Ethylacetate heptane → (R)-2-methyl-N-[(1S)-1-[4-(trifluoromethoxy)phenyl]ethyl]propane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

To a solution of (R,E)-2-methyl-N-(4-(trifluoromethoxy)benzylidene)propane-2-sulfinamide (7.7 g, 26.3 mmol) in CH2Cl2 (150 mL), cooled to 0° C. (water/ice bath), under nitrogen, was added 3M methyl magnesium bromide (35 mL, 105 mmol) in Et2O. The reaction mixture was stirred at 0° C. for 30 min, then allowed to warm up to room temperature and stirred additional 4 hrs. The reaction mixture was cooled again to 0° C. and quenched with the slow addition of a saturated NH4Cl solution. The by-phasic mixture was diluted with DCM and Water and the aqueous extracted with DCM two times. The organic phases were combined, washed with brine, dried (Na2SO4), filtered and concentrated to 11.5 g crude white solid. Silica gel column chromatography (EtOAc/Heptane 0 to 30%) afforded (R)-2-methyl-N—((S)-1-(4-(trifluoromethoxy)phenyl)ethyl)propane-2-sulfinamide (5.08 g, 16.2 mmol, 62% yield) as a white crystalline solid. 1H NMR (400 MHz, CDCl3) δ 1.21 (s, 9H) 1.53 (d, J=6.70 Hz, 3H) 3.31 (d, J=2.74 Hz, 1H) 4.59 (qd, J=6.67, 3.37 Hz, 1H) 7.18 (d, J=8.02 Hz, 2H) 7.36 (d, J=8.66 Hz, 2H). LCMS m/z 310.2 (M+H)+, Rt 0.90 min.

Provenance & Evidence