5-Bromo-2-iodopyrimidine (5.00 g, 17.6 mmol) and tetrakis(triphenylphosphine)palladium(0) (5.70 mg, 5.00 mmol) were dissolved in tetrahydrofuran (80 mL). Cyclopropylmagnesium bromide (0.5 mol/L in THF, 70.0 mL, 35.0 mmol) was added slowly and dropwise under nitrogen protection. The reaction mixture was stirred at 70 °C for 2 hours. After completion of the reaction, the reaction solution was diluted with water (20 mL) and subsequently extracted with ethyl acetate (50 mL x 3). The organic phases were combined and dried over anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure and the resulting crude product was purified by silica gel column chromatography (petroleum ether/ethyl acetate = 50:1) to afford 5-bromo-2-cyclopropylpyrimidine (1.20 g, 35% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 8.51 (s, 2H), 2.17-2.11 (m, 1H), 1.04-1.02 (m, 4H). Mass spectrum (ESI) showed m/z 199 ([M + H]+).
