Sodium Carbonate → 1,4-bis(7-bromo-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazol-4-yl)benzene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of Intermediate A (90%, 2.40 g, 6.14 mmol), 1,4-benzenediboronic acid (248 mg, 1.5 mmol), sodium carbonate (530 g, 5 mmol) in water (4 mL), tetrakis(triphenylphosphine)palladium (0) (500 mg, 0.43 mmol), n-butanol (20 mL), and toluene (20 mL) was stirred and heated under argon at 110° C. for 68 hours. The reaction mixture was poured into water (300 mL), treated with 5N NaOH (50 mL), stirred for 1 hour, and extracted with dichloromethane (3×200 mL, low solubility in dichloromethane). The volatiles were removed under reduced pressure, and the residue was chromatographed (silica gel, chloroform/tetrahydrofuran 9:1). The obtained product was triturated with ethyl acetate (30 mL), filtered off and dried in a vacuum oven to give 1,4-bis(7-bromo-2-(pyridin-4-yl)-2H-benzo[d][1,2,3]triazol-4-yl)benzene (Intermediate G), yellow crystals, 610 mg (purity 80%, yield 65%). 1H NMR (400 MHz, CDCl3): δ 8.86 (m, 4H, pyridine), 8.39 (m, 4H, pyridine), 8.26 (s, 4H, benzotriazole), 7.79 (d, J=7.7 Hz, 2H, benzene), 7.62 (d, J=7.7 Hz, 2H, benzene).

Herkunft & Nachweise