Reaktion #1137870

Reaktionsgleichung

Intermediate A

4,7-dibromo-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole

tributyl(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)stannane

→

4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe volatiles were removed under reduced pressure
2. 2
   Sonstigethe crude product was purified by column chromatography (silica gel, dichloromethane/ethyl acetate 75:25)
3. 3
   Waschenwashing with ethanol (20 mL)

Vorschrift

A mixture of Intermediate A (0.71 g, 2.0 mmol), tributyl(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)stannane (2.27 g, 5.0 mmol), bis(triphenylphosphine)palladium(II) dichloride (0.20 g, 0.28 mmol), and anhydrous dimethylformamide (20 mL) was stirred under argon and heated at 100° C. for 4 hours. The volatiles were removed under reduced pressure, and the crude product was purified by column chromatography (silica gel, dichloromethane/ethyl acetate 75:25) and washing with ethanol (20 mL) to give 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazole (Example 10) as orange crystals, 0.47 g (49%). 1H NMR (400 MHz, CDCl3): δ 8.82 (m, 2H, pyridine), 8.37 (m, 2H, pyridine), 8.20 (s, 2H, benzotriazole), 6.53 (s, 2H, thiophene), 4.39 (s, 4H, OCH2CH2O), 4.30 (s, 4H, OCH2CH2O). UV-vis spectrum (dichloromethane): λmax=448 nm. Fluorimetry (dichloromethane): λmax=559 nm.

Quelle