反应详情

Sodium hydride (60%, oily, 1.94 g) was added to a mixture of 1-benzyl-3-benzyloxy-1H-pyrazole-4-carbaldehyde (12.90 g), ethyl diethylphosphonoacetate (9.60 ml), and N,N-dimethylformamide (200 ml) at 0° C., and the mixture was stirred at room temperature for 2 hours. The reaction mixture was poured into water, which was extracted with ethyl acetate. The ethyl acetate layer was washed with diluted hydrochloric acid and then with saturated aqueous sodium chloride solution, dried (MgSO4), and then concentrated. The crystals obtained were collected by filtration to yield ethyl(E)-3-(1-benzyl-3-benzyloxy-1H-pyrazol-4-yl)propenoate (14.50 g, yield: 91%). This was recrystallized from ethyl acetate-hexane. Melting point: 88–89° C.

1. extractionwas extracted with ethyl acetate
2. washThe ethyl acetate layer was washed with diluted hydrochloric acid
3. dry with materialwith saturated aqueous sodium chloride solution, dried (MgSO4)
4. concentrationconcentrated
5. customThe crystals obtained
6. filtrationwere collected by filtration