Hexafluoroacetylacetone → HCID 23036563, compound

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Reaction Steps

1,1,1,5,5,5-Hexafluoro-2,4-pentanedione (0.56 g, 2.70 mmol) is added to a solution of 2,6-dichloro-4-nitrophenylhydrazine (0.30 g, 2.35 mmol) in 20 ml of methanol chilled in an ice bath. The mixture is stirred overnight at RT, after which the methanol is removed in vacuo. The residue is dissolved in toluene and a catalytic amount of p-toluenesulfonic acid (pTSOH) added. The mixture is heated under reflux and stirred for 2 hours, after which it is allowed to cool to RT and the solvent is removed in vacuo. The resulting crystals are dissolved in xylene, 40 mg of pTSOH is added and the mixture is heated under reflux for 2 hours. The resulting mixture is cooled, washed with methylene chloride, concentrated in vacuo and purified by flash chromatography to give 3,5-bis(trifluoromethyl)-1-(2,6-dichloro-4-nitrophenyl)pyrazole. Following the procedure of Example 5, the nitrophenylpyrazole is reduced by treatment with platinum dioxide and hydrogen to give 3,5-dichloro-4-[3,5-bis-(trifluoromethyl)-1-pyrazolyl]aniline.

Provenance & Evidence