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1.
[reaction: see text] It is demonstrated that o-quinones, generated by the electrochemically driven oxidation of the catechols (1a-d) at physiological pH, are rapidly scavenged by 2-mercaptobenzoxazole (3) to give related catecholthioethers (4a-d) via an EC electrochemical mechanism pathway. The electrochemical syntheses of 4a-d have been successfully performed in one-pot in ambient conditions and in an undivided cell using an environmentally friendly method with high atom economy. 相似文献
2.
The present work describes the synthesis of the beta-isomer of 1-alpha-D-(5-deoxy-5-iodoarabinofuranosyl)-2-nitroimidazole (IAZA). Radioiodinated IAZA ((123)I-IAZA) has been extensively studied as a radiopharmaceutical for the diagnosis of regional and/or focal tissue hypoxia in a variety of clinical pathologies. The beta-anomer of IAZA, 1-beta-D-(5-deoxy-5-iodoarabinofuranosyl)-2-nitroimidazole (beta-IAZA, 1), was synthesized via an unconventional route starting from 1-beta-D-(ribofuranosyl)-2-nitroimidazole (AZR), with a change of configuration at the C-2'-position to afford 1-beta-D-(arabinofuranosyl)-2-nitroimidazole (beta-AZA, 7). Nucleophilic iodination of the 5'-O-toluenesulfonyl-2',3'-di-O-acetyl precursor of beta-AZA, 9, followed by deprotection, afforded 1 in satisfactory yield. beta-IAZA (1) was also synthesized from 7 using molecular iodine and triphenylphosphine. 相似文献
3.
Ramin Ghorbani-Vaghei Davood Azarifar Ardeshir Khazaei Behrooz Maleki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1877-1881
1,3,5-Trisubstituted pyrazolines were converted to the corresponding pyrazoles in good yields under heterogeneous and solvent-free conditions by N,N′,N,N′-tetrabromo-benzene-1,3-disulfonylamide [TBBDA] at ambient temperature. 相似文献
4.
Hamid Reza Momenian Sousan Gholamrezaei Masoud Salavati-Niasari Behnam Pedram Farhang Mozaffar Davood Ghanbari 《Journal of Cluster Science》2013,24(4):1031-1042
In this work Mg(OH)2, Ca(OH)2, CaCO3, SrCO3 and BaCO3 nanoparticles were synthesized via a simple sonochemical reaction at room temperature. Nanoparticles were synthesized via a surfactant-free reaction solvent water. Nanostructures materials were characterized by scanning electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy. The photocatalytic behavior of nanoparticles was evaluated using the degradation of a methyl orange aqueous solution under ultraviolet light irradiation. The results show that metal hydroxide and metal carbonate nanoparticles are promising materials with excellent performance in photocatalytic applications. 相似文献
5.
A new environmentally benign, convenient, and facile methodology for the N-formylation of amines is reported using ultrasound irradiation under solvent- and catalyst-free conditions at room temperature. Compared with conventional methods, the main advantages of the present procedure are milder, cleaner and greener conditions, shorter reaction time, higher purity and yields, simpler work-up, and lower generation of waste or pollutions. 相似文献
6.
Mohammad Yousefi Elham Noori Davood Ghanbari Masoud Salavati-Niasari Tahereh Gholami 《Journal of Cluster Science》2014,25(2):397-408
In this work, poly vinyl alcohol–ZnO nanocomposites were synthesized via two different in situ and ex-situ methods. In ex-situ, at first zinc oxide nanostructures were synthesized by one-step precipitation reaction between zinc acetate and sodium hydroxide. The effect of different surfactants such as poly vinyl pyrrolidone, poly vinyl alcohol and poly ethylene glycol on the morphology of ZnO nanostructures was investigated. Nanostructures were characterized by X-ray diffraction, scanning electron microscopy. The influence of ZnO nanostructures on the flame retardancy of the poly vinyl alcohol matrix was studied using underwriter laboratories UL-94 analysis. 相似文献
7.
Electrochemical oxidation of 2,3‐dihydroxypyridine in aqueous phosphate buffer solution at a glassy carbon electrode has been studied using cyclic voltammetry and controlled potential coulometry. The results indicate that oxidation of 2,3‐dihydroxypyridine on glassy carbon electrode shows an irreversible feature in aqueous solution. This data indicates that the electrochemically generated pyridindione is unstable and via an oxidative conversion pathway converts to a novel highly oxygenated heterocyclic compound. By means of the obtained electrochemical data, an efficient, one‐pot method for the synthesis of this heterocyclic compound based on the oxidative cyclization of 2,3‐dihydroxypyridine under green conditions, and in a good yield and purity is described. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
8.
Mohammad Mehdi Khodaei Davood Kordestani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2403-2405
Abstract Direct conversion of acylals to the corresponding bisulfites can be easily performed in the presence of bismuth (III) nitrate pentahydrate in ethanol at room temperature in good yields. 相似文献
9.
Saleh Ashrafi Okhtay Jahanbakhsh Davood Alizadeh Behrooz Salehpour 《Central European Journal of Physics》2013,11(5):560-567
Compton scattering tomography is widely used in numerous applications such as biomedical imaging, nondestructive industrial testing and environmental survey, etc. This paper proposes the use of the genetic algorithm (GA), which utilizes bio-inspired mathematical models, to construct an image of the insides of a test object via the scattered photons, from a voxel within the object. A NaI(Tl) scintillation detector and a 185 MBq 137Cs gamma ray source were used in the experimental measurements. The obtained results show that the proposed GA based method performs well in constructing images of objects. 相似文献
10.
The electrochemical oxidation of 1,4-dihydroxyanthraquinone has been studied in the presence of acetylacetone and benzoylacetone as nucleophiles in a mixture of ethanol/water by means of cyclic voltammetry as a diagnostic technique.The results indicate the participation of electrochemically produced anthraquinone in the Michael addition reaction with acetylacetone and benzoylacetone to form the corresponding new anthraquinone derivatives.On the basis of the EC mechanism,the observed homogeneous rate constants(kobs)of the reaction of anthraquinone with acetylacetone and benzoylacetone were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results. 相似文献