1-(2,4-Difluoro-phenyl)-6-fluoro-7-(4-{2-fluoro-4-[5-(R)--(1-hydroxy-prop-2-inyl)-2-oxo-oxazolidin-3-yl]-phenyl}-piperazin-1-yl)-4-oxo-1,4-dihydro-[1,8] naphthyridine-3-carboxylic acid AIDS-167310 AIDS167310