[2,6-Dichloro-4-(trifluoromethyl)phenyl]hydrazine → [5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-methylsulfanyl-1H-pyrazol-4-yl]-(2,5-dimethylphenyl)methanone

Participants

Reaction Steps

A suspension of 7.94 g (28.6 mmol) of the product of step C and 7.01 g (28.6 mmol) of 2,6-dichloro-4-trifluoromethylphenylhydrazine in 100 mL of ethanol was heated at reflux for 2 hours, solution occurring as the reaction mixture was warmed. Then the ethanol was mostly removed on the rotary evaporator and the residues were partitioned between dilute aqueous hydrogen chloride solution and ethyl acetate. The organic phase was washed once with water and with brine, then dried with magnesium sulfate and treated with decolorizing carbon. The filtered solution was evaporated and the residues crystallized from 10:1 hexane/ethyl acetate to give 12.00 g (88%) of the title product in two crops, m.p. 130°-132° C.

Provenance & Evidence