Triethylamine → 5-methyl-1-pyridin-4-yl-1H-pyrazole-4-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

Dissolve 2-dimethylaminomethylene-3-oxo-butyric acid ethyl ester (0.550 g, 2.96 mmol), pyridin-4-yl-hydrazine hydrochloride (0.454 g, 3.12 mmol) and triethylamine (0.435 mL, 3.12 mmol) in ethanol (12 mL) and reflux for 2 hr. Evaporate the mixture then dilute with saturated sodium bicarbonate and extract 3 times with ethyl acetate. Dry (sodium sulfate) the solution, filter and concentrate. Purify using silica gel chromatography, eluting with 50:50 ethyl acetate:hexane to give 5-methyl-1-pyridin-4-yl-1H-pyrazole-4-carboxylic acid ethyl ester as a tan solid (0.520 g, 76%). MS (ES): m/z=232 [M+H]+.

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