微波诱导催化合成N-乙基咔唑

咔唑是染料、香料、医药等产品的中间体 [1] ,它及其衍生物是一类杂环芳香烃化合物 ,有些咔唑衍生物还是很好的有机先导材料。 N—乙基咔唑是合成染料硫化还原蓝 GNX及颜料永固紫RL的中间体 [2 ,3] ,其合成方法均以咔唑为原料 ,在适当的溶剂中 ,先与碱生成钾盐 ,再与烷基化试剂反应得到产物。目前主要有氯乙烷法 [2 ] 、硫酸二乙酯法 [4]、对甲基苯磺酸乙酯法 [5 ] ,或采用 PTC—KO H方法进行 N—烷基化 [6 ]。氯乙烷法需在加压下进行 ;硫酸二乙酯法中硫酸二乙酯有毒 ,且采用苯、氯苯、二氯苯等有毒溶剂 ;而对甲苯磺酸乙酯法成本较高 …     

N-乙基咔唑合成工艺的研究进展

介绍了N-乙基咔唑的几种合成方法:一般合成法、催化合成法和微波诱导催化合成法,比较3种方法得出,相转移催化法是合成N-乙基咔唑的最佳途径。     

N—乙基咔唑的合成

咔唑先制成钾盐,再与硫酸二乙酯反应合成N-乙基咔唑,收率95％。文中讨论了影响反应收率的几个主要因素。N一乙基咔哇是合成染料硫化还原蓝 GNx及颜料永固紫RL的中间体     

N-乙基,N-氯乙基间甲苯胺的合成及应用

综述了N-乙基，N-氯乙基间甲苯胺的合成方法及应用。     

甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物的研制

以甲基丙烯酸乙基咔唑酯、N-乙烯基咔唑为原料,以偶氮二异丁腈为引发剂,采用共聚合方法合成甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物。分别用IR、UV—vis对其结构进行了表征。利用凝胶渗透色谱仪测定了共聚物的相对分子质量,并讨论了影响相对分子质量的因素,提高引发剂浓度、反应温度都使相对分子质量下降,而延长反应时间则有利于增加相对分子质量。     

相转移催化法合成N-乙基咔唑的研究

以咔唑和溴乙烷为原料,在季铵盐相转移催化剂的条件下合成了N-乙基咔唑,考察了温度、催化剂种类、催化剂用量以及投料比等因素对N-乙基咔唑收率的影响,确定了最佳的催化剂及工艺条件。结果表明,四丁基溴化铵具有最佳的催化活性,在适宜反应条件下,N-乙基咔唑的收率可达97%。     

N-乙基-3-咔唑丙烯酸的合成及性质研究

用N-乙基咔唑合成N-乙基-3-咔唑甲醛,在吡啶介质中以六氢吡啶为缩合剂,通过N-乙基-3-咔唑甲醛与丙二酸的Knoevenagel缩合反应合成N-乙基-3-咔唑丙烯酸,并对影响产率的因素进行了研究。结果表明,当n(N-乙基-3-咔唑甲醛)∶n(丙二酸)∶n(吡啶)∶n(六氢吡啶)=1.0000∶3.0000∶2.0000∶0.0015时,在105℃下反应2h,N-乙基-3-咔唑丙烯酸的产率为85%,纯度为99.45%。     

3—硝基—9—乙基咔唑的合成研究

本文提出一种合成３－硝基－９－乙基咔唑的新方法，并研究了硝酸浓度、用量及溶剂得因素对产品纯度及收率的影响，确定了较佳的反应条件。     

N-乙基间甲氧基苯胺的合成

以Cu／Zn／Ni混合氧化物为催化剂，常压气相催化合成N—乙基间甲氧基苯胺。转化率为90％，选择性为94％，反应温度：230℃—240℃，醇胺比为1：1．2，反应空速：0．75h-1。     

N-乙基-N',N'-二甲基-N-苯基乙二胺的合成研究

介绍了N－乙基－N‘,N‘-二甲基－N－苯基乙二胺的合成方法,确定了以N－乙基－N－氯乙基苯胺和二甲胺水溶液为原料合成N－乙基－N‘,N‘-二甲基－N－苯基乙二胺的工艺条件,得到收率97％、纯度98％以上的产品。     

芴醇的简便合成

研究了芴与N-溴代丁二酰亚胺(NBS)的光化学反应及其溴代产物的水解反应，提供了一种温和、简便的制备芴醇的方法。结果表明，NBS与芴的物质的量比为1．1：1时，反应80min，芴高选择性地转化为9-溴芴，9-溴芴在碱性溶液中水解得到定量的芴醇。同时对反应机理进行了初步探讨。     

A simple additive-free approach for the synthesis of uniform manganese monoxide nanorods with large specific surface area

A simple additive-free approach is developed to synthesize uniform manganese monoxide (MnO) one-dimensional nanorods, in which only manganese acetate and ethanol were used as reactants. The as-synthesized MnO nanorods were characterized in detail by X-ray diffraction, scanning and transmission electron microscopy (TEM) including high-resolution TEM and selected-area electron diffraction, Fourier transform infrared spectrum, and nitrogen adsorption isotherm measurements. The results indicate that the as-synthesized MnO nanorods present a mesoporous characteristic with large specific surface area (153 m² g⁻¹), indicating promising applications in catalysis, energy storage, and biomedical image. On the basis of experimental results, the formation mechanism of MnO one-dimensional nanorods in the absence of polymer additives was also discussed.     

A novel approach to the rapid synthesis of high-entropy carbide nanoparticles

A novel strategy for the rapid synthesis of high-entropy carbide particles is proposed that involves the transformation of multicomponent intermetallic intermediates to multicomponent carbides (high-entropy carbide precursors). (Ti_0.25V_0.25Nb_0.25Ta_0.25)C nanoparticles with a uniform solute distribution were successfully synthesized in an Al matrix by heating Al-Ti-V-Nb-Ta-C powder mixtures at 1500°C for 10 minutes. The multicomponent aluminide intermediates led to the rapid formation of multicomponent carbides during heating to 1100°C, which transformed into a high-entropy solid solution during heating to 1500°C. We developed a new rapid approach for the synthesis of high-entropy ceramic particles.     

一种合成高级1-溴代烷的简便方法

介绍了一种以市售1-溴代烷和α,ω-二醇为原料,经α,ω-二醇单溴代、与对甲苯磺酰氯成酯,再与1-溴代烷的格氏试剂偶联来合成更高级1-溴代烷的简便方法。     

4-氨基喹唑啉的简便合成

以取代(或未取代)邻氨基苯腈为原料,与三氯氧磷反应后水解并环化,一步制得9个取代(或未取代)的标题化合物,收率58%～85%.     

Spectroelectrochemical study of N‐ethyl‐carbazole in the presence of acrylamide

Polymerization of N‐ethylcarbazole (NECz) in the presence of acrylamide (AAm) has been investigated by in situ and ex situ UV–visible spectrophotometric measurements to obtain information about the reaction pathway, because NECz gives soluble oligomeric species allowing such measurements. A tentative mechanism is proposed in the light of these results. The redox properties of the new polymers have been studied for possible sensor application. © 2001 Society of Chemical Industry     

N-乙酰氨基葡萄糖合成方法的改进

改进了N－乙酰氨基葡萄糖的合成方法，后处理过程简单，产率提高至96．7％。     

A graphical approach to process synthesis and its application to steam reforming

It is common practice in chemical engineering to design processes sequentially. The type of product desired determines the choice of the feed materials that are introduced into the reactor networks. These in turn lead into the separation networks. The flows of heat and work are the final part of the sequence to be considered, with the application of heat exchanger networks, and any deficiency or excess in these flows is usually compensated for with the use of utilities. Although the ongoing research into reactor, separation, and heat exchanger optimization is of indubitable value, an aspect that is often overlooked in conventional research is the question: How do changes to one of the elements in the sequence affect the others? Most process designers do not address such matters until the next optimization of the sequence begins. The result of this sequential approach to design is that processes may contain a few very efficient units, but may also have others that are highly inefficient. A graphical technique that incorporates the flows of heat and work into the design of the process at a very early stage is proposed. The technique can be used to prepare flow sheets that represent a synthesized version of the elements that make up the complete process, rendering each component highly efficient. This new design tool uses the thermodynamic properties of enthalpy (representative of process heat requirements) and Gibbs free energy (representative of process work requirements) to develop process flow sheets that operate as close to reversibly as possible, and can be used as a foundation for more detailed refinements to achieve the best possible result. A case was described in a previous paper in which the graphical technique was applied to gasification. The application of the technique to the production of syngas by the steam reforming of natural gas is detailed. We show that the steam reforming process can be operated with increased reversibility and can actually consume carbon dioxide, thus representing a process with a carbon efficiency of greater than 100%, if the way in which all the process units interact with one another is used to utmost advantage. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3714–3729, 2013     

简法合成6,6''''-二溴-2,2''''-二烷氧基-1,1''''-联萘

6,6'-二溴-2,2'-二烷氧基-1,1'-联萘是合成具有手性光学活性联萘高分子的重要反应中间体,文献报道主要有两种制备方法:一种是先在-78℃对联萘酚6,6'位低温溴化,然后加热对酚羟基进行烷基化;另一种方法是先对联萘酚烷基化,然后再进行溴化.前者溴化时需要低温(-78℃),一般实验室难以达到.后者在溴化时不仅在6,6'位外,同时在4,4'位也很容易引入溴.我们改进的合成方法,将溴化反应在冰水浴中进行,中间产物无须纯化可直接进行下一步酚羟基烷基化反应,反应时间短,后处理及提纯操作方便,产率达94%.合成路线如下.     

A simple synthesis of the refractory ceramic sulfide CeS by electron beam irradiation

A new, relatively fast and simple synthesis of the refractory sulfide CeS using electron beam irradiation has been developed. Differently from the most common procedures involving highly reactive and/or toxic precursors such as cerium hydride and carbon disulfide, the approach here presented is based on the electron beam irradiation of pellets composed of a mixture of cerium sesquisulfide, cerium dioxide and graphite powders, i.e., nontoxic and nonreactive materials in ambient conditions that do not need any special caution during their use. CeS with a purity ≥98 wt% has been obtained, being Ce₂O₂S the impurity and whose amount can be lowered by annealing on a graphite surface.