反应详情

A solution of 11.94 g of the 3:2 mixture of ethyl 3-bromo-4-(2-methoxy-5-bromophenyl)-2-oxobutanoate and ethyl 3-(2-methoxy-5-bromophenyl)propanoate in 150 mL of ethanol is treated with 2.85 g (30.0 mmol) of 2-aminopyrazine and heated to reflux temperature for 16 hr. The reaction mixture is cooled to room temperature and treated with 10 g of potassium carbonate. The mixture is filtered through Celite and the solvent removed in vacuo to yield the crude material. The resulting residue is flash chromatographed with initially 1% methanol in dichloromethane and then 3% methanol in dichloromethane to afford 3.7 g (48% based on starting material) ethyl 3-[(5-bromo-2-methoxyphenyl)methyl]-imidazolo[1,2-a]pyridine-2-carboxylate.

1. temperatureheated
2. temperatureto reflux temperature for 16 hr
3. filtrationThe mixture is filtered through Celite
4. customthe solvent removed in vacuo
5. customto yield the crude material
6. customchromatographed with initially 1% methanol in dichloromethane