Halogenation reactions in position 3 of quinoline-2,4-dione systems by electrophilic substitution and halogen exchange
摘要:
3-Substituted 4-hydroxy-2(1 H)-quinolones 3, 5, 7 are halogenated with bromine or sulfuryl chloride to yield the quinolinediones 9 or 10. Reaction of 3, 5, 7 with chloroform gives the dichloromethyl quinolinediones 11. Halogen exchange leads from the chloro quinolinediones 10 to fluoro quinolinedones 12 and to azido quinolinediones 13. Similarly the dichloro quinolinedione 10 an reacts to the difluoro quinolinedione 14, which is reduced to the 3-fluoro-4-hydroxyquinolone 16 and reacts again with sulfuryl chloride to give the mixed 3-chloro-3-fluoroquinolinedione 15.
3-氯喹啉-2,4-二酮不与磷酰氯反应,但是,在N,N-二甲基苯胺存在下会形成2,4-二氯喹啉和/或4-氯喹啉-2-酮。与这些化合物一起,分离出少量的4-羟基喹啉-2-酮的新型磷酸二氢酯。我们概述了一个简单的步骤,可以以中等到良好的产率制备这些化合物。所有化合物均通过1 H和13 C NMR,IR,EI-MS和ESI-MS光谱进行表征,在某些情况下通过31 P NMR光谱进行表征。