Acetone → 4,7-bis(4-phenoxyphenyl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole

Participants

Reaction Conditions

Reaction Steps

A mixture of Intermediate A (704 mg, 2 mmol), 4-phenoxyphenylboronic acid (2.14 g, 10 mmol), tetrakis(triphenylphosphine)palladium (0) (0.50 g, 0.43 mmol), sodium carbonate (2.12 g, 20 mmol) in water (8 mL), n-butanol (20 mL), toluene (20 mL), and acetone (5 mL) is heated under argon at 110° C. for 16 hours. The reaction mixture is poured into water (100 mL), diluted with dichloromethane (100 mL), stirred for 1 hour, and the dichloromethane layer is separated. The aqueous phase is washed with dichloromethane (100 mL). Both dichloromethane solutions are combined, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The crude product is purified by column chromatography (silica gel, dichloromethane/ethyl acetate 9:1) and recrystallization from ethyl acetate to give 4,7-bis(4-phenoxyphenyl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole (Example 2), yellow-green crystals, 865 mg (81%). 1H NMR (400 MHz, CDCl3): δ 8.82 (m, 2H, pyridine), 8.35 (m, 2H, pyridine), 8.12 (d, J=8.7 Hz, 4H, p-phenylene), 7.69 (s, 2H, benzotriazole), 7.40 (m, 4H, Ph), 7.18 (d, J=8.7 Hz, 4H, p-phenylene), 7.17 (m, 2H, Ph), 7.13 (m, 4H, Ph). UV-vis spectrum (dichloromethane): λmax=386 nm. Fluorimetry (dichloromethane): λmax=499 nm.

Provenance & Evidence