(NE,R)-N-[[5-(4-chlorophenyl)-1,2-oxazol-3-yl]methylidene]-2-methylpropane-2-sulfinamide → (R)-N-((S)-1-(5-(4-chlorophenyl)isoxazol-3-yl)ethyl)-2-methylpropane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

A solution of methylmagnesium bromide (3.0 M in diethyl ether, 12.8 mL, 38.4 mmol, 4 equiv) was added to a solution of (R,E)-N-((5-(4-chlorophenyl)isoxazol-3-yl)methylene)-2-methylpropane-2-sulfinamide (2.98 g, 9.6 mmol) in DCM (96 mL) at 0° C. The solution became orange, then faded to yellow. The reaction was stirred at 0° C. for 30 min and then carefully quenched with saturated aqueous ammonium chloride (100 mL). The layers were separated and the aqueous layer was extracted with DCM (40 mL). The combined organic layers were washed with water (50 mL), saturated aqueous sodium chloride (50 mL), dried over Na2SO4, filtered and concentrated. Silica gel column chromatography (EtOAc/Heptane) provided (R)—N—((S)-1-(5-(4-chlorophenyl)isoxazol-3-yl)ethyl)-2-methylpropane-2-sulfinamide (1.0 g, white solid) in 32% yield. 1H NMR (400 MHz, CDCl3) δ 7.71 (d, J=8.6 Hz, 2H), 7.45 (d, J=8.6 Hz, 2H), 6.50 (s, 1H), 4.75 (m, 1H), 3.47 (m, 1H), 1.70 (d, J=6.8 Hz, 3H), 1.25 (s, 9H). MS m/z 327.0 (M+H)+; Rt-0.94 min.

Provenance & Evidence