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2-Amino-4-bromopyridine (5.0 g) and 2-chloroacetaldehyde (40% aqueous, 12 mL, 2.5 eq.) were dissolved in anhydrous ethanol (50 mL) and sodium bicarbonate (4.89 g, 2.0 eq.) was added. The reaction mixture was heated to reflux for 6 hours. Upon completion of the reaction, the organic solvent was removed by vacuum rotary evaporation. The residue was extracted with ethyl acetate (60 mL) and washed sequentially with water and saturated saline. The organic layer was dried with anhydrous sodium sulfate, filtered and purified by silica gel column chromatography to afford 7-bromoimidazo[1,2-a]pyridine (4.38 g, 78% yield) as a brown solid.

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