Hydrogen Bromide → HCID 13745458, compound

Participants

Reaction Steps

To ethyl 6,7-difluoro-1-(4-methoxyphenyl)-1,4-dihydro-4-oxoquinoline-3-carboxylate (0.70 g) is added 48% hydrobromic acid (8 ml), and the mixture is stirred at 100°-110° C. for 3 hour. After cooling, the precipitated crystals are separated by filtration, washed with water and recrystallized from dichloromethane-ethanol to give 6,7-difluoro-1-(4-hydroxyphenyl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (0.57 g) as colorless needles, m.p. 288°-290° C.

Provenance & Evidence