反应详情

To a solution of methyl 5-nitro-1H-pyrazole-3-carboxylate (5.97 g, 34.9 mmol) in acetone (100 mL) was added potassium carbonate (24.1 g, 174 mmol) and 1,2-dibromoethane (19.7 g, 9.02 ml, 105 mmol) and the resulting solution heated to reflux for 2 h and then stirred at room temperature overnight. The resulting mixture was filtered and concentrated and the residue purified by flash chromatography (silica gel, SF65-400 g, 20% to 70% ethyl acetate in hexanes) to give methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylate (4.86 g, 50%) as a light yellow solid.

1. temperaturethe resulting solution heated
2. temperatureto reflux for 2 h
3. filtrationThe resulting mixture was filtered
4. concentrationconcentrated
5. customthe residue purified by flash chromatography (silica gel, SF65-400 g, 20% to 70% ethyl acetate in hexanes)