To a stirred solution of 5-bromo-4-cyclopropyl-6-methoxy-pyrimidine in toluene and tetrahydrofuran was added triisopropyl borate at room temperature under nitrogen atmosphere. The mixture was cooled down to -70 °C. To the above mixture was slowly added n-butyl lithium dropwise at -70 °C. The resulting mixture was stirred for additional 15 min at -70 °C. The reaction was quenched with 1N HCl at -70 °C. The mixture was purified by RP-Flash, the collected fractions were combined and concentrated under reduced pressure to afford (4-Cyclopropyl-6-methoxypyrimidin-5-yl)boronic acid (3.5 g, 18.04 mmol, 94% yield) as a white solid.
