反应详情

1.0 g of 9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid and 2.85 g of N-methylpiperazine were added to 15 ml of dimethylsulfoxide. The mixture was stirred at a temperature of from about 100° to 110° C. (bath temperature) for 12 hours and the reaction mixture was concentrated to dryness in vacuo and 40 ml of water was added to the residue. Then the product was extracted with chloroform. The extract was dried and concentrated to dryness in vacuo. The residue was recrystallized from ethanol to provide 550 mg of 9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid as colorless needles with m.p. 250°-257° C. (with decomposition).

1. concentrationthe reaction mixture was concentrated to dryness in vacuo and 40 ml of water
2. additionwas added to the residue
3. extractionThen the product was extracted with chloroform
4. customThe extract was dried
5. concentrationconcentrated to dryness in vacuo
6. customThe residue was recrystallized from ethanol