反应详情

To the stirred suspension of ethyl 5-hydroxy-1H-pyrazole-3-carboxylate (7.0 g, 45 mmol) and 24.9 g g of potassium carbonate in 500 ml of acetonitrile was added 8.0 g of 3-bromo-tetrahydro-pyran-4-one, and refluxed for 16 hours. The reaction mixture was allowed to cool to room temperature, then filtered, the solid was washed with acetonitrile. The filtrate was concentrated to an oil. The residue was dissolved in ethyl acetate and extracted with water. The organic phase was dried over MgSO4 and evaporated to dryness. 9.0 g (78%) of the desired product was obtained as a white solid. M.Pt. 121-123° C.; (M+H) 255.

1. temperaturerefluxed for 16 hours
2. filtrationfiltered
3. washthe solid was washed with acetonitrile
4. concentrationThe filtrate was concentrated to an oil
5. dissolutionThe residue was dissolved in ethyl acetate
6. extractionextracted with water
7. dry with materialThe organic phase was dried over MgSO4
8. customevaporated to dryness