排序方式: 共有102条查询结果,搜索用时 15 毫秒
71.
G. V. Panakala Rao B. Rajitha Y. Thirupathi Reddy P. Narsimha Reddy V. Naveen Kumar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2119-2126
In this article, we describe the synthesis of various substituted Chromene-[1, 3]thiazolo [2, 1, 3] benzothiadiazoles 4a-l by conventional (Method A) and microwave-assisted (Method B) which achieved reductions in reaction times, higher yields, and a cleaner reaction than the conventional method. A comparative study of these two methods has been discussed. 相似文献
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Thirupathi Rapolu Pavan Kumar K. V. P. Korupolu Raghu Babu Satheesh Kumar Dende Rajashekar Reddy Nimmareddy 《合成通讯》2019,49(10):1308-1315
A rapid and efficient one-pot method for the synthesis of 2-ethylamino benzimidazole, benzoxazole, and benzothiazole derivatives has been described. The reaction of o-phenylenediamines or o-aminophenols or 2-mercaptoanilines with EDC.HCl under microwave irradiation afforded the corresponding 2-ethylamino benzimidazole, benzoxazole and benzothiazole derivatives in excellent yields. 相似文献
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Y. Jayaprakash Rao G. Thirupathi Ch. Prasad Rao Y. Hemasri 《Russian Journal of General Chemistry》2016,86(5):1126-1131
A simple and efficient one pot method has been developed for the synthesis of some new functionalized pyrano fused flavone derivatives, alkyl 4,8-dioxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-10-carboxylates and dialkyl 4-oxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-8,9-dicarboxylates, from 7-hydroxy flavones and 7-hydroxy 8-formyl flavones using dialkylacetalynedicarboxylates in the presence of triphenyl phosphine. The structures of all synthesized compounds were elucidated by FT-IR, 1H and 13C NMR and Mass spectral analysis. 相似文献
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Thirupathi Gudi Kamana Porwal 《Numerical Methods for Partial Differential Equations》2016,32(1):36-59
In this article, we propose a C0 interior penalty method for the frictional plate contact problem and derive both a priori and a posteriori error estimates. We derive an abstract error estimate in the energy norm without additional regularity assumption on the exact solution. The a priori error estimate is of optimal order whenever the solution is regular. Further, we derive a reliable and efficient a posteriori error estimator. Numerical experiments are presented to illustrate the theoretical results. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 32: 36–59, 2016 相似文献
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Thirupathi N Stricklen PM Liu X Oshel R Guzei I Ellern A Verkade JG 《Inorganic chemistry》2007,46(22):9351-9363
Bicyclic P(CH2NMe)3P was synthesized, and its reactions with MnO2, elemental sulfur, p-toluenesulfonyl azide, BH3.THF, and W(CO)5(THF) were shown to furnish a variety of products in which the PC3 and/or the PN3 phosphorus are oxidized/coordinated. In contrast, reactions of the previously known P(CH2NPh)3P with Mo(0) and Ru(II) precursors were shown to afford products in which only the PC3 phosphorus is coordinated. The contrast in reactivity of P(CH2NR)3P (R = Me, Ph) with the aforementioned reagents is discussed in terms of steric and electronic factors. The new compounds are characterized by analytical and spectroscopic (IR, 1H, 31P, and 13C NMR) methods. The results of crystal and molecular structure X-ray analyses of the previously known compounds P(CH2O)3P and P(CH2NPh)3P and 6 of the 14 new compounds obtained in this investigation are presented. Salient features of these structures and the analysis of the Tolman cone angles calculated from their structural parameters are discussed in terms of the effects of constraint in the bicyclic moieties. Evidence is presented for greater M-P sigma bonding effects on coordination of the PC3 phosphorus of P(CH2NR)3P (R = Me, Ph) than are present in PMe3 analogues of group 6B metal carbonyls. From 1JBP data on the BH3 adducts of P(CH2NMe)3P, it is suggested that the free bases MeC(CH2NMe)3P < P(CH2NMe)3P < (Me2N)3P < P(MeNCH2CH2)3N increase in Lewis basicity at the PN3 phosphorus in the order shown. Substantial differences in 31P chemical shifts in the bicyclic compounds discussed herein relative to their acyclic analogues do not seem to be associated with the relatively small bond angle changes that occur around either the PN3 or the PC3 trivalent phosphorus atoms. 相似文献
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G. Thirupathi E. Yadaiah Goud Y. Hemasri MD. Suban Ali Y. Jayaprakash Rao 《Journal of the Iranian Chemical Society》2017,14(2):477-483
A facile, convenient, efficient and high-yielding synthesis of 3-aroylcoumarinoflavones has been developed by the condensation of easily synthesized 7-hydroxy-8-formylflavones and benzoyl acetonitriles in the presence of catalytic amount of l-proline in ethanol reflux. All the synthesized compounds were evaluated for their antioxidant activity. Some of the compounds showed very good activity compared to standard BHT. 相似文献
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Dr. Thirupathi Ravula Dr. Sudheer Kumar Ramadugu Giacomo Di Mauro Prof. Ayyalusamy Ramamoorthy 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(38):11624-11628
Polymer‐based nanodiscs are valuable tools in biomedical research that can offer a detergent‐free solubilization of membrane proteins maintaining their native lipid environment. Herein, we introduce a novel ca. 1.6 kDa SMA‐based polymer with styrene:maleic acid moieties that can form nanodiscs containing a planar lipid bilayer which are useful to reconstitute membrane proteins for structural and functional studies. The physicochemical properties and the mechanism of formation of polymer‐based nanodiscs are characterized by light scattering, NMR, FT‐IR, and TEM. A remarkable feature is that nanodiscs of different sizes, from nanometer to sub‐micrometer diameter, can be produced by varying the lipid‐to‐polymer ratio. The small‐size nanodiscs (up to ca. 30 nm diameter) can be used for solution NMR spectroscopy studies whereas the magnetic‐alignment of macro‐nanodiscs (diameter of > ca. 40 nm) can be exploited for solid‐state NMR studies on membrane proteins. 相似文献