4′-Trifluoromethyl-biphenyl-2-carboxylic acid (3-amino-4-formyl-phenyl)-amide (769 mg, 2.0 mmol) and ethyl acetoacetate (260 mg, 2.0 mmol) were dissolved in 10 ml of acetic acid and heated at 80 C. After 2.5 h, the mixture was cooled to room temperature, diluted with water and brought to pH 10 with 2N NaOH. The mixture was extracted with ethyl acetate (2×50 ml), the combined organic layers washed with brine, dried over magnesium sulfate, and concentrated to give 815 mg of a yellow solid. This material was purified by chromatography on silica gel eluting with 0 to 10% ethyl acetate in dichloromethane to provide 349 mg (36%) of the title compound as a yellow foam.
