Piperazine → Ciprofloxacin

Participants

Reaction Steps

A mixture of 19.7 g of 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, 30.1 g of anhydrous piperazine and 100 ml of dimethyl sulphoxide is heated at 135°-140° C. for 2 hours. The solvent is distilled out under high vacuum, and the residue is suspended in H2O, filtered off with suction and washed with water. For further purification, the moist crude product is boiled with 100 ml of water, filtered with suction at room temperature, the solid is washed with H2O and dried to constant weight over CaCl2 in a vacuum oven at 100° C. 19.6 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)quinoline-3-carboxylic acid, of decomposition point 255°-257° C., are obtained; RF value: 0.07.

Provenance & Evidence