Diisopropylamine → 1-(2,2,2-Trifluoroethyl)-4-((trimethylsilyl)ethynyl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

4-Iodo-1-(2,2,2-trifluoroethyl)-1H-pyrazole (Preparation 146, 970 mg, 3.51 mmol) was dissolved in DMF (4.9 mL) and TMS-acetylene (0.7 ml, 486 mg, 4.96 mmol) was added; followed by di-isopropylamine (0.65 mL), copper(I) iodide (44 mg) and triphenylphosphine (184 mg). The reaction was flushed with nitrogen. Palladium acetate (52.5 mg) was added and the reaction flushed again with nitrogen (×3) before heating at 60° C. for 60 minutes. The reaction was cooled and added to water (50 mL). The product was extracted with ether (3×25 mL). The combined organic layers were washed with water (3×20 mL) and brine, then dried (MgSO4) and concentrated in vacuo. The residue was purified using silica gel column chromatography eluting with 1:2 ethyl acetate:cyclohexane to afford the title compound (844 mg, 97%). 1H-NMR (CDCl3, 500 MHz): δ 0.24 (s, 9H), 4.68 (q, J=8.20, 2H), 7.66 (s, 1H), 7.67 (s, 1H).

Provenance & Evidence