Acetic Acid → 1-Cyclopropyl-7,9-difluoro-8-(4-furfurylpiperazin-1-yl)-4-oxo-1,4-dihydrobenzo[b][1,8]-naphthyridine-3-carboxylic acid

Participants

Reaction Steps

A suspension of 1.5 g of ethyl 1-cyclopropyl-7,9-difluoro-8-(4-furfurylpiperazin-1-yl)-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylate was heated, with stirring, at a temperature around 80° C. for approximately 1 hour 30 in 15 cm3 of ethanol and 14 cm3 of 1 N potassium hydroxide solution, 32 cm3 of 5% acetic acid were added at this same temperature and the suspension was stirred for 20 minutes. After recrystallizing from a mixture of 15 cm3 of dimethylformamide and 15 cm3 of ethanol, 0.7 g of 1-cyclopropyl-7,9-difluoro-8-(4-furfurylpiperazin-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 241° C.

Provenance & Evidence