反应详情

To a solution of 4-nitro-1H-pyrazole (3.0 g) in N,N-dimethylacetamide (30 mL) was added sodium hydride (60% in mineral oil, 1.2 g) in an ice bath, and the mixture was stirred at the same temperature for 30 min. To the reaction mixture was added methyl 2,4-dibromobutanoate (6.9 g) in an ice bath, and the mixture was stirred at room temperature for 10 hr. The reaction mixture was poured into water, and the reaction mixture was extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (3.4 g).

1. stirringthe mixture was stirred at room temperature for 10 hr
2. extractionthe reaction mixture was extracted with ethyl acetate
3. washThe obtained organic layer was washed with saturated brine
4. dry with materialdried over anhydrous magnesium sulfate
5. customthe solvent was evaporated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate)