4, 2-Dibromoanthracene Analysis

2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)anthracene (D1)
2,6‐Dibromoanthracene (2.00 g, 6.46 mmol) 1, bis(pinacolato)diboron (4.16 g, 16.16 mmol), PdCl2 (dppf) (0.164 g, 26.38 mmol), and potassium acetate (KOAc) (2.5 g, 26.38 mmol) were added to a Schlenk flask and kept under vacuum for 10 min. Under an argon flow, anhydrous 1, 4‐dioxane (40 mL) was added to the resulting mixture, and the mixture was stirred at room temperature for 30 min, heated at 80 °C, and further stirred for 20 h. The resulting mixture was quenched by adding water and extracted with ethyl acetate (100 mL). The combined organic layers were washed with brine, dried over anhydrous Na2SO4, and filtered. After removing the solvent, a dark red solid was obtained, which was purified by silica gel chromatography by using 5% ethyl acetate in hexane as eluent to afford the title compound as yellow solid (2.0 g, 71%). 1H NMR (400 MHz, CDCl3): δ 8.55 (s, 2H), 8.44 (s, 2H), 8.01 (dd, 2H), 7.76 (dd, 2H), 1.39 (s, 24H). 2,6-dibromo-9,10-bis(2-ethylhexyloxy)-9,10-dihyroanthracene (1) 2,6-dibromo-9,10-anthraquinone (2.0 g, 5.4 mmol), tetrabutylammonium bromide (1.6 g, 4.9 mmol), Na2S2O4 (1.9 g, 11 mmol), and water (50 mL) were added under nitrogen flow. The mixture was stirred for 10 min, and CH2Cl2 (60 mL) was added. When the solution turned to a green color, 20% NaOH (aq) was added and stirred for 2 h. To this solution was added 2-ethylhexyl bromide (8.8 g, 54 mmol), and the mixture was stirred for 8 h. The product was purified on a silica column using hexane/CH2Cl2 (5:1) as the eluent. Yield: 2.0 g (70%). Mp: 127–129 °C. 1H NMR (400 MHz, CDCl3): δ 8.36 (d, 2H), 8.21 (s, 2H), 7.64 (dd, 2H), 4.11 (t, 4H), 1.69 (m, 4H), 1.28 (m, 12H), 0.91 (t, 6H). 2,2′-(9,10-bis(2-ethylhexyloxy)-9,10-dihydroanthracene-2,6-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (s) Bu-Li was added to a solution of 2,6-dibromo-9,10-bis(2-ethylhexyloxy)-9,10-dihyroanthracene (1.4 g, 2.4 mmol) in THF at −78 °C. …show more content…
After stirring for 1 h, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was added to the solution. The reaction mixture was warmed to room temperature and stirred for 24 h. The resulting mixture was quenched by adding water and extracted with methylene chloride. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, and filtered. After removing the solvent, the crude product was purified by silica gel chromatography by using hexane/CH2Cl2 (4:1) as the eluent to afford the title compound as yellow solid (1.23 g, 76%). 1H NMR (400 MHz, CDCl3): δ 8.55 (s, 2H), 8.44 (s, 2H), 8.01 (dd, 2H), 7.76 (dd, 2H), 1.39 (s, 24H). 4,7-Dibromo-5,6-bis(octyloxy)-benzo-2,1,3-thiadiazole (2a) A solution of bromine (0.15 mL, 0.48 g, 3.0 mmol) in 5 mL 40% hydrobromic acid was added dropwise to a mixture of 5,6-Bis(octyloxy)-benzo-2,1,3-thiadiazole (0.39 g, 1.0 mmol) in 10 mL 40% hydrobromic acid at room temperature. After being refluxed at 120 °C for 6 h, the excess bromine was completely neutralized by saturated NaHSO3 solution. Then, the reaction mixture was extracted with CH2Cl2 (3 × 50 mL), and the combined organic layers were dried over anhydrous Na2SO4. The organic solvent was evaporated under reduced pressure, and the crude product was purified by silica column chromatography eluting with petroleum ether/ethyl acetate (v:v, 20:1) to afford compound 6 as a white solid (0.50 g, 90%). M.p.: 44–45 °C; 1H-NMR (400 MHz, CDCl3, ppm): δ 4.16 (t, J = 6.6 Hz, 4H), 1.92–1.85 (m, 4H), 1.58–1.50 (m, 4H), 1.41–1.30 (m, 16H), 0.90 (t, J = 6.6 Hz, 6H). 5,6-Bis(octyloxy)-4,7-di(thiophene-2-yl)-benzo-2,1,3-thiadiazole (3a) A solution of n-BuLi (2.5 M in hexane, 3.2 mL, 8.0 mmol) was added dropwise to a mixture of thiophene (0.48 mL, 0.50 g, 6.0 mmol) in 30 mL dry THF under nitrogen atmosphere at −78 °C, and the reaction mixture was stirred at that temperature for 1 …show more content…
The resulting mixture was stirred in the dark for 3 days at room temperature and then poured into aqueous NaOH solution (10 g in 200 mL). The aqueous phase was extracted with CH2Cl2; the combined organic extracts were washed with brine and concentrated under reduced pressure to afford a crude solid that was purified by column chromatography [SiO2, hexane/CH2Cl2, 9:1 (v/v)] to afford a white solid (2.2 g, 79%). 1H NMR (400 MHz, CDCl3): δ 4.13 (t, J = 9 Hz, 4H), 1.89–1.80 (m, 4H), 1.53–1.29 (m, 20H), 0.88 (t, J = 6.6 Hz,