反应详情

To a mixture of 1-benzyl-3-benzyloxy-1H-pyrazole-4-carbaldehyde (12.90 g), diethylphosphonoethyl acetate (9.60 ml) and N,N-dimethylformamide (200 ml) was added hydride (60% in oil, 1.94 g) at 0° C., and the mixture was stirred at room temperature for 2 hrs. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was dilute hydrochloric acid, washed successively with saturated brine, dried (MgSO4) and concentrated. The obtained crystals were collected by filtration to give ethyl (E)-3-(1-benzyl-3-benzyloxy-1H-pyrazol-4-yl)propenoate (14.50 g, yield 91%). The crystals were recrystallized from ethyl acetate-hexane. melting point: 88–89° C.

1. extractionthe mixture was extracted with ethyl acetate
2. washwashed successively with saturated brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated
5. filtrationThe obtained crystals were collected by filtration