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1.
超声波作用下的糖精相转移催化N-苄基化反应的研究嵇学林刘华黄昆(江苏镇江医学院有机化学教研室镇江212001)关键词超声波相转换催化糖精苄基化有机声化学近年来,由于超声波(Ultrasoun,缩写U.S)在有机合成中应用的不断发展,逐渐形成了一门新兴...  相似文献   
2.
A silver(I)-saccharinato (sac) complex with nicotinamide (nia), [Ag(sac)(nia)] n has been synthesized and characterized by elemental analysis, IR spectroscopy, DTA-TG analyses and single crystal X-ray diffractometry. The complex crystallizes in monoclinic space group P21/n with unit cell parameters of a=7.0258(4) Å, b=24.3784(10) Å, c=8.4301(5) Å, β=109.407(5)°, V=1361.85(13) Å3 and Z=4. [Ag(sac)(nia)] n contains [Ag(sac)(nia)] units, which are doubly bridged by both nia and sac ligands, leading to a linear one-dimensional polymeric chains running along the a axis. The silver(I) ion has a highly distorted AgN2O2 tetrahedral geometry and the coordination polymer exhibits relatively short intra-chain ligand supported Ag···Ag separations of 3.1593(4) Å. The one-dimensional chains are crosslinked by N–H···O hydrogen bonds and aromatic π(sac)···π(nia) stacking interactions to generate a two-dimensional layer structure. IR spectra and thermal analysis data are in agreement with the crystal structure.  相似文献   
3.
A new assembly [Cu2(sac)2(μ‐dmea)2(μ‐H2O)]n (sac = saccharinate and Hdmea = 2‐dimethylaminoethanol) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X‐ray diffraction. The complex crystallizes in the monoclinic space group C2/c and consists of dinuclear modules of [Cu2(sac)2(dmea)2]. The sac ligand is N‐coordinated, while the dmea ligand is in the deprotanated form by losing the ethanol hydrogen atom and acts as a bidentate donor through the alkoxo group and N atom. The alkoxo group also serves as a bridge between two copper(II) ions, leading to an intra‐dimer Cu···Cu separation of 3.0229(7) Å. The dimeric units are bridged by aqua ligands to generate a one‐dimensional water‐bridged helical chain, in which the copper(II) ions exhibit a distorted square‐pyramidal CuN2O3 coordination. The Cu–Cu distance in the chain separated by the bridging aqua ligands is 5.297Å. The polymeric chains are further linked by π(sac)···π(sac) and C–H···π(sac) interactions into a two‐dimensional supramolecular network.  相似文献   
4.
A silver(I) complex of saccharinate (sac) with pyrazine (pyz), [Ag(sac)(pyz)] n , has been synthesized and characterized by elemental analysis, IR, thermal analysis, and single-crystal X-ray diffractometry. The complex crystallizes orthorhombic space group Pnma with unit cell parameters of a = 13.0073(9) Å, b = 6.4907(6) Å, c = 13.4007(9) Å, V = 1131.37(15) Å3, and Z = 4. [Ag(sac)(pyz)] n is a one-dimensional coordination polymer, in which the sac ligand acts as a monodentate ligand through the N atom and the trigonal silver centers are linked by the bridging pyz ligands. The individual chains are connected into two-dimensional supramolemular network by aromatic π(sac)···π(pyz) stacking interactions. The FTIR spectrum of [Ag(sac)(pyz)] n has been recorded in the region and 4,000–400 cm?1. The optimized geometry, frequency, and intensity of the vibrational bands of [Ag(sac)(pyz)] n were obtained by density functional theory (DFT) at the B3LYP level. The vibrational frequencies were calculated and the scaled values have been compared with the experimental FTIR data. The observed and calculated frequencies are found to be in good agreement.  相似文献   
5.
6.
Nanocrystalline Zn-Ni (crystallite sizes 13-68 nm) alloy coatings were produced from an alkaline glycinate bath containing saccharin as additive. X-ray diffraction (XRD) was used to determine the phase composition and average crystallite size of nanocrystalline Zn-Ni alloy coatings. The average grain size of a deposit was also studied by transmission electron microscopy (TEM). The effects of saccharin concentration and current density on the crystallite size and surface roughness of the coatings were studied. Crystallite size and average surface roughness were diminished as a result of increasing saccharin concentration. Scanning electron microscopy (SEM) examination showed that coatings had a colony-like morphology and the colony size was increased with increasing current density. Microhardness testing was carried out in order to determine the degree of dependence of this mechanical property on the crystallite size. It was found that microhardness did not depend on crystallite size (Hall-Petch).  相似文献   
7.
测定不同温度下阿德福韦酯(AD)在系列浓度糖精(SAC)乙醇溶液中的溶解度及AD在恒温下系列浓度糖精水溶液中的溶解度, 研究AD-SAC共晶形成的热力学, 得到了共晶的溶度积(Ksp)、络合常数(K11)及反应自由能(ΔG0)等热力学参数, 建立了不同温度下的AD-SAC-乙醇三相图. 结果表明: 在乙醇中, 温度对Ksp和K11有极显著性影响(P<0.01), 随着温度的降低, Ksp逐渐减小, K11增大, 共晶的溶解为吸热过程, 共晶的形成为吸热的自发过程, 温度的下降有利于增加AD与SAC在乙醇中的络合效应. AD在SAC水溶液中的溶解度随SAC浓度的升高呈现三阶段特征, 先线性增长至平台区后再倒数下降.  相似文献   
8.
美洛昔康的合成   总被引:1,自引:0,他引:1  
许佑君  刘锋 《合成化学》1999,7(2):118-120
从糖精钠出发,经4步反应合成美洛昔康,总收率43.5%,首次分离,纯化了甲基化反应的重要副产物,经元素分析、氢谱,质谱确定为双甲基化产物。用重结晶方法对单甲基化物进行纯化。  相似文献   
9.
The dinuclear ruthenium complexes [Ru2(μ-sac)2(CO)6] (1), [Ru2(μ-sac)2(CH3CN)2(CO)4] (3), [Ru2(μ-sac)2(CO)5(PPh3)] (4) and [Ru2(μ-sac)2(CO)4(PPh3)2] (5) as well as the tetranuclear ruthenium complex [Ru2(μ-sac)2(CO)5]2 (2) (sac = saccharinate, C7H4NO3S) were synthesized starting from Ru3(CO)12 and saccharin. X-ray crystal structure analysis of 1, 3A × p-xylene, 4 × CH2Cl2 and 5 × 3CH2Cl2 showed that the core is bridged through the amidate moieties of the two saccharinate ligands, with a head-tail arrangement in complexes 1, 3A and 5, and a head-head arrangement in 4. For complex 3, an equilibrium mixture of the head-head regioisomer 3A and a second species 3b exists in solution. Complexes 1 and 2 are suitable catalysts for the cyclopropanation of nucleophilic alkenes (styrene, cyclohexene and 2-methyl-2-butene) with methyl diazoacetate.  相似文献   
10.
Mixed-ligand complexes of general formula, [Cu(NNS)(sac)] (NNS′ = S-benzyl-β-N-(2-acetylpyrid-2-yl)methylenedithiocarbazate, NNS″ = S-benzyl-β-N-(2-benzoylpyrid-2-yl)methylenedithiocarbazate and NNS? = S-benzyl-β-N-(6-methylpyrid-2-yl)methylenedithio-carbazate, sac = the saccharinate anion) have been synthesized by reacting [Cu(sac)2(H2O)4] · 2H2O with the appropriate ligands in ethanol and characterized by various physico-chemical techniques. Magnetic and spectral evidence indicate that the complexes are four-coordinate in which the Schiff bases coordinate as NNS ligands and the sac- anion coordinates as a unidentate N-donor ligand. An X-ray crystallographic structural analysis of [Cu(NNS′)(sac)] shows that the complex has a distorted square-planar geometry with the Schiff base coordinated to the copper (II) ion as a uninegatively charged tridentate chelating agent via the pyridine nitrogen atom, the azomethine nitrogen atom and the thiolate sulphur atom while the fourth coordination position is occupied by the N-bonded saccharinate anion. The complexes have been evaluated for their biological activities against selected pathogens and cancer cell lines. They display weak activity against the pathogenic bacteria and fungi. The complexes were highly active against the leukemic cell line (HL-60) but only [Cu(NNS′)(sac)] was found to exhibit strong cytotoxicity against the ovarian cancer cell line (Caov-3). All complexes were inactive against the breast cancer cell line (MCF-7).  相似文献   
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