反应详情

温度

180 °C

A mixture of ethyl 3-methyl-1H-pyrazole-4-carboxylate (7.95 g), 2-chloropyridine (5 ml), sodium hydride (0.60%, oil, 2.32 g) and N,N-dimethylformamide (150 ml) was stirred overnight at 180° C. The reaction mixture was poured into water and 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 ethyl 3-methyl-1-(2-pyridyl)-1H-pyrazole-4-carboxylate (8.31 g, yield 73%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:9, volume ratio). The crystals were recrystallized from ethyl acetate-hexane. melting point: 79-80° C.

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