Reaktion #166423

Reaktionsgleichung

Ethyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate

lithium hydroxide monohydrate

tetrahydrofuran ethanol water

Water

→

7-bromoimidazo[1,2-a]pyridine-3-carboxylic acid

Ausbeute 61.5%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was removed under vacuum
2. 2
   Sonstigeto give a yellow gum
3. 3
   Sonstigethe phases were separated
4. 4
   TemperaturThe aqueous phase was cooled in an ice-water bath
5. 5
   SonstigeThe product precipitated
6. 6
   Filtrationwas collected by filtration
7. 7
   Waschenwas washed with a small amount of water (50 mL)
8. 8
   Sonstigethen dried under vacuum

Vorschrift

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.

Quelle