反应详情

温度

110 °C

Under nitrogen gas atmosphere, phosphorous oxychloride (9.4 mL, 101.3 mmol) and dimethylaniline (2.6 mL, 20.3 mmol) was added successively to the intermediate, 7-hydroxy-5-(methylthio)pyrazolo[1,5-a]pyrimidine-6-carbonitrile, prepared above (4.1 g, 19.7 mmol). The mixture was heated at 110° C. for 4 hours then excess POCl3 was removed under vacuum. The residue was made basic with 3N NaOH solution (pH=9-10) and extracted with ethyl acetate (3×). The combined organic layers were dried over anhydrous Na2SO4, filtered, and concentrated under vacuum. The residue was purified by recrystallization from ethyl acetate hexanes to provide the product, 7-chloro-5-(methylthio)pyrazolo[1,5-a]pyrimidine-6-carbonitrile (80% yield). LCMS (M+1=225)

1. customprepared above (4.1 g, 19.7 mmol)
2. customexcess POCl3 was removed under vacuum
3. extractionextracted with ethyl acetate (3×)
4. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated under vacuum
7. customThe residue was purified by recrystallization from ethyl acetate hexanes