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

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Reaction Steps

A mixture of 6-amino-5-bromonicotinonitrile (6.3 g), potassium 2-chloro-3-ethoxy-3-oxoprop-1-en-1-olate (15 g), sulfuric acid (2.2 mL) and ethanol (160 mL) was heated with reflux for 30 hr. To the reaction mixture was added saturated aqueous sodium bicarbonate solution, and the mixture was extracted with ethyl acetate. The extract was 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) to give the title compound (4.3 g).

Provenance & Evidence