反应详情

1.10 g (0.008 mole) of potassium carbonate was added to a solution of 1.13 g (0.004 mole) of ethyl 6,7-difluoro-4-hydroxy-8-methoxyquinoline-3-carboxylate (IX) [prepared as described in Preparation 14 (B3)] in 20 ml of dimethylformamide and the mixture was stirred at room temperature for 3 hours. 0.81 g (0.0041 mole) of O-(2,4-dinitrophenyl)hydroxylamine was then added, and the mixture was stirred at room temperature for 6 hours. At the end of this time, the solvent was distilled from the reaction mixture under reduced pressure. The residue was washed, in turn, with water and with ethanol. The solid produced was extracted with chloroform, and the solvent was stripped from the extract, to give 0.62 g of ethyl 1-amino-6,7-difluoro-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylate (XV) as an ocherous powder.

1. stirringthe mixture was stirred at room temperature for 6 hours
2. distillationAt the end of this time, the solvent was distilled from the reaction mixture under reduced pressure
3. washThe residue was washed, in turn, with water and with ethanol
4. customThe solid produced
5. extractionwas extracted with chloroform