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KI催化酯交换合成碳酸二正辛酯的研究 总被引:4,自引:0,他引:4
研究了碳酸二甲酯与正辛醇酯交换合成碳酸二正辛酯(DOC)的反应,比较了卤化钾与系列碳酸钾复合催化剂的性能,考察了物料配比、反应温度、反应时间诸因素对该反应的影响,得出了该反应的最佳工艺条件.结果表明,KI具有较好的催化活性和选择性;在最佳反应条件(常压、反应温度140℃、反应时间为4h、n(DMC):n(n-OctOH)=1:4、催化剂用量为总重1.25%。)下,DMC的转化率为83.7%,DOC的收率为70.0%,DOC的选择性为83.7%,甲基辛基碳酸酯(MOC)的收率为13.7%. 相似文献
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本文研究了扁桃酸对映体在含二(2-乙基己基)磷酸(D2EHPA)与酒石酸衍生物复合手性选择剂的正辛醇-水两相体系中的萃取分配行为,考察了酒石酸衍生物的种类和初始浓度、D2EHPA的初始浓度、扁桃酸的初始浓度、萃取温度对分配系数和分离因子的影响.结果显示,复合手性选择剂能提高分配系数和分离因子,D2EHPA与D-酒石酸衍生物的复合手性选择剂与L-扁桃酸对映体比与D-扁桃酸对映体形成更稳定的非对映体复合物;且D2EHPA与二对甲基苯甲酰酒石酸(DTTA)的复合手性选择剂的手性选择性大于D2EHPA与二苯甲酰酒石酸(DBTA)的复合手性选择剂;同时,扁桃酸的初始浓度、萃取温度对分配系数和分离因子的影响较大. 相似文献
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二硫代二乙二醇水基抗磨剂的合成及性能研究 总被引:1,自引:0,他引:1
以硫磺、硫化钠、2-氯乙醇为起始原料合成了二硫代二乙二醇。以乙醇为溶剂,硫化钠187mmol,n(2-氯乙醇):n(硫磺):n(硫化钠)=1.8:1.2:1.0,回流反应30min,二硫代二乙二醇(其中硫醚硫含量为39.54%)产率达88.5%。含二硫代二乙二醇85.7%的水基抗磨剂具有优良的极压性(PB=804N),但抗磨性不理想(D30min^196N=0.72mm)。 相似文献
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用H2O2氧化苯乙烯合成苯甲酸 总被引:2,自引:1,他引:1
摘要:以30%H2O2做为氧化剂,钨酸钠与含O双齿有机配体(草酸)形成的络合物为催化剂,在无有机溶剂、无相转移剂的条件下,研究了苯乙烯氧化制苯甲酸的反应。研究结果表明,最佳反应条件为:苯乙烯100.0mmol,n(钨酸钠):n(草酸):n(苯乙烯):n(30%H2O2)=2.0:3.2:100.0:440.0,于92℃反应24h,苯甲酸收率98.6%。用GC—MS跟踪了氧化过程中4种主要物质苯乙烯、1-苯基邻二醇、羟基苯乙酮及苯甲酸含量随反应时间的变化关系,提出了其主要氧化机理为苯乙烯经过环氧化反应、水解生成生成1-苯基邻二醇,1-苯基邻二醇再氧化为羟基苯乙酮、最后氧化为苯甲酸。 相似文献
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丙烯酸十八酯的合成新方法 总被引:6,自引:0,他引:6
以十八醇和丙烯酸为原料,在不加带水剂的条件下合成了丙烯酸十八酯。用正交实验确定了最佳合成工艺:十八醇108g(0.4mol),n(十八醇):n(丙烯酸)=1.0:1.2,对甲苯磺酸1.0%(催化剂,以醇酸总质量计),对苯二酚0.7%(阻聚剂,以醇酸总质量计),反应温度135℃,反应时间6h,酯化率在92%以上。产物结构经元素分析,IR和^1H NMR表征。 相似文献
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以对氨基苯磺酰胺、丙烯酰氯(或甲基丙烯酰氯)为原料合成了N-[4-(磺酰胺)苯基]丙烯酰胺(ASPAA)和N-[4-(磺酰胺)苯基]甲基丙烯酰胺(ASPMAA),其结构经^1H NMR,IR和元素分析表征。合成ASPAA的最佳条件:对氨基苯磺酰胺13.76g(80mmol),n(对氨基苯磺酰胺):n(丙烯酰氯)=1.0:1.1,n(丙烯酰氯):n(NaHCO3):1.00:1.14,0℃~2℃反应3h,反应液倾入10倍体积的的甲醇-水[V(甲醇):V(水)=1:10]中析出产物,收率在60%以上。合成ASPMAA的最佳条件:对氨基苯磺酰胺6.88g(40mmol),n(对氨基苯磺酰胺):n(甲基丙烯酰氯)=1.00:1.05,n(三己胺):n(甲基丙烯酰氯):1.0:1.0,在0℃~2℃滴加甲基丙烯酰氯后先在室温下反应1h,然后在60℃反应1h,反应液倾入700mL石油醚中析出产物,收率50%~60%. 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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袁都奇 《化学物理学报(中文版)》2001,14(3):381-384
把有限时间热力学理论用于化学过程的研究,将会得到一系列新的结论,开展这方面的研究是很有意义的.文献[1]以燃料电池为例,在同时考虑化学反应及传热不可逆性的情况下,研究了燃料电池的性能界限,文献[2]指出了文献[1]计算化学反应及传热不可逆性而引起系统与有关环境的总熵产生率的错误以及由此而导致的结论所存在的问题,并进行了富有启发性的分析与讨论.但文献[2]对于系统与有关环境的总熵产生率的计算也是不正确的,由此得到的其它结论自然不能成立.本文将就此情况下系统与有关环境的总熵产生率的计算再次进行讨论,并给出电池功率和效率的有限时间热力学性能界限. 相似文献