tert-Butylsulfinamide, (R)-(+)- → (NE,R)-N-[1-(6-bromo-3-fluoro-4-triethylsilylpyridin-2-yl)-2,2-difluoroethylidene]-2-methylpropane-2-sulfinamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 1-(6-bromo-3-fluoro-4-(triethylsilyl)pyridin-2-yl)-2,2-difluoroethanone (0.666 g, 1.808 mmol), (R)-2-methylpropane-2-sulfinamide (0.219 g, 1.808 mmol) and tetraethoxytitanium (0.758 ml, 3.62 mmol) in THF (4.52 ml) in a sealed microwave vial was stirred at 80° C. for 3 h. After cooling to RT, the reaction mixture was poured into an ice-cold saturated NaCl solution, stirred for 10 min, and the precipitate was filtered through a pad of celite and washed with EtOAc. The aqueous layer was back extracted with EtOAc (2×) and the combined EtOAc layers were dried (MgSO4) and concentrated. The crude material was purified by chromatography through a Redi-Sep pre-packed silica gel column (40 g), eluting with a gradient of 0% to 30% EtOAc in hexane, to provide (R,E)-N-(1-(6-bromo-3-fluoro-4-(triethylsilyl)pyridin-2-yl)-2,2-difluoroethylidene)-2-methylpropane-2-sulfinamide (0.481 g, 1.020 mmol, 56.4% yield) as dark-brown oil.

Herkunft & Nachweise