共查询到20条相似文献,搜索用时 15 毫秒
1.
M. A. Volodina A. P. Terent'ev V. A. Kudryashova 《Chemistry of Heterocyclic Compounds》1967,2(2):225-226
As compounds of potential physiological activity, new sulfamide derivatives, Schiffs bases derived from N-arylpyrrolines, are obtained by reacting sulfanilamide, 2-(p-aminobenzenesulfamide) thiazole, 2-(p-aminobenzenesulfamido)-pyrimidine, and 1-phenyl-3-ethyl-4-methyl-5-(p-aminobenzenesulfamido) pyrazole with -(2-chloroethyl)--chlorocrotonaldehyde.For Part XIV see [1]. 相似文献
2.
Martin Irrgeher Harald Schmidt Klaus Bretterbauer Herbert Gabriel Clemens Schwarzinger 《Monatshefte für Chemie / Chemical Monthly》2011,287(4):849-854
Abstract
Vinyl functionalized melamine derivatives for cross-linking based on polymerization were synthesized as potential substitutes for harmful formaldehyde in melamine resins. Methylmelamines undergo direct vinylation with acetylene to the corresponding vinylmelamines in more than 95% conversion. Their chemical structures were fully characterized by mass spectrometry, Fourier transform infrared (FTIR) spectroscopy, elementary analysis, 1H, 13C, and 2D correlation nuclear magnetic resonance (NMR) experiments. Linear and cross-linked polymers were prepared by free radical polymerization neat and in solution and characterized by size exclusion chromatography (SEC) and matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) mass spectrometry. 相似文献3.
4.
5.
E. Lukevics L. Ignatovich L. Khokhlova S. Belyakov 《Chemistry of Heterocyclic Compounds》1997,33(2):239-241
A series of tolylgermatranes were synthesized. Their structures and the length of the transannular N→Ge bond were determined. It was shown that arylgermatranes are less toxic than the corresponding silatranes. 相似文献
6.
7.
8.
C. G. Overberger G. Montaudo S. Ishida 《Journal of polymer science. Part A, Polymer chemistry》1969,7(1):35-46
The syntheses of N,N′-divinylureas and some related compounds are reported. Polymerization of these monomers and determination of the structures of the resulting polymers are described. Evidence is presented which supports the tendency of vinylureas to react through their tautomeric form. 相似文献
9.
Over the years, various strategies have been reported for the synthesis of imidazo[1,2‐a]pyridines due to their importance in different fields. In this account, we represent the methods developed by our group for the synthesis and functionalization of imidazo[1,2‐a]pyridines. Different synthetic strategies have been developed using easily accessible reactants for this purpose. We envisage that these newly developed protocols will be very useful for the synthesis of functionalized molecules bearing imidazo[1,2‐a]pyridine scaffolds. These strategies will also be attractive for the construction of other pharmaceutically important heterocycles.
10.
Adel M. Kamal El-Dean Maisa E. Abdel-Moneam 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2745-2751
5-Ethoxycarbonyl-4-methyl-2-phenylpyrimidin-6(1H)-thione ( 3 ), which was prepared from the reaction of ethyl g -aminocrotonate 1 with benzoyl isothiocyanate ( 2 ) in refluxing acetone, was reacted with a series of halopgenated reagents to give S-alkyl derivatives 4a-g . Upon treatment of compounds 4a-c with sodium ethoxide were cyclized into thienopyrimidine 10a-c . Pyrimidinethione 3 was reacted with hydrazine hydrate to give hydroxypyrazolopyrimidine derivative 6 . The later compound was obtained by heating compound 4a with hydrazine hydrate under neat conditions, but when the reaction was carried using hydrazine hydrate in ethanol, the corresponding carbohydrazide 5 was produced. 相似文献
11.
Hendrik Tinnermann Christian Wille Dr. Manuel Alcarazo 《Angewandte Chemie (International ed. in English)》2014,53(33):8732-8736
A new family of cationic ligands, N‐alkyl/aryl pyridiniophosphines, has been synthesized through a short, scalable, and highly modular route. Evaluation of their electronic properties evidenced weak σ‐donor and quite strong π‐acceptor character when used as ancillary ligands. These attributes confer a substantially enhanced π‐acidity to the PtII and AuI complexes thereof derived and, as result, they depict an improved ability to activate alkynes towards nucleophilic attack. This superior performance has been demonstrated along several mechanistically diverse PtII‐ and AuI‐catalyzed transformations. 相似文献
12.
John W-P. Lin 《Journal of polymer science. Part A, Polymer chemistry》1979,17(12):3797-3810
Several N-vinylarylamines have been prepared by direct N-vinylation of arylamine salts with acetylene at atmospheric pressure. Nuclear magnetic resonance (NMR) spectra of the various N-vinylarylamines were recorded and chemical shift assignments were made for the first time. The vinyl protons of the enamines generally exhibit an ABX pattern. The electron-rich monomers are sensitive to acid-catalyzed hydrolysis in a wet solvent. Polymerizations of the monomers were carried out at low temperatures with phosphorous pentafluoride as an initiator. It was found that PF5 generated directly from thermal decomposition of p-chlorobenzenediazonium hexafluorophosphate is useful in the preparation of an extremely high-molecular-weight poly(N-vinylcarbazole) (M w = 3 × 106) with a narrow molecular weight distribution (MWD = 2.1). The polymerizability of N-vinylarylamines appears to vary with the amine functional groups of the monomers. N-vinylarylamine containing a planar amine moiety such as carbazole forms a higher-molecular-weight polymer than the monomers with the nonplanar bulky amine groups. 相似文献
13.
Starting from 5,5,9-trimethyl--1-decalone (4), short and highly efficient syntheses of three drimane natural products, euryfuran (1), valdiviolide (2), and confertifolin (3) have been developed. 相似文献
14.
Yu. A. Sedov A. I. Z Abolot-Skaya N. V. Koba 《Chemistry of Heterocyclic Compounds》1973,9(12):1542-1544
The first representatives of the previously unknown N-quinoxalylformazans were synthesized. Their chemical properties were investigated, and their structure and chromaticity are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1705–1707, December, 1973. 相似文献
15.
Weckhuysen BM Ramachandra Rao R Pelgrims J Schoonheydt RA Bodart P Debras G Collart O Van Der Voort P Vansant EF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(16):2960-2970
Chromium acetyl acetonate [Cr(acac)3] complexes have been grafted onto the surface of two mesoporous crystalline materials; pure silica MCM-41 (SiMCM-41) and Al-containing silica MCM-41 with an Si:Al ratio of 27 (AlMCM-41). The materials were characterized with X-ray diffraction, N2 adsorption, thermogravimetrical analysis, diffuse reflectance spectroscopy in the UV-Vis-NIR region (DRS), electron spin resonance (ESR) and Fourier transform infrared spectroscopy. Hydrogen bonding between surface hydroxyls and the acetylacetonate (acac) ligands is the only type of interaction between [Cr(acac)3] complexes and SiMCM-41, while the deposition of [Cr(acac)3] onto the surface of AlMCM-41 takes place through either a ligand exchange reaction or a hydrogen-bonding mechanism. In the as-synthesized materials, Cr3+ is present as a surface species in pseudo-octahedral coordination. This species is characterized by high zero-field ESR parameters D and E, indicating a strong distortion from O(h), symmetry. After calcination, Cr3+ is almost completely oxidized to Cr6+, which is anchored onto the surface as dichromate, some chromate and traces of small amorphous Cr2O3 clusters and square pyramidal Cr5+ ions. These materials are active in the gas-phase and slurry-phase polymerization of ethylene at 100 degrees C. The polymerization activity is dependent on the Cr loading, precalcination temperature and the support characteristics: a 1 wt % [Cr(acac)3]-AlMCM-41 catalyst pretreated at high temperatures was found to be the most active material with a polymerization rate of 14000 g polyethylene per gram of Cr per hour. Combined DRS-ESR spectroscopies were used to monitor the reduction process of Cr(6+/5+) and the oxidation and coordination environment of Cr(n+) species during catalytic action. It will be shown that the polymer chains initially produced within the mesopores of the Cr-MCM-41 material form nanofibres of polyethylene with a length of several microns and a diameter of 50 to 100 nanometers. These nanofibres (partially) cover the outer surface of the MCM-41 material. The catalyst particles also gradually break up during ethylene polymerization resulting in the formation of crystalline and amorphous polyethylene with a low bulk density and a melt flow index between 0.56 and 1.38g per 10 min; this indicates the very high molecular weight of the polymer. 相似文献
16.
Rolf Appel 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):297-300
Abstract The synthesis of various mono-, di- and mphosphabutadienes, of two hiphosphapentadienes and of several mono-, di- and tetraphospha-hexadienes is being reported. Their chemistry demonstrates an astonishing relationship to the corresponding olefinic compounds. 相似文献
17.
18.
Zaitsev B. A. Khramova G. I. Tsygankova T. S. 《Russian Journal of Applied Chemistry》2003,76(4):634-638
Novel thermosetting resins Rolivsans were prepared, and their structure, composition, and properties were studied. The structural parameters of Rolivsans as influenced by the synthesis conditions were determined. 相似文献
19.
Four blue-emitting thienyltriazoles with desired N and O coordination atoms were prepared in high yield via click chemistry for potential incorporation into metal complexes. Three of their crystal structures were determined by X-ray crystallography. The electrochemical properties, electronic structures of these thienyltriazoles, 1-4, and their correlations were studied using cyclic voltammetry and differential pulse voltammetry techniques along with density function theory (DFT) calculations. All of the compounds underwent irreversible redox reactions, leading to unstable electrogenerated radical cations and anions. Electrochemical gaps determined from the differences between first formal reduction and oxidation reactions were correlated to HOMO-LUMO energy gaps obtained from UV-vis spectroscopy and the DFT calculations as well as energies of excited states measured from photoluminescence spectroscopy. We observed weak electrochemiluminescence (ECL) from annihilation of these thienyltriazole radicals in acetonitrile containing 0.1 M tetra-n-butylammonium perchlorate as electrolyte. An enhancement in ECL efficiency ranging from 0.16 to 0.50% was observed upon addition of benzoyl peroxide as a coreactant in the above electrolyte solutions. The generation of excimers in solutions of 1-4 was observed as seen by the red-shift in ECL maxima relative to their corresponding photoluminescence peak wavelengths. Our work is of importance for the development of efficient blue-emitting fluorophores via click chemistry that could be potential luminophores in metal complexes. 相似文献
20.
Treatment of γ-bromodypnone with arylhydrazines gives differently structured products, i.e. γ-bromo-dypnone hydrazones, 1-aryl-3,5-diphenyl-1,4-dihydropyridazines,
1-aryl-3,5-diphenyl-1,6-dihydro-pyridazines, and aromatic 1,3,5-triarylpyridazinium salts. We have studied the pattern of
formation of all of the products and their properties. Heating an alcohol solution of 1,3,5-triphenyl-1,4-dihydro-pyridazine
gives N,2,4-triphenyl-1H-pyrrole-1-amine or to a 1,3,5-triphenylpyridazinium salt dependent upon the acidity of the medium.
The product of addition of HBr to the 1,6-dihydropyridazine system is 5-bromo-1-(4-nitrophenyl)-3,5-diphenyl-1,4,5,6-tetrahydropyridazine. 相似文献