A mixture of (R)[[3-[4[(1S,4S)-2-thia-5-azabicyclo[2.2.1]heptane-5-yl]-3-fluorophenyl]-2-oxo-5-oxazolidinyl]methyl]methanesulfonate (1.56 g, 3.88 mmol), 1:1 THF/i-PrOH (4 mL) and 30% NH4OH (4 mL) was heated to 95° C. in a sealed tube for 14 h and then cooled to ambient temperature. TLC analysis (5% MeOH/CHCl3) revealed the reaction to be complete. The mixture was diluted with CH2Cl2 (75 mL), washed with saturated aqueous NaHCO3 (15 mL) and brine (15 mL), dried over Na2SO4, filtered and concentrated under reduced pressure to give a syrup. The crude 5-(aminomethyl)oxazolidinone intermediate was dissolved in CH2Cl2 (75 mL) and treated with pyridine (0.35 mL, 4.27 mmol) and acetic anhydride (0.403 mL, 4.27 mmol) at ambient temperature. After 1 h, TLC analysis (5% MeOH/CHCl3) indicated the elation to be completed. The reaction mixture was washed with H2O and brine, dried over Na2SO4, filtered and concentrated under reduced pressure to an amber solid. Chromatography over silica gel (125 g), eluting with 1-3% MeOH/CHCl3, afforded, after concentration of appropriate fractions, 1.23 g (87%) of the title oxazolidinone antibacterial agent as a solid with mp 90-95° C. and MS(EI) 365 (M+).
