4-Bromo-3-methylbenzoic acid (1 g, 4.65 mmol) and pinacol ester of bisboronic acid (1.77 g, 6.97 mmol) were used as raw materials in the [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride complex with dichloromethane (1:1) (379 mg, 0.46 mmol) and potassium acetate (2.3 g, 23.2 mmol) in the in N,N-dimethylformamide (23 mL) in the presence of potassium acetate (2.3 g, 23.2 mmol) were heated in a microwave reaction system (Biotage Initiator sixty) at 120 °C for 15 min. Upon completion of the reaction, the solvent was removed by evaporation under reduced pressure and the residue was suspended in a 2N HCl/ethyl acetate mixture (40 mL, 1:1 v/v). Filtered through sintered glass, the aqueous phase was extracted with ethyl acetate. The organic layers were combined, washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by fast column chromatography on silica gel, using hexane/ethyl acetate (7:3) as eluent, to afford 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (1.1 g, yield 90%) as a white solid.1H-NMR (CDCl3) δ: 1.36 (s, 12H), 2.59 (s, 3H), 7.85-7.90 (m, 3H).
