反应详情

温度

80 °C

A mixture of ethyl 3-hydroxy-1H-pyrazole-4-carboxylate (11.53 g), benzyl bromide (18 ml), potassium carbonate (21.12 g), and N,N-dimethylformamide (300 ml) was stirred for 5 hours at 80° C. 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 residue was subjected to silica gel column chromatography, and ethyl 1-benzyl-3-benzyloxy-1H-pyrazole-4-carboxylate (13.52 g, yield: 95%) was obtained as colorless crystals from the fraction eluted with ethyl acetate-hexane (1:4, volume ratio). This was recrystallized from ethyl acetate-hexane. Melting point: 71–72° 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