反应详情

3.5 g (0.01 mol) of 1-cyclopropyl-6,8-difluoro-7-(piperazin-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid are dissolved in a mixture of 0.4 g of sodium hydroxide in 20 ml of water, and a solution of 1 g of succinic anhydride in 10 ml of dioxane, and a solution of 0.4 g of sodium hydroxide in 10 ml of water, are simultaneously added dropwise at 20° C. After standing for 12 hours, the mixture is adjusted to pH 5 with 2N hydrochloric acid, and the precipitate is filtered off under suction, washed with water, heated with methanol, filtered off under suction and dried. 2.5 g of 7-[4-(3-carboxypropionyl)-piperazin-1-yl]-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid having a decomposition temperature of 217°-219° C. are obtained.

1. filtrationthe precipitate is filtered off under suction
2. washwashed with water
3. temperatureheated with methanol
4. filtrationfiltered off under suction
5. customdried