【作者】 刘劭钢；

【导师】 梁逸曾；

【作者基本信息】 中南大学 ， 应用化学， 2004， 硕士

【摘要】 Hantzsch反应是一著名的吡啶环合成反应，本研究工作较深入地探讨了这一反应在卫生分析化学中的应用，并对应用过程中所发生的化学反应、反应产物、反应机理进行了探讨，主要取得以下成果： 1 用与文献所叙方法一致的条件，合成了乙酰丙酮法测定甲醛的化学反应产物，并利用质谱、核磁共振波谱研究了该产物，证实该产物为2，6-二甲基-3，5-二乙酰基-1，4-二氢吡啶，纠正了我国出版物中关于乙酰丙酮分光光度法测定甲醛产物的错误描述。并对产物在水溶液中的紫外可见光谱进行了研究，试验表明产物在413nm处的摩尔吸光系数为6.639×10³Lmol^-1cm^-1。在实际测定过程中，产物在反应体系中的最大吸收波长应为415nm。 2 乙酰乙酸乙酯在弱酸性的乙酸铵缓冲溶液中与甲醛及氨反应，并形成有色化合物。利用该反应建立了测定食品和环境水样中微量甲醛的新方法。反应产物在所选条件下于375nm处有最大吸收，以甲醛计的摩尔吸光系数为5.533×10³Lmol^-1cm^-1；甲醛浓度在0.08～3.2mg／L范围内符合比尔定律。 3 该方法所形成的产物经用质谱分析证实为2，6-二甲基-1，4-二氢-3，5-吡啶二乙酸乙酯，表明在水溶液中该反应仍遵循Hantzsch吡啶合成法的原理。通过与乙酰丙酮法的比较，认为在反应过程中，成环物质的烯醇型的化合物含量对反应速度有影响，烯醇型的化合物含量越高，反应温度越低。反应体系温度的升高，有利于烯醇型的化合物含量的增加。 4 建立了以Hantzsch反应为原理的间接测定毒鼠强的新方法。在酸性条件下，毒鼠强在硫酸的作用下发生水解，产生的甲醛经水蒸汽蒸馏而与干扰物质分离，用乙酰丙酮及乙酸铵缓冲溶液与分解出的甲醛反应，根据甲醛的量换算毒鼠强的含量。本方法测定毒鼠强的线性范围为5～40mg／Kg。更多还原

【Abstract】 Hantzsch reaction is a famous reaction commonly used to synthesize chemicals containing pyridine cycle. In this study the application of Hantzsch reaction in hygienic analytical chemistry was studied:1. According to the method mentioned in literature, we synthesized the chemical which can be used to analyze formaldehyde in acetyl acetate method. The chemical was studied with MS and NMR method and proved to be 2,6-Dimethyl-3,5-Diacetyl-1,4-Di- hydropyridine. The solution of the chemical was studied with ultraviolet spectrophotometry and the result showed the molar absorption coefficient of the chemical was 6.639x103 Lmol-1 cm-1 at 413nm. In practical determining process the maximum absorption wavelength of the chemical was at 415nm. This result corrected the inaccurate description about the determination of formaldehyde by spectrophotometry with acetyl acetate in Chinese publications.2. Acetylacetate ester can react with formaldehyde and ammonia to form a colored compound under weak acidic buffer of ammonium acetate. Using this reaction we established a new method to determine trace formaldehyde in food and environmental water, the maximum absorption of the product under chosen condition was at 375nm and molar absorption coefficient based on formaldehyde was 5.533x103 Lmol-1 cm-1; The measurement of formaldehyde obeyed Beer’s law at the range of its concentration from 0.008mg/L to 0.40mg/L.3. The product formed by this method was proved to be 2,6-Ddimethyl -3,5-bis(ethoxycarbonyl) -1,4-dihydropyridine with MS analysis, demonstrating that the reaction in aqueous solution still followed the mechanism of Hantzsch’ method for synthesizing pyridine. In comparison with acetyl acetate method we found that in the reaction process the concentration of enol-like compound had some effect on the reaction rate. The more the conctntration of enol-like compound, the lower the reaction temperature.4. A new method to indirectly determine Detrimine was established based on the mechanism of Hantzsch reaction. In acidic solution Detrimine was hydrolyzed in the presence of sulfuric acid, then the formaldehyde decomposed from Detrimine reacted with acetyl acetate in ammonium acetate buffer. The content of Detrimine was calculated from the concentration of formaldehyde. The linear range for determining Detrimine was between 5-40mg/Kg更多还原