[Br:1][C:2]1[CH:3]=[C:4]([N:8]2[CH:12]=[C:11]([C:13](=O)[CH3:14])[CH:10]=[N:9]2)[CH:5]=[CH:6][CH:7]=1.[CH3:16][C:17]([S@:20]([NH2:22])=[O:21])([CH3:19])[CH3:18]>O1CCCC1.[O-]CC.[Ti+4].[O-]CC.[O-]CC.[O-]CC>[Br:1][C:2]1[CH:3]=[C:4]([N:8]2[CH:12]=[C:11](/[C:13](=[N:22]/[S@@:20]([C:17]([CH3:19])([CH3:18])[CH3:16])=[O:21])/[CH3:14])[CH:10]=[N:9]2)[CH:5]=[CH:6][CH:7]=1A solution of 1-[1-(3-bromo-phenyl)-1H-pyrazol-4-yl]-ethanone (1.0 g, 4.53 mmol), (R)-2-methylpropane-2-sulfinic acid amide (0.66 g, 5.43 mmol) and titanium (IV) ethoxide (2.1 ml, 9.96 mmol) in tetrahydrofuran (20 ml) was refluxed for 12 hours. The reaction mixture was cooled to 25° C., quenched with brine (20 ml), and extracted with ethyl acetate (5×20 ml). The combined organic layers were washed with brine (50 ml), dried over sodium sulphate, and evaporated at reduced pressure. The crude material thus obtained was purified by column chromatography on silica gel using a gradient of hexane/ethyl acetate=85:15 to 80:20 as the eluent to give the (R)-2-methyl-propane-2-sulfinic acid [1-[1-(3-bromo-phenyl)-1H-pyrazol-4-yl]-eth-(E)-ylidene]-amide (1.0 g, 60% yield) as a yellow solid. MS (ISP): m/z=368.0 [M+H]+.
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