Pyridine → N-(3-cyano-2,4-difluorophenyl)-1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxamide

Participants

Reaction Conditions

Reaction Steps

Oxalyl chloride (0.85 ml, 1.2 g, 9.8 mmol) followed by DMF (3 drops) were added to 1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxylic acid (2.03 g, 6.50 mmol) in dichloromethane (15 ml), and the mixture was heated to 50° C. After 5 h at 50° C., the mixture was concentrated under reduced pressure, THF (15 ml) and pyridine (1.1 ml, 1.0 g, 13 mmol, 2 eq.) were added, followed by 3-amino-2,6-difluorobenzonitrile (1.0 g, 6.5 mmol, 1.0 eq.) in THF (3 ml). The mixture was left at room temperature for 24 h, HC10N aq. solution) was added, the mixture was extracted with ethyl acetate and the extract was washed with HC10N aq. solution) and NaOH (2N aq. solution). The extract was dried over MgSO4 and filtered through silica gel. After concentration under reduced pressure, the product was purified by column chromatography on silica gel (hexane/ethyl acetate), giving N-(3-cyano-2,4-difluorophenyl)-1-methyl-3-(pentafluoroethyl)-4-(trifluoromethyl)-1H-pyrazole-5-carboxamide (1.29 g, 44%).

Provenance & Evidence