共查询到19条相似文献,搜索用时 125 毫秒
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本文研究了二(对硝基苯氧基)-甲烷或对硝基苯酚在浓硫酸的存在下与过量多聚甲醛的反应,合成得到含两个和三个苯环的对硝基苯酚亚甲基桥齐聚物的苯并二噁环衍生物。柱层析分出四个纯品,经IR,~1H NMR,MS分析鉴定,其中三个为新化合物。这类化合物作为合成子可用于硝基取代的杯芳烃或长链亚甲基桥齐聚物的收敛性分步合成。 相似文献
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FOX-7的合成和反应机理研究 总被引:11,自引:0,他引:11
以2-甲基咪唑为原料合成出1,1-二氨基-2,2-二硝基乙烯(FOX-7)并进行了结构表征,从中间体过滤母液中分离出副产物2-甲基-4(5)-硝基咪唑和仲班酸.直接合成的2-甲基-4(5)-硝基咪唑和仲班酸,最佳收率分别为67.3%和63.3%.首次提出了一个较为完整而详细的合成FOX-7的反应机理,硝基重排成亚硝酸酯是反应的关键步骤.FOX-7主要是通过2-甲基咪唑→2-甲基-4(5)-二氢-5-咪唑啉酮→2-(二硝基亚甲基)-5,5-二硝基-4-咪唑烷二酮→2-(二硝基亚甲基)-4,5-咪唑烷二酮→FOX-7步骤形成.论述了各中间体形成的详细过程并进行了证明,应用该机理解释了硝化过程中主产物和副产物的变化规律. 相似文献
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1,1-二氨基-2,2-二硝基乙烯的合成研究进展 总被引:1,自引:0,他引:1
1,1-二氨基-2,2-二硝基乙烯(FOX-7)是一种低感度高能量的新型含能材料.现有的1,1-二氨基-2,2-二硝基乙烯的合成包括以2-甲基咪唑、盐酸乙脒与乙二酸二乙酯、2-甲基-4,6-二羟基嘧啶为前体的三条合成路线.使用硫酸/硝酸体系硝化2-甲基-4,6-二羟基嘧啶可得到2-二硝基亚甲基-5,5-二硝基嘧啶-4,6-二酮,然后水解可得到FOX-7,正相硅胶薄层色谱可对该反应进行监测.使用曲拉通X-100/正己烷体系的反相微乳法可制备FOX-7球形纳米晶;FOX-7球形纳米晶具有良好的应用前景,对其合成工艺与路线进行探索和研究具有一定的意义. 相似文献
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Ponzio 用一系列芳香醛肟与四氧化二氮反应生成相应的芳基二硝基甲烷,曾用于合成苯环上有一个偕二硝基甲基取代的芳基二硝基甲烷;Rowley 和 Frankel 报道用 VictorMeyer 和 ter Meer 反应合成苯环上有两个偕二硝基甲基取代化合物,如对一双(二硝基甲基)苯(1a),但他们的方法和步骤繁冗,试剂昂贵,操作条件苛刻.我们曾报道运用 Ponzio 反应,由对苯二醛二肟合成la,并由间苯二醛二肟合成间-双(二硝基甲基)苯(1b).本文报道 相似文献
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(一)葡萄糖或转化糖在碱性溶液中能把硝基酚类、亚硝基酚类及对磺酸苯偶氮酚类化合物还原成为相应的氨基酚类化合物。得到正面结果的有:阾硝基苯酚、对硝基苯酚、4-硝基2-甲基苯酚、2,6-二氯-4-硝基苯酚、对亚硝基苯酚、4-亚硝基-2-甲基苯酚、α-亚硝基-β-萘酚、对磺酸苯偶氮苯酚、橙Ⅱ等九种化合物。结果可称满意。(二)间硝基苯酚与2,4-二硝基苯酚在上述条件下,得不到相应的氨基酚类化合物。 相似文献
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Triptycene‐Based Chiral Macrocyclic Hosts for Highly Enantioselective Recognition of Chiral Guests Containing a Trimethylamino Group
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Geng‐Wu Zhang Peng‐Fei Li Zheng Meng Han‐Xiao Wang Ying Han Prof. Chuan‐Feng Chen 《Angewandte Chemie (International ed. in English)》2016,55(17):5304-5308
A new class of chiral macrocyclic arene composed of three chiral 2,6‐dihydroxyltriptycene subunits bridged by methylene groups was designed and synthesized. Structural studies showed that the macrocyclic molecule adopts a hex‐nut‐like structure with a helical chiral cavity and highly fixed conformation. Efficient resolution was achieved through the introduction of chiral auxiliaries to give a couple of enantiopure macrocycles, which exhibited high enantioselectivity towards three pairs of chiral compounds containing a trimethylamino group. 相似文献
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Rudolf Nastke Klaus Dietrich Gerhard Reinisch Gerald Rafler Herbert Gajewski 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):579-596
The concentration-time relationships of the individual active species in the oligocondensation stage of the reaction of melamine with formaldehyde have been investigated, mainly by electrochemical methods. Based on the reaction equations, a kinetic model of the overall reaction was established and the rate constants were calculated by numerical methods. The results suggest the hydroxy-methylamines are converted to methylene and dimethylene ether bridged compounds by acid- and base-catalyzed reactions, respectively. At pH 7-10 the formation of methylene bridges by base-catalyzed scission of dimethylene ether bridges may occur. 相似文献
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The type of the stationary phase for reversed-phase liquid chromatography significantly affects the sample polarity range that can be covered using gradients of organic solvents in water. The polarity range available for gradient separations of samples containing compounds differing in the lipophilic parts of the molecules can be characterized by "gradient lipophilic capacity", Pl, based on the retention of standard compounds with a repeat lipophilic structural unit, such as a methylene group. The gradient lipophilic capacity is also suitable to characterize the separation possibilities of the columns in non-aqueous reversed-phase gradient elution of strongly non-polar compounds, such as triacylglycerols. In the same way, the suitability of various columns for reversed-phase gradient separations of oligomers can be characterized by "gradient oligomer capacity", as demonstrated in the example of oligo(ethylene glycols). To enable a comparison of the properties of stationary phases independent of column efficiency and dimensions, the gradient lipophilic capacity or the gradient oligomer capacity should be normalized for a "standard" column plate number, gradient range and volume (in column hold-up volume units). The gradient lipophilic capacity or the gradient oligomer capacity and the number of compounds that can be resolved during a gradient run decrease as the initial concentration of the strong solvent in the mobile phase increases and (or) the gradient time decreases. These quantities can be used to select a suitable column and to adjust the optimum gradient profile (the initial composition of the mobile phase and the gradient steepness) with respect to the time of analysis and the number of oligomers or other compounds with regular repeat structural groups that can be resolved during the gradient run. 相似文献
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Schiff base oligomer of 2-[(4-fluorophenyl) imino methylene] phenol (FPIMP) was synthesized via oxidative polycondensation reaction in an alkaline medium. Oligomer-metal complex compounds were synthesized from the reactions of oligo-2-[(4-fluorophenyl) imino methylene] phenol (OFPIMP) with Co+2, Ni+2 and Cu+2 ions. The synthesis was achieved by oxidative coupling based on air oxygen as an oxidant. While synthesized Schiff base oligomer was soluble in most common organic solvents, its metal complexes were only soluble in dimethylsulfoxide. Electrochemical HOMO and LUMO band gap (Eg) of monomer, oligomer and its metal complexes were calculated from oxidation and reduction onset values. According to cyclic voltammetry (CV) and UV-vis measurements, electrochemical energy gaps and optical band gap (Eg) values of monomer and oligomer were found to be 3.26 and 3.10; 3.15 and 2.96 eV, respectively. Conductivity measurements of doped and undoped Schiff base oligomer and its metal complexes were carried out by electrometer at a room temperature and atmospheric pressure and were calculated from four-point probe technique. When iodine was used as doping agent, conductivity of this oligomer and its metal complexes were observed to be increased. 相似文献
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Timothy R. Dargaville Felix N. Guerzoni Mark G. Looney Devon A. Shipp David H. Solomon Xiaoqing Zhang 《Journal of polymer science. Part A, Polymer chemistry》1997,35(8):1399-1407
The number- and weight-average molecular weights of several statistical and high ortho novolac resins were determined using gel permeation chromatography (GPC). The standards used were pure compounds having between 2 and 12 phenol units bridged via methylene linkages. Three series of compounds were studied: (i) those with methylene linkages substituted in only the ortho positions relative to the phenolic hydroxyl group; (ii) those in which all para positions, together with sufficient ortho positions, were used to synthesize the compounds; and (iii) those in which the methylene linkages were substituted at a mixture of ortho and para positions. Such compounds, having known molecular architecture and units similar to the segments of industrial novolac resins, provide for a more exact measurement of the molecular weight than do the commonly used poly(styrene) standards. Using these new standards the number average molecular weights of the resins determined by GPC were in good agreement with the average molecular weight obtained by 1H-NMR spectra of the resins, particularly for low molecular weight resins. GPC analysis of higher molecular weight resins tends to underestimate the molecular weights because of complications introduced by hydrogen bonding. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1399–1407, 1997 相似文献
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Sung‐Seen Choi 《先进技术聚合物》2002,13(2):94-104
p‐t‐Octylphenol formaldehyde resole resins have two linkage types of methylene‐ and dimethylene ether‐linkages and have three terminal types of hydrogen, methylol, and o‐methylene quinone. Variation of structural characteristics of the resins due to different types of linkages and terminals were studied using molecular dynamics and molecular mechanics. The structural characteristics of the methylene‐bridged resins were intramolecular hydrogen bonds between hydroxyl groups of the adjacent p‐t‐octylphenols. In the dimethylene ether‐bridged resin, the intramolecular hydrogen bonds between oxygen atoms of the dimethylene ether‐linkages and hydroxyl groups of the neighboring phenolic units were found. For the resins with both methylol terminals, one of both terminals of the resins was hidden at the center of the molecule when the resin size is large. The number of hydrogen bonds in the resins with the methylol terminal was larger than for the resins with the o‐methylene quinone terminal. Variation of the structural characteristics of the resins by dehydration of the terminal methylol was discussed. Using the calculated results, dissociation of the dimethylene ether linkage and crosslinking reaction of rubber chains by the resin were explained. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Liu L Tang S Liu M Xie Z Zhang W Lu P Hanif M Ma Y 《The journal of physical chemistry. B》2006,110(28):13734-13740
The stability of fluorene-based compounds and polymers, especially at the bridged C-9 position under photoirradiation and thermal treatment, has claimed wide attention. We report the electronic, vibrational, and MALDI-TOF mass spectral combined studies for the fluorene oligomers with alkyl and aromatic substitutions under UV-light irradiation. The low-energy emission and the formation of ketonic defects after degradation highly depend on the proportion of alkyl substitution. The oligomer with fully aromatic substitution shows good stability, but when the proportion of alkyl substitution increases, their photostability rapidly decreases. The mass spectra show not only the mass of the fluorenone-fluorene trimer but also another new degradation product with a large mass (pristine oligomer plus 14) from alkyl oxidation, which testify to the assistance of alkyl side chain during degradation. We propose that the degradation of fluorene is a radical chain process propagated by alkyl side chains, and then the different stability between alkyl and aromatic substitution can be well explained. 相似文献
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Elena Reinhardt Simon Thamm Dr. Jörg Stierstorfer Prof. Dr. Thomas M. Klapötke 《European journal of organic chemistry》2023,26(23):e202300304
Starting from 3,5-dinitro-4-methylaminopyrazole ( 2 ), six different energetic salts and three new derivatives of methylene bridged nitropyrazoles were synthesized. The derivatives bear a methylamino ( 4 ), methylnitramino ( 5 ), and azido group ( 7 ). All compounds were intensively characterized using single crystal X-ray diffraction, multinuclear NMR spectroscopy, IR spectroscopy, mass spectrometry, elemental analysis and DTA/TGA measurements. The sensitivities were determined according to BAM standard methods and the energetic properties calculated using the EXPLO5 code. The energetic salts were compared with each other and with ANTA in terms of their energetic properties. On the basis of the methyl- and ethyl bridged derivatives, it was shown how the introduction of methylamino ( 4 ) and methylnitramino ( 5 ) groups in an alkyl-bridged nitropyrazole system modify its properties (performance & sensitivities). In addition, azido compound 7 was contrasted with its literature-known constitutional isomer and investigated for its suitability as a potential metal-free primary explosive. 相似文献
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S. V. Berin D. É. Tosunyan E. V. Kuznetsov Yu. A. Zhdanov 《Chemistry of Heterocyclic Compounds》1990,26(3):266-271
The reaction of 2-benzopyrylium salts with vinyl ethyl ether, ethyl acetoacetate, malonodinitrile, and nitromethane gives variously substituted naphthalene derivatives. It is proposed that the reaction with vinyl ether proceeds through [4+2] cycloaddition, while the reaction with the compounds with an active methylene group proceeds either through the ANRORC mechanism or through the formation of bridged intermediates, depending on the conditions.For Communication 38, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 315–320, March, 1990. 相似文献