Water → N-[(1R)-1-(5-bromo-3-fluoropyridin-2-yl)ethyl]-2-methylpropane-2-sulfinamide

Participants

Reaction Steps

A solution of N-[(1E)-(5-bromo-3-fluoropyridin-2-yl)methylidene]-2-methyl-propane-2-sulfinamide (18.63 g, 60.65 mmol) in CH2Cl2 (375 mL) was cooled to −50° C. under N2. Methylmagnesium chloride (3M in THF, 30.32 mL, 90.97 mmol) was added dropwise, the reaction was stirred for 1 h. Additional methylmagnesium chloride (5.0 mL, 15.0 mmol) was added after 30 minutes to drive the reaction to completion. Water (200 mL) and brine (200 mL) were added, and the reaction allowed to warm to room temperature. The aqueous layer was extracted 4× with CH2Cl2, and the combined organics were dried over Na2SO4, filtered and concentrated under vacuum. The residue was subjected to silica gel chromatography eluted with 10–40% ethyl acetate in hexanes to provide N-[(1R)-1-(5-bromo-3-fluoropyridin-2-yl)ethyl]-2-methylpropane-2-sulfinamide that gave proton NMR spectra consistent with theory and a mass ion (ES+) of 325.0 for M+H+(81Br).

Provenance & Evidence