Hydrochloric Acid → N-(3-acetyl-4-chlorophenyl)-1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxamide

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Reaction Conditions

Reaction Steps

Oxalyl chloride (0.65 ml, 0.95 g, 7.5 mmol, 1.5 eq.) followed by DMF (3 drops) were added to 1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxylic acid (1.56 g, 5.00 mmol) in dichloromethane (20 ml), and the mixture was heated to 40° C. After 9 h at 40° C., the mixture was concentrated under reduced pressure, THF (20 ml) and pyridine (0.8 ml, 0.8 g, 2.0 eq.) were added, followed by 1-(5-amino-2-chlorophenyl)ethanone (0.85 g, 5.00 mmol, 1.0 eq.) in THF (5 ml). The mixture was left at room temperature for 2 d. HCl N aq. solution) was added, the mixture was extracted with ethyl acetate and the extract was washed with HCl (1N aq. solution), NaOH ON aq. solution) and sat. aq. sodium chloride solution. The extract was dried over MgSO4 and, after concentration under reduced pressure, the product was purified by column chromatography on silica gel (hexane/ethyl acetate) to give N-(3-acetyl-4-chlorophenyl)-1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxamide (1.85 g, 80%).

Provenance & Evidence