反应详情

To a solution of 2-(4-fluorophenyl)pyrazolo[1,5-a]pyrimidine (5.8 g, 0.027 mol) in chloroform (60 mL) is added, at 0° C., N-bromosuccinimide (4.8 g, 0.027 mol). The mixture is stirred at room temperature for 1 h 30. The reaction mixture is then poured into water and extracted with dichloromethane (3×100 mL). The organic layer is dried over anhydrous magnesium sulphate, filtered and concentrated under reduced pressure. The crude material is filtered through a short pad of silica. 6 g (75%) of 3-bromo-2-(4-fluorophenyl)pyrazolo[1,5-a]pyrimidine are obtained as a brown solid which is used in the next step without further purification.

1. extractionextracted with dichloromethane (3×100 mL)
2. dry with materialThe organic layer is dried over anhydrous magnesium sulphate
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. filtrationThe crude material is filtered through a short pad of silica