Under an atmosphere of argon, 500 mg (2.31 mmol) of methyl 2-bromoisonicotinate and 694 mg (3.47 mmol) of 2-(trifluoromethyl)phenylboronic acid were dissolved in 10 ml of toluene. 106 mg (0.12 mmol) of tris(dibenzylideneacetone)dipalladium, 91 mg (0.23 mmol) of tri-tert-butylphosphine and 982 mg (4.63 mmol) of potassium phosphate were then added, and under argon the mixture was heated to 110° C. for 20 h. For work-up, the mixture was diluted at RT with 15 ml of ethyl acetate and 15 ml of water, the organic phase was separated off and the aqueous phase was extracted two more times with in each case 15 ml of ethyl acetate. The combined organic phases were dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 20:1, then 10:1). This gave 498 mg (59% of theory) of the target compound in a purity of 77%. A second product fraction of lower purity was purified further according to Method 19. This gave a further 54 mg (8% of theory) of the target compound.
