General method: m-Bromobenzoic acid (1.0 eq.) was dissolved in a solvent mixture of water and dioxane (1:1). 3-Hydroxyphenylboronic acid (1.5 eq.) and potassium phosphate (5.0 eq.) were added. The solution was degassed by vacuum/argon cycles (10 times) and further degassed (5 times) before addition of PdCl2(PPh3)2 (10 mol%). The resulting mixture was stirred at 95 °C and under argon atmosphere for 16-20 hours. Upon completion of the reaction, the reaction mixture was filtered through diatomaceous earth, diluted with water (~30 mL) and then washed with chloroform (3 x 30 mL). The aqueous phase was concentrated under reduced pressure and subsequently purified by a C18 pre-column and further purified on a 10 g or 60 g C18 column using a gradient elution with aqueous acetonitrile (10-100%) to give 3'-hydroxybiphenyl-3-carboxylic acid.
