Synthesis
The general procedure for the synthesis of (3-fluoro-4'-propyl-[1,1'-biphenyl]-4-yl)boronic acid from triisopropyl borate and 3-fluoro-4-propylbiphenyl was as follows: 3-fluoro-4-propylbiphenyl (22.2 g, 0.104 mol) and 150 mL of tetrahydrofuran were added to a reaction vessel equipped with a dropping funnel. The mixture was heated to 70 °C, followed by the slow dropwise addition of 124 mL of sec-butyllithium solution (1.0 mol/L). The reaction mixture was stirred at 70 °C for 2 h. Triisopropyl borate (25.3 g, 0.135 mol) was added dropwise. After continued stirring for 2 hours, the reaction mixture was cooled to 0 °C and 300 mL of 10% hydrochloric acid solution was added slowly and dropwise. After stirring for 1 h at room temperature, aqueous washing was performed to remove the salts. Eventually, by concentration and drying treatment, (3-fluoro-4'-propyl-[1,1'-biphenyl]-4-yl)boronic acid (25.7 g, 0.0995 mol) was obtained.
