HCID 59475093, compound → HCID 59475102, compound

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Reaction Steps

In a sulfonation flask 2.07 g (7.2 mmol) of the amine isomer mixture prepared in example P5b) and 1.45 g (14.4 mmol) triethylamine are dissolved in 50 ml of methylenechloride. Then a mixture of 1.65 g (7.2 mmol) 3-trifluoromethyl-1-methyl-1-H-pyrazole 4-carboxylic acid chloride and 50 ml methylenechloride is added at room temperature under stirring. After stirring for 16 hours the solvent is evaporated in a water jet vacuum and the residue purified by column chromatography over silicagel (eluent: ethylacetate/heptane 1:2-2:1). 1.52 g of an isomeric mixture of amides is obtained in the form of slightly brown crystals (m.p.: 134-138° C.). The mixture consists of 27% of 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid [2-(2-bromo-4,5-dichlorothiophen-3-yl)-1-methylethyl]amide, 30% of 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid [2-(5-bromo-2,4-dichlorothiophen-3-yl)-1-methylethyl]amide and 43% of the undesired 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid [2-(2,4,5-trichlorothiophen-3-yl)-1-methylethyl]amide.

Provenance & Evidence