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排序方式: 共有147条查询结果,搜索用时 31 毫秒
31.
We report a new environmentally-benign, convenient, and facile methodology for the synthesis of 2-substituted-1H-imidazo[4,5-b]pyridine. The reaction of 2,3-diaminopyridine with substituted aryl aldehydes in water under thermal conditions without the use of any oxidative reagent has been studied. The reaction has yielded 1H-imidazo[4,5-b]pyridine derivatives by an air oxidative cyclocondensation reaction in one step in an excellent yield. Furthermore, a series of compounds were synthesized and characterized by melting point, EI-MS, NMR, and IR tools. For comparison, the reference samples were prepared by the reported method. Utilization of aqueous medium, easy reaction conditions, isolation, and purification make this manipulation very interesting from an economic and environmental perspective. 相似文献
32.
Punam A. Jadhav Rajendra P. Panmand Deepak R. Patil H. Fouad Suresh W. Gosavi Bharat B. Kale 《Journal of nanoparticle research》2017,19(6):218
In this paper, we report synthesis and study of magneto-optic Faraday effect for dilute magnetic semiconductor nanostructure. The colloidal CdS nanocrystals were prepared via hot injection method and successfully doped with Mn2+ cations. The synthesized nanoparticles were characterized by using UV–Vis spectroscopy, X-ray diffraction, photoluminescence spectroscopy, transmission electron microscopy, and electron spin resonance spectroscopy. Systematic studies on effect of Mn2+ doping on photoluminescence, electron spin resonance, and magneto-optical properties are carried out. UV–Vis spectral analysis confirms blue shift in bandgap of CdS nanoparticles due to quantum confinement effect. The X-ray diffraction study confirms hexagonal wurtzite phase formation of CdS nanoparticles without any impurity phases. TEM analysis confirms uniform particle size, having particle size distribution around 5 nm. As-synthesized undoped CdS shows triangular-shaped nanocrystals with hexagonal structure; however, triangular shape of CdS nanoparticles is not conserved after Mn2+ doping. The photoluminescence characteristic spectra of Mn2+-doped CdS nanocrystals showed emission band at 660 nm and its intensity was found to increase with increasing Mn2+ concentration. Electron spin resonance signal, with six-line hyperfine structure splitting, confirmed doping of Mn2+ ions in CdS lattice. Magneto-optic measurements showed linear variation of Faraday rotation with respect to applied magnetic field, indicating paramagnetic behavior of Mn-doped CdS. The highest Verdet constant 24.81 deg/T cm was observed for 2% Mn-doped CdS nanocrystals, which further decreases with increasing Mn2+ concentration. 相似文献
33.
A novel, one-pot, and highly facile protocol has been devised for an easy access of a series of novel glycosyl carboxamides from aldehydes using diacetoxyiodobenzene in the presence of ionic liquid at ambient temperature. 相似文献
34.
Sarkate A. P. Gavane D. S. Kale B. D. Karnik K. S. Narula I. S. Khandare A. L. Rajhans A. P. Jambhorkar V. S. 《Russian Journal of Organic Chemistry》2020,56(7):1300-1303
Russian Journal of Organic Chemistry - Diaryl sulfides have been synthesized in moderate to excellent yield by S-arylation of arenethiols with arylboronic acids using copper slag as a catalyst.... 相似文献
35.
Ashok Kale Nagaraju Medishetti Jagadeesh Babu Nanubolu Krishnaiah Atmakur 《Tetrahedron letters》2018,59(47):4168-4171
Regioselective synthesis of 2-benzoyl-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-ones have been accomplished through a novel protocol involving β-amino enone, N-chlorosuccinimide and dimedone in a one pot catalyst-free reaction at an ambient temperature. On the other hand, the same reaction when conducted with two equivalents of N-chlorosuccinimide under similar reaction conditions, exclusive formation of 2-benzoyl-3-(dimethylamino)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-ones were observed. Simple and metal-free reaction conditions, selective product formation and excellent yields are the advantages of this protocol. 相似文献
36.
A. B. Deshpande S. M. Kale S. L. Kapur 《Journal of polymer science. Part A, Polymer chemistry》1973,11(9):2105-2109
Styrene is polymerized with chromium acetylacetonate–triisobutylaluminum catalyst at 40°C in a benzene medium. At the stoichiometric ratio of Al/Cr of 4, the activity for polymerization was found to be maximum. Further, the kinetic studies were carried out at this ratio of Al/Cr of maximum activity. The kinetics of polymerization and the total activation energy around 10.00 kcal/mole suggest a coordinate anionic mechanism. 相似文献
37.
The kinetics of oxidation of L-ascorbic acid by 2,6-dichlorophenolindophenol in aqueous solution has been studied. The rate of the reaction decreases with increasing pH since the hydrogen ascorbate ion is less reactive than the unionized L-ascorbic acid. The rate constants for the oxidation of the two species have been evaluated and a plausible mechanism of the reaction is suggested.
L- 2,6-- . pH, , L- . .相似文献
38.
Biomaterials are renewable sources which are widely distributed, locally accessible, high possibility of recycling and biodegradation behavior. This investigation deals with the extraction and characterizing of new fiber obtained from Serte plant leaf that is found in Ethiopia. The physical, chemical and mechanical characters of the fiber had been tested and comparison with other plant fibers was done for the first time. Optimization of fiber extraction process has been done by varying the extraction variables like NaOH concentration, temperature and extraction time. Fibers possessing 56% cellulose content along with significant amount of hemicellulose, lignin and ash with tensile strength of 330?MPa were obtained. FTIR as well as X-ray diffraction analysis were also done to further analyze the fiber. This new plant leaf fiber can be another alternative resource in place of synthetic fibers depending on their application such as reinforcing polymer matrices. 相似文献
39.
Jamble Shweta N. Ghoderao Karuna P. Kale Rohidas B. 《Research on Chemical Intermediates》2019,45(3):1381-1399
Research on Chemical Intermediates - Photocatalytic degradation of toxic dyes is an important topic across the globe. This paper reports the photocatalytic degradation of methylene blue (MB) dye... 相似文献
40.
André V.-H. Soares Sumeet S. Kale Udo Armbruster Fabio B. Passos Shubhangi B. Umbarkar Mohan K. Dongare Andreas Martin 《国际化学动力学杂志》2019,51(8):634-640
Glycerol acetylation is a very interesting reaction for studies of consecutive kinetics. In this short communication, we present a pseudo-homogeneous model for the synthesis of triacetyl glycerol from the reaction of glycerol and acetic acid over strongly acidic Amberlyst-15 and Amberlyst-70 catalysts, considering a dimerization of diacetyl glycerol (DAG) into diglycerol tetraacetate as a parallel reaction and compare the results with a model without side reactions. The best fits were obtained for apparent zeroth-order dimerization and first-order consecutive reactions in the presence of acetic acid in excess and with removal of water. An adaptation was made for DAG. The proposed model shows that the formation of DAG is faster than the consumption of glycerol, which could be an explanation for the occurrence of DAG dimerization instead of other parallel reactions in acetylation. 相似文献