反应详情

A mixture of 3-benzyloxy-1-phenyl-1H-pyrazole-5-carboxylic acid (33.00 g), methyl iodide (8.5 mL), potassium carbonate (18.88 g) and N,N-dimethylformamide (300 mL) was stirred overnight at room temperature. The reaction mixture was poured into dilute hydrochloric acid, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give methyl 3-benzyloxy-1-phenyl-1H-pyrazole-5-carboxylate (33.48 g, yield 97%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:4, v/v). The crystals were recrystallized from ethyl acetate-hexane. melting point: 53-54° C.

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