反应详情

To a solution of ethyl 5-acetyl-1H-pyrazole-3-carboxylate (0.050 g, 0.274 mmol) in DMF (3 mL), Cs2CO3 (0.134 g, 0.412 mmol) and methyl iodide (0.022 mL, 0.357 mmol) were added. The reaction was continued at r.t. overnight then AcOEt (20 mL) was added and the organic phase washed with water (20 mL). The aqueous fraction was extracted with AcOEt (20 mL). The organic fractions were combined, dried over Na2SO4, filtered, and concentrated in vacuo. Purification by flash chromatography on silica gel (eluant: AcOEt/hexane 2/8) provided 37 mg (68% yield) of ethyl 3-acetyl-1-methyl-1H-pyrazole-5-carboxylate.

1. washthe organic phase washed with water (20 mL)
2. extractionThe aqueous fraction was extracted with AcOEt (20 mL)
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customPurification by flash chromatography on silica gel (eluant: AcOEt/hexane 2/8)