水杨酸三甘醇酯的合成.doc

摘要 水杨酸甲酯与硝酸钇在乙酸乙酯中回流反应，能发生特殊的显色反应，形成在660nm附近有较强吸收的绿色产物。本研究通过测定不同反应配比和反应时间下反应溶液或产物的循环伏安图，并与其电子吸收光谱在660nm处的吸光度进行了关联,证明了循环伏安图上还原峰的出现及峰电流大小与绿色化合物的形成及吸光度大小有直接关系.由于绿色产物及其酸化溶液的循环伏安图上的还原峰均表现出芳香亚硝基化合物的特征，且用KI淀粉法检测到了反应溶液中亚硝酸根的存在。因此，这一显色反应可认为是一典型的亚硝基化反应。一些反应中间体或产物的红外光谱，紫外-可见吸收光谱、红外光谱、核磁共振氢谱和质谱也为亚硝基化反应提供证据。基于上述事实，我们认为正是由于稀土离子与水杨酸甲酯的配位作用诱导了氮氧化物和亚硝酸根的形成, 进而导致这些氮氧化物和亚硝酸根继续与水杨酸甲酯钇配合物发生亚硝基化反应，形成绿色产物。 当酯基为配位能力更强和空间位阻更大的三甘醇时，仍能观察到类似的反应。只是由于酯基的空间位阻效应而使反应速度变慢，析出的固体绿色化合物更多。 关键词：水杨酸甲酯；硝酸稀土；亚硝基化；二水杨酸三甘醇酯；循环伏安，氮氧化物； ABSTRACT A characteristic coloration reaction between yttium nitrate and methyl salicylate in ethyl acetate solution occurs at refluxing temperature and forms a green product with strong absorption at around 660nm. In this paper, the reaction solutions or products formed under different reaction conditions, such as feeding mole ratio and reaction time, were characterized by means of cyclic voltammetry and UV, IR, HNMR, MS techniques. It was found that the appearance of reduction peaks in the cyclic voltammetry curves was directly related to the formation of green product, and the peak current values were proportional to the absorbance at around 660nm. At the same time, the green solution turned to blue when reacting with KI-amylum, indicating the existing of NO2- in the resulting solution. These facts showed that there exists a typical nitrosation reaction, because the reduction peaks in the I-V curves of green product and its acidified solution could be ascribed to typical nitroso aromatic compound. Furthermore, the IR spectra, HNMR spectra and MS spectra of some intermediates or products also provided evidences for the nitrosation reaction. Based on above facts, we suggested that it was the coordination reaction of methyl salicylate with yttrium ion that induced the formation of nitrous oxides NOX and NO-2, and resulted in the subsequent nitrosation reaction between methyl salicylate yttrium coordination compound and nitrous oxides NOX or NO-2. In the case of triethylene