Yield:188200-93-3 98%

Reaction Conditions:

with potassium iodide;potassium hydroxide in dimethyl sulfoxide at 20; for 24 h;Inert atmosphere;

Steps:

2,7-dibromo-9,9-bis(2-ethylhexyl)-9H-fluorene (5b)

2,7-dibromofluorene 4b (3.24 g, 10.0 mmol) and KOH (6.605 g, 100 mmol) was added to a flask. Then DMSO (20 mL) and KI (0.166 g, 1.0 mmol) were added to the mixture at rt. After 3-(bromomethyl)heptane C₈H₁₇Br (7.880 g, 40 mmol, dissolved in 5 mL DMSO) was added dropwise at rt under N₂, the reaction mixture was stirred at rt for 24 h. Then the reaction mixture was poured into ice (300 g) and extracted with AcOEt (2 * 200 mL). The organic extracts were washed with Na₂S₂O₃ (aq.), dried over anhydrous MgSO₄ and concentrated under vacuum. The residue was purified by flash chromatography (silica gel, petroleum ethter) to afford the crude product. Then the crude product was purified by flash chromatography (silica gel, petroleum ethter) to afford a pure title compound 5b. Yield 98.0%; Colorless sticky oil; ¹H NMR (400 MHz, CDCl₃): δ 0.54-0.88 (m, 30H), 1.89-1.98 (m, 4H), 7.41-7.46 (m, 2H), 7.48-7.53 (m, 4H). ¹³C NMR (100 MHz, CDCl₃): δ 10.65, 14.37, 23.06, 27.40, 28.35, 33.92, 35.01, 44.65, 55.69, 121.32, 127.72, 130.42, 139.50, 152.77.

References:

Huang, Yi-Bing;Cui, Yu;Zeng, Liu-Fang;Shen, You-Yu;Feng, Ling-Zhu;Shi, Xue-Feng;Ye, Li-Yi;Yin, Ying-Wu;Tu, Song [Journal of Fluorine Chemistry,2015,vol. 178,p. 195 - 201]