The synthesis of triphenylene-based discotic mesogens New and improved routes
The synthesis of triphenylene-based discotic mesogens New and improved routes
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DOI：
10.1080/02678299308036504
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发表时间：
1993-12
期刊：
影响因子：
2.2
通讯作者：
N. Boden;R. C. Borner;R. Bushby;A. Cammidge;M. Jesudason
中科院分区：
文献类型：
--
作者：
N. Boden;R. C. Borner;R. Bushby;A. Cammidge;M. Jesudason
基于苯并菲核的离散液晶材料的合成通常涉及六羟基苯并菲的制备。传统上，这是通过四氯苯醌促进的1，2-二甲氧基苯的三聚反应，然后将所产生的六甲氧基苯并菲脱甲基来实现的。六羟基苯并菲随后被烷基化以得到所需的衍生物。该三步方法的总产率低，并且难以大规模进行。本文表明，使用氯化铁III代替四氯对苯醌的改进程序在单一步骤中产生六烷氧基三苯基。该反应产率高，可大规模进行。这也提供了比目前可用于制备聚合物分散液晶合成中所需的不对称取代的三亚苯基的那些更好的路线。本文还讨论了有关苯并菲核的一些阐述。
The synthesis of discotic liquid crystal materials based on the triphenylene core normally involves the preparation of hexahydroxytriphenylene. This has traditionally been accomplished by a chloranil promoted trimerization of 1,2-dimethoxy-benzene followed by demethylation of the hexamethoxytriphenylene produced. Hexahydroxytriphenylene is subsequently alkylated to give the required derivative. The overall yield of this three step procedure is low and it is difficult to perform on a large scale. It is herein shown that a modified procedure using iron III chloride instead of chloranil yields hexa-alkoxytriphenylenes in a single step. The reaction is high yielding and can be performed on a large scale. This also provides a better route than those currently available for making the unsymmetrically substituted tri-phenylenes required in the synthesis of polymeric discotic liquid crystals. Some related elaborations of the triphenylene nucleus are also discussed.