Reaction Steps
A mixture of Intermediate E (90%, 488 mg, 0.50 mmol), dibenzo[b,d]thiophen-4-ylboronic acid (456 mg, 2.00 mmol), sodium carbonate (530 mg, 5 mmol) in water (4 mL), tetrakis(triphenylphosphine)palladium (0) (240 mg, 0.20 mmol), n-butanol (20 mL), and toluene (20 mL) was stirred and heated under argon at 110° C. for 48 hours. The reaction mixture was poured into water (200 mL), treated with 5N NaOH (25 mL), stirred for 1 hour, and extracted with dichloromethane (3×200 mL). The volatiles were removed under reduced pressure, and the residue was chromatographed (silica gel, dichloromethane/tetrahydrofuran 9:1). The obtained product was recrystallized from acetone to give 2,7-bis(7-(dibenzo[b,d]thiophen-1-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazol-4-yl)-9,9-dihexyl-9H-fluorene (Example 25), yellow-green crystals, 465 mg (85%). 1H NMR (400 MHz, CDCl3): δ 8.80 (m, 4H, pyridine), 8.33 (m, 4H, pyridine), 8.30 (dd, J=7.7 Hz, 2H, dibenzothiophene), 8.27 (s, 2H, fluorene), 8.25 (m, 2H, dibenzothiophene), 8.22 (dd, J=8.1 and 2.4 Hz, 2H, fluorene), 8.10 (d, J=7.7 Hz, 2H, benzotriazole), 8.04 (dd, J=7.3 and 0.7 Hz, 2H, dibenzothiophene), 8.01 (d, J=8.1 Hz, 2H, fluorene) 7.92 (d, J=7.4 Hz, 2H, benzotriazole), 7.86 (m, 2H, dibenzothiophene), 7.51 (m, 4H, dibenzothiophene), 2.23 (m, 4H, hexyl), 1.21 (m, 4H, hexyl), 1.15 (m, 8H, hexyl), 0.97 (m, 4H, hexyl), 0.75 (t, J=7.0 Hz, 6H, hexyl). UV-vis spectrum (dichloromethane): λmax=411 nm. Fluorimetry (dichloromethane): λmax=496 nm.
