反应详情

Phosphorus oxychloride (88 ml) was added to ethyl 7-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (58 g, 235 mmol) and the mixture was heated at reflux for 45 minutes under anhydrous conditions. Upon cooling to ambient temperature, phosphorus oxychloride was evaporated and the solid residue was added in portions to a mixture of ammonia (150 ml) and ice (200 g). External cooling as well as further addition of ammonia to maintain the pH around 8 was needed during this hydrolysis step. The aqueous phase was extracted with dichloromethane and the organic phase was washed with water and brine, dried (MgSO4) and concentrated to about 300 ml. Pentane (400 ml) was added and the precipitate formed collected by filtration. Drying under vacuum gave 4-chloro-3-ethoxycarbonyl-7-methoxyquinoline (45.5 g, 73%).

1. temperaturethe mixture was heated
2. temperatureat reflux for 45 minutes under anhydrous conditions
3. customphosphorus oxychloride was evaporated
4. additionthe solid residue was added in portions to a mixture of ammonia (150 ml) and ice (200 g)
5. temperatureExternal cooling as
6. additionwell as further addition of ammonia
7. temperatureto maintain the pH around 8
8. customwas needed during this hydrolysis step
9. extractionThe aqueous phase was extracted with dichloromethane
10. washthe organic phase was washed with water and brine
11. dry with materialdried (MgSO4)
12. concentrationconcentrated to about 300 ml
13. additionPentane (400 ml) was added
14. customthe precipitate formed
15. filtrationcollected by filtration
16. customDrying under vacuum