反应详情

A mixture of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylic acid (2.95 g), 3-methylaminopiperidine dihydrochloride (6.69 g) and triethylamine (10 g) in acetonitrile (50 ml) was refluxed with stirring for 12 hours. The reaction mixture was concentrated in vacuum, and the residue was extracted with chloroform. The extract was washed with a saturated NaCl solution and concentrated in vacuo. The residue was purified by silica gel column chromatography (chloroform:methanol:ammoniumhydroxide=15:5:1) to give 1.28 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-(3-methylaminopiperidin-1-yl)-4-oxoquinoline-3-carboxylic acid, which was recrystallized from acetonitrile-water, colorless needles. m.p. 134°-135° C.

1. temperaturewas refluxed
2. concentrationThe reaction mixture was concentrated in vacuum
3. extractionthe residue was extracted with chloroform
4. washThe extract was washed with a saturated NaCl solution
5. concentrationconcentrated in vacuo
6. customThe residue was purified by silica gel column chromatography (chloroform:methanol:ammoniumhydroxide=15:5:1)