Trimethylsilyl chloride (125 μL, 0.98 mmol) is added to a solution of cyclohexane-1,3-s dione (100 mg, 0.89 mmol), 6-formylnicotinonitrile (118 mg, 0.89 mmol) and 1-(3-(trifluoromethyl)phenyl)urea (182 mg, 0.89 mmol) in a mixture of N,N-dimethyl-formamide (670 μL) and acetonitrile (1.2 mL), and the mixture is stirred at room temperature for 1.5 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: 330 mg; ESI mass spectrum [M+H]+=431, Retention time HPLC: 0.63 min (V011_S01).
