4-NITRO-1-(2,2,2-TRIFLUOROETHYL)-1H-PYRAZOLE synthesis

Yield:919278-38-9 96%

Reaction Conditions:

with potassium carbonate in N,N-dimethyl-formamide at 20; for 3 h;

Steps:

52.1

To a solution of 4-nitropyrazole (1.13 g, 10 mmol) and2,2,2-trifluoroethyltriflate (3.48 g, 15 mmol) in N,N- dimethylformamide (10 mL) was added potassium carbonate (2.76 g, 20 mmol), and the mixture was stirred at room temperature for 3 hr. The reaction mixture was concentrated under reduced- pressure, diluted with water and extracted with ethyl' acetate.The organic layer was concentrated under reduced pressure, and the residue was purified by column chromatography (silica gel, hexane/ethyl acetate=100/0->60/40) to give the title compound (1.87 g, 96%) as a white solid.¹H-NMR (CDCl₃, 300 MHz) δ 4.77 (2H, q, J = 8.1 Hz), 8.16 (IH, s) , 8.29 (IH, s) .

References:

WO2007/4749,2007,A1 Location in patent:Page/Page column 137