非光气法合成1,5-萘二氨基甲酸甲酯的研究

SYNTHESIS OF 1,5-NAPHTHALENE DICARBAMATE BY NON-PHOSGENE METHOD

研究了用碳酸二甲酯(DMC)代替光气与1,5-萘二胺(NDA)反应合成1,5-萘二氨基甲酸甲酯(NDC)的过程。利用Joback法对体系中各物质的基本热力学数据进行了估算,依此计算了该反应在不同温度下的平衡常数。考察了多种金属有机酸盐催化剂对该反应的催化活性,并对反应后的乙酸锌和硬脂酸锌进行了XRD表征。结果表明,该反应在热力学上是可行的;所考察的有机酸锌催化剂中,乙酸锌、三甲基乙酸锌、硬脂酸锌等具有较好的活性,NDC的产率最高可达95.0%;各种有机酸锌的比活性顺序为:苯甲酸锌<乙酸锌<三甲基乙酸锌<戊酸锌<辛酸锌<硬脂酸锌。有机酸锌对应衍生酸的pKa值与其比活性有关,当有机酸锌对应衍生酸的pKa值大于4.19时,其锌盐具有较好的比活性。氧化锌的生成是催化剂失活的原因。还推测了以有机酸锌为催化剂的反应机理。

The synthesis of 1,5-naphthalene dicarbamate （NDC） was carried out with 1,5- naphthalene diamine （NDA） and dimethyl carbonate （DMC） in place of phosgene as raw materials. The basic thermodynamics data of the reaction were estimated by the method of Joback. The catalytic activity of zinc salts of organic acid for this reaction was investigated. Zinc acetate and zinc stearate after the reaction were characterized by XRD. The result showed that the reaction was feasible. Zinc salts of organic acid, such as zinc acetate, zinc trimethylacetate and zinc stearate, etc, exhibited better catalytic activity. The yield of NDC was 95.0%. The sequence of the specific activity was as follows： zinc henzoate〈zinc acetate〈zinc trimethylacetate〈zinc pentanoate〈 zinc octotate 〈 zinc stearate. It was found that the pKa of the derived organic acid of the catalyst affected the specific activity. Based on the data of experiments, when the pKa of the relatived organic acid of the zinc salt was greater than 4.19, the zinc salt of organic acid had better specific activity. The formation of ZnO was the reason of the catalyst deactivation. The reaction mechanism was also conjectured.