Compound 19 is prepared according to the General Procedure Synthesis of Quinolone-7-yl Linked Oxazolidinones from 1-acetyl-3-amino-2-(S)-oxypropylamine (2 mmol) using 3-carboxy-1-cyclopropyl-7-chloro-6-fluoro-1,4-dihydroquinoline-4-one (0.282 g, 1 mmol). The first reaction step is performed at 120-130° C. for 48 h. The mixture is cooled to room temperature (r.t.), and a majority of the solvent removed under vacuum. The resulting amino alcohol intermediate is purified by silica gel column chromatography (eluent: dichloromethane-MeOH). Cyclization is performed by dissolving the amino alcohol (1 mmol) in an aprotic organic solvent (e.g., THF or NMP) (2-5 mL), in the presence of carbonyldiimidazole (1.1 mmol) and adding imidazole (1.0 mmol). The mixture is stirred at 20-40° C. for 1-3 h. The solvent is removed under vacuum, and the product is purified by silica gel column chromatography (eluent: dichloromethane--MeOH).
