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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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芳亚苄基丙二腈;二甲基环己二酮;无催化剂条件下2-氨基-3-氰基-4-芳基-7;7-二甲基-5-氧代-5;6;7;8-四氢-4H-苯并吡喃的合成 相似文献
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在NaHSO4催化下,以苯甲醛和邻氨基苯甲酰胺为底物,在室温下合成了一系列2-芳基-2,3-二氢-4(1H)-喹唑啉酮类化合物,该反应产率高、操作简单、并且避免使用有毒的金属催化剂. 相似文献
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应用芳基异氰酸酯与烯基膦亚胺1的氮杂Wittig反应,得到的碳二亚胺2,再与水合肼作用得到氨基咪唑啉酮衍生物4.而后用4与芳基异氰酸酯(或酰氯)、三苯基膦、六氯乙烷和三乙胺"一锅"反应,得到4,5-二氢咪唑并[1,2-b]-1′,2′,4′-三唑-4-酮衍生物6或7.探讨了所合成新型稠杂环化合物的生物活性,结果表明部分化合物表现出良好的杀菌活性.如7c在50 mg/L浓度时,对棉花枯萎菌、稻瘟菌、黄瓜灰霉菌和油菜菌核菌的抑制率均达100%. 相似文献
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本文报道了以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚为催化剂(20 mol %),1,2-二氯乙烷为溶剂,反应温度为60 oC,可以60-92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物,化合物3a-k均未见文献报道,其结构均经过1H NMR, 13C NMR以及高分辨质谱进行确定。 相似文献
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构建147个有机物分子结构与其热导率值之间的定量结构-性质关系(QSPR)模型, 探讨影响有机物热导率的结构因素. 以147个化合物作为样本集, 随机选择118个作为训练集, 29个作为测试集. 应用CODESSA软件计算了组成、拓扑、几何、静电和量子化学等描述符, 通过启发式方法(HM)筛选得到5个结构参数并建立线性回归模型; 用所选5个结构参数作为支持向量机(SVM)的输入, 建立非线性的支持向量机回归模型. 预测结果表明: 支持向量机回归模型的性能(复相关系数R2=0.9240)虽略低于启发式回归模型的性能(R2=0.9267), 但是支持向量机方法预测性能(R2=0.9682)高于启发式方法的预测性能(R2=0.9574), 对于QSPR模型来说, 预测性能更重要. 因此, 总体来说支持向量机方法优于启发式方法. 支持向量机方法和启发式方法的提出为工程上提供了一种根据分子结构预测有机物热导率的新方法. 相似文献
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The MM4 force field has been extended to include aliphatic amines. About 20 amines have been examined to obtain a set of useful molecular mechanics parameters for this class. The vibrational spectra of seven amines (172 frequencies) calculated by MM4 have an overall rms error of 27 cm(-1), compared with corresponding MM4 value of 24 cm(-1) for alkanes. The rms and signed average errors of the moments of inertia of nine simple amines compared with the experimental data were 0.18% and -0.004%, respectively. The heats of formation of 30 amines were also studied. The MM4 weighted standard deviation is 0.41 kcal/mol, compared with experiment. Electronegativity effects occur in the hydrocarbon portion of an amine from the nitrogen, and are accounted for by including electronegativity induced changes in bond lengths and angles, and induced dipole-dipole interactions in the molecule. Negative hyperconjugation results from the presence of the lone pair of electrons on nitrogen, and leads to the Bohlmann bands in the infrared, and also to strong and unusual geometric changes in the molecules (Bohlmann effect), all of which are fairly well accounted for. The conformational energies in amines appear to be less straightforward than those for most other classes of molecules, apparently because of the Bohlmann effect, and these are probably not yet completely understood. In general, the agreement between the MM4 calculated results and the available data is reasonably good. 相似文献
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Hwangseo Park 《Journal of computer-aided molecular design》2014,28(3):175-186
Extended solvent-contact model was applied to the blind prediction of the hydration free energies of 47 organic molecules included in the SAMPL4 data set. To obtain a suitable prediction tool, we constructed a hydration free energy function involving three kinds of atomic parameters. With respect to total 34 atom types introduced to describe all SAMPL4 molecules, 102 atomic parameters were defined and optimized with a standard genetic algorithm in such a way to minimize the difference between the experimental hydration free energies and those calculated with the hydration free energy function. In this parameterization, we used a training set comprising 77 organic molecules with varying sizes and shapes. The estimated hydration free energies for the SAMPL4 molecules compared reasonably well with the experimental results with the associated squared correlation coefficient and root mean square deviation of 0.89 and 1.46 kcal/mol, respectively. Based on the comparative analysis of experimental and computational hydration free energies of the SAMPL4 molecules, the methods for further improvement of the present hydration model are suggested. 相似文献
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K.S. Levchenko K.A. Chudov E.V. Zinoviev K.A. Lyssenko A.N. Fakhrutdinov D.U. Demin N.O. Poroshin P.S. Shmelin E.P. Grebennikov 《Tetrahedron letters》2019,60(23):1505-1508
A series of new chromophores based on 4-(dicyanomethylene)-2-vinyl 4H-chromenes was synthesized and their physical properties (UV–Vis, NMR, mass spectrometry) were studied. The chromophores show moderate or good solubility in organic solvents. Solvatochromism was investigated for compounds in solvents of low (1.4-dioxane, chlorobenzene, methylene chloride) and high polarity (acetone, acetonitrile). The calculations of the first hyperpolarizability (β) was performed using M052X/6-31+G(d) approximation. Chromophore’s molecules are characterized by high calculated values of the first hyperpolarizability (β) that is only 15% lower than that of FTC analogs. 相似文献
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To estimate the thermochemical properties, bond dissociation energies and atomization energies of sulfur organic derivatives, the complete basis set (CBS) method was employed at the lower computational level (CBS‐4) owing to the large molecular size of a number of the molecules chosen. By comparison with experimental values, calculated values of thermochemical properties are subject to error, which increases in line with the increase in molecular complexity. The main source of error affecting the calculated enthalpy of formation stems from the difference between the energy of the molecule and that of the single atoms: the greater the size of the molecule, the greater the accumulation of error. By acting on the empirical correction to the CBS energy and minimizing the error due to the contribution of the single atoms to the dissociation energy a parameter di for each atom i is obtained. Application of these corrections does not greatly affect the heats of formation of the small molecules included in test sets employed for previous comparisons of calculated and experimental values, while there is a great improvement in the case of large molecules, for example, diphenyl disulfide. The mean absolute deviation turns out to be 2.52, which is greater than that obtained in recent reexaminations of model chemistry methods including the G3 and G3(MP3) approaches. The improvement in the results calculated for large molecules, whose heats of formation are calculated with large errors at the CBS‐4 level, in comparison also with the CBS‐4M version, justify our approach. © 2000 John Wiley & Sons, Inc. J Comput Chem 21: 1405–1418, 2000 相似文献
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On the basis of the calculated atomic polar tensors the generalized atomic polar tensor charges have been calculated for 4-isopropylphenol (4-IP) and related compounds: benzene, quinone, phenol and p-nitroaniline (p-NA). The second order Möller–Plesset perturbation method and Huzinaga–Dunning's double valence ζ basis set supplemented by d polarisation function on heavy atoms and p on hydrogen atoms (D95V**) have been used. Analysis of the atomic charges has been done. It is found that the phenyl rings of the 4-IP and p-NA molecules have an intermediate structure between the aromatic ring and the quinoid one. 相似文献
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Introduction4-Mercaptopyridine(4MPY)has been always em-ployed as a model molecule and a probe molecule forRaman spectra in many studies because of its specialstructure with two active groups and its excellent signalin a Raman spectrum.Therefore,4MPY has b… 相似文献
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Wu SY Dong HN Wei WH 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(13-14):2886-2890
The spin-Hamiltonian (SH) parameters g factors g(parallel), g(perpendicular) and the hyperfine structure parameters A(parallel) and A(perpendicular) for Er3+ at the tetragonally distorted dodecahedral Th4+ site in ThGeO4 are theoretically investigated by using the perturbation formulas of the SH parameters for a 4f11 ion in tetragonal symmetry. In these formulas, the contributions to the SH parameters from the second-order perturbation terms and the admixture of various energy levels are taken into account. The related crystal-field parameters are calculated from the geometrical relationship of the impurity center and the superposition model. Based on the studies, the lowest Kramers doublet is found to be Gamma7, rather than Gamma6 suggested in the previous work. The calculated SH parameters for Gamma7 doublet in this work are smaller than those obtained for Gamma6 doublet in the previous work and in good agreement with the observed values. The various contributions to the SH parameters are discussed. 相似文献
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Four studies of the 1H NMR spectrum for the aromatic protons of 4-fluoroaniline between 1958 and 1974 give three very different solutions to the second-order, AA′BB′X, spectrum. A re-evaluation of the second-order spectrum was done at 300 MHz. Simultaneous simulations of the 1H NMR spectrum and 19F NMR spectrum for 4-fluoroaniline were done using WINDNMR-Pro, and a new set of parameters for the six coupling constants was obtained from the optimized simulations. This new set of parameters was used as a basis to evaluate the AA′BB′X spectrum for the aromatic protons in N4-(4′-fluorophenyl)succinamic acid and in N4-(4′-fluorophenyl)-3,3-difluorosuccinamic acid by simultaneous simulations of the 1H NMR spectrum and 19F NMR spectrum for each using WINDNMR-Pro. Formation of the amide bond results in small, but significant, changes in the values for the set of parameters in both molecules. These results confirm that second-order analyses as an AA′BB′X system are required for derivatives of 4-fluoroaniline, rather than first-order analyses that have been used in previous reports. 相似文献
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Karabacak M Postalcilar E Cinar M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2012,85(1):261-270
In this work, the molecular conformation and vibrational analysis of 2-, 3-, 4-nitrobenzenesulfonamide (abbreviated as 2-, 3-, 4-NBSA) were presented for the ground state using experimental techniques (FT-IR and FT-Raman) and density functional theory (DFT) employing B3LYP exchange correlation with the 6-311++G(d,p) basis set. The complete assignments of fundamental vibrations were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The effects of the nitro group substituent on the characteristic benzene sulfonamides bands in the spectra were discussed. Raman activities calculated by DFT method have been converted to the corresponding Raman intensities using Raman scattering theory. Optimized structure of compounds were interpreted and compared with the earlier reported experimental values for studied molecules. The observed and the calculated geometric parameters and vibrational wavenumbers were compared and found to be in good agreement. 相似文献