A mixture of 1-(2-phenylamino-6-trifluoromethyl-pyridin-3-yl)-ethanone (4.28 g, 15.3 mmol) in methanol (60.4 mL) at 25° C. was treated with methyl 4-formylbenzoate (3.01 g, 18.3 mmol) and sodium methoxide in methanol (25% wt, 6.99 mL, 30.5 mmol). The reaction was stirred at 25° C. for 2 d. At this time, the reaction was diluted with water (50 mL), neutralized with a 2N aqueous hydrochloric acid solution, and extracted with methylene chloride (3×75 mL). The combined organics were dried over sodium sulfate and filtered. Silica gel was added to the filtrate, concentrated in vacuo and dried under high vacuum. Flash chromatography (40 g silica column, 10-100% ethyl acetate/hexanes) afforded 4-[(E)-3-oxo-3-(2-phenylamino-6-trifluoromethyl-pyridin-3-yl)-propenyl]-benzoic acid methyl ester (4.04 g, 62%) as an orange solid.
