To 5.1 g of the resulting 4′-(4-bromophenyl)-6-(5H-pyrido[4,3-b]indol-5-yl)-[2,2′;6′,2″]terpyridine were added 1.1 g of phenylboronic acid, 0.5 g of tetrakis(triphenylphosphine)palladium, 23 mL of a 2 M aqueous potassium carbonate solution, 72 mL of toluene, and 18 mL of ethanol, followed by heating with reflux while stirring for 5.5 hours. After cooling to room temperature, a precipitate was collected by filtration. To the precipitate, 200 mL of chloroform was added and insoluble matter was removed by filtration. The filtrate was concentrated under a reduced pressure to obtain a concentrate. The concentrate was dissolved in chloroform and subjected to adsorptive purification with NH silica gel. Thereafter, the filtrate was concentrated under a reduced pressure to obtain a crude product. The crude product was washed with methanol to obtain 2.9 g (yield, 57%) of 4′-(biphenyl-4-yl)-6-(5H-pyrido[4,3-b]indol-5-yl)-[2,2′;6′,2″]terpyridine (Compound 133) as a white powder.
