The unprecedented use of 2,2,2-trifluoroethanol as reaction solvent provided a facile and convenient access to symmetrically 3,3-disubstitued quinoline-2,4-diones in moderate to excellent yields and high regioselectivity, by reaction of 4-hydroxy-2-quinolones with electrophiles like methyl iodide, as well as benzyl and allyl bromides in the presence of K₂CO₃. Silver (I) oxide is required to increase the yield of the methylations.

中文翻译：

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2,2,2-三氟乙醇促进获得对称的3,3-二取代喹啉-2,4-二酮

通过2,2,2-三氟乙醇作为反应溶剂的空前使用，通过4-羟基-苯酚的反应，以中等至极好的收率和高区域选择性提供了一种方便且便捷的途径，可对称地获得3,3-二取代的喹啉-2,4-二酮。在K ₂ CO ₃存在下，具有亲电试剂的2-喹诺酮类化合物，如甲基碘，以及苄基和烯丙基溴。需要氧化银（I）以增加甲基化的产率。