Diisopropylamine → 1-(Difluoromethyl)-4-((trimethylsilyl)ethynyl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

4-Iodo-1-difluoromethylpyrazole (521 mg, 1.81 mmole) was dissolved in DMF (3 mL). TMS-acetylene (0.43 ml) was added followed by di-isopropylamine (395 uL), copper(I) iodide (27 mg) and triphenylphosphine (112 mg). The reaction was flushed with nitrogen. Palladium acetate (32 mg) was added and the reaction flushed again with nitrogen (×3) and was heated at 60° C. for 65 minutes. The reaction was cooled and diluted with ethyl acetate (20 mL). The solution was washed with water (3×10 mL) and with brine then dried and concentrated in vacuo. The residue was purified using preparative TLC eluting with 1:1 dichloromethane:cyclohexane to afford the title compound (413 mg 1.92 mmole). 1H-NMR (CDCl3, 500 MHz): δ 0.25 (s, 9H), 7.15 (t, J=60.2 Hz, 1H), 7.71 (s, 1H), 7.94 (s, 1H).

Provenance & Evidence