反应详情

(prepared in a procedure analogous to that outlined in WO 2004/026229 A2) Step A: 5-Methyl-2H-pyrazol-3-ylamine (1 g, 0.0103 mol) was suspended in AcOH (7 ml), 3-oxo-3-phenylpropionic acid ethyl ester (1.95 ml, 1.1 eq) was added and the mixture heated at reflux for 3 h. The mixture was cooled to rt and concentrated under reduced pressure. The residue was stirred with EtOAc and the solid collected by filtration to give 1.83 g of 2-methyl-5-phenyl-4H-pyrazolo[1,5-a]pyrimidin-7-one. Step B: The product of step A (1.83 g) was dissolved in POCl3 (8.6 ml), pyridine (0.43 ml) was added and the mixture stirred for 3 days at rt. The resulting dark solution was diluted with Et2O and filtered. The filtrate was cooled to 0° C. and quenched with water; once the quench was complete, additional water was added and the organic layer removed. The aqueous layer was further extracted with Et2O, the combined organic layers were washed with NaHCO3 (sat), dried (Na2SO4), and concentrated under reduced pressure to give 1.92 g of 7-chloro-2-methyl-5-phenylpyrazolo[1,5-a]pyrimidine which was used without further purification. LCMS: MH+=244.1.

1. custom(prepared in a procedure analogous to
2. temperaturethe mixture heated
3. temperatureat reflux for 3 h
4. concentrationconcentrated under reduced pressure
5. filtrationthe solid collected by filtration