Triethylamine → 5-Bromo-2-[(tert-butyldimethylsilanyl)ethynyl]-3-fluoropyridine

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Reaction Steps

Under an argon atmosphere, 2.62 mL (13.811 mmol) of tert-butylethynyldimethylsilane was added to a solution of 3.20 g (12.56 mmol) of 2,5-dibromo-3-fluoropyridine, 5.22 mL of triethylamine (37.67 mmol), 59.8 mg (0.31 mmol) of CuI, and 220.3 mg (0.31 mmol) of bis(triphenylphosphane)palladium (II) chloride in 30 mL of absolute THF at 15° C. and the mixture was stirred for 2 hours at RT. 1 mL of tert-butylethynyldimethylsilane was added and the mixture was again stirred for 1 hour at RT. The reaction mixture was evaporated down in vacuo and the residue was taken up in EtOAc. The organic phase was washed with semisaturated aqueous sodium bicarbonate solution, 5% aqueous ammonia, and water, dried over magnesium sulfate, and evaporated down in vacuo. The crude product was purified by column chromatography (silica gel, PE/DCM 9:1). Yield: 1.62 g (41% of theoretical); C13H17BrFNSi (M=314.269); calc.: molpeak (M+H)+: 314/316 (Br); found: molpeak (M+H)+: 314/316 (Br); HPLC-MS: 7.85 minutes (method B).

Provenance & Evidence