4-Hydroxy-6-trifluoromethylquinoline (50 mg, 0.2 mmol) was used as starting material and synthesized with reference to the method reported in Bioorganic & Medicinal Chemistry Letters, 2005, 15(4), 1015-1018. The raw material was added to phosphorus trichloride (108 mg, 0.7 mmol). After the addition was completed, the reaction mixture was heated to 90 °C and stirred continuously for 2 hours. Upon completion of the reaction, the pH was adjusted to 8-9 by slow dropwise addition of saturated sodium bicarbonate solution.Subsequently, extraction was carried out with ethyl acetate (30 mL x 3). The organic phases were combined and concentrated under reduced pressure to afford the target product 4-chloro-6-(trifluoromethyl)quinoline (60 mg, colorless oil), which could be used directly in the subsequent reaction without further purification.
