 ml), 3-(2-fluorophenyl)-3-oxopropionic acid ethyl ester (4.67 ml, 1.1 eq) was added and the mixture heated at reflux for 3 h. The mixture was cooled to rt and concentrated underreduced pressure. The residue was stirred with EtOAc and the solid collected by filtration to give 2 g of 2-cyclopropyl-5-(2-fluorophenyl)-4H-pyrazolo[1,5-a]pyrimidin-7-one. Step B: The compound from step A (1 g, 0.00371 mol) was dissolved in POCl3 (12 ml) and cooled to 0° C. N,N-dimethylaniline (1.4 ml, 3 eq) was added and the mixture heated at 80° C. for 16 h. The mixture was cooled to rt and the volatiles removed. The resulting residue was dissolved in CH2Cl2, poured onto ice, and taken to pH 8 with NaHCO3 (s). The CH2Cl2 layer was removed, washed with water, dried (MgSO4), and concentrated under reduced pressure. The residue was purified by flash chromatography (SiO2, hexane-EtOAc/hexane 1:9) to give 0.85 g of the title compound. LCMS: MH+=288.1.

1. temperaturethe mixture heated
2. temperatureat reflux for 3 h
3. concentrationconcentrated underreduced pressure
4. filtrationthe solid collected by filtration