A mixture of N,N-dimethyl-5-ethyl-2-iodophenylacetamide (2.0 g, 6.3 mmol), 2-fluoro-methyl-3-trifluoromethylaniline (2.4 g, 12.6 mmol), copper (0.2 g, 3.2 mmol), cuprous iodide (0.6 g, 3.2 mmol), and K2CO3 (0.9 g, 6.3 mmol) in xylenes (6.0 mL) are heated at reflux for 24 h. After cooling, the crude reaction mixture is diluted with EtOAc and filtered through Celite®. The filtrate is concentrated under reduced pressure. The residue is purified by flash chromatography, eluting with hexanes, then up to 25% EtOAc/hexane mixtures to give the target compound 5-ethyl-2-(2′-fluoro-4′-methyl-3′-trifluoromethylanilino)phenylacetic acid N,N-dimethyl amide.
