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1,4-二氢-4-芳基-3,5-吡啶二羧酸酯的合成及表征 总被引:1,自引:0,他引:1
基于二氢吡啶化合物的构效关系, 设计了一系列1,4-二氢-4-芳基-3,5-吡啶二羧酸酯新化合物. 含有易于水解基团的1,4-二氢-4-芳基-3,5-吡啶二羧酸酯类化合物在碱性条件下水解合成了重要中间体1,4-二氢-4-芳基-3,5-吡啶二羧酸单酯, 收率93%~99.8%. 该二羧酸单酯与α-溴代芳基乙酮在相转移剂催化下反应合成目标化合物, 收率74%~99%. 中间体和目标化合物经1H NMR, 13C NMR, IR, MS和元素分析等确证. 相似文献
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1,4-二氢-2,6-二甲基-4-(3-硝基苯基)-3,5-吡啶二羧酸单甲酯(简称单甲酯,结构见图1)是1,4.二氢吡啶类药物的一个重要中间体。消旋二氢吡啶类药物很难直接进行化学拆分,光学纯的二氢吡啶类药物多利用单甲酯的单一对映体合成得到。Delee等将蛋白质类手性固定相用于高效液相色谱拆分单甲酯对映体。本文将Chiralpak AD-H直链淀粉氨基甲酸酯类手性固定相用于高效液相色谱直接对单甲酯对映体进行拆分,方法简便、快捷,分离效果较好。 相似文献
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稻秆木素侧链13C同位素示踪及固体13CNMR分析 总被引:18,自引:0,他引:18
在水稻(Oryza sativa L.)生长过程中,向其茎秆部节间的空腔分别注入在侧链α,β,γ位带有13C标记的松柏醇葡萄糖甙,得到13C标记的稻秆木素,用高分辨率固体核磁13CNMR对其组织进行分析,发现外源性的松柏醇葡萄糖甙并不影响水稻中木素的正常合成.证明了β-O-4,β-β,β-5和β-1结构是稻秆原本木素中的主要结构,另外还有少量的松柏醇和阿魏酸类结构,并证实木素在α位与糖类等组分有共价键形成. 相似文献
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Synthetic way for 13C-labeled oleanolic acid 1 and myricerone 2 has been developed, starting from the parent 1 and 2. The procedure involves ring opening and closure of the A rings of these oleanane triterpenes. 13C was introduced into the 2-position by 13C-MeLi as an isotope source. Chelation controlled addition of methyllithium to -hydoxypentanone 11 is a common crucial step for labeling of 1 and 2, and judicious choice of protecting groups is essential for 2. 相似文献
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Glycitein is one of the soy isoflavones which have attracted considerable interest in recent years due to their possible beneficial effects on human health. However, glycitein has been much less studied than other members of this family due to the lack of good methods for its synthesis. Herein we report a short high yielding synthesis of a multiply 13C-labelled glycitein derivative, [2,3,4-13C3]glycitein, which has been employed as an internal standard in LC–MS analysis. A key feature is a rapid and efficient synthesis of 2,4-dihydroxy-5-methoxy-[1′,2′-13C2]acetophenone via acetylation of isovanillin with [13C2]acetyl chloride followed by a Baeyer–Villiger reaction, selective hydrolysis and finally a BF3 catalysed Fries rearrangement. An aldol reaction using 4-benzyloxy-[carbonyl-13C]benzaldehyde gave a chalcone and then thallium(III) mediated oxidative rearrangement, deprotection and cyclisation provided the [2,3,4-13C3]glycitein. The overall yield for the 8 step reaction sequence, based on [13C2]acetyl chloride, was 57%. 相似文献
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Acenaphthylene-1-13C (1) rearranges at high temperatures in a flow system to give acenaphthylene-5-13C (2) and acenaphthylene-4-13C (3) in a 1:1 ratio as the primary products. This apparent migration of a labeled carbon atom from the bridge to the most remote sites in the molecule can be understood in terms of a benzenoid ring contraction mechanism. 相似文献
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Rudolph Willem Ann Delmotte Inge De Borger Monique Biesemans Marcel Gielen Franois Kayser Edward R. T. Tiekink 《Journal of organometallic chemistry》1994,480(1-2):255-259
The synthesis of (Z)-2-methyl-3-triphenylstannyl-3-pentene-2-ol and its characterization by an X-ray diffraction study and multinuclear NMR are reported. The tin atom exhibits a distorted tetrahedral SnC4 geometry with the four Sn---C bond distances experimentally equivalent. The slight distortion from the ideal tetrahedral geometry is because of the presence of a weak intramolecular HO → Sn interaction of 3.012(3) Å which produces a loose four-membered ring. The title compound was characterized in solution by 1H, 13C and 119Sn NMR, and the persistence of the weak intramolecular HO → Sn coordination in solution was revealed by 13C and 119Sn secondary isotope multiplet of partially labelled entities (SIMPLE-NMR) experiments. 相似文献
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针对环境监测的特点和要求,建立了同位素稀释-高分辨气相色谱/高分辨质谱测定大气中多溴联苯醚(PBDEs)和多溴联苯153(BB153)的方法。采用正己烷/二氯甲烷(1:1, v/v)及正己烷分别对PBDEs和BB153进行快速溶剂萃取,并通过复合硅胶柱净化。在校准曲线最高浓度的10%和90%加标水平下得到的天然内标的平均回收率分别为100%和104%,平均相对标准偏差(n=7)分别为5%和6%;二至十溴代联苯醚和BB153相应的13C同位素标准物质回收率在36.5%~133%之间;而一溴代联苯醚13C同位素标准物质回收率较差,可能是由于物化性质与其他化合物不同。在实际采样体积为300 m3的情况下,未发生污染物穿透现象;分析物检出限低于2×10-4 ng/Nm3,提取内标回收率在56%~126%之间(一溴代联苯醚除外)。实验结果表明该方法能对化合物准确定量,适用于大气中二至十溴代联苯醚和BB153的分析。 相似文献
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The orientational order of a liquid crystalline phase which has a specific solute-liquid crystal interaction was investigated using nuclear magnetic resonance. Three isotopically substituted species of palmitic acid (palmitic acid-d31, 1-13C-2.2-H2-palmitic acid-d29 and 2,2,3,3-H4-palmitic acid-d27) were dissolved in the liquid crystal p-octyloxybenzoic acid (p-OOBA) and the proton, deuteron and carbon 13 NMR spectra recorded as a function of temperature. 1H-13H dipolar couplings were observed using a spin echo pulse sequence which removes heteronuclear dipolar couplings to the chain deuterons. In the case of the carbon 13 labelled compound, 1H-13C dipolar couplings could be observed by applying an additional refocusing pulse to the 13C spins. The dipolar and quadrupolar couplings were used to calculate the complete orientational order matrix of the alpha methylene segment of palmitic acid in p-OOBA. The liquid crystal was shown to largely determine the orientational order of the head group and this was attributed to intermolecular hydrogen bonding. The dipolar and quadrupolar couplings for the rest of the chain were interpreted in terms of a mean field equilibrium statistical model, based on the Samulski Inertial Frame Model. Hydrogen bonding was shown to be of greater importance in the orientational ordering of the solutes in the liquid crystal than are electrostatic interactions in the ordering of the amphiphile in the potassium palmitate/water system. 相似文献
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The 19F , 13C and 1H shielding in methyl fluoride and its deuterated isotopomers has been calculated from ab initio shielding surfaces for selected temperatures. In each case it is the stretching which contributes most to the nuclear motion corrections which total −9.425 ppm for the 19F shielding, −4.558 ppm for the 13C shielding and −0.601 ppm for the proton shielding. However, some second-order stretching and bending contributions are significant. The deuterium induced isotope shifts are substantial and should be easily measurable. There is a predicted nonadditivity in the 19F and 13C isotope shifts which can be traced to two of the bending contributions. 相似文献
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以丁基替换环己基,合成了20种二丁基一环己基锡羧酸酯。利用IR、NMR及元素分析表征了化合物的结构,确定了化合物的质谱裂解机制。对化合物进行了生物活性普筛试验。结果表明,这类化合物同时具有高效杀菌和杀螨活性。 相似文献