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1-苯基-3-甲基-5-吡唑啉酮与二羰基化合物的固相反应研究 总被引:1,自引:0,他引:1
报道了苯偶酰及其衍生物、对二甲氨基苯偶姻、邻苯二甲酰亚胺与1-苯基-3-甲基-5-吡唑啉酮的固相热反应研究;这个热反应以较高的选择性生成1:1缩合产物的一种异构体,通过IR、1HNMR、MS和元素分析确定了新产物的结构,并通过X射线衍射分析确定了其中一个产物的构型。 相似文献
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以丹皮酚和2,4-二羟基苯乙酮为研究对象,采用Q Exactive四极杆-静电场轨道阱高分辨质谱系统,及内置有Ⅰ相和Ⅱ相代谢途径分析的MetWorks代谢物鉴定软件,系统分析丹皮酚经肝微粒体代谢的Ⅰ相代谢及其Ⅰ相代谢产物2,4-二羟基苯乙酮经微粒体代谢的Ⅱ相代谢产物。结果表明,丹皮酚在大鼠肝微粒体中经Ⅰ相代谢后产物主要为4位去甲基化的2,4-二羟基苯乙酮和1位相邻羰基的脱甲基化的2-羟基-4-甲氧基苯甲醛以及5位的羟基化代谢产物2,5-二羟基-4-甲氧基苯乙酮,而2,4-二羟基苯乙酮的Ⅱ相代谢产物主要为4位葡萄糖醛酸化的糖苷化代谢产物2-羟基-4’-O-葡萄糖醛酸苯乙酮。 相似文献
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α-烷基-α-氨基酸的合成 总被引:2,自引:0,他引:2
本文研究了八种酮在相转移催化剂存在下与氯仿和氨水的作用。一步得到α-烷基-α-氨基酸和它们的酰胺。用脂肪族甲基酮和环戊酮作原料时,仅得到α-烷基-α-氨基酸一种产物。 相似文献
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使用四丁基溴化铵为相转移催化剂,以4-氯-1-丁醇作为起始原料,与邻苯二甲酰亚胺钾盐反应制备N-(4-羟基丁基)邻苯二甲酰亚胺(中间产物),中间产物在氢氧化钠的作用下水解得到4-氨基-1-丁醇。通过高分辨质谱、核磁共振谱等对中间产物和产品进行了测定和结构表征。考察了反应溶剂、4-氯-1-丁醇与邻苯二甲酰亚胺钾盐摩尔比、反应温度、反应时间、四丁基溴化铵与邻苯二甲酰亚胺钾盐摩尔比对中间产物收率的影响,优化反应条件之后4-氨基-1-丁醇最佳的总收率为77. 2%。此工艺路线具有合成方法简便、反应条件温和、产品收率高等优点,可以进行工业放大。 相似文献
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N,N,N',N'-四丁基-3-氧-戊二酰胺(TBOPDA)是一种新合成的萃取剂,它可以在高酸度情况下萃取铀等锕系元素,在高废液的萃取处理中具有良好的应用前景。曾有报道采用GC方法分析辐照后的气相产物,本文采用固相微萃取技术萃取TBOPDA部分挥发性和半挥发性液相辐照产物,结合GC-MS进行鉴定,确定了其液相辐照产物主要为二丁胺、二正丁基甲酰胺、二正丁基乙酰胺。结果表明这是一种简便、快速、可靠的分析方法,具有较高的分析灵敏度。 相似文献
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Parameters such as solution concentrations and composition of the ambient atmosphere are known to be important in phase and morphology control in the solvothermal synthesis of CdS semiconductor nanorods (NRs), but a clear understanding of the underlying mechanisms involved is lacking. In this work, a series of experiments were performed to demonstrate that the key factor affecting the phase and morphology of CdS NRs is the amount of O(2) in the space above the reaction solution in the sealed vessel relative to the amount of precursors in solution: O(2)-depleted conditions resulted in more cubic phase CdS and thick polycrystalline NRs with an aspect ratio usually less than 3, which have small blue shifts in band-edge emission and little surface trap emission, while O(2)-rich conditions resulted in more hexagonal-phase CdS and slim single-crystal NRs, which have significantly blue shifted band-edge emission and relatively strong surface trap emission. Thus, increasing the amount of solution in the vessel, changing the ambient atmosphere from air to N(2), and increasing the reagent concentration all lower the molar ratio of O(2) to reagents and lead to more cubic phase and thicker NRs. The results indicate that the composition of the "empty" section of the reaction vessel plays as important a role as the composition of the liquid in determining the phase and morphology, something that has been overlooked in earlier work. A mechanism to explain the effect of oxygen on the nucleation and growth stages has been proposed on the basis of those results and further supported by shaking experiments and ZnS NR synthesis manipulation. The CdS NRs synthesized under different conditions showed obvious differences in photocatalytic activity, which indicated that controlling the synthetic process can lead to materials with tailored photocatalytic activity. 相似文献
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The generation of diverse chemical libraries using the "libraries from libraries" concept by combining solid-phase and solution-phase methods is described. The central features of the approaches presented are the use of solid-phase synthesis methods for the generation of a combinatorial polyamine library. Following cleavage from the resin with HF, the polyamine library was reacted with ethyl nitrite in the solution phase to yield the desired nitrosamine library in good yield and purity. The approaches described enable the efficient syntheses of individual nitrosamines as well as mixture-based nitrosamine libraries. 相似文献
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Pirok G Maté N Varga J Szegezdi J Vargyas M Dórant S Csizmadia F 《Journal of chemical information and modeling》2006,46(2):563-568
Predicting "realistic" compounds of given chemical reactions with virtual synthesis tools usually requires the manual intervention of experienced chemists in the enumeration phase for the selection of appropriate reactants, assignment of the corresponding reaction sites, and removal of the unlikely products. To automate the virtual synthesis process, we have moved the expertise intensive parts from the compound library design phase to the reaction library design phase. ChemAxon is building an in silico reaction library containing important preparative transformations, where each reaction definition contains a generic transformation scheme and additional rules to handle the various starting compounds according to the corresponding chemo-, regio-, and stereoselectivity issues. Having well designed reaction definitions in hand, our software tool is able to generate synthetically feasible compound libraries with minimal effort in the enumeration phase. 相似文献
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Carbocations have been generally considered to be relatively unstable and transient species. But the "cation pool" method enables the easy accumulation of carbocations in conventional reaction media such as dichloromethane. In the "cation pool" method, carbocations are generated by low-temperature electrochemical oxidation and accumulated in a solution. In the next step, the carbocations thus produced are allowed to react with various nucleophiles. Combinatorial parallel synthesis based upon the "cation pool" method has also been developed. The applicability of the "cation pool" method depends upon the stability of the cation that is accumulated. This problem can be overcome by the "cation flow" method. In the "cation flow" method, carbocations are generated in a microflow electrochemical system. Short residence times and efficient temperature control of the microflow system are advantageous. Combinatorial sequential synthesis has been achieved based on the "cation flow" method. 相似文献
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Pivonka DE 《Journal of combinatorial chemistry》2000,2(1):33-38
This report introduces two novel methodologies for the on-bead, functional group quantitation of solid phase synthesis using vibrational spectroscopy. "Analogue bleed" quantitation is an infrared spectroscopic technique in which combinatorial library bead spectral data are regressed against solution phase functional analogue spectra of a ligand in question. "Dual Analogue" quantitation is introduced as an infrared or Raman technique in which ligand-to-styrene band ratios of solution phase ligand/styrene monomer standards are used to generate an internally path length referenced calibration which can then be applied to solvent swollen beads. These technologies have application across a wide range of functional groups and can be applied throughout each step of a resin bound synthesis. 相似文献
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Shu-Li You 《Tetrahedron letters》2005,46(15):2567-2570
The first total synthesis of didmolamides A (1) and B (2) has been accomplished by the solid phase assembly of thiazole-containing amino acids and commercially available Fmoc-protected amino acids. The synthesis of didmolamide B was also achieved in high yield using solution phase peptide synthesis. The thiazole-containing amino acid composing 1 and 2 was synthesized by a MnO2 oxidation of a thiazoline, prepared from an Ala-Cys dipeptide using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate. The final macrolactamization was accomplished efficiently by PyBOP and DMAP in solution. 相似文献
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Kirschning A Monenschein H Wittenberg R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(24):4445-4450
A polymer-assisted organic synthesis that combines the concept of solid-phase synthesis with the idea of polymer-supported scavenging reagents has recently appeared on the chemistry scene. This technique has frequently been termed the "resin-capture-release" methodology and is initiated by the immobilization of a small molecule on a polymeric support. This intermediate is subjected to a second transformation by adding a new reaction partner in solution. This reactant plays two roles: a) the chemical alteration of the polymer-bound intermediate and b) the simultaneous release of this reaction product from the resin back into solution. This new concept is presented and future prospects are discussed. 相似文献
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Park JI Kim MG Jun YW Lee JS Lee WR Cheon J 《Journal of the American Chemical Society》2004,126(29):9072-9078
The structure, magnetism, and phase transition of core-shell type CoPt nanoparticles en route to solid solution alloy nanostructures are systematically investigated. The characterization of Co(core)Pt(shell) nanoparticles obtained by a "redox transmetalation" process by transmission electron microscopy (TEM) and, in particular, X-ray absorption spectroscopy (XAS) provides clear evidence for the existence of a core-shell type bimetallic interfacial structure. Nanoscale phase transitions of the Co(core)Pt(shell) structures toward c-axis compressed face-centered tetragonal (fct) solid solution alloy CoPt nanoparticles are monitored at various stages of a thermally induced annealing process and the obtained fct nanoalloys show a large enhancement of their magnetic properties with ferromagnetism. The relationship between the nanostructures and their magnetic properties is in part elucidated through the use of XAS as a critical analytical tool. 相似文献
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Synthesis of "solid solution" and "core-shell" type cobalt--platinum magnetic nanoparticles via transmetalation reactions 总被引:5,自引:0,他引:5
In this article, we report the synthesis of "solid solution" and "core-shell" types of well-defined Co--Pt nanoalloys smaller than 10 nm. The formation of these alloys is driven by redox transmetalation reactions between the reagents without the need for any additional reductants. Also the reaction proceeds selectively as long as the redox potential between the two metals is favorable. The reaction between Co(2)(CO)(8) and Pt(hfac)(2) (hfac = hexafluoroacetylacetonate) results in the formation of "solid solution" type alloys such as CoPt(3) nanoparticles. On the other hand, the reaction of Co nanoparticles with Pt(hfac)(2) in solution results in "Co(core)Pt(shell)" type nanoalloys. Nanoparticles synthesized by both reactions are moderately monodispersed (sigma < 10%) without any further size selection processes. The composition of the alloys can also be tuned by adjusting the ratio of reactants. The magnetic and structural properties of the obtained nanoparticles and reaction byproducts are characterized by TEM, SQUID, UV/vis, IR, EDAX, and XRD. 相似文献
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本文针对多肽合成中缩合反应存在"困难肽段"的情况, 反析了影响缩合率的原因,归纳了改善缩合率的措施。 它们对提高经典液相法及固相法肽合成的质量均有实际意义。 相似文献