反应详情

A mixture containing 98 g of ethyl 1-ethyl-6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylate, 50 ml of 35% aqueous sodium hydroxide solution, 500 ml of water and 100 ml of methanol was refluxed with stirring for 90 minutes and the resulting brown solution was acidified with acetic acid whereupon a light yellow precipitate separated. The mixture was allowed to stand at room temperature for about 2 hours and the precipitate was collected, washed successively with water and ethanol and then dried at 90°-95° C. to yield 86.8 g (95%) of 1-ethyl-6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylic acid, m.p. >310° C.

1. temperaturewas refluxed
2. customseparated
3. waitto stand at room temperature for about 2 hours
4. customthe precipitate was collected
5. washwashed successively with water and ethanol
6. customdried at 90°-95° C.