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1.
1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane was firstly used to catalyze the direct substitution of 9H‐xanthen‐9‐ol with indoles at room temperature to afford a class of 3‐(9H‐xanthen‐9‐yl)‐1H‐indole derivatives in good to excellent isolating yield. Moreover, other nucleophiles (such as diketone and pyrrole) could also proceed smoothly in this methodology. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
2.
A novel method for the synthesis of α‐chloroacetophenones using 1,3‐dichloro‐5,5‐dimethylhydantoin (DCDMH) and p‐toluenesulfonic acid in methanol at 30–35°C is described. Substituted acetophenones at the para position or meta position of aromatic ring give α‐chloroacetophenones in high yield. However, reaction of o‐nitroacetophenone does not take place under the same condition. 相似文献
3.
《Magnetic resonance in chemistry : MRC》2002,40(5):337-345
The temperature and pressure dependences of 35Cl nuclear quadrupole resonance (NQR) frequency and spin–lattice relaxation time (T1) were investigated for 1‐chloro‐2,4‐dinitrobenzene and 1,2‐dichloro‐3‐nitrobenzene. T1 was measured in the temperature range 77–300 K. Furthermore, the NQR frequency (ν) and T1 for these compounds were measured as a function of pressure up to 5.1 kbar at 300 K. Relaxation was found to be due to the torsional motion of the molecule and the reorientation motion of the nitro group. By analysing the temperature dependence of T1, the activation energy for the reorientation motion of the nitro group was obtained. The temperature dependence of the average torsional lifetimes of the molecules and the transition probabilities W1 and W2 for the Δm = ±1 and Δm = ±2 transitions, were also obtained. Both compounds showed a non‐linear variation of NQR frequency with pressure. The pressure coefficients were observed to be positive. A thermodynamic analysis of the data was carried out to determine the constant‐volume temperature coefficients of the NQR frequency. The spin–lattice relaxation time T1 for both the compounds was found to be weakly dependent on pressure, showing that the relaxation is mainly due to the torsional motions. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
4.
Gang Feng Yongguang Jia Lingyan Liu Weixing Chang Jing Li 《Journal of polymer science. Part A, Polymer chemistry》2010,48(24):5992-6002
A series of novel organotin‐containing core‐cross‐linked knedels and shell‐cross‐linked knedels were first synthesized facilely from poly(styrene)‐b‐poly(acrylate acid) nanoparticles in different selective solvents [Tetrahydrofuran (THF)/H2O or THF/n‐octane] by using organotin compound 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane as a new cross‐linker. The formation of the 1‐chloro‐3‐carboxylato‐tetra‐n‐butyl‐distannoxane layer in our cross‐linking reaction was supported by Fourier transform infrared (FT‐IR) and inductive coupled plasma emission spectrometer (ICP) analysis of the resulting shell‐cross‐linked knedels and core‐cross‐linked knedels. Transmission electron microscopy (TEM) study showed the spherical morphology and the size of the core‐cross‐linked knedels and shell‐cross‐linked knedel. Especially, the layer structure of the core‐cross‐linked knedels was clearly displayed in TEM image. The increase of extent of cross‐linking lead to the increasing of diameter for the shell‐cross‐linked knedels, whereas there was no significant effect on the core‐cross‐linked knedels. Dynamic light scattering (DLS) measurements gave hydrodynamic diameters of the core‐cross‐linked knedels that were in agreement with the TEM diameters. Moreover, the wall thickness of the shell layer of the core‐cross‐linked knedels could be easily modified by varying the block copolymer composition. Notably, the organotin‐containing core‐cross‐linked knedel exhibited highly efficient catalytic activity for the aqueous esterification reaction under nearly neutral conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
5.
The Identification of a Novel Highly Condensed Pentacyclic Heteroaromatic Ring System 1,3,5,5b,6,8,10,10b‐Octaazacyclopenta[h,i]Aceanthrylene and its Application in the Synthesis of 5,7‐Substituted Pyrazolo[4,3‐d]Pyrimidines 下载免费PDF全文
Libor Havlíček Daniela Moravcová Vladimír Kryštof Miroslav Strnad 《Journal of heterocyclic chemistry》2015,52(3):669-673
Pyrazolo[4,3‐d]pyrimidines are of interest as potential kinase inhibitors. This article describes the formation of a novel highly conjugated, condensed, centrosymmetric heteroaromatic compound, 4,9‐dichloro‐2,7‐diisopropyl‐1,3,5,5b,6,8,10,10b‐octaazacyclopenta[h,i]aceanthrylene ( 3 ), during the chlorination of 5,7‐dihydroxypyrazolo[4,3‐d]pyrimidine ( 1 ) with phenylphosphonic dichloride. The nucleophilic attack of benzylamine on 3 afforded N‐benzyl‐5‐chloro‐3‐isopropyl‐1H‐pyrazolo[4,3‐d]pyrimidin‐7‐amine ( 6 ), which was further substituted to yield a pyrazolo[4,3‐d]pyrimidine analogue of roscovitine, a well‐known cyclin‐dependent kinase inhibitor. 相似文献
6.
高效液相色谱法测定除草剂中二氯喹啉酸的含量 总被引:1,自引:0,他引:1
本文报道酸抑制反相色谱法测定除草剂中二氯喹啉酸的含量,该法采用PC8-10/S2504(4.0mmi.d.×250mm,10μm)柱,以甲醇-0.1%醋酸为流动相,紫外检测波长为240nm,0.08AUFS,以2,4-二硝基氯苯为内标物,样品用四氢呋喃提取,该法灵敏度及回收率高,结果定量准确,操作简便可靠。 相似文献
7.
Pratibha Sharma Ashok Kumar Priti Pandey 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):583-594
1,2-Dialkyl-3-arylazo quinolinium chloride 1 having N-methylene group activated by the insertion of arylazo site react with phosphorus trichloride to give N-(dichloro phosphinomethylene) quinolinium ylide 2 . The site of the reaction is determined by the relative activation of 1- and 2-methylene groups, in the absence of sufficient activation of N-methylene group, reactions occur at the 2-methylene group to give dichloro phosphinylated anhydrobases 5 and 11. 相似文献
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9.
The particle structure of polyvinyl chloride is controlled by the shear field imposed on the monomer droplet and the interfacial behavior of the vinyl chloride/water phases during polymerization. The inter facial tension in the presence of hydroxypropyl methylcellulose (HPMC) was measured as a function of concentration and temperature. The molecular weight distribution of HPMC was determined by coupled GPC-LALLS (low angel laser light scattering) technique. By monitoring the concentration of HPMC in the aqueous phase during polymerization, the coverage powers of HPMC were calculated and compared with the theoretical value based on Langmuir layer consideration. The effects of agitation on resin porosity were also examined. These results are discussed with respect to the particle structure. 相似文献
10.
The oxidation of 1‐(3,8‐dimethylazulen‐1‐yl)alkan‐1‐ones 1 with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (=4,5‐dichloro‐3,6‐dioxocyclohexa‐1,4‐diene‐1,2‐dicarbonitrile; DDQ) in acetone/H2O mixtures at room temperature does not only lead to the corresponding azulene‐1‐carboxaldehydes 2 but also, in small amounts, to three further products (Tables 1 and 2). The structures of the additional products 3 – 5 were solved spectroscopically, and that of 3a also by an X‐ray crystal‐structure analysis (Fig. 1). It is demonstrated that the bis(azulenylmethyl)‐substituted DDQ derivatives 5 yield on methanolysis or hydrolysis precursors, which in a cascade of reactions rearrange under loss of HCl into the pentacyclic compounds 3 (Schemes 4 and 7). The found 1,1′‐[carbonylbis(8‐methylazulene‐3,1‐diyl)]bis[ethanones] 4 are the result of further oxidation of the azulene‐1‐carboxaldehydes 2 to the corresponding azulene‐1‐carboxylic acids (Schemes 9 and 10). 相似文献