Ethylacetate heptane → (R)-N-((S)-1-(4-bromo-2,5-difluorophenyl)ethyl)-2-methylpropane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

To a solution of (R,E)-N-(4-bromo-2,5-difluorobenzylidene)-2-methylpropane-2-sulfinamide (7.2 g, 22.2 mmol in CH2Cl2 (200 mL) cooled to 0° C. (water/ice bath) under nitrogen, was added 3M methyl magnesium bromide (29.6 mL, 89 mmol) in Et2O. Reaction mixture allowed to stir for 5 hours at 0° C. then quenched with the slow addition of a saturated solution of NH4Cl. Aqueous mixture adjusted to pH 8 with HCl (1 N) and extracted with DCM. Organic phases combined, washed with water, brine, dried (Na2SO4), filtered and concentrated onto silica gel. Silica gel column chromatography (EtOAc/Heptane 30 to 100%) provided (R)—N—((S)-1-(4-bromo-2,5-difluorophenyl)ethyl)-2-methylpropane-2-sulfinamide (6.86 g, 20.2 mmol, 91% yield) LCMS m/z 342.1 (M+H)+, Rt 0.96 min.

Provenance & Evidence