应用ESR谱技术研究超声作用下1—氰基—2,3,5—三—β—D苯甲酰基呋喃核…

在非水溶液中，以Ｎ－溴代丁二酰亚胺（ＮＢＳ）为溴化剂，在四氯化碳溶液中对１－氰基－２，３，５－三－β－Ｄ苯甲酰基呋喃核糖进行了声溴化和光溴化反应。     

1—溴—4—溴甲基苯的简易合成及应用

以 对溴甲苯为原料，Ｎ－溴代丁二酰亚胺为溴化剂，利用光引发的自由基反应合成了１－溴－４－溴甲基苯，产率可达８０％，并利用它制得了一个新的有机合金属前体。     

1－溴－4－溴甲基苯的简易合成及应用

以对溴甲苯为原料，Ｎ－溴代丁二酰亚胺为溴化剂，利用光引发的自由基反应合成了１－溴－４－溴甲基苯，产率可达８０％，并利用它制得了一个新的有机金属前体。     

α,α,α′,α′,4—五溴邻二甲苯的合成

本文介绍了用Ｎ－溴代丁二酰亚胺进行溴代反应合成α,α,α′,α′,４－五溴邻二甲苯的新方法,并与传统的溴素溴化法进行了比较。‘     

氯铬酸甲铵/硅胶对苯偶姻的氧化研究

介绍了氯铬酸甲铵／硅胶对苯偶姻体系的氧化反应合成相应的苯偶酰类化合物。反应条件为：反应时间１４ｈ,反应温度５５～６０℃,收率７８％～９４％。     

合成苊烯的新方法

在常温常压下，以苯作为溶剂，加入喹啉，使苊与Ｎ－溴代丁二酰亚胺发生光化学脱氢反应生成苊烯。采用正交试验法，在优化的条件下苊烯产率达５９．０９％ 。此法可作为温和条件下苊烯合成的一种新方法。     

肟菌酯关键中间体的合成研究

以邻甲基苯乙酮为原料,依次经相转移催化下的高锰酸钾碱性氧化、甲醇酯化、甲氧胺盐酸盐肟化和N-溴代丁二酰亚胺（NBS）溴化后,得到制备肟菌酯的关键中间体——(E)-2-(2'-溴甲基苯基)-2-羰基乙酸甲酯-O-甲基酮肟。产品结构经熔点和1H-NMR表征。通过优化反应条件,总收率可达52%。     

肟菌酯关键中间体的合成

以邻甲基苯乙酮为原料,依次经相转移催化下的高锰酸钾碱性氧化、甲醇酯化、甲氧胺盐酸盐肟化和N-溴代丁二酰亚胺(NBS)溴化后,得到制备肟菌酯的关键中间体——(E)-2-(2'-溴甲基苯基)-2-羰基乙酸甲酯-O-甲基酮肟。产品结构经熔点和1HNMR表征。通过优化反应条件,总收率可达52%。     

2,6-二溴代呋喃基-4-对甲苯基吡啶的合成及性质研究

以2-乙酰呋喃和对甲基苯甲醛为原料，氨水为氮源，水/乙醇为溶剂，经Krohnke吡啶合成反应制备了2,6-二呋喃基-4-对甲苯基吡啶。以该化合物为原料，N-溴代丁二酰亚胺为溴化剂，THF为溶剂，三氯化铁为催化剂，在无水无氧条件下经亲电取代反应合成了2,6-二溴代呋喃基-4-对甲苯基吡啶。采用核磁共振氢谱、质谱、紫外可见光谱，分析了2,6-二呋喃基-4-对甲苯基吡啶和2,6-二溴代呋喃基-4-对甲苯基吡啶的结构及光谱性质。结构分析表明，溴代可能发生在两个呋喃环的5号位碳原子上。紫外可见吸收光谱分析发现，2,6-二溴代呋喃基-4-对甲苯基吡啶相对于2,6-二呋喃基-4-对甲苯基吡啶红移了9 nm。这表明溴代后，溴和呋喃环发生p-π共轭，化合物能隙降低，最大吸收波长发生红移。     

N,N‘—二甲基Bei四羧酸二酰亚胺化合物溴化反应过程的研究

本文研究了不同温度和催化剂条件下的Ｎ，Ｎ’－二甲基Ｂｅｉ四羧酸二酰亚胺的溴化反应过程，通常，一取代溴化反应发生在室温的条件下，而四取代的溴化反应由多级的溴化反应过程完成，这一结果可以由ＮＭＲ光谱证实，本文还讨论了溴化反应中化合物的不同取代位置。     

Ketonic resins as free radical photoinitiators

Photoreactive cyclohexanone‐formaldehyde and acetophenone‐formaldehyde resin‐bound benzoin and benzoin isobutyl ether resins were successfully prepared by the method of in situ modification of ketonic resins. These photoinitiators were used to polymerize styrene using UV lamp with wavelength of 350 nm. Initiating efficiencies of ketonic resin‐bound benzoin and benzoin ether were much higher than benzoin and benzoin ether. The products were ketonic‐resin‐polystyrene block copolymers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 927–934, 1999     

Mechanism of action of benzoin as a degassing agent in powder coatings

The mechanism of action of benzoin as a degassing agent in powder coatings has been analyzed. The gas bubble shrinkage was monitored using a light microscope equipped with a hot stage. In the absence of benzoin, the air bubbles start to shrink very slowly as a result of a diffusion-controlled process. Because of the continuing cross-linking reaction and increase in the viscosity, the bubble shrinkage halts at elevated temperatures. Quite remarkably, we observed that in the presence of benzoin the process of bubble shrinkage is accelerated to such an extent that most air bubbles disappear before any significant increase in the viscosity occurs. This suggests that benzoin functions by accelerating the rate of bubble shrinkage. To analyze the mechanism of action of benzoin in detail, we studied the coating formulations using various techniques. X-ray diffraction in combination with deuterium NMR using labeled benzoin indicated that benzoin dissolves on a molecular level in polyester resin and becomes mobile above the glass transition temperature of the matrix. Mass spectroscopy experiments revealed that benzoin, in its oxidized form (benzil), starts to evaporate above 100 °C. At 200 °C more than 90% of the initial concentration of benzoin has evaporated from the coating. As was to be expected, the conversion of benzoin to benzil halted when the experiments were carried out in nitrogen. We postulated that the action of benzoin as a degassing agent is somehow related to its ability to oxidize in situ. This claim is substantiated by the results of bubble dissolution experiments using different gases such as oxygen and nitrogen. It is shown that in the presence of benzoin oxygen bubbles shrink much faster than air bubbles. On the other hand, the shrinkage of nitrogen bubbles is not affected by benzoin. Based on the above results, a two-step mechanism is proposed for the action of benzoin as a degassing agent. This mechanism has been successfully used as a guideline to identify alternative degassing agents with higher efficiency and fewer side-effects, such as less severe yellowing.     

超声辐射合成光敏剂苯偶姻

苯甲醛在超声辐射下发生苯偶姻缩合反应 ,能以 85 %的高产率得到光敏剂苯偶姻 ,提供了一种方便地合成苯偶姻的方法     

Polymeric photoinitiators having benzoin methylether moieties connected to the main chain through the benzyl aromatic ring and their activity for ultraviolet-curable coatings

New polymeric UV photoinitiators, bearing the benzoin methyl ether moiety linked to the side chain through the 4′ position, were synthetized by radical homopolymerization of the corresponding monomers, 4′-methacryloyloxy benzoin methyl ether and 4′-methacryloyloxy α-methyl benzoin methyl ether, prepared in turn after a thorough investigation of synthetic methods. For comparison, low molecular weight structural models of the repeating co-units of the polymers having the pivaloyloxy group linked to the 4′ position of the benzoin methyl ether moiety were also prepared. All polymeric and model compounds were fully characterized and employed in the photoinitiated polymerization and crosslinking of a standard acrylic formulation for clear UV curable coatings. The photoinitiating activity of these systems, measured by microwave dielectrometry, indicates a higher cure fastness for the model compounds with respect to the corresponding polymeric derivatives, and such a behaviour is tentatively interpreted in terms of the fragmentation mechanism of the benzyl methyl ether radicals formed on α-photocleavage of the benzoin moiety.     

光敏树脂的研究

本文以安息香乙醚、安息香、联苯甲酰为光敏剂,用红外跟踪法以及在不同的固化阶段测定树脂的硬度,机械强度等.研究了光引发动力学.     

Insoluble Polymer-Supported Conjugate Bases of Thiazolium Ions As Catalysts in Organic Chemistry

The synthetic possibilities of the generalized benzoin condensation are examined: benzoin condensation in its strict sense and closely related reactions, Michael type additions of aldehydes to activated double bonds, and oxidative benzoin condensation. In solid phase chemistry, comments are made on cyanide resins and details are given on the preparation of insoluble 5-(2-hydroxyethyl)-4-methyl-3-(polystyrylmethyl)thiazolium chloride and of 4-methyl-3-(polystyrylmethyl)thiazolium chloride. Examples of the use of polymer thiazolium salts in the three types of reactions mentioned are presented and information on the stability of these salts is presented.     

苯偶酰的简便合成

以冰醋酸为溶剂,硝酸铵为助剂,单质Cu及其氯化物能将苯偶姻氧化成苯偶酰。研究了Cu、CuCl、CuCl2对反应的影响,通过实验得到其最佳反应条件为:2.12 g苯偶姻,1 g硝酸铵,14 mL冰醋酸0.05 g铜丝。收率95%,产物的熔点,及红外光谱与文献一致。     

丙烯酸酯单体紫外固化机理初探

本文选用了二缩三乙二醇双甲基丙烯酸酯为单体，安息香，安息香甲（乙、异丙）醚，二苯甲酮，α－羟甲基安息香甲醚、联苯酰二甲基缩酮，加入三乙胺和Ｎ，Ｎ－二甲基对甲苯胺等叔胺，在紫外照射下合，以红外光谱定量跟踪反应进行程度，实验结果表明，在单体中加入光引发剂后，紫外光照射时，聚合固化反应迅速进行，照射５分钟后反应程度达８６％～５０％，以安息香异丙醚得到的反应程度较高，加入叔胺后，降低了初始反应速度，但命名     

苯甲醛安息香缩合反应催化合成苯偶姻新方法

制备了不同取代基的噻唑盐催化剂,研究了噻唑盐催化苯甲醛合成苯偶姻的安息香缩合反应,考察了噻唑盐取代基、催化剂用量、反应温度及反应时间对苯甲醛安息香缩合反应的影响规律。结果表明,以3-乙基-4-甲基-5-羟乙基噻唑溴盐为催化剂,噻唑盐用量为1．5％（以苯甲醛计,n／n,在反应温度为100％,反应时间为6h时,苯偶姻收率达72．5％,且反应过程中不需添加任何有机溶剂,具有环境友好的特点。     

Lichtinitiierte Polymer- und Polymerisationsreaktionen. III. Photoinduzierte Zersetzung von Aryldiazoniumsalzen durch Benzoinderivate

Light Induced Polymer and Polymerization Reactions. III. Photoinduced Decomposition of Arene Diazonium Salts by Benzoin Derivatives The combination benzoin derivate/arene diazonium salt is suitable as a bivalent photoinitiator system for radicalic and cationic photopolymerization. By means of product analysis, quantum yield measurements and photo-CIDNP-studies a mechanism was proposed including the electron transfer from α-substituted benzyl radicals formed by benzoin derivate photolysis to arene diazonium salts. The quantum yields for diazonium salt decomposition in acetonitril were about 0.65. They show only a small dependence on substituents of diazonium salt but are strong influenced by the solvent. In methanol or dioxane quantum yields were found from 11 to 460. ¹³C-photo-CIDNP-measurements agree with a mechanism of benzoin ether photolysis on the triplet state.