3-Fluoro-4-(tributylstannyl)pyridine → 3''-Fluoro-5'-nitro-3,2':3',4''-terpyridin-6'-amine

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Reaction Steps

An oven dried resealable Schlenk tube was charged with 3-bromo-5-nitro-2,3′-bipyridin-6-amine (4.51 g, 15.3 mmol), 3-fluoro-4-(tributylstannyl)pyridine (11.8 g, 30.6 mmol) and dimethylformamide (150 mL). The Schienk tube was subjected to three cycles of evacuation-backfilling with argon, and bis(triphenylphosphino)-palladium (II) chloride (1.1 g, 1.53 mmol) and copper (I) iodide (291 mg, 1.53 mmol) were added. After three new cycles of evacuation-backfilling with argon, the Schlenk tube was capped and placed in a 160° C. oil bath. After 3 h, the solvent was evaporated and the crude residue was treated with 2N hydrogen chloride (130 mL) aqueous solution for 45 minutes. The aqueous solution was washed with ethyl acetate and then neutralised with 6N sodium hydroxide aqueous solution. The solution was extracted with ethyl acetate, dried (MgSO4) and evaporated. The residue was purified by silica gel flash chromatography (95:5 dichloromethane/methanol) to give the title compound (2.39 g, 51%) as a solid.

Provenance & Evidence