[CH3:1][N:2]1[C:6]([C:7]([F:10])([F:9])[F:8])=[C:5]([CH:11]=O)[CH:4]=[N:3]1.[CH3:13][C:14]([S@:17]([NH2:19])=[O:18])([CH3:16])[CH3:15].C(OCC)(=O)C.C(OCC)(=O)C.CCCCCCC>C1COCC1.[Cl-].[Na+].O.ClCCl>[CH3:13][C:14]([S@:17](/[N:19]=[CH:11]/[C:5]1[CH:4]=[N:3][N:2]([CH3:1])[C:6]=1[C:7]([F:10])([F:9])[F:8])=[O:18])([CH3:16])[CH3:15]
1-Methyl-5-(trifluoromethyl)-1H-pyrazole-4-carbaldehyde (1.0 g, 0.0056 mole) was dissolved in THF (20 ml) and Ti(OEt)4 (2.56 g, 0.011 mole) in THF (5 ml) added and the solution stirred under nitrogen. (R)-(+)-2-methyl-2-propanesulfinamide (680 mg, 0.0056 mole) was added in a single portion and the reaction stirred under reflux and nitrogen for 6 hours. The solution was cooled to 0-5° C. and added to a cooled mix of brine and ethyl acetate (1:1, 120 ml) with rapid stirring. The mixture was filtered through Celite and the solids washed with more ethyl acetate. The organic layer was separated and back-washed with brine (2×60 ml). The organic layer was separated, dried (Na2SO4), filtered and evaporated to give a cloudy oil. Yield 1.7 g. The oil was dissolved in dichloromethane and purified using an ISCO Companion (40 g silica col., hexane to hexane:ethyl acetate 1:1). The appropriate fractions were combined and evaporated to give an oil, which solidified on standing. Yield 1.43 g, 90%. 1H NMR (400 MHz, CDCl3) δ 8.63 (s, 1H) 8.02 (s, 1H) 4.07 (s, 3H) 1.25 (s, 9H). MS (ESI) m/z 282 (M+H)+. LC-MS ESLD 100% m/z 282 (M+H)+. TLC ethyl acetate:heptane 1:1 0.8 UV +ve. GC-MS Cl+ m/z 282 (M+H)+.
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