Sulfuric Acid → Ethyl 8-bromo-6-chloroimidazo[1,2-a]pyridine-3-carboxylate

Participants

Reaction Steps

A mixture of 3-bromo-5-chloropyridin-2-amine (1.0 g), potassium 2-chloro-3-ethoxy-3-oxoprop-1-en-1-olate (2.27 g), sulfuric acid (0.334 mL) and ethanol (20 mL) was heated with reflux overnight. The solvent was evaporated under reduced pressure, the residue was neutralized with saturated aqueous sodium bicarbonate solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated brine, and dried over anhydrous magnesium 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 (0.84 g).

Provenance & Evidence