反应详情

A mixture of 18 ml of picoline, 10.3 g of anhydrous piperazine, and 8.9 g of 1-ethyl-6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester was refluxed with stirring for 5 hrs. The reaction mixture was concentrated under reduced pressure, and the residue was treated by the same manner described in Example 1 to give 8.2 g (79% yield) of 1-ethyl-6-fluoro-7-(1-piperazinyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester. mp: 178°-180° C.

1. temperaturewas refluxed
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. additionthe residue was treated by the same manner