Acetic Acid → 5-Benzylamino-1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Steps

Twenty milliliters of a mixture of conc. sulfuric acid, glacial acetic acid and water (1:8:6) was added to 4.4 g of ethyl 5-(N-acetylbenzylamino)-1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate, and the mixture was heated under reflux for 6 hours. After cooling, water was added to the reaction mixture, and the crystals were collected by filtration and successively washed with water and ethanol. The crystals were recrystallized from chloroform/ethanol to give 3.0 g of 5-benzylamino-1-cyclopropyl-6,7-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid. m.p. 214°-216° C.

Provenance & Evidence