Methyl Acetate → (R)-N-(bis(3-(trifluoromethoxy)phenyl)-methylene)-2-methylpropane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

(R)—N-(bis(3-(trifluoromethoxy)phenyl)methylene)-2-methylpropane-2-sulfinamide was prepared as described for Procedure 11. Under an argon atmosphere, CH3COOMe (0.70 mL, 8.83 mmol, 2.0 eq) was stirred in anhydrous Et2O (50 mL) in an oven-dried round bottomed flask at −78° C. LDA (2.0 M, 4.4 mL, 8.8 mmol, 2.0 eq) was added dropwise. The resulting mixture was stirred at −78° C. for 30 min. (R) —N-(bis(3-(trifluoromethoxy)phenyl)methylene)-2-methylpropane-2-sulfinamide (2.0 g, 4.42 mmol) in Et2O (10 mL) was added dropwise to the above stirred solution. The reaction mixture was stirred at −78° C. for 1.5 h. Saturated NH4Cl was added, followed by the addition of EtOAc. The organic layer was washed with H2O and brine, dried over Na2SO4, filtered, and concentrated to dryness. The residue was purified by flash chromatography (silica gel, EtOAc/Hexanes=0 to 100%) to give N-(2-cyano-1,1-bis(3-(trifluoromethoxy)phenyl)-ethyl)-2-methylpropane-2-sulfinamide as light tan oil (1.96 g, yield: 84.1%). LC-MS (ESI) 528.34 (M+H), retention time=4.00 min (10-90% MeOH in H2O with 0.1% TFA in a 4-min run); NMR (400 MHz, CDCl3) δ ppm 7.36 (d, J=8.0 Hz, 2H), 7.31 (t, J=8.0 Hz, 1H), 7.25-7.18 (m, 2H), 7.14-7.05 (m, 3H), 6.14 (s, 1H), 3.93 (d, J=16.1 Hz, 1H), 3.54 (d, J=15.9 Hz, 1H), 3.86 (m, 2H), 3.49 (s, 3H), 1.26 (s, 9H). 13C NMR (400 MHz, CDCl3) δ ppm 22.71, 43.84, 51.68, 56.41, 63.69, 118.63, 119.52, 120.49, 121.35, 124.27, 125.73, 129.81, 129.92, 143.83, 147.52, 149.33, 171.93.

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