摘要
以乙基麦芽酚和对苯二胺为原料,通过微波辅助合成法制备N-对胺基苯基-2-乙基-3-羟基-4-吡啶酮;然后用氯化苄对其羟基进行保护,再与丙二酰氯发生酰胺化反应,得到N,N′-二[对-(2-乙基-3-苄氧基-4-吡啶酮)苯基]丙二酰胺;最后在Pd/C的催化作用下进行氢解反应,生成目标产物N,N′-二[对-(2-乙基-3-羟基-4-吡啶酮)苯基]丙二酰胺。通过试验得到各步反应的适宜工艺条件,同时用UV-Vis、FT-IR、1HNMR和MS等测试手段确定了各反应产物的结构。
This paper is aimed to introduce our work on synthesizing a novel tetradentate hydroxypyridinone, which is actually a kind of chelators for treating heavy metal pollutants. For our purpose, first of all, we have synthesized the structural unit for our experiments through microwave-supported organic reaction, which takes ethyl maltol and p-phenylene diamine as the raw material to form N-(4-amino-phenyl)-2-ethyl-3-hydroxy-4-pyridinone. As a result, it has been made possible for the yield of compound 3 synthesized to be as high as by 55% on the condition that the microwave oven has a power of 400 W, with 1:1.8 molar ratio of ethyl maltol and p-phenylene diamine, the reaction time to 60 min and the reaction temperature to 95℃. Since it is necessary to protect its hydroxyl, seeing that the hydroxyl of compound 3 tends to disturb the following reactions, in the second step, the hydroxyl of compound 3 should be protected by benzyl chloride in order to get N-(4-amino-phenyl)-2-ethyl-3-benzyloxy-4-pyridinone. To carry out the reaction of protecting hydroxyl with the microwave radiation method, we have investigated the factors that are likely to affect the yield. Through careful study, we have found that the optimum reaction conditions should be 26.6% of compound 4 microwave oven power 300 W, with 1:1.2 molar ratio of compound 3 and benzyl chloride, the reaction time being 30 min and the reaction temperature 65℃. By following the above said method, we have prepared malonyl dichloride (compound 6) by heating malonic acid and thionyl chloride. Then through the amidation reaction between N-(4-amino-phenyl)-2-ethyl-3-benzyloxy-4-pyridinone and malonyl dichloride, N, we have made the yield of N, N'-bis--malonamide increase by 38% on the condition that the reaction conditions are 2:1 molar ratio of N-(4-amino-phenyl)-2-ethyl-3-benzyloxy-4-pyridinone and malonyl dichloride, with the trithylamine as acid binding agent at room temperature stirring for 12 h. In hoping to obtain the final product of N,N'-bis--malonamide, we have conducted the de-protection reaction in the component solvent of methanol and water (10:1 volume ratio) with the catalysis of Pd/C and hydrogen, also known as hydrogenolysis, and the yield of compound 8 going up to 80%. Thus, the target compound tetradentate hydroxypyridinone can be synthesized through the above four steps, and the structure of these compounds can respectively be identified via IR, HNMR, and UV-Vis, MS.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第2期227-231,共5页
Journal of Safety and Environment
基金
碳纳米材料四川省青年科技创新研究团队专项(2011JTD0017)
国防基础科研计划项目(B1520110007
A3120110005
A3120133002)
关键词
有机化学
二齿HOPO
四齿HOPO
制备
合成工艺
organic Chemistry
bidentate hydroxypyridinone
tetradentate hydroxypyridinone
preparation
synthesistechnology