p-Toluenesulfonic acid → 1-(3-methyl-4-nitrobenzyl)-5-pentafluoroethyl-1H-pyrazole

Participants

Reaction Steps

(3-Methyl-4-nitrobenzyl)-hydrazine (1.81 g) and 5-ethoxy-1,1,1,2,2-pentafluoro-4-penten-3-one (2.18 g) were refluxed in ethanol (60 ml) for 8 hours, and p-toluenesulfonic acid (0.10 g) was added thereto and the mixture was further refluxed for 6 hours. After finishing the reaction, the solvent was distilled off and the obtained residue was purified by silica gel column chromatography (mixed solvent of n-hexane and ethyl acetate) to obtain 1-(3-methyl-4-nitrobenzyl)-5-pentafluoroethyl-1H-pyrazole (0.96 g) as the first elution portion and 1-(3-methyl-4-nitrobenzyl)-3-pentafluoroethyl-1H-pyrazole (0.50 g) as the second elution portion.

Provenance & Evidence