[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][C:3]=1[C:9](=O)[CH2:10][F:11].[CH3:13][C:14]([S@:17]([NH2:19])=[O:18])([CH3:16])[CH3:15]>C1COCC1.[Cl-].[Na+].O.C(O[Ti](OC(C)C)(OC(C)C)OC(C)C)(C)C>[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[CH:4][C:3]=1/[C:9](=[N:19]\[S@@:17]([C:14]([CH3:16])([CH3:15])[CH3:13])=[O:18])/[CH2:10][F:11]To a solution of 1-(2,3-difluorophenyl)-2-fluoroethanone (18.9 g, 109 mmol) in THF (400 mL) was added (R)-(+)-2-methyl-2-propanesulfinamide (26.3 g, 217 mmol) followed by tetraisopropoxytitanium (93 g, 326 mmol). The reaction was heated to reflux for 2 h. The mixture was allowed to cool to room temperature and then treated with brine (400 ml). The resulted suspension was stirred for 15 min and filtered through a pad of celite. The filter cake was washed with EtOAc. The filtrate was extracted with EtOAc (2×). The organic extracts were washed with brine, dried over Na2SO4 and filtered. The filtrate was concentrated and purified by silica gel column (0-20% EtOAc/hexane) to afford (R,E)-N-(1-(2,3-difluorophenyl)-2-fluoroethylidene)-2-methylpropane-2-sulfinamide (12.3 g, 44.4 mmol, 40.9% yield) as yellow oil, MS m/z=278.0 [M+H]+. calculated for C12H14F3NOS: 277.3
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