General procedure for the synthesis of 3-(2-pyridyl)benzoic acid from 2-bromopyridine and 3-carboxyphenylboronic acid: to a mixed solution of acetonitrile (40 mL) and water (40 mL) containing 3-carboxyphenylboronic acid (1.66 g, 10 mmol) and 2-bromopyridine (1.72 g, 11 mmol), potassium carbonate (5.5 g, 40 mmol) and bis(triphenylphosphine) palladium(II) chloride (400 mg, 0.37 mmol). The reaction mixture was degassed and displaced three times with nitrogen. Subsequently, the mixture was stirred and reacted at 100 °C for 24 hours. After completion of the reaction, the reaction suspension was filtered while hot and the filtrate was concentrated to half of the original volume. The concentrated aqueous phase was washed with dichloromethane, and then the pH of the aqueous phase was adjusted to 3 with 1 M hydrochloric acid.The precipitated solid was collected by filtration, washed with water, and finally dried under vacuum to give 1.69 g of the white solid product 3-(2-pyridyl)benzoic acid in 85% yield. The product was detected by LC-MS (ESI), m/z: 200 (M + 1)+.
