183 mg (0.983 mmol) of 4-ethinyl-1,5-dimethyl-3-(trifluoromethyl)-1H-pyrazole, 2.3 mg (0.01 mmol) of palladium acetate and 3.9 mg (0.02 mmol) of copper(I) iodide are weighed into a round-bottom flask and placed under protective gas. Subsequently, 9.1 mg (0.04 mmol) of di(tert-butyl)phenylphosphine, 300 mg (1.03 mmol) of 3,5-bis(trifluoromethyl)bromobenzene, 137 mg (1.08 mmol) of cyclohexyldimethylamine and dimethylacetamide (5 ml) are added and the mixture is heated to 110° C. for 12 h. After the end of the reaction, the mixture is cooled, poured onto cold, dilute hydrochloric acid and extracted with ether. The combined ether phases which have been dried over MgSO4 are concentrated. The product is obtained as a solid in an 85% yield.
