2-Chloro-4-{[(2-methylphenyl)methyl][(3S)-5-oxo-1-(2-propen-1-yl)-3-pyrrolidinyl]amino}benzonitrile (30.0 mg, 0.08 mmol) and 4-methyl morpholine oxide (37.5 mg, 0.16 mmol) were dissolved in a mixture of THF/t-BuOH/H2O (0.5 mL/0.2 mL/0.1 mL). To this solution was added an osmium tetroxide/2-methyl-2-propanol solution (2.5 wt %, 81.3 mg, 0.008 mmol), and the mixture stirred at room temperature for 18 h. The reaction mixture was quenched with 5% NaHSO3 (2 mL), and the organic layer was separated and concentrated to afford the desired product as a white solid (12.0 mg, 37% yield). LC-MS (ES) m/e 413.7 (M+H)+.
