||Compound 4 was prepared according to the previous report [38c]. Under the protection of argon, 1,4-dibromobutane (23.9 mL, 200 mmol) and K2CO3 (22.1 g, 160 mmol) were mixed and refluxed in 500 mL of CH3CN in a three-neck flask. Compound 3 (3.96 g, 10.0 mmol) in 100 mL of CH3CN was injected slowly. After 2 days, the mixture was filtered and the filtrate was concentrated under vacuum. The residue was purified by column chromatography using petroleum ether:ethyl acetate = 30:1 to 20:1 as eluent to obtain compound 4 as a white solid powder (6.02 g, yield 64.3%). 1H NMR (600 MHz, CDCl3, 298 K) δ (ppm): 6.91 (d, J = 6 Hz, 8H), 6.61 (d, J = 6 Hz, 8H), 3.92 (t, J = 6 Hz, 8H), 3.47 (t, J = 6 Hz, 8H), 2.05 (m, 8H), 1.90 (m, 8H).
||With 18-crown-6 ether; potassium carbonate; In acetonitrile; at 70℃; for 12h;Inert atmosphere;
||Add 18-crown-6 (0.1 g) and potassium carbonate (1.92 g) to dissolve TPE-OH (0.5 g)In a solution of acetonitrile (25 ml), it was placed in a 70 C oil bath and stirred. Under a nitrogen atmosphere, 1,4-dibromobutane (6.0 g) was added dropwise, and the mixture was reacted for 12 hours. Filtration and evaporation of the filtrate gave a yellow solution. Purification by silica gel column chromatography gave TPE-Br, weighed 0.4 g, yield 35%
||With potassium carbonate; In acetone; for 24h;Reflux;
||To a mixture of DHTPE (0.4 g, 20 mmol) and potassium carbonate in acetone, 1,4-dibromobutane (3 ml) was added and the mixture was heated to reflux and stirred for 24 h. After filtration and concentration, the product was isolated and purified by silica gel chromatography using chloroform/hexane (1:1 v/v) as eluent. The product 1,1,2,2-tetrakis(4-(4-bromobutoxy)phenyl)ethane (BrC4-TPE-C4Br) was obtained as white powder in 21% yield. Characterization data of BrC4-TPE-C4Br: 1H NMR (300 MHz, CDCl3), δ (ppm): 7.08-6.99 (m, 8H), 6.81-6.60 (m, 8H), 3.94-6.86 (m, 8H), 3.49-3.42 (m, 8H), 2.07-2.00 (m, 8H), 1.92-1.85 (m, 8H). 13C NMR (75 MHz, CDCl3), δ (ppm): 157.2, 136.6, 132.7, 129.5, 114.3, 66.9, 33.9, 29.9, 28.3. MS (FAB), m/e: 937.0 ([M]+, calcd. 936.4).