Selective synthesis of naphthalenedicarboxylic acid

1，2，6-萘二甲酸（2，6-NDA）是合成高性能聚合物和液晶化合物的重要中间体。聚2，6-萘二甲酸乙二醇酯（PET）在薄膜的力学性能、热稳定性和气体阻隔性方面均优于PET，具有上级的优点。以2，6-二烷基萘为原料，氧化2-烷基-6-酰基萘为原料，合成了2，6-NDA。本文对β-环糊精（β-CyD）催化2-萘甲酸选择性羧化反应进行了初步研究。本论文的主要工作如下：1.以2-萘甲酸、四氯化碳和铜粉为原料，在碱性条件下，利用β-CyD选择性合成2，6-NDA。2，6-NDA的产率随β-CyD用量的增加而增加，在β-CyD与2-萘甲酸的初始摩尔比下，产率达到最大值（39mol%，选择性78 关于我们 id为1.0，其中2，7-DNA和1，6-NDA分别为9.1mol%和1.7mol%。当用α-CyD或γ-CyD代替β-CyD时，反应几乎不能进行. 2，6-NDA的产率随着四氯化碳用量的增加而增加，并且在四氯化碳与2-萘甲酸的初始摩尔比为5.0时具有最大值（58mol%，选择性为83%）。四氯化碳的有效加入受到影响。通过向含有2-萘甲酸、β-CyD和铜粉的氢氧化钠水溶液中加入0.6mmol四氯化碳开始反应，并通过以15分钟间隔向反应混合物中加入0.6mmol四氯化碳继续反应8小时。2，6-NDA的产率为67 mol%，选择性为84%.本文用核磁共振波谱技术，在旋转坐标系上用^1H Homologous Overhauser增强技术测定了β-CyD-2-萘甲酸包合物在碱溶液中的构象。非常高的选择性归因于β-CyD-2-萘甲酸包合物的构象。少

1.2, 6-Naphthalenedicarboxylic acid (2, 6-NDA) is a useful intermediate for the syntheses of high performance polymers and liquid crystalline compounds. Poly (ethylene 2, 6-naphthalene-dicarboxylate) is superior to poly (ethylene terephthalate) in mechanical properties, thermostability and gas-barrier ability of films. The synthesis of 2, 6-NDA was attempted by oxudation of 2, 6-dialkylnaphthalene, and by oxidation of 2-alky-6-acylnaphthalene. We reported preliminarily the selective carboxylation of 2-naphthalenecarboxylic acid using beta-cyclodextrin (beta-CyD) as catalyst. The present research has been carried out to search the optimum conditions for the selective synthesis of 2, 6-NDA from 2-naphthalenecarboxylic acid, carbon tetrachloride and copper powder in aqueous alkali by the use of beta-CyD.2. The yield of 2, 6-NDA increased with increasing amounts of beta-CyD, and took a maximum (39 mol% with 78% selectivity) at the initial mole ratio of beta-CyD to 2-naphtalenecarboxylic ac … More id of 1.0, where the 2, 7-DNA and 1, 6-NDA were 9.1 mol% and 1.7mol%, respectivelv. When alpha-CyD or gamma-CyD was used instead of beta-CyD, the reaction hardly proceeded.3. The yield of 2, 6-NDA increased with increasing amounts of carbon tetrachloride, and had a maximal value (58 mol% with 83% selectivity) at the initial mole ratio of carbon tetrachloride to 2-naphthalenecarboxylic acid of 5.0. The efficient addition of carbon tetrachloride was affempted. The reaction was started with the addition of 0.6 mmol of carbon tetrachloride to the aqueous sodium hydroxide solution containing 2-naphthalenecarboxylic acid, beta-CyD and copper powder, and was continued for 8 h by adding 0.6 mmol or carbon tetrachloride to the reaction mixture at 15 min intervals. The resulting yields of 2, 6-NDA was 67 mol% with 84% selectivity.4. The conformation of beta-CyD-2-naphthalenecarboxylate inclusion complex in aqueous alkali was determined by the nuclear magnetic resonance spectroscopy using ^1H homonuclear Overhauser enhancement on the rotating frame. The very high selectivity was ascribed to the conformation of the beta-CyD-2-naphthalenecarboxylate inclusion complex. Less