Dimethylformamide → HCID 53954290, compound

Participants

Reaction Steps

To 13.70 mL (146.95 mmol) of phosphorus oxychloride at 0° C. was added 13.92 mL (179.77 mmol) of anhydrous N,N-dimethylformamide dropwise. The resulting solution was stirred for 15 min at room temperature. Then, 10.00 g (48.98 mmol) of [4-(trifluoromethyl)phenyl]acetic acid in 24 mL of anhydrous N,N-dimethylformamide was added dropwise. The resulting mixture was stirred for 19 h at 70° C., and then poured onto ice. Following neutralization with potassium carbonate, 30 g of sodium hydroxide was added, and the resulting solution was heated at 50° C. for 15 min. It was then cooled to 0° C. and filtered. The filter cake was washed with water and dried under a vacuum to give 3-(dimethylamino)-2-[4-(trifluoromethyl)phenyl]-2-propenal. This dry solid was dissolved in 122 mL of methanol, 3.07 mL (97.97 mmol) of hydrazine was added, and the solution was stirred for 6 h at room temperature. It was poured into water, and the resulting mixture was filtered. The filter cake was washed with water, followed by hexanes, and dried under vacuum to give 8.35 g (80% yield) of 4-[4-(trifluoro)phenyl]-1H-pyrazole. Rf=0.26 (1:19 methanol:dichloromethane); 1H-NMR (300 MHz, DMSO-d6): δ 13.09 (br s, 1H), 8.34 (s, 1H), 8.04 (s, 1H), 7.82 (d, J=8 Hz, 2H), 7.68 (d, J=8 Hz, 2H); ES-LCMS m/z 213 (M+H).

Provenance & Evidence