To a solution of (4S,5R)-5-[3,5-bis(trifluoromethyl)phenyl]-3-[(3-bromo-6-chloropyridin-2-yl)methyl]-4-methyl-1,3-oxazolidin-2-one (INTERMEDIATE 24, 2.2 g, 4.25 mmol) in DMSO (25 mL) under nitrogen, were added 3,3-difluoroazetidine hydrochloride (2.75 g, 21.3 mmol) and sodium bicarbonate (2.14 g, 25.5 mmol). The resulting mixture was stirred at 150° C. overnight. Water was added and extracted 3 times with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with ethyl acetate in hexanes to afford the titled compound. 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).
