To a solution of 4-chloro-N-{5-chloro-2-[(2-chloro-6-fluoro-phenyl)-hydroxy-methyl]-pyridin-3-yl}-N-methoxymethyl-3-trifluoromethyl-benzenesulfonamide (144 mg, 0.252 mmol) in CH2Cl2 (5 mL) was added Dess-Martin periodinane (213.5 mg, 0.5 mmol) and stirred for 3 h at room temperature. 10% aqueous Na2S2O3 (5 mL) and saturated aqueous NaHCO3 solution (5 mL) were added to the reaction mixture and stirred for 30 min. The aqueous layer was then extracted with EtOAc (2×25 mL). The combined organic extracts were subsequently washed with saturated aqueous NaHCO3 solution (20 mL) and brine (20 mL), dried (Na2SO4), and concentrated to obtain 4-chloro-N-[5-chloro-2-(2-chloro-6-fluoro-benzoyl)-pyridin-3-yl]-N-methoxymethyl-3-trifluoromethyl-benzenesulfonamide (107 mg) in 75% yield which was used without further purification. MS m/z: 539 (M−MeOH+H), 593 (M+Na).
