反应详情

An ethanol suspension (400 mL) of methyl 3-bromo-2-oxobutyrate (46.6 g) and 2-amino-5-nitropyridine (33.3 g) was stirred at 90° C. for 24 hours. The precipitated solid was taken out through filtration, and the obtained solid was suspended in ethyl acetate, washed with aqueous saturated sodium hydrogencarbonate solution, and purified through silica gel column chromatography (hexane/ethyl acetate=2/1) to obtain methyl 3-methyl-6-nitroimidazo[1,2-a]pyridine-2-carboxylate (13.0 g) as a yellow crystal.

1. filtrationThe precipitated solid was taken out through filtration
2. washwashed with aqueous saturated sodium hydrogencarbonate solution
3. custompurified through silica gel column chromatography (hexane/ethyl acetate=2/1)