Acetic Acid → HCID 9829429, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 1.2 g of ethyl 7,9-difluoro-1-(2,4-difluorophenyl)-8-[4-(4-fluorophenyl)piperazin-1-yl]-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylate in 15 cm3 of ethanol and 16 cm3 of 1N aqueous potassium hydroxide solution was heated with stirring at a temperature around 80° C. for 2 hours. 10 cm3 of a 10% aqueous acetic acid solution were added, at approximately 80° C., to the solution obtained. The insoluble material was filtered off at this temperature, washed 2 times with 30 cm3 of water and recrystallized from a mixture of 12.5 cm3 of ethanol and 12.5 cm3 of dimethylformamide. 0.75 g of 7,9-difluoro-1-(2,4-difluorophenyl)-8-[4-(4-fluorophenyl)piperazin-1-yl]-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid was obtained in the form of a yellow solid melting at about 284-286° C.

Provenance & Evidence