反应详情

A mixture of ethyl 5-amino-7-fluoro-1-[2-(S)-fluoro-1-(R)-cyclopropyl]-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylate (2.68 g, 7.92 mmol), acetic acid (20 ml) and concentrated hydrochloric acid (20 ml) was heated under reflux for 3 hours. After cooling there action solution with ice, water (200 ml) was poured therein and the precipitated crystals were filtered out. After washing with excess water, a small amount of cold ethanol and excess diethyl ether in that order, the crude crystals obtained were purified by recrystallization in a mixed solvent of chloroform/methanol and then dried under a reduced pressure. 1.26 g (51%) of the title compound was thereby obtained in the form of yellow crystals.

1. temperaturewas heated
2. temperatureunder reflux for 3 hours
3. additionwas poured
4. filtrationthe precipitated crystals were filtered out
5. washAfter washing with excess water
6. customa small amount of cold ethanol and excess diethyl ether in that order, the crude crystals obtained
7. customwere purified by recrystallization in a mixed solvent of chloroform/methanol
8. customdried under a reduced pressure