A suspension of 4-bromo-2,5-dimethoxybenzoic acid [prepared in the manner of Bortnik et al., Zh. Org. Khim. 8, 340 (1972)] (2.43 g, 9 mmol), 2-trifluoromethylphenyl boronic acid (5.3 g, 28 mmol), and potassium carbonate (6.21 g, 60 mmol) in dioxane (40 mL) was sparged with nitrogen and treated with tetrakis(triphenylphosphine)palladium(0) (0.328 g, 0.2 mmol). The mixture was heated to reflux for 48 hours, cooled, acidified with 1N hydrochloric acid and extracted with ethyl acetate The extracts were dried over anhydrous magnesium sulfate, filtered and stripped to a solid which was used as such in the next step.
