反应详情

温度

60 °C

5-Phenyl-2H-pyrazole-3-carboxylic acid methyl ester (9.10 g, 45.0 mmol) is taken up in 100 mL acetonitrile and heated to 60° C. Ethyl 4-bromobutanoate (8.78 g, 45.0 mmol) and potassium carbonate (8.09 g, 58.5 mmol) are added and the reaction mixture is heated to 85° C. and stirred under reflux for 5 h. The reaction mixture is filtered and the filtrate is concentrated under reduced pressure. The residue is taken up in water and extracted with ethyl acetate. The combined organic phases are dried over Na2SO4 and concentrated under reduced pressure. The residue is purified by flash column chromatography (silica gel, 8-40% ethyl acetate in heptane). Yield: 10.3 g. Rf (silica gel, 2% methanol in DCM)=0.41.

1. temperaturethe reaction mixture is heated to 85° C.
2. temperatureunder reflux for 5 h
3. filtrationThe reaction mixture is filtered
4. concentrationthe filtrate is concentrated under reduced pressure
5. extractionextracted with ethyl acetate
6. dry with materialThe combined organic phases are dried over Na2SO4
7. concentrationconcentrated under reduced pressure
8. customThe residue is purified by flash column chromatography (silica gel, 8-40% ethyl acetate in heptane)