4,4,4-Trifluoro-1-(2-furanyl)-1,3-butanedione → 3,5-dichloro-2-(5-(furan-2-yl)-3-(trifluoromethyl)-1H-pyrazol-1-yl)pyridine

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Reaction Steps

To a 250 mL flask, 4,4,4-trifluoro-1-(furan-2-yl)butane-1,3-dione (5.50 g, 26.7 mmol), 3,5-dichloro-2-hydrazinylpyridine (4.75 g, 26.7 mmol) and glacial acetic acid (100 mL) were added. The reaction mixture was heated to reflux. When the reaction completed, the reaction mixture was concentrated by rotary evaporator. Then ethyl acetate (300 mL) and water (150 mL) was added, the organic extracts were washed with saturated sodium bicarbonate solution (150 mL) and brine (150 mL) in sequence, dried over anhydrous magnesium sulfate and concentrated by rotary evaporator. The residue was purified by silica gel column chromatography (Fluent: ethyl acetate/petroleum ether=1/5) to give the product (5.66 g) as a yellow oil in 61% yield. 1H NMR (300 MHz, CDCl3): 8.514 (d, 1H), 7.974 (d, 1H), 7.362 (d, 1H), 6.917 (s, 1H), 6.388 (dd, 1H), 6.148 (d, 1H).

Provenance & Evidence