Dimethylformamide → ethyl 3-methyl-1-(2-pyridyl)-1H-pyrazole-4-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of ethyl 3-methyl-1H-pyrazole-4-carboxylate (7.59 g), 2-chloropyridine (5 ml), sodium hydride (60%, oily, 2.32 g) and N,N-dimethylformamide (150 ml) was stirred at 180° C. overnight. The reaction mixture was poured into water, which was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated aqueous sodium chloride solution, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography to obtain ethyl 3-methyl-1-(2-pyridyl)-1H-pyrazole-4-carboxylate (8.31 g, yield 73%) from the fraction eluted with ethyl acetate-hexane (1:9, volume ratio). This was recrystallized from ethyl acetate-hexane. Melting point: 79–80° C.

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