反应详情

温度

50 °C

A mixture of ethyl 3-hydroxy-1-methyl-1H-pyrazole-4-carboxylate (25.50 g), benzyl bromide (17.8 ml), potassium carbonate (31.10 g) and N,N-dimethylformamide (250 ml) was stirred overnight at 50° C. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was dilute hydrochloric acid, washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and ethyl 3-benzyloxy-1-methyl-1H-pyrazole-4-carboxylate (31.90 g, yield 82%) was obtained as a colorless crystal from a fraction eluted with ethyl acetate-hexane (1:1, volume ratio) and recrystallized from ethyl acetate-hexane. melting point: 66–67° C.

1. extractionthe mixture was extracted with ethyl acetate
2. washwashed with saturated brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated