共查询到20条相似文献,搜索用时 67 毫秒
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2-硝基咪唑是一种重要的医药中间体,可用于合成多种抗癌药物,通过对其结构进行修饰,有望开发新型活性药物分子。以2-氨基嘧啶和3-溴丙酮酸乙酯为起始原料,经过缩合环化、肼解、氧化和取代合成了一系列1-烷基-2-硝基-1H-咪唑-5-甲酸乙酯(7a~7d)及其同分异构体1-烷基-2-硝基-1H-咪唑-4-甲酸乙酯(8a~8d),该方法克服了传统合成路线中氮原子上取代基仅为甲基的局限性。研究不同取代基对2种异构体比例的影响,结果表明:随着取代基团的给电子能力增强,更加有利于化合物7的生成。所有合成化合物的结构都经过1H NMR,13C NMR和MS(ESI)确证或表征。 相似文献
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硫化钠和二硫化钠分别在95%乙醇中与2,5-二甲氧基-4-氯硝基苯反应, 原本期望得到2,5-二甲氧基-4-氯苯胺, 然而对产物结构的1H NMR, 13C NMR, MS以及元素分析结果表明, 2,5-二甲氧基-4-氯硝基苯中的硝基没有被硫化钠和二硫化钠还原成氨基, 而是其中的氯原子被硫离子(或二硫离子)取代, 分别生成了4,4’-硫代-2,2’,5,5’-四甲氧基-双硝基苯和4,4’-双硫代-2,2’,5,5’-四甲氧基-双硝基苯. 根据这个实验事实, 讨论了上述亲核取代反应的机理. 相似文献
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酚在碱性条件下与卤代烃反应生成相应的芳香醚,是典型的亲核取代反应,对于2,4-二硝基酚和二氟溴甲基膦酸二乙酯在碱性条件下的反应,其实验过程包括室温中和,甲苯回流脱水和亲核取代等三步反应。对产物进行了提纯和一系列的表征,结果发现主要生成了一种酚醚化合物。 相似文献
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在胺存在下,3,7-二硝基二苯并溴五环硫酸氢盐与二甲基亚砜反应生成2-溴-4,4'-二硝基-3'-二甲基锍-2'-联苯酚内盐(3).3的X射线晶体结构分析数据表明其分子具有内盐结构但酚氧负离子的负电荷是部分离域的,分子内两苯环所成的两面角为117.3°.3在熔解时发生重排及热分解分别生成2-溴-2'-甲氧基-3'-甲硫基-4,4'-二硝基联苯(6)及3,7-二硝基-4-甲硫基-二苯并呋喃(7).3与盐酸反应生成相应的锍盐(8). 相似文献
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2-Azido-4-nitroimidazole and its derivatives have been synthesized for energetic material applications. The synthesized compounds were fully characterized by 1H, 13C NMR spectroscopy and elemental analysis. Most of them were determined by single crystal X-ray diffraction. The calculated densities of the compounds range between 1.71 and 1.92 g,cm-3. The calculated detonation pressures (P) for these derivatives fall in the range of 25.17 to 32.62 GPa and the detonation velocities (D) are distributed from 7.65 to 8.55 km·s-1. 相似文献
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利用固-液相转移催化法合成了7种α,ω-双[1-(2-甲基-4-硝基咪唑基)]烷烃和20种1-烷基-2-甲基-4-硝基咪唑类化合物,大多数化合物收率在85%以上。初步生物活性试验结果表明,部分化合物具有一定的抗炎、抗菌、镇痛、镇静或抗脑缺氧活性。 相似文献
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The electrochemical reduction of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDT) is studied with the aid of cyclic voltammetry and electrolysis at a constant potential on a glassy-carbon electrode in a 0.1 M solution of Bu4NBF4 in dimethylformamide. Cyclic voltamograms for DBEDT exhibit two irreversible peaks corresponding to successive abstraction of bromine atoms. Electrolysis at potentials more negative than the potential of the first peak and more positive than the potential of the second peak leads to the formation of an electrochemically active film of poly(3,4-ethylenedioxythiophene) (PEDT). Cathodic polymerization of dibromothiophene with the formation of an electroactive film is performed for the first time ever without a catalyst. The poor stability of the film is attributed to the presence of exceedingly unstable monobromo-3,4-ethyl-enedioxythiophene in it. PEDT, obtained from DBEDT with the aid of thermal polymerization, forms a stable electrochemically active film when rubbed onto a glassy-carbon electrode. 相似文献
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Synthesis and Characterization of Some N-Aryl-4-nitroimidazoles as Potential Insensitive Energy Materials 总被引:2,自引:0,他引:2
N‐Aryl derivatives of 4‐nitroimidazole have been synthesized under CuI/TBAB catalytic system in excellent yields, using KOH as base in DMF solvent. 相似文献
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Syntheses of 2,5-bis(4-methyl-2-thienyl)thiophene 3 and 2,5-bis(4-methyl-2-thienyl)pyrrole 4 are described. The key step involves Stetter reaction between 4-methyl-2-thiophenecarboxaldehyde and divinyl sulfone. Cyclizaton of the resulting 1,4-bis-(4-methyl-2-thienyl)-1,4-butanedione 2 with Lawesson's reagent gives 2,5-bis(4-methyl-2-thienyl)thiophene 3, whereas condensation with ammonium acetate provides the 2,5-bis(4-methyl-2-thienyl)pyrrole 4. 相似文献
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2,5-Dimethoxy-2,5-dihydrofuran (DDF) reacts with dichloroketene to give 7,9-dimethoxy-3,3,5,5-tetrachloro-8-oxabicyclo[4,3,0]-noan-2,4-dione (I), and methyl chloro-(2,5-dihydro-5-methoxy-2-furanylidene) acetate (II). The reactions of 2,5-dihydrofuran and 2,5-dimethoxy-tetrahydrofuran with dichloroketene were also-studied for comparison. Compound II was derived from the insertion of a molecule of dichloroketene into the C-O bond of DDF with subsequent dehydrochlorination. Compound I resulted from the cycloaddition of two molecules of dichloroketene to the C=C bond of DDF. A mechanism involving a 1,5-dipolar intermediate is proposed to account for this novel reaction. 相似文献
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Fluoroquinolonesareeffectivemedicinesagainstbacteria,evenagainsttumor.Overtenexcellentfluoroquinol0nemedicineshavebeen0nthemarket.Duet0thehigherselectivity,yieldatbrondnationof3-flu0rotoluenethanchlorination,and0theradvantages'-',2,4-dibromo-5-flu0r0benzoicacidhasreplaced2,4-dichloro-5-fluor0-benzoicacidandbecomethekeystartingmaterialofpreparingfluoroquinoIonemedicines'.S0itisofgreatsignificancetofindaneffectivesyntheticpathfor2,4-dibromo-5-fluor0benz0icacid.Therehavebeenproposedtwomethodsf0r… 相似文献
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2,5-Dimethylene-2,5-dihydrofuran (3), generated flash pyrolitically, underwent di- and trimerization reactions to give cyclic dimer and trimer. Compound 3 was trapped with methanol, ethanol, bromine, acetic acid, thiophenol and oxygen. Results from trapping experiments suggest that the diradical form of 3 is involved. 相似文献