Oxygen → (E)-5-Bromo-2-fluoro-3-(3-fluorostyryl)pyridine

Participants

Reaction Steps

To a 100 mL round bottom flask was added 1-fluoro-3-vinylbenzene (1.2 g, 9.82 mmol), 5-bromo-2-fluoropyridin-3-ylboronic acid (3.24 g, 14.74 mmol), and Sodium carbonate (2.60 g, 24.56 mmol) in dimethylformamide (32.7 ml). The reaction vessel was sealed and purged with oxygen via a balloon for 5 min. After purging with oxygen, palladium (II) acetate (0.221 g, 0.982 mmol) added and immediately purged with oxygen for (15 min.). The reaction was kept under a blanket of oxygen and left to stir overnight at room temperature. The reaction was then quenched with water and extracted with ethylacetate (3×). The organic layer was separated, washed with brine, dried over sodium sulfate, and concentrated in vacuo. The crude oil was loaded onto 90 g silica gel cartridge and the product was eluted with 5% DCM/Hex. The product fractions were collected and concentrated to afford 0.712 g (22%) as an off white crystalline solid. 1H-NMR (CDCl3, 400 MHz) δ 8.16 (s, 1H), 8.09 (dd, J=8.5, 2.3, 1H), 7.42-7.29 (m, 2H), 7.27-7.17 (m, 2H), 7.11-7.01 (m, 2H), LC/Mass spec. (Analytical HPLC method 2): RT=2.88 min. Mass=296.01 (MH)+.

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