反应详情

To a stirred suspension of 3-methyl-pyrazolo[3,4-d]pyrimidin-4-one (7.50 g, 50.0 mmol, Example 2) in phosphorus oxychloride (150 mL) was added diisopropylethylamine (31 mL, 175 mmol, Aldrich). The mixture was heated at reflux for 2.5 hours before the solvent was evaporated under reduced pressure. The residue was treated with ice (200 g) and made slightly basic with 4N aqueous sodium hydroxide solution and extracted with ethyl acetate (3×250 mL). The combined organic extracts were washed with water, brine, dried and concentrated to give 4-chloro-3-methyl-1H-pyrazolo[3,4-d]pyrimidine as a white solid. (Yield 6.38 g).

1. temperatureThe mixture was heated
2. temperatureat reflux for 2.5 hours before the solvent
3. customwas evaporated under reduced pressure
4. additionThe residue was treated with ice (200 g)
5. extractionextracted with ethyl acetate (3×250 mL)
6. washThe combined organic extracts were washed with water, brine
7. customdried
8. concentrationconcentrated