The general procedure for the synthesis of (4-(pyridin-4-yl)phenyl)boronic acid from 4-(4-bromophenyl)pyridine and triisopropyl borate was as follows: 23.4 g of 4-(4-bromophenyl)pyridine, 22.6 g of triisopropyl borate, and 350 mL of tetrahydrofuran were added to a 500 mL three-necked flask. The reaction mixture was cooled to -78 °C (using liquid nitrogen for cooling) and 0.12 mol of butyllithium was slowly added dropwise. After the dropwise addition was completed, the reaction mixture was kept at -78 °C for 1 hour. Subsequently, the reaction was quenched with saturated ammonium chloride solution and the pH was adjusted to 6 with dilute hydrochloric acid. the reaction mixture was filtered and the solid product was collected. The filter cake was washed with ethyl acetate to give a final product of 19.7 g of 4-(4-phenylboronic acid)pyridine.
