THE ABSOLUTE-CONFIGURATION OF (R)-(-NADIFLOXACIN())

The optically active (+)-enantiomer of 5,6-difluoro-2-methyl-1,2,3,4-t etrahydroquinoline was obtained as a salt with dibenzoyl-D-tartaric ac id by the optical resolution method and was determined to be R-configu ration by X-ray analysis, Since -5,6-difluoro-2-methyl-1,2,3,4-tetrahy droquinoline is the optically resolved synthetic intermediate of optic ally active (+)-enantiomer of hyl-1-oxo-1H,5H-benzo[i.j]quinolizine-2- carboxylic acid, OPC-7251, 1], the absolute configuration of (+)-1 was assigned to R.