Potassium Fluoride → 6'-Chloro-2,5'-difluoro(3,4'-bipyridin)-3'-amine

Beteiligte Stoffe

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Reaktionsschritte

A degassed mixture of 6-chloro-5-fluoro-4-iodopyridin-3-ylamine (98.7 g, 362 mmol), 2-fluoropyridine 3-boronic acid (68.3 g, 485 mmol), bis[di-tert-butyl(4-dimethylaminophenyl)phosphine]dichloropalladium(II) (7.7 g, 10.9 mmol) and potassium fluoride (63 g, 1.09 mol) in a mixture of acetonitrile (900 mL) and water (275 mL) was heated at 90° C. for 2 hours. The reaction mixture was allowed to cool to ambient temperature and filtered through Celite© and washed through with ethyl acetate. The filtrate was diluted with ethyl acetate and the organic layer collected, dried (Na2SO4), filtered and concentrated in-vacuo to afford a residue. The resultant residue was triturated with diethyl ether to afford the title compound as a grey solid (65.8 g, 75%). The trituration liquors were concentrated and purified by flash chromatography (silica: dichloromethane to 20% ethyl acetate/dichloromethane) to afford, after trituration with ether, an additional batch of the title compound as a grey solid (9.7 g, 11%). Total yield=75.5 g, 86%. 1H NMR (400 MHz, CDCl3): 8.39 (ddd, J=4.9, 2.0, 1.1 Hz, 1H), 7.86-7.84 (m, 2H), 7.39 (ddd, J=7.4, 4.9, 1.9 Hz, 1H).

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