Cesium carbonate → 1-(2-Cyanophenyl)-5-furyl-3-trifluoromethylpyrazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 2-fluorobenzonitrile (0.605 g, 5 mmol) and 5-furyl-3-trifluoromethyl-3-hydroxypyrazoline (1.1 g, 5 mmol) in DMF (10 mL) was added Cs2CO3 (1.63 g, 5 mmol), and the resulting mixture was stirred at 110° C. for 16 hours. The mixture was diluted with EtOAc, washed with brine (×5), dried over MgSO4, and purified by column chromatography with a gradient solvent (hexane to ethyl acetate) to give 1-(2-cyanophenyl)-5-furyl-3-trifluoromethylpyrazole and 1-(2-cyanophenyl)-3-furyl-5-trifluoromethylpyrazole (1.27 g, 83.8%) in a ratio of 95 to 5. 1H NMR (CDCl3) δ7.82 (dd, J=7.7 Hz, J=1.5 Hz, 1H), 7.77 (dd, J=7.7 Hz, J=1.5 Hz, 1H), 7.66 (td, J=7.7 Hz, J=1.1 Hz, 1H), 7.61 (d, J=7.7 Hz, 1H), 7.39 (d, J=1.4 Hz, 1H), 6.96 (s, 1H), 6.37 (dd, J=3.3 Hz, J=1.4 Hz, 1H), 6.04 (d, J=3.3 Hz, 1H); 19F NMR (CDCl3): δ−62.98; ESMS(+): 304 (M+H, 100).

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