Stannane, [2,2'-bithiophen]-5-yltributyl- → 4,7-di([2,2'-bithiophen]-5-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole

Participants

Reaction Conditions

Reaction Steps

A mixture of Intermediate A (704 mg, 2.0 mmol), 50% [2,2′-bithiophen]-5-yltributylstannane (2.50 g, 5.5 mmol), bis(triphenylphosphine)palladium(II) dichloride (200 mg, 0.28 mmol), and anhydrous dimethylformamide (20 mL) was stirred under argon and heated at 90° C. for 1 hour. TLC indicated no starting material left. Heating at 90° C. was continued for an additional 2 hours. The volatiles were removed under reduced pressure, and the crude product was purified by column chromatography using silica gel and dichloromethane/ethyl acetate (9:1) as an eluent. The obtained product was washed with ethyl acetate (50 mL) and dried in a vacuum oven to give 4,7-di([2,2′-bithiophen]-5-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole (Example 9) as red crystals, 150 mg (14%). 1H NMR (400 MHz, CDCl3): δ 8.88 (m, 2H, pyridine), 8.40 (m, 2H, pyridine), 8.09 (d, J=4.0 Hz, 2H, thiophene), 7.65 (s, 2H, benzotriazole), 7.31 (dd, J=3.7 and 1.1 Hz, 2H, thiophene), 7.29 (m, 2H, thiophene), 7.27 (m, 2H, thiophene), 7.08 (dd, J=5.2 and 3.7 Hz, 2H, thiophene). UV-vis spectrum (dichloromethane): λmax=478 nm. Fluorimetry (dichloromethane): λmax=584 nm.

Provenance & Evidence