反应详情

Ethyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate (15 g, 56 mmol) and lithium hydroxide monohydrate (3 g, 71.4 mmol) were mixed with a 1:2:1 mixture of tetrahydrofuran/ethanol/water (560 mL). The mixture was stirred at ambient temperature for 16 hours. The solvent was removed under vacuum to give a yellow gum. Water (300 mL) and dichloromethane were added and the phases were separated. The aqueous phase was cooled in an ice-water bath before adjusting the pH to 3 using 2N sulfuric acid. The product precipitated, was collected by filtration and was washed with a small amount of water (50 mL) then dried under vacuum to give 7-bromoimidazo[1,2-a]pyridine-3-carboxylic acid (8.3 g) as an off-white solid.

1. customThe solvent was removed under vacuum
2. customto give a yellow gum
3. customthe phases were separated
4. temperatureThe aqueous phase was cooled in an ice-water bath
5. customThe product precipitated
6. filtrationwas collected by filtration
7. washwas washed with a small amount of water (50 mL)
8. customthen dried under vacuum