Trimethylsilyl chloride (125 μL, 0.982 mmol) is added to a solution of cyclohexane-1,3-dione (100 mg, 0.892 mmol), 4-formylbenzonitrile (117 mg, 0.892 mmol) and 1-(4-(tri-fluoromethyl)pyridin-2-yl)urea (183 mg, 0.892 mmol) in a mixture of N,N-dimethylformamide (670 μL) and acetonitrile (1.2 mL), and the mixture is heated at 50° C. for 1 h. The reaction mixture is cooled to room temperature and poured into a mixture of water and ice. The mixture is filtered, and the precipitate is washed with water and dried under reduced pressure. Yield: 293 mg; ESI mass spectrum [M+H]+=431, Retention time HPLC: 0.63 min (V011_S01).
