Ethanol → HCID 70030230, compound

Participants

Reaction Steps

7-Fluoro-8-[4-(4-fluorophenyl)piperazin-1-yl]-1-methylamino-4-oxo-1,4-dihydrobenzo[b][1,8]naph-thyridine-3-carboxylic acid was prepared under the conditions of Example 2, but from 3.2 g of 8-chloro-7-fluoro-1-methylamino-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid and 9 g of 4-(4-fluorophenyl)piperazine in 30 cm3 of pyridine for 28 hours. After concentrating the reaction mixture to dryness under reduced pressure (20 kPa) at approximately 60° C., the residue was taken up twice in 30 cm3 of ethanol and concentrated under reduced pressure under the above conditions. The solid was taken up into 50 cm3 of water and 10 cm3 of 30% aqueous potassium hydroxide solution. 20 cm3 of water and approximately 10 cm3 of 10% acetic acid were added to the precipitate formed. The suspension was extracted 3 times with 50 cm3 of trichloromethane. The trichloromethane was concentrated under reduced pressure (20 kPa) and the solid obtained was taken up in 2 times 20 cm3 of ethanol. After crystallizing once from 42 cm3 and then recrystallizing once from 15 cm3 of dimethylformamide, 1.33 g of 7-fluoro-8-[4-(4-fluorophenyl)piperazin-1-yl]-1-methylamino-4-oxo-1,4-dihydrobenzo[b][1,8]naph-thyridine-3-carboxylic acid were obtained in the form of a brown solid melting at about 304-305° C.

Provenance & Evidence