To a solution of 8-(2-methoxy-pyridin-3-yl)-2-(4-trifluoromethoxy-phenyl)-2,8-diaza-spiro[4.5]decan-1-one (described in example 9, 40 mg, 0.095 mmol) in acetonitrile (2 mL) at 0° C. was added NaI (28.5 mg, 0.19 mmol). TMSCl (24 uL, 0.19 mmol) was added, and the mixture was stirred and allowed to warm to rt over overnight. 1N Hydrochloric acid (1 mL), 38% aqueous sodium bisulfite solution (0.5 mL), brine and EtOAc (10 mL) were added, and the mixture was stirred for 30 min. The phases were separated, and the aqueous phase was extracted with additional EtOAc. The combined organic phases were washed with sat. NaHCO3, brine, dried (Na2SO4), filtered and evaporated under reduced pressure to yield the title compound as a light green solid (25 mg, 65%). MS (ESI): 408.3 (MH+).
