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邻氨基二苯醚类重氮盐的水解及分子内缩合反应 总被引:1,自引:0,他引:1
用邻氨基二苯醚类化合物进行重氮化水解反应制备邻羟基二苯醚类化合物, 对影响氯代邻氨基二苯醚重氮盐水解反应和分子内关环反应的因素进行了系统研究, 讨论了取代基、金属及其离子催化等对两类反应的影响规律, 揭示了在金属离子催化下, 邻氨基二苯醚类化合物重氮盐发生分子内关环反应的规律, 并推测了反应机理. 相似文献
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苯氧乙酸类化合物的合成研究 总被引:2,自引:0,他引:2
二苯醚型苯氧基乙(丙)酸类除草剂是一类用于禾本科杂草的除草剂,具有选择性强,内吸迅速,对环境危害小和使用安全等优点,被广泛应用于农林业生产。为了寻找更高效、低毒和低残留的除草剂,本文以相应结构的取代羟基二苯醚为骨架,以氯代乙酸乙酯为原料,经亲核取代反应制得此类化合物。在反应过程中为提高产率,加入了相转移催化剂;由于羟基二苯醚类化合物在空气中容易被氧化,在反应过程中采用氮气保护,得到了较纯产物,产率较高。共合成了苯氧基苯氧基乙酸乙酯类化合物5个,目标物的合成路线如下: 相似文献
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以自制的4,4'-双甲酰基二苯醚类化合物、β-酮酸酯及脲为原料,在Fe C13·6H2O的催化下,通过Biginelli反应合成了12种新型双嘧啶酮二苯醚类衍生物(6a~6l),探讨了双嘧啶酮合成的反应历程并对反应条件进行优化.另外,对4,4'-双甲酰基二苯醚类化合物的合成方法进行了改进,通过控制对氟苯甲醛的加入时间,提高了产率,并大大缩短了反应时间.对所有化合物进行了室内毒力测试,结果表明,化合物6d,6h和6i的抗菌效果较好,对西瓜枯萎病的EC95值均小于对照药三唑酮;当取代基R2为CF3时,化合物的杀菌抑菌活性较好. 相似文献
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以二甘醇二苯醚作为气相色谱的固定液,对其色谱性能、分离效率作了初步研究,它对醇类、酯类、含氮类、芳香类化合物、氯代烃及高沸点有机混合物,其分离度大于1.5,分离效率达99.7%,分离效果好,显示了较高的柱效能和广谱特性。 相似文献
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综合考虑二苯醚类杀菌剂结构与活性关系的前期研究结果, 以双羟基二苯醚为原料, 经酸酐保护、硝化、去保护得到含硝基的双羟基二苯醚, 再经过溴代反应合成了7个新的溴代2,2'-, 2,4'-和4,4'-二羟基硝基二苯醚; 所有这些化合物的结构均经1H NMR, MS, IR和元素分析所证实; 并检测了合成的溴代二羟基硝基二苯醚化合物对两种有害菌的抑菌活性, 结果表明: 它们对所测试菌种具有优良的抑制效果, 其中3个化合物在质量分数为5×10-6的浓度下抑菌率超过100%, 能完全控制细菌的生长. 相似文献
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Hongyuan Liu Jing Jin Huifu Xue Cuicui Guo Feng Ren Xiaolin He Jiping Chen Chun Hu 《Journal of separation science》2022,45(13):2334-2343
Based on the size- and shape-selective sorption, 13X molecular sieves were developed as solid-phase extraction adsorbents to cleanup serum extract for the determination of polybrominated diphenyl ethers. The important parameters affecting the cleanup efficiency were investigated including the amount of sorbents, the type, and volume of solvents. Under the optimized conditions, the capacity for removing impurities was evaluated via gel permeation chromatography and gas chromatography with mass spectrometry. The results demonstrated that up to 99% of lipids in corn oil (13 mg) can be removed after cleanup, and endogenous compounds in serum can also be effectively eliminated. The cleanup efficiency is not only superior to hydrophile-lipophile balance column, but also close to acid silica gel and multifunction impurity sorbents. Generally, the developed cleanup method exhibited higher recovery for polybrominated diphenyl ethers with more than four bromines, especially for nona- and deca-brominated diphenyl ethers (99.1˗117.8%). The cleanup method can be coupled with gas chromatography and tandem mass spectrometry for polybrominated diphenyl ethers analysis in human serum. The method detection limits were 0.01˗0.27 ng/mL and average recovery was 50.9˗113.3%, except 2,3',4',6-tetrabrominated, 2,3',4,4',6-pentabrominated, and 2,3,3',4,4',5',6-heptabrominated diphenyl ethers. 2,2',4,5'-Tetrabrominated diphenyl ethers had the highest detection frequency (95%) in human serum, whereas decabrominated diphenyl ethers had the maximum mean concentration (0.50 ng/mL). 相似文献
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Natural sunlight and sun simulator photolysis studies of tetra- to hexa-brominated diphenyl ethers in water using solid-phase microextraction 总被引:1,自引:0,他引:1
Sánchez-Prado L Lores M Llompart M García-Jares C Bayona JM Cela R 《Journal of chromatography. A》2006,1124(1-2):157-166
Photo-solid-phase microextraction (photo-SPME) is combined for the first time with natural and simulated sunlight to study the photochemical behaviour of environmental concerning tetra- to hexa-brominated diphenyl ethers. The sunlight photodegradation kinetics of five brominated diphenyl ethers (BDE 47, BDE 100, BDE 99, BDE 154 and BDE 153) has been studied. These BDEs are the most abundant congeners in penta-BDE commercial formulations used as flame-retardants and are considered among the most toxic ones. The five studied BDEs were photolytically labile. The detected photodegradation products include more stable lower brominated diphenyl ethers and polybrominated dibenzofurans (PBDFs). The photoformation and decay kinetics of these photoproducts were also monitorized by photo-SPME. Aqueous photodegradation studies have also been carried out. In this case, SPME is only used as the extraction technique. Obtained results in the aqueous photodegradation experiments were compared with those obtained in photo-SPME experiments. 相似文献
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Bernd Renger 《Journal of heterocyclic chemistry》1983,20(6):1601-1603
In contrast to literature data, m-chloro, bromo or methyl substituents on diphenyl ethers do not block attack ortho to them in the reaction with phosphorus trichloride and aluminium chloride. By reacting diphenyl ethers 3 and 6 mixtures of the isomeric phenoxaphosphinic acids 4/5 and 7/8 were obtained, which were easily separated by crystallisation. 相似文献
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《Journal of separation science》2017,40(3):709-716
Two simplified sample preparation procedures for simultaneous extraction and clean‐up of tetrabromobisphenol A, α‐, β‐, and γ‐hexabromocyclododecane and polybrominated diphenyl ethers in human serum were developed and validated. The first procedure was based on solid‐phase extraction. Sample extraction, purification, and lipid removal were carried out directly on an Oasis HLB cartridge. The second procedure was a quick, easy, cheap, effective, rugged, and safe‐based approach using octadecyl‐modified silica particles as a sorbent. After sample extraction and cleanup, tetrabromobisphenol A/hexabromocyclododecane was separated from polybrominated diphenyl ethers by using a Si‐based cartridge. Tetrabromobisphenol A and hexabromocyclododecane were then detected by high‐performance liquid chromatography coupled to tandem mass spectrometry, while polybrominated diphenyl ethers were detected by gas chromatography coupled to tandem mass spectrometry. The results of the spike recovery test using fetal bovine serum showed that the average recoveries of the analytes ranged from 87.3 to 115.3% with relative standard deviations equal to or lower than 13.4 %. Limits of detection of the analytes were in the range of 0.4–19 pg/mL except for decabromodiphenyl ether. The developed method was successfully applied to routine analysis of human serum samples from occupational workers and the general population. Extremely high serum polybrominated diphenyl ethers levels up to 3.32 × 104 ng/g lipid weight were found in occupational workers. 相似文献
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Effect of the Structure of Benzo- and Dibenzocrown Ethers on Their Reaction with the Aerosil Surface
O. V. Zakolodyazhnaya L. V. Litvinova N. S. Kraevskaya S. A. Kotlyar G. L. Kamalov 《Theoretical and Experimental Chemistry》2005,41(4):259-264
The adsorption of 4-substituted benzo- and 5,5′-disubstituted dibenzocrown ethers from benzene by aerosil A-300 was studied.
The ethers included a total of 45 compounds with diphenyl oxide, diphenyl, and diphenyl sulfide fragments. Analysis of the
Henry coefficients (KH) and the extent of desorption, the IR spectra of the adsorbed compounds, and the relationship between their structure and
adsorption capacity indicated that all structural fragments of the crown ethers studied interact to some extent with aerosil
surface fragments. The number of oxygen atoms in the polyether fragment and the size of the macrocycle are the predominant
factors. A large, nonadditive increase in KH is observed in going from pentadentate to hexadentate crown ethers.
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Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 247–251, July–August, 2005. 相似文献