To a stirred, degassed mixture of 2-bromo-6-methylpyridine (3 g, 17 mmol), sodium carbonate (10.8 g, 100 mmol) and 4-carboxybenzeneboronic acid (2.3 g, 14 mmol) in DME (150 ml) and water (150 ml) under an argon atmosphere was added tetrakis(triphenylphosphine) palladium (0) (350 mg) and the mixture heated to reflux for 18 h. On cooling, ˜50% of the solvent was removed in vacuo and the residual aqueous solution was washed with EtOAc, then acidified to pH1 with concentrated HCl and washed with further EtOAc. The aqueous was then adjusted to pH 5 by addition of potassium carbonate causing formation of a white precipitate which was collected by filtration, washed with water and dried to give the title compound as a white solid (2.3 g). MS (ES): MH+ 212.
