共查询到20条相似文献,搜索用时 850 毫秒
1.
Verkhozina O. N. Kizhnyaev V. N. Vereshchagin L. I. Rokhin A. V. Smirnov A. I. 《Russian Journal of Organic Chemistry》2003,39(12):1792-1796
Polynuclear blocks consisting of nonfused heterocycles of the azole series, connected through methylene bridges, were synthesized by successive addition of azole units via cycloaddition of organic azides to the triple bond of N-(2-propynyl)azoles, as well as via reaction of azide ion at the cyano group of cyanomethylazoles. Initial N-(2-propynyl)azoles were prepared by reaction of 2-propynyl bromide with 1,2,3-triazoles, benzotriazole, and tetrazoles; cyanomethylazoles were obtained by alkylation of azoles with chloroacetonitrile. An analogous scheme was used to add heterocyclic units to 2-phenyl-1,2,3-triazole-4-carbonitrile. In this case, the first two heterocyclic units are linked through the ring carbon atom. 相似文献
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Sebastian Juli Pilar Sala Jos Del Mazo Manuel Sancho Carmen Ochoa Jos Elguero Jean-Pierre Fayet Marie-Claire Vertut 《Journal of heterocyclic chemistry》1982,19(5):1141-1145
Thirteen N,N-diazolylmethanes, including derivatives of pyrazole, imidazole, 1,2,4-triazole, benzimidazole and indazole were prepared by reaction of azoles with methylene chloride under phase transfer catalysis conditions. The relative amounts of isomeric mixtures obtained with ‘asymmetric’ azoles or with equimolar mixtures of azoles are compared with literature results on monoalkylation of azoles. Proton and carbon-13 nmr spectra of the N,N'-diazolylmethanes are discussed. 相似文献
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将间接电合成苯甲醛与电还原马来酸制备丁二酸的过程有机结合, 构建了一个新的成对电解体系, 即在隔膜电解槽中, 以纯Pb为阴极, PbO2/Pb为阳极, 硫酸溶液为介质, 在施加超声波的条件下, 阳极氧化Ce3+为Ce4+, 阴极还原马来酸生成丁二酸; 同时, 在槽外采用Ce4+氧化甲苯生成苯甲醛. 实验结果表明, 阴极和阳极电解的平均电流效率分别为92.71%和87.81%, 总的电流效率高达180.52%; 且Ce4+槽外氧化甲苯为苯甲醛的收率为95.78%, 马来酸电还原为丁二酸的转化率为92.09%; 电解的槽电压与单一电解氧化Ce3+相比降低了0.25 V. 相似文献
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Min CHEN* Ren Xian ZHOU Xiao Ming ZHENG Institute of Catalysis Zhejiang University Xixi Campus Hangzhou 《中国化学快报》2001,(2)
p-tert benzaldehyde is an important raw material of chemical industry. It is widely used in foodstuff, medicine and also used as intermediates of perfume. The conventional method of production of p-tert benzaldehyde resulted in waste water, which is easy to cause environmental pollution1-3. We tried to produce p-tert benzaldehyde from catalytic gas phase selective oxidation method. The study of the gas phase selective oxidation of p-tert butyl toluene to p-tert benzaldehyde is sparsely reporte… 相似文献
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嫁接型席夫碱配合物的制备及其催化性能 总被引:1,自引:0,他引:1
应用超声波技术在温和条件下以氯丙基三甲氧基硅烷为偶联剂, 制得了嫁接过渡金属Zn, Cu, Fe和Co的N,N-双水杨醛缩二乙烯三胺席夫碱配合物[SiO2-M(NNOO)], 并与传统加热搅拌法制得的样品的物性和催化性能做了比较. 应用IR和UV-Vis谱学技术对其进行了初步表征, 结果表明, 两种方法制得的嫁接型配合物的红外光谱均呈现出胺基和席夫碱相应基团的特征吸收, 配体和配合物红外和紫外光谱之间的差别表明配合物结构的存在. 将所制得的样品在苯乙烯选择氧化制苯甲醛反应中进行了催化性能的测试, 考察了反应时间和催化剂对苯乙烯转化率和选择性的影响, 结果表明苯乙烯转化率均在90%以上, 苯甲醛选择性最高可达93.5%, 产物选择性与反应时间和催化剂中过渡金属的类型均有关系. 相似文献
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Yasumitsu Tamura Hironori Hayashi Yoshiro Nishimura Masazumi Ikeda 《Journal of heterocyclic chemistry》1975,12(2):225-230
1-Alkyl-3-aminobenzimidazolium salts react with dimethyl acetylenedicarboxylate or dibenzoylacelylene in the presence of base to produce unusual 1:1 adducts, 1-(2′-alkylaminophenyl)-pyrazole derivatives. Treatment of the 3-amino salts with benzaldehyde in the presence of alkali gives benzaldehyde 2-(N,N-acylalkylamino)phenylhydrazones. The same hydrazones are obtained by alkaline treatment of 1 -alkyl-3-benzaliminobenzimidazolium salts, which are prepared from the 3-amino salts and benzaldehyde. 相似文献
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CuCl2掺杂聚苯胺催化合成苯甲醛1,2-丙二醇缩醛 总被引:3,自引:0,他引:3
缩醛是一类重要化合物,具有原料来源丰富、生产工艺简单、化学性质稳定等优点,近20年来作为新型香料在日用香精和食品香精中均有广泛应用[1-2]。根据酸催化机理,Lewis酸可增强羰基碳的正电性,有利亲核试剂的进攻。研究表明,不少无机盐都是这类反应的高效、高选择性的催化剂,又因为无机盐价廉、易得等优点,所以用其作为催化剂具有更加重要的实际意义。聚苯胺(PAn)以其独特的掺杂现象及良好的稳定性为催化载体的选择提供了新的途径[3-4]。若以PAn为载体,将具有催化活性的路易斯酸掺杂其中,可降低路易斯酸的流失量,并克服其易潮解、腐蚀设备… 相似文献
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VOx/SBA-15催化剂上甲苯气相部分氧化 总被引:1,自引:0,他引:1
采用等体积浸渍法制备了不同负载量的VOx/SBA-15催化剂。UV-Vis和H2-TPR等表征结果表明,在较低钒负载量下,钒物种的分散程度较高,主要以孤立的VO4 3-以及少量聚合体V-O-V形式存在;钒负载量较高时会有大量的聚合体V-O-V甚至晶相V2O5出现,而且,催化剂的酸性随着钒物种的高度分散而降低。甲苯气相部分氧化反应结果表明,随着钒负载量的提高,苯甲醛的选择性先升后降,CO、CO2等选择性逐渐提高。这是由于催化剂存在大量的聚合体V-O-V和晶相V2O5时,聚集态钒物种表面较多的酸量促使苯甲醛深度氧化。在相同钒负载量下,催化剂VOx/SBA-15的钒物种分散状态优于VOx/MCM-41和VOx/SiO2,从而使得催化剂VOx/SBA-15呈现较高的苯甲醛选择性。 相似文献
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Di Gioia ML Leggio A Le Pera A Liguori A Napoli A Perri F Siciliano C 《Journal of chromatography. A》2005,1066(1-2):143-148
In this paper we describe an analytical method for the determination of p-phenylenediamine (PPDA) in hair dyes. In the adopted methodology the analyte is transformed into the corresponding imine derivative by treatment with benzaldehyde, and then analyzed by gas chromatography (GC) combined to mass spectrometry (MS), operating in SIM conditions. The direct and simultaneous chemical derivatization of the two amino functions of the analyte with benzaldehyde enhances the instrumental responses enabling the use of a sensitive and accurate method. Concentrations of PPDA in a set of commercial hair coloring creams are determined making use of N-benzylidene-4-methylbenzene-amine as a very stable internal standard which is easily prepared by condensation of 4-methylbenzene-amine with benzaldehyde. The regression calibration curves for PPDA in hair dyes are linear within 0.1 +/- 25 mg/ml with 0.99 as a typical correlation coefficient. 相似文献
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《Tetrahedron letters》2004,45(37):6937-6939
The synthesis of methyl bis(azol-1-yl)propionates is reported for the first time. These bridge-functionalized bis(azol-1-yl)methanes are prepared by a double Michael addition of azoles to methyl propiolate, representing a new methodology for the synthesis of polydentate ligands. 相似文献
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溶胶-凝胶法制备Fe2(MoO4)3超微粒子催化剂 总被引:1,自引:0,他引:1
以硝酸铁和钼酸铵为原料,采用溶胶-凝胶法和微波加热技术制备了F 2(MoO4)3超微子催化剂,使用DTA-TG,IR,XRD以及BET比表面测试等手段,考察了制备条件对复合氧化物超微粒子形成、晶相和比表面积的影响。同时测试了该样品对甲苯选择性氧化制苯甲醛的催化性能。结果表明:制备Fe2(MoO4)2超微粒子的适宜条件为:初始溶液pH=1.0,mol柠檬酸:mol(铁+钼)=0.4。在此条件下制得的干凝胶,经微波加热处理后粒子的比表面积为36.4m^2/g,粒径约为35nm。在由甲苯气相选择氧化制苯甲醛的反应中表现出较高的催化活性。 相似文献
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Data on the effect of the acid-base properties of the medium on the yield and composition of the products of N-dimethoxyphenylation of azoles (pyrazole, triazole, their substituted derivatives, and tetrazole) upon galvanostatic electrolysis
of azole—1,4-dimethoxybenzene mixtures in nucleophilic (MeOH) and neutral (MeCN) media were considered and the trends of this
process were discussed. The generation of arenium cations (1,4-dimethoxy-1-azolylbenzenium in MeCN and 1,1,4-trimethoxybenzenium
in MeOH) as the key intermediates of electrosynthesis of N-(dimethoxyphenyl)azoles, was proved experimentally. A new approach to the synthesis of N-(dimethoxyphenyl)azoles through electrosynthesis of 1,1,4,4-tetramethoxycyclohexa-2,5-diene by electrooxidation of 1,4-dimethoxybenzene
in MeOH as the first step and the reaction of this quinone diketal with azoles as the second step was suggested. The efficiency
of this route to N-(dimethoxyphenyl)azoles is comparable with the efficiency of the purely electrochemical one-step process.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2101–2109, November, 2007. 相似文献
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Reda Mahmoud Abd El-Aal 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):681-692
A series of some spiro azoles (pyrazolone, oxazolone, and/or imidazolone) inconjucton with heterocyclic thiazolidinone derivatives were prepared as starting materials in the synthesis of polymethine cyanine dyes. Reaction of spiro 2-formyl (oxime) azoles thiazolidinone derivatives with equi- and/or molar ratios of 2(4)-methyl substituted heterocyclic quaternary salts afforded the corresponding compound pentamethine, aza-mero cyanine, and azapentamethine cyanine dyes respectively. Elemental analyses, IR, 1 H-NMR, and mass-spectra identified the new spiro heterocyclic compounds and polymethine cyanine dyes. The visible absorption spectra of all new polymethine cyanine dyes were investigated. 相似文献
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Gas Phase Selective Catalytic Oxidation of Toluene to Benzaldehyde on V2O5-Ag2O/η-Al2O3 Catalyst 总被引:1,自引:0,他引:1
TonglaiZhang LiqiuMao WeihuaLiu 《天然气化学杂志》2004,13(4):238-243
Gas phase selective catalytic oxidation of toluene to benzaldehyde was studied on V2O5-Ag2O/η-Al2O3 catalyst prepared by impregnation. The catalyst was characterized by XRD, XPS, TEM,and FT-IR. The catalytic results showed that toluene conversion and selectivity for benzaldehyde on catalyst sample No.4 (V/(V Ag)=0.68) was higher than other catalysts with different V/Ag ratios. This was attributed to the higher surface area, larger pore volume and pore diameter of the catalyst sample No.4 than the other catalysts. The XRD patterns recorded from the catalyst before and after the oxidation reaction revealed that the new phases were developed, and this suggested that silver had entered the vanadium lattice. XPS results showed that the vanadium on the surface of No.4 and No.5 sample was more than that in the bulk, thus forming a vanadium rich layer on the surface. It was noted that when the catalyst was doped by potassium promoter, the toluene conversion and selectivity for benzalde hydewere higher than those on the undoped catalyst. This was attributed to the disordered structure of V2O5 lattice of the K-doped catalyst and a better interfacial contact between the particles. 相似文献
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The configurations of 6-methoxyaurone prepared by the condensation of 6-methoxy- coumaran-3-one and benzaldehyde and of its photoisomer are assigned on the basis of chemical and NMR evidence. 相似文献
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以硝酸铈和钼酸铵为原料 ,采用溶胶 -凝胶法和微波加热技术制备了Ce2 Mo3 O12 超微粒子催化剂 ,使用DTA -TG ,IR ,XRD以及BET比表面测试等表征手段 ,考察了制备条件对复合氧化物超微粒子形成 ,晶相和比表面积的影响 .同时 ,测试了该样品对甲苯选择性氧化制苯甲醛反应的催化性能 .结果表明 :制备Ce2 Mo3 O12 超微粒子的适宜条件为 :初始溶液pH =1.0 ,柠檬酸 / (铈 +钼 )摩尔比等于 0 .4 ,在此条件下制得的干凝胶 ,经微波加热处理后 ,粒子的比表面积为 35 .8m2 /g ,粒径约为 4 0nm .在由甲苯气相选择氧化制苯甲醛的反应中表现出较好的催化活性 相似文献
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A new complex (1) was prepared by mixing pyridinium polystyrylsulfonate resin and aqueous fluoboric acid, followed by being dehydrated. 1 can be used as an acidic catalyst for the acetalization of benzaldehyde with n-butanol with a highly catalytic activity. The characterization and reusability of 1 are discussed. 相似文献