Cesium carbonate → N-(2,4-dimethylphenyl)-3,5-difluoro-N-isobutyl-4-vinylbenzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a vial was added potassium trifluoro(vinyl)borate (0.744 g, 5.55 mmol), triphenylphosphine (0.073 g, 0.278 mmol), 4-bromo-N-(2,4-dimethylphenyl)-3,5-difluoro-N-isobutylbenzenesulfonamide (2 g, 4.63 mmol) suspension in tetrahydrofuran (THF) (22 mL), cesium carbonate (4.52 g, 13.88 mmol), water (2.200 mL) and palladium(II) chloride (0.016 g, 0.093 mmol). The mixture was divided evenly between two microwave vials and the vessels then sealed and heated by microwaves (Biotage Initiator) to 140° C. for 30 minutes. LCMS analysis showed some conversion, so additional 0.5 equivalent of potassium trifluoro(vinyl)borate was added to each reaction, along with extra water (2 mL) and THF (2 mL). The reactions were reheated by microwaves for a further 1 hour at 140° C. The reactions were then diluted with dichloromethane (5 mL) and water (2 mL), filtered through celite and dried using a hydrophobic frit. The organics were concentrated and purified by flash silica (Si) chromatography (0-25% ethyl acetate-cyclohexane gradient). The appropriate fractions were combined and evaporated in vacuo to give two batches of the required product, 769 mg and 856 mg, as yellow oils. LCMS [LCMS2] Rt 1.60 min, m/z (ES+) 380 (M+H).

Provenance & Evidence