反应详情

5-Bromo-2-methylimidazole-4-carbaldehyde (400 mg) was dissolved in conc. hydrochloric acid (6 ml), and the mixture was refluxed under heating for 24 hr. Saturated aqueous sodium hydrogencarbonate solution was added under ice-cooling until the mixture assumed weak alkalinity and the mixture was extracted twice with ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogencarbonate solution and then brine. The organic layer was dried over anhydrous magnesium sulfate and the solvent was evaporated under reduced pressure. Hexane was added to the residue and the crystals were collected by filtration to give 5-chloro-2-methylimidazole-4-carbaldehyde (222 mg) as yellow crystals.

1. temperaturethe mixture was refluxed
2. temperatureunder heating for 24 hr
3. temperaturecooling until the mixture
4. extractionthe mixture was extracted twice with ethyl acetate
5. washThe organic layer was washed with saturated aqueous sodium hydrogencarbonate solution
6. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
7. customthe solvent was evaporated under reduced pressure
8. additionHexane was added to the residue
9. filtrationthe crystals were collected by filtration