Diethyl Ether → (S)-N-((R)-1-Cyclobutylethyl)-2-methylpropane-2-sulfinamide

Participants

Reaction Conditions

Reaction Steps

Into a 10-L 4-neck round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of (S)—N-[(1E)-cyclobutylmethylidene]-2-methylpropane-2-sulfinamide (200 g, 1.07 mol) in tetrahydrofuran (3000 mL). This was followed by the addition of methylmagnesium bromide in ether (1070 mL, 3.00 equiv) dropwise with stirring at −78° C. over 1 hr. The resulting solution was stirred for 1 h at −70° C., 1 h at −60° C., 1 h at −50° C. and 2 h at −40° C. The reaction was then quenched by the addition of 10 L of saturated aqueous NH4Cl solution. The resulting solution was extracted with 2×3 L of ether. The organic layers were combined, washed with 2×3 L of brine, dried over anhydrous sodium sulfate, and concentrated under vacuum. The residue was diluted with 250 mL of n-hexane. The resulting solid was collected and washed with 2×100 mL of cold n-hexane to afford (S)—N-[(1R)-1-cyclobutylethyl]-2-methylpropane-2-sulfinamide.

Provenance & Evidence