(NE,R)-N-[[4-(1,1-difluoroethyl)-2-fluorophenyl]methylidene]-2-methylpropane-2-sulfinamide → N-((S)-1-(4-(1,1-difluoroethyl)-2-fluorophenyl)ethyl)-2-methylpropane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

To a solution of (R,E)-N-(4-(1,1-difluoroethyl)-2-fluorobenzylidene)-2-methylpropane-2-sulfinamide (497 mg, 1.706 mmol) in DCM (9.59 mL) was added methylmagnesium bromide (3M in diethylether; 1.20 mL) at 0° C. The reaction mixture was allowed to stir for 1 hr at 0° C., gradually allowed to warm to room temperature and stirred for 1 hr at room temperature. The mixture was cooled to 0° C., additional methylmagnesium bromide (3M in diethylether; 0.5 mL) was added and stirring was continued for 30 min at 0° C. The reaction mixture was carefully quenched with saturated aqueous ammonium chloride solution (6 mL) and diluted with water (20 mL). The separated aqueous phase was extracted with DCM (30 mL). The combined organic layers were washed with brine (50 mL), concentrated under reduced pressure. The residue was purified by column chromatography [SiO2, 24 g, heptane/ethyl acetate] providing N—((S)-1-(4-(1,1-difluoroethyl)-2-fluorophenyl)ethyl)-2-methylpropane-2-sulfinamide (349 mg) as a white solid. LCMS m/z 308.2 (M+H)+, Rt 0.91 min.

Provenance & Evidence