反应详情

温度

70 °C

Cyclohexyl-hydrazine hydrochloride (0.276 g, 1.59 mmol, CAS #24214-73-1, purchased from Aldrich), 2-dimethylaminomethylene-4,4,4-trifluoro-3-oxo-butyric acid ethyl ester (0.459 g, 1.67 mmol) and anhydrous sodium acetate (0.188 g, 2.29 mmol) were combined in ethanol (2.9 mL) and heated at 70° C. for 15 hours. After cooling to room temperature, the reaction mixture was partitioned between methylene chloride and water. The organic phase was washed with water and brine. Each aqueous phase was back extracted with a second portion of methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography, eluting with a 5-40% ethyl acetate-hexanes gradient, yielded 1-cyclohexyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (0.270 g, 55%). Mass spectrum: m/z: 291.3 (M+H).

1. temperatureAfter cooling to room temperature
2. customthe reaction mixture was partitioned between methylene chloride and water
3. washThe organic phase was washed with water and brine
4. extractionEach aqueous phase was back extracted with a second portion of methylene chloride
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated in vacuo
7. customPurification by flash chromatography
8. washeluting with a 5-40% ethyl acetate-hexanes