反应详情

温度

50 °C

A mixture of ethyl 3-hydroxy-1-phenyl-1H-pyrazole-4-carboxylate (7.76 g), benzyl bromide (3.97 mL), potassium carbonate (6.91 g) and N,N-dimethylformamide (75 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 washed successively with dilute hydrochloric acid and saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give ethyl 3-benzyloxy-1-phenyl-1H-pyrazole-4-carboxylate (8.29 g, yield 77%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:1, v/v). The crystals were recrystallized from ethyl acetate-hexane. melting point: 113-114° C.

1. extractionthe mixture was extracted with ethyl acetate
2. washThe ethyl acetate layer was washed successively with dilute hydrochloric acid and saturated brine
3. dry with materialdried over anhydrous magnesium sulfate
4. concentrationconcentrated