反应详情

A mixture of 6.08 g (19.7 mmoles) of 6,7-difluoro-1-(1,1-dimethylethyl)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid ethyl ester and 19.7 mmoles of 2N aqueous sodium hydroxide in 80 mL of ethanol was stirred overnight. The resulting mixture was concentrated in vacuo, taken up with 200 mL of water and extracted with dichloromethane. About 8 mL of 2N HCl was added to the aqueous layer to adjust the pH to 3. The precipitate was collected by filtration, washed with H2O and dried to give 4.47 g, of titled compound. MP >260° C.

1. concentrationThe resulting mixture was concentrated in vacuo
2. extractionextracted with dichloromethane
3. additionAbout 8 mL of 2N HCl was added to the aqueous layer
4. filtrationThe precipitate was collected by filtration
5. washwashed with H2O
6. customdried
7. customto give 4.47 g