4-Fluoro-3-methoxyaniline (1.4 g) was added to a chloroform solution (10 ml) of ethyl 3-ethoxy-2-(2,4,5-trifluoro-3-methylbenzoyl)acrylate synthesized from ethyl 2,4,5-trifluoro-3-methylbenzoylacetate (2.6 g) in accordance with a method known per se in the art. The mixture was concentrated under reduced pressure, and anhydrous potassium carbonate (3.0 g) and N,N-dimethylformamide (7 ml) were added to the residue, followed by stirring at 90° C. for 15 minutes. The reaction mixture was allowed to cool, and chloroform (100 ml) and distilled water (250 ml) were added to the mixture, thereby conducting liquid separation. A chloroform layer was then washed twice with distilled water (250 ml), dried over anhydrous magnesium sulfate and concentrated under reduced pressure. Deposits were dispersed in ethanol, collected by filtration and washed with ethanol and diisopropyl ether in that order to obtain the title compound (2.59 g) as a colorless powder.
