Triethylamine → 3-Bromo-5-(prop-1-yn-1-yl)pyridine

Participants

Reaction Steps

3,5-Dibromopyridine (30 g, 127 mmol), copper(I) iodide (7.24 g, 38.0 mmol) and tetrakis(triphenylphosphine)palladium(0) (4.39 g, 3.80 mmol) were mixed in toluene (120 mL) under nitrogen atmosphere. 1-(Trimethylsilyl)-1-propyne (26.36 mL, 164.5 mmol), triethylamine (53.0 mL, 380 mmol) and tetra-n-butylammonium fluoride (12.66 mL, 12.66 mmol) were added. The mixture was heated to reflux and stirred under nitrogen overnight. Water (100 mL) was added to the reaction mixture was filtered and the phases separated. The organic phase was washed with 1 M HCl aq. (100 mL). The organic phase was concentrated and dissolved in MeOH (200 mL), filtered and concentrated. The mixture was dissolved in DCM and evaporated with silica gel to dryness, and then transferred to a silica gel column (300 g). The product was eluted with a gradient of EtOAc (0-5%) in heptane. The fractions containing the pure product was combined and evaporated to give the title compound (16.39 g, 66% yield): 1H NMR (500 MHz, CDCl3) δ ppm 2.08 (s, 3 H), 7.82 (t, 1 H), 8.52 (d, 1 H), 8.55 (d, 1 H); MS (APCI+) m/z 197.0 [M+H]|.

Provenance & Evidence