Sulfuric Acid → ethyl 8-(1H-1,2,4-triazol-1-yl)-6-(trifluoromethyl)imidazo[1,2-a]pyridine-3-carboxylate

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Reaction Steps

A mixture of 3-(1H-1,2,4-triazol-1-yl)-5-(trifluoromethyl)pyridin-2-amine (2.4 g), potassium 2-chloro-3-ethoxy-3-oxoprop-1-en-1-olate (4.54 g), sulfuric acid (0.670 mL) and ethanol (100 mL) was heated with reflux for 3 days. The reaction mixture was concentrated under reduced pressure, ethyl acetate was added thereto, and the mixture was washed with water. The aqueous layer was neutralize with saturated aqueous sodium bicarbonate solution, and extracted with ethyl acetate. The organic layers were combined, washed with water and saturated brine, and dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane), and the obtained solid was recrystallized from ethyl acetate/hexane to give the title compound (2.22 g).

Provenance & Evidence