Piperazine → Ciprofloxacin

Participants

Reaction Steps

A mixture of 19.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid, 30.1 g of anhydrous piperazine and 100 ml of dimethylsulphoxide is heated at 135°-140° C. for 2 hours. The solvent is distilled off under a fine vacuum, the residue is suspended in water and the solid is filtered off with suction and washed with water. For further purification, the moist crude product is boiled up with 100 ml of water and the solid is filtered off with suction at room temperature, washed with water and dried to constant weight over calcium chloride in a vacuum drying cabinet at 100° C. 19.6 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinolinecarboxylic acid of decomposition point 255°-257° C. are obtained.

Provenance & Evidence