反应详情

1.60 g (0.0057 mole) of ethyl 6,7-difluoro-4-hydroxy-8-methoxyquinoline-3-carboxylate (IX) [prepared as described in step (B3) above] were dissolved in 20 ml of dimethylformamide, and 1.20 g (0.0085 mole) of potassium carbonate and 2.40 g (0.017 mole) of methyl iodide were added to the resulting solution. The mixture was then stirred at 60°-65° C. for 17 hours. At the end of this time, the solvent was distilled off under reduced pressure. The residue was extracted with methylene chloride, and the methylene chloride extract was washed with water, dried and concentrated by evaporation under reduced pressure to give 1.60 g of ethyl 6,7-difluoro-8-methoxy-1-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (X, R9' =methyl) as a pale brown powder.

1. distillationAt the end of this time, the solvent was distilled off under reduced pressure
2. extractionThe residue was extracted with methylene chloride
3. extractionthe methylene chloride extract
4. washwas washed with water
5. customdried
6. concentrationconcentrated by evaporation under reduced pressure