Alkylation of 5- and 6-Methylindolo[2,3-<i>b</i>]quinoxalines: Revised Structures of the<i>N</i>,<i>N′</i>-Dimethylated Salts
作者:Philippe Helissey、Stéphanie Desbène-Finck、Sylviane Giorgi-Renault
DOI:10.1002/ejoc.200400386
日期:2005.1
N,N′-Dialkylation of indolo[2,3-b]quinoxaline could theoretically furnish three isomers, that is, salts dialkylated at the 5,6-, the 6,11-, and the 5,11-positions. By using the 2,3-dimethylated derivatives as models, the regioisomeric salts were selectively synthesized either by alkylation of the tetracycle or by cyclization of 1-methylisatin with N,4,5-trimethylbenzene-1,2-diamine. The structure of
吲哚[2,3-b]喹喔啉的N,N'-二烷基化理论上可以提供三种异构体,即在5,6-、6,11-和5,11-位二烷基化的盐。通过使用 2,3-二甲基化衍生物作为模型,通过四环的烷基化或 1-甲基靛红与 N,4,5-三甲基苯-1,2-二胺的环化,选择性地合成了区域异构盐。N,N'-二甲基盐的结构由 NMR 相关序列(1H-1H NOESY、1H-13C HMQC 和 1H-13C HMBC)明确确定。这些研究的结果表明,之前对吲哚喹喔啉二烷基化的研究结果需要修正。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)