Triethylamine → 3-[5-(5-Fluoro-pyridin-3-ylethynyl)-pyridin-2-yl]-5,5-dimethyl-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

5,5-Dimethyl-3-(5-trimethylsilanylethynyl-pyridin-2-yl)-oxazolidin-2-one (Example 29, step 1) (100 mg, 0.35 mmol) was dissolved in THF (3 ml). 3-Fluoro-5-iodopyridine (100 mg, 0.45 mmol, 1.3 equiv.), Et3N (145 μl, 1.04 mmol, 3 equiv.), Bis-(triphenylphosphine)-palladium(II)dichloride (10 mg, 14 μmol, 0.05 equiv.), triphenylphosphine (11 mg, 17 μmol, 0.05 equiv.), triphenylphosphine (3 mg, 10 μmol, 0.03 equiv.) and copper(I) iodide (1 mg, 3.5 mmol, 0.01 equiv.) were added under nitrogen and the mixture was heated to 60° C. TBAF 1M in THF (520 μl, 0.52 mmol, 1.5 equiv.) was added dropwise in 20 minutes at 60° C. The reaction mixture was stirred for 3 hours at 60° C. Sat. NaHCO3 solution was added and the mixture was extracted with dichloromethane. The organic extracts were dried with sodium sulfate, filtered and evaporated. The crude product was purified by flash chromatography on silica gel (dichloromethane/methanol gradient 100:0 to 90:10). The desired 3-[5-(5-fluoro-pyridin-3-ylethynyl)-pyridin-2-yl]-5,5-dimethyl-oxazolidin-2-one was obtained as a white solid (55 mg, 51% yield), MS: m/e=312.3 (M+H+).

Provenance & Evidence