Triethylamine → Balofloxacin

Participants

Reaction Steps

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.

Provenance & Evidence