Morpholine → 1-Cyclopropyl-6-fluoro-8-methoxy-7-morpholino-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

1.2 g (0.012 mole) of morpholine was added to a solution of 0.9 g (0.003 mole) of 1-cyclopropyl-6,7-difluoro-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (IIc) (prepared as described in Preparation 6) in 5 ml of dimethyl sulfoxide, and the mixture was stirred at 70° C. for 6 hours. At the end of this time, the solvent and the excess morpholine were removed at the same temperature by evaporation under reduced pressure. The residue was washed with ethyl acetate and then subjected to silica gel column chromatography eluted with methanol, to afford 0.65 g of 1-cyclopropyl-6-fluoro-8-methoxy-7-morpholino-1,4-dihydro-4-oxoquinoline-3-carboxylic acid as a pale brown powder melting at 235°-237° C.

Provenance & Evidence