To an orange solution of (S)-tert-butyl 1-(2-nitro-4-(trifluoromethyl)phenyl)piperidin-3-ylcarbamate (1.50 g, 3.9 mmol) in DMF at 0 deg. C. was added sodium hydride, 60% dispersion in mineral oil (0.19 g, 4.8 mmol). Bubbling was observed, and the solution became darker orange. After about 20 min, iodomethane (0.30 ml, 4.8 mmol) was added dropwise via syringe. The orange mixture was allowed to warm to room temperature over 30 min. Water was added, followed by diethyl ether. The organics were washed 1×H2O, 1×brine, dried over anhydrous Na2SO4, filtered, and concentrated to give (S)-tert-butyl methyl(1-(2-nitro-4-(trifluoromethyl)phenyl)piperidin-3-yl)carbamate as an orange semi-solid which was used without further purification. MS m/z=404 [M+H]+. Calc'd for C18H24F3N3O4: 403.
