Toluene → 4,7-di(benzofuran-2-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole

Participants

Reaction Conditions

Reaction Steps

A mixture of Intermediate A (1.41 g, 4 mmol), benzofuran-2-ylboronic acid (1.60 g, 9.8 mmol), tetrakis(triphenylphosphine)palladium (0) (0.50 g, 0.43 mmol), sodium carbonate (2.12 g, 20 mmol) in water (10 mL), n-butanol (25 mL), and toluene (25 mL) is heated under argon at 110° C. for 3 days. The reaction mixture is poured into water (200 mL), diluted with dichloromethane (100 mL), and stirred for 1 hour. The solid is filtered off, washed with water (50 mL) followed by dichloromethane (20 mL) and dried to give 4,7-di(benzofuran-2-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole (Example 3), yellow crystals, 745 mg (43%). 1H NMR (400 MHz, CDCl3): δ 8.92 (m, 2H, pyridine), 8.47 (m, 2H, pyridine), 8.16 (s, 2H, benzotriazole), 8.01 (s, 2H, benzofuran), 7.74 (d, J=7.4 Hz, 2H, benzofuran), 7.59 (d, J=7.4 Hz, 2H, benzofuran), 7.37 (td, J=7.7 and 1.1 Hz, 2H, benzofuran), 7.30 (td, J=7.5 and 1.1 Hz, 2H, benzofuran). UV-vis spectrum (dichloromethane): λmax=436 nm. Fluorimetry (dichloromethane): λmax=481 nm.

Provenance & Evidence