[F:1][C:2]1[CH:7]=[C:6]([C:8](=[N:10][S:11]([C:13]([CH3:16])([CH3:15])[CH3:14])=[O:12])[CH3:9])[CH:5]=[C:4]([F:17])[C:3]=1[NH:18][S:19]([CH3:22])(=[O:21])=[O:20].[BH4-].[Na+].CO>C1COCC1>[F:1][C:2]1[CH:7]=[C:6]([CH:8]([NH:10][S:11]([C:13]([CH3:16])([CH3:14])[CH3:15])=[O:12])[CH3:9])[CH:5]=[C:4]([F:17])[C:3]=1[NH:18][S:19]([CH3:22])(=[O:21])=[O:20]To a solution of N-(4-acetyl-2,6-difluoro-phenyl)-methanesulfonamide (1.84 g, 7.38 mmol) and (R)-(+)-2-methyl-2-propanesulfinamide (1.07 g, 8.86 mL) in THF (15 mL) was added dropwise Ti(OEt)4 (2.61 mL, 12.6 mmol) at room temperature. The mixture was stirred overnight at 90° C. The mixture cooled to room temperature and then was added brine. After the mixture was extracted three times with EtOAc, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The crude residue was purified by chromatography to yield N-{2,6-difluoro-4-[1-(2-methyl-propane-2-sulfinylimino)-ethyl]-phenyl}-methanesulfonamide (2.2 g, 85%). To a solution of N-{2,6-difluoro-4-[1-(2-methyl-propane-2-sulfinylimino)-ethyl]-phenyl}-methanesulfonamide (2.2 g, 6.24 mmol) in THF (20 mL) was added portionwise NaBH4 (944 mg, 24.9 mmol) dissolved in THF (2 mL) at −48° C. The mixture was stirred for 10 hours at −48° C. room temperature, and then CH3OH was added dropwise until gas was no longer evolved. The mixture was concentrated under reduced pressure, and then was purified by chromatography to afford N-{2,6-difluoro-4-[1-(2-methyl-propane-2-sulfinylamino)-ethyl]-phenyl}-methanesulfonamide (1.89 g, 50%).
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