Example 7 Synthesis of 2-bromo-7-iodofluorene: 2-bromofluorene (12.61 g, 50 mmol), acetic acid (125 mL), water (9 mL), concentrated sulfuric acid (4 mL), iodine (5.1 g, 20.1 mmol), and iodic acid (2.2 g, 12.5 mmol) were mixed and heated to react for 2 hr at 80-90 °C. After completion of the reaction, the mixture was cooled and filtered. The resulting solid was washed sequentially with acetic acid (100 mL) and water (500 mL) to afford the target product 2-bromo-7-iodofluorene 14.7 g in 79% yield and melting point 179-185 °C. The product was analyzed by mass spectrometry. The results of mass spectrometry analysis (m/z): 418 (M + diiodo), 370, 372 (M + iodobromo), 322, 324, 326 (M + dibromo).
