Acetonitrile → 1-ethyl-5-(2-hydroxy-2-methylpropyl)-4-(3-trimethylsilylprop-1-ynyl) 1H-pyrazole-3-carbonitrile

Participants

Reaction Steps

Under a nitrogen atmosphere, 1-ethyl-5-(2-hydroxy-2-methylpropyl)-4-iodo-1H-pyrazole-3-carbonitrile (900 mg, 2.81 mmol), propargyltrimethylsilane (0.8 mL, 5.6 mmol), copper(I) iodide (107 mg, 0.562 mmol), dichlorobis(triphenylphosphine)palladium(II) (197 mg, 0.281 mmol), triethylamine (1.2 mL, 8.4 mmol) and acetonitrile (14 mL) were combined and then heated at reflux for five hours. The reaction mixture was cooled to ambient temperature, diluted with ethyl acetate, and then filtered through a layer of silica gel. The filtrate was concentrated under reduced pressure. The residue was purified by chromatography on a HORIZON HPFC system (40+M cartridge, eluting with a gradient of 0 to 80% ethyl acetate in hexanes) to provide 1-ethyl-5-(2-hydroxy-2-methylpropyl)-4-(3-trimethylsilylprop-1-ynyl)-1H-pyrazole-3-carbonitrile as a yellow oil.

Provenance & Evidence