A reaction vessel was charged with (4S,5R)-5-[3,5-bis(trifluoromethyl)phenyl]-3-[(3-bromo-6-chloropyridin-2-yl)methyl]-4-methyl-1,3-oxazolidin-2-one (50 mg, 0.097 mmol), 3,3-difluoroazetidine hydrochloride (125 mg, 0.966 mmol) and sodium bicarbonate (162 mg, 1.932 mmol). DMSO (2 mL) was added. The reaction was heated to 150° C. under an atmosphere of N2. After 16 hours, the reaction was cooled to r.t., diluted with EtOAc (40 mL), and washed with water and brine (10 mL each). The organic layer was dried over Na2SO4, filtered, and concentrated. Purification of the residue by flash chromatography on silica gel with 0 to 80% EtOAc/hexanes afforded (4S,5R)-5-[3,5-bis(trifluoromethyl)phenyl]-3-{[3-bromo-6-(3,3-difluoroazetidin-1-yl)pyridin-2-yl]methyl}-4-methyl-1,3-oxazolidin-2-one contaminated with a minor impurity. This material was used in subsequent reactions without further purification. LCMS=575.9 (M+H)+ 1H NMR (CDCl3, 500 MHz) δ 7.89 (s, 1H), 7.78 (s, 2H), 7.63 (d, J=8.7 Hz, 1H), 6.24 (d, J=8.7 Hz, 1H), 5.75 (d, J=8.4 Hz, 1H), 4.87 (d, J=17.1 Hz, 1H), 4.23-4.40 (m, 6H), 0.79 (d, J=7.6 Hz, 3H).
