1-Cyclopropyl-6,7,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid → 7-[1-(t-Butoxycarbonylamino)-3-azabicyclo[3.2.0]hept-3-yl]-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Steps

1.9 g of 1-(t-butoxycarbonylamino)-3-azabicyclo[3.2.0]heptane and 0.83 g of 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid were added to 15 ml of pyridine, followed by heating under reflux for 4 hours. After the solvent was distilled off under reduced pressure, the resulting residue was purified by silica gel column chromatography (using a 100:1 mixture of chloroform and methanol as the eluent) and recrystallization (from ethyl acetate-diisopropyl ether) to obtain 0.99 g of 7-[1-(t-butoxycarbonylamino)-3-azabicyclo[3.2.0]hept-3-yl]-1-cyclopropyl-6,8-difluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (m.p. 211-215° C.).

Provenance & Evidence