反应详情

To a solution of 4-nitro-1H-pyrazole (5.05 g, 44.7 mmol) in N,N-dimethylformamide (250 mL) was added sodium hydride (2.7 g, 68 mmol, 60% mineral oil suspension) at 0° C. in portions and then followed by bromomethylcyclopropane (6.5 mL, 67 mmol) dropwise at same temperature. The mixture was stirred at room temperature for 4 h and diluted with water (300 mL) and extracted with EtOAc (300 mL×3). The combined organic phases were washed with brine (500 mL), dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (EtOAc/PE (v/v)=1/50 to 1/20) to give the product as yellow oil (7.38 g, 98.9%).

1. extractionextracted with EtOAc (300 mL×3)
2. washThe combined organic phases were washed with brine (500 mL)
3. dry with materialdried over anhydrous Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by silica gel column chromatography (EtOAc/PE (v/v)=1/50 to 1/20)