Potassium Iodide → 2,7-Dibromo-9,9-dibutyl-9H-fluorene

Participants

Reaction Conditions

Reaction Steps

A mixture of 12.0 g (37 mmol) of 2,7-dibromofluorene 2-7, 12 mL (111 mmol) of 1-bromobutane, 6.3 g (1 mmol) of potassium hydroxide, 0.9 g (6 mmol) of potassium iodide, 0.29 g (1 mmol) of 18-crown-6 and 120 mL of DMF was stirred and heated to 90° C. for overnight under N2. After cooling to room temperature, the solution was poured to cold water and extracted with dichloromethane (3×50 mL). The combined organic layer was washed with water, dried over anhydrous NaSO4, filtered and evaporated to dryness. The crude product was purified by silica gel column chromatography using petroleum ether as eluent affording the desired product as a white solid (12.9 g, 80%). Mp: 116.8-118.5° C. 1H NMR (400 MHz, CDCl3, δ) 7.53 (d, J=8.8 Hz, 2H), 7.46 (dd, J=7.2 Hz, J=2.2 Hz, 4H), 1.90-1.94 (m, 4H), 1.06-1.11 (m, 4H), 0.70 (t, J=7.4 Hz, 3H), 0.54-0.59 (m, 4H). 13C NMR (100 MHz, CDCl3, δ) 152.5, 139.1, 130.2, 126.2, 121.5, 121.2, 55.6, 40.1, 25.8, 22.9, 13.8. MS (FAB) m/z 436.1 (M+).

Provenance & Evidence