4-Bromopyridinium chloride → 4-[2-[4-(Trifluoromethyl)phenyl]ethynyl]pyridine

Participants

Reaction Conditions

Reaction Steps

Under argon, a mixture of 1.20 g (6.17 mmol) of 4-bromopyridine hydrochloride, 1.57 g (9.26 mmol) of 1-ethynyl-4-(trifluoromethyl)benzene, 88 mg (0.46 mmol) of copper(I) iodide and 251 mg (0.31 mmol) of Pd(dppf)Cl2 in 10 ml of triethylamine is heated at 90° C. for 3 h. After concentration, the reaction mixture is taken up in 100 ml of ethyl acetate and washed with 2×100 ml of 1M HCl. The aqueous phase is adjusted to pH 10 using aqueous sodium hydroxide solution and extracted with 3×100 ml of chloroform. The combined organic phases are washed with saturated aqueous NaCl solution, dried over Na2SO4 and freed from the solvent under reduced pressure. This gives 380 mg (24%) of the desired product; log P(HCOOH): 2.86; 1H-NMR (DMSO-d6) δ: 8.66 (d, 2H), 7.84 (s, 4H), 7.58 (d, 2H)

Provenance & Evidence