Cyclisation of 9-(benzotriazol-1-yl)acridine 1 to the pentacycle 8H-quino[4,3,2-kl]acridine 5 in a range of low-boiling solvents is mechanistically distinct from previously published photochemical (carbene) and thermolytic (radical) cyclisations. Fragmentation of the triazole ring of 1 to a diazonium intermediate 7, and its subsequent heterolysis (–N2) and cyclisation is facilitated by solvation of intermediate zwitterionic species. Derivatives of 2- and 3-aminoquinoacridines methylated in the 8-position can be converted to 8,13-dimethylquino[4,3,2-kl]acridinium iodide salts with methyl iodide and were required for biological examination as potential telomerase inhibitors. The chloro group in 3-chloro-8-methyl-8H-quino[4,3,2-kl]acridine can be replaced efficiently by benzylamino, 4-morpholinyl and cyano substituents in palladium(0) mediated reactions.
9-(1,2,3-苯并
三氮唑-1-基)
吖啶1在低沸点溶剂中环化生成五元环8H-
喹喔啉[4,3,2-kl]
吖啶5的机理与先前报道的光
化学(碳烯)和热解(自由基)环化反应不同。1的苯并
三氮唑环断裂生成中间体重氮盐7,随后发生异裂脱氮(-N2)和环化,这一过程得益于中间体两性离子的溶剂化作用。2-和3-
氨基喹喔
吖啶的甲基化衍
生物在8-位甲基化后,可以通过甲基
碘转化为8,13-二甲基
喹喔啉[4,3,2-kl]
吖啶碘盐,这些产物作为潜在的端粒酶
抑制剂,需进行
生物学检测。3-
氯-8-甲基-8H-
喹喔啉[4,3,2-kl]
吖啶中的
氯基可以高效地被苯甲
氨基、4-吗啉基和
氰基取代,这些反应都是通过
钯(0)催化的反应完成的。