反应详情

Preparation of 1-ethyl-6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylic acid was then carried out by refluxing the EMME adduct of Example 4B in Dowtherm A to produce ethyl 6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylate (Example 4C), ethylating the compound of Example 4C by heating it with ethyl iodide in dimethylformamide in the presence of anhydrous potassium carbonate to produce ethyl 1-ethyl-6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylate (Example 4D) and hydrolyzing the compound of Example 4D by refluxing it in aqueous sodium hydroxide solution containing methanol to produce 1-ethyl 6-fluoro-1,4-dihydro-7-(2,6-dimethyl-4-pyridinyl)-4-oxo-3-quinolinecarboxylic acid (Example 4E).