[CH3:1][C:2]([S@:5]([NH2:7])=[O:6])([CH3:4])[CH3:3].[Br:8][C:9]1[CH:10]=[C:11]([C:16](=O)[CH2:17][F:18])[C:12]([F:15])=[N:13][CH:14]=1.O.C(=O)(O)[O-]>CCOC(C)=O>[Br:8][C:9]1[CH:10]=[C:11](/[C:16](=[N:7]\[S@@:5]([C:2]([CH3:4])([CH3:3])[CH3:1])=[O:6])/[CH2:17][F:18])[C:12]([F:15])=[N:13][CH:14]=1Titan (IV)-ethoxide tech. (0.298 mL, 1.441 mmol) was added to a solution of (R)-2-methyl-2-propanesulfinamide (1.44 mmol) and 1-(5-bromo-2-fluoropyridin-3-yl)-2-fluoroethanone (170 mg, 0.720 mmol) in methylene chlorice (15 mL). The reaction mixture was stirred at room temperature (light-yellow solution) for 4 h (or until complete conversion by LCMS). The reaction mixture was poured into water and saturated aqueous bicarbonate solution and EtOAc were added. The suspension was stirred vigorously for 20 min. The organic phase was separated. The aqueous phase was extracted twice with EtOAc. The organic phases were combined and filtered through a pad of celite. The filtrate was washed with brine and dried over MgSO4. The solvent was removed under reduced pressure. The residue (239 mg of a yellow oil) was purified by column chromatography (silica gel, 10-70% hexanes/EtOAc) to yield (R,E)-N-(1-(5-bromo-2-fluoropyridin-3-yl)-2-fluoroethylidene)-2-methylpropane-2-sulfinamide as a yellow oil (106 mg; 43%). MS m/z=338.9 [M+H]+. Calculated for C11H13BrFN2OS: 339.2.
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