摘要/Abstract
研究了一种新颖、绿色的六氯丙酮成环反应.首先，在水作溶剂的条件下，对六氯丙酮合成联苯并噻唑的反应条件进行了优化，成功地合成了高纯的联苯并噻唑.研究发现，底物的亲核能力对成环反应起关键作用.进而通过隔氧和氯化银沉淀实验，确定了反应体系中氧气的参与以及游离氯离子的存在.最后提出了成环反应机理：第一个噻唑环通过邻氨基苯硫醇亲核进攻六氯丙酮，氯仿离去，再在氧气的氧化下首先形成；随后，另一分子的邻氨基苯硫醇再次发起亲核进攻，三个氯离子离去，形成第二个噻唑环.将该方法应用于底物2，5-二氨基对苯硫醇和均苯四胺，分别成功地制得聚苯撑二噻唑和聚苯撑二咪唑两个高分子聚合物，实验条件温和，产率高，应用价值高.
关键词: 六氯丙酮, 联苯并噻唑, 联苯并咪唑, 聚苯撑二噻唑, 聚苯撑二咪唑
A novel cyclization reaction by using hexachloroacetone as C2 synthon has been studied. The optimal condition was obtained by synthesis of bibenzothiazole in the presence hexachloroacetone in water. Experimental results showed that the nucleophilicity of substrates played a key role in the cyclization reaction, and catalytical amount of oxygen in reactions was also vital to trigger ring fusion in the formation of target compounds. Accordingly, the mechanism of cyclization reaction was proposed:the thiazole ring is formed in the first place by a nucleophillic attack of 2-aminobenzenethiol, followed by CCl3 cleavage from hexachloroacetone. Then the second 2-aminobenzenethiol launches another nucleophilic attack, and three chloride ions leave to form the second thiazole ring. The method was applied to the substrates of 2,5-diaminobenzene-1,4-dithiol and benzene-1,2,4,5-tetraamine, respectively and two polymers of polyphenylene dithiazole and polyphenylene diimidazole were successfully prepared. The experimental conditions were mild, the yield was high and the application value was high.
Key words: hexachloroacetone, bibenzothiazole, bibenzimidazole, polyphenylene dithiazole, polyphenylene diimidazole
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