反应详情

To a solution of 2-ethyl-imidazo[1,2-a]pyridine (2.17 g, 14.9 mmol) in ethanol (25 mL) was added bromine (2.0 g, 12.5 mmol) in water (5 mL) dropwise at rt. After stirring at rt for 4h, ethanol was evaporated under reduced pressure. The residue was basified with aqueous sodium bicarbonate and extracted with methylene chloride (3×). The organic phase was washed with brine and dried over anhydrous magnesium sulfate. Concentration followed by flash chromatography eluting with 20 % ethyl acetate in hexanes, followed by 50% ethyl acetate in hexanes afforded the title compound (1.88 g) as a viscous oil.

1. customwas evaporated under reduced pressure
2. extractionextracted with methylene chloride (3×)
3. washThe organic phase was washed with brine
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationConcentration
6. washeluting with 20 % ethyl acetate in hexanes