5-Bromo-2-cyclopropylpyrimidine (12A, 0.8 g, 4.02 mmol) and pinacol ester of bisboronic acid (1.16 g, 4.82 mmol) were reacted in the presence of Pd(dppf)Cl2 (147 mg, 0.20 mmol) and KOAc (592 mg, 6.03 mmol) in dioxane (20 mL). The reaction mixture was heated to 90 °C and kept at this temperature overnight. After completion of the reaction, the mixture was cooled and subsequently concentrated. Purification of the residue by silica gel column chromatography (eluent ratio from 1/50 to 1/10 ethyl acetate/petroleum ether) afforded the target product 2-cyclopropyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrimidine (12B, 0.38 g, 39% yield) as a yellow solid.ESI m/z 247.1 [M + H].
