Dissolve {2-[4-(6-cyanopyridin-2-yloxy)phenyl]ethyl}carbamic acid tert-butyl ester (0.814 g, 0.240 mmol) in DMSO (4.8 mL). Add K2CO3 (0.166 g, 0.120 μmol) and then 30% H2O2 (0.071 mL 0.624 mmol). Stir at room temperature for 3 hours. Quench the reaction mixture with water (30 mL). Extract with ethyl acetate (1× 60 mL). Wash the organic layer with water (1× 30 mL), dry over MgSO4, filter and concentrate to give the title compound (68.1 g, 79.5%): MS ES+ 357.9 (M+H)+, base peak ES+ 301.9 (M+2H—C(CH3)3), MS ES− 356.1 (M−H)−; HPLC [YMC-Pack Pro C-18 (150×4.6 mm, S-microm), acetonitrile in water containing 0.01% concentrated HCl at 1.0 mL/min, 30-99% over 19 min], tR=18.5 min, 94.5% purity.
