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121.
One-pot reactions to produce isomeric 4′-(pyridyl) 2,2′:6′,2″-terpyridine under moderate conditions are described using imidazolium-based ionic liquid and quaternary ammonium-based molten salts as solvent media. The use of eutectic molten salts as a reaction media proved effective in sequential aldol and Michael addition reactions, leading to substituted terpyridines. The desired product was obtained in reasonable yield via a simple, one-pot reaction. 相似文献
122.
Shivaji H. Shelke Pravin C. Mhaske Pankaj Hande Vivek D. Bobade 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1262-1270
A novel series of 1-((4-methyl-2-substituted thiazol-5-yl)methyleneamino)-2-substituted isothiourea derivatives was synthesized by alkylation of (Z/E)-1-((4-methyl-2-substituted thiazol-5-yl)methylene)thiosemicarbazide with alkylhalide in acetone. All the newly synthesized compounds were characterized by spectral (IR, 1H NMR, 13C NMR, and mass spectrometry) methods. The newly synthesized compounds were screened for in vitro antimicrobial activity. Most of the compounds show moderate to excellent antimicrobial activity. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures and tables.] 相似文献
123.
Chukwuyem C. Obuseh Basu D. Paudel 《Journal of Dispersion Science and Technology》2013,34(9):1379-1384
In this article, we studied experimentally the fluidization of binary mixture in particulate flows. A laboratory fluidized bed is built with water being used as carrying fluid. Three types of solid particles, nylon, glass, and aluminum of the same size and different densities, were used in the experiments. We investigated the wall effect to the fluidization of a single particle, the fluidization of binary mixture of nylon and aluminum with a density ratio of 0.42, and the fluidization of binary mixture of glass and aluminum with a density ratio of 0.91. Our results show that the presence of narrow walls reduces the minimum fluidization velocity for a single particle up to 40%. We also found that in the case of binary mixture of glass and aluminum particles, uniform mixing can be easily achieved with no segregation observed; on the other hand, in the case of binary mixture of nylon and aluminum particles, significant segregation and separation are observed. Based on experimental results, correlation relationships between fluidization velocity and bed height are also reported. 相似文献
124.
Pravin K. Johri 《Mathematical Methods of Operations Research》1994,39(1):85-92
This note shows that half spaces play a very special role in the development of duality. In addition to the minimum norm duality, the duality in linear programming, and Wolfe's and Johri's formulations in nonlinear programming can all be derived via half spaces by following an identical five step procedure. 相似文献
125.
Indus-2 is a synchrotron radiation source that is operational at RRCAT, Indore, India. It is essentially pertinent in any synchrotron radiation facility to store the electron beam without beam loss. During the day to day operation of Indus-2 storage ring, difficulty was being faced in accumulating higher beam current. After examination, it was found that the working point was shifting from its desired value during accumulation. For smooth beam accumulation, a fixed desired tune in both horizontal and vertical plane plays a significant role in avoiding beam loss via the resonance process. This required a betatron tune feedback system to be put in the storage ring. After putting ON this feedback, the beam accumulation was smooth. The details of this feedback and its working principle are described in this paper. 相似文献
126.
Deepak M. Maher Samadhan S. Nagane Uday A. Jadhav Pravin H. Salunkhe Bhausaheb V. Tawade Prakash P. Wadgaonkar 《Journal of polymer science. Part A, Polymer chemistry》2019,57(14):1516-1526
Expanding on our strategy to synthesize aromatic step‐growth polymers containing pendant clickable azido groups via functional monomer approach, we have now designed and synthesized a new cardo bisphenol, viz., 2‐(2‐azidoethyl)‐3, 3‐bis(4‐hydroxyphenyl) isoindolin‐1‐one (PPH‐N3). PPH‐N3 was conveniently synthesized starting from commercially available phenolphthalein by a three‐step route in an overall yield of 65% using simple organic transformations. Aromatic (co)polyesters bearing pendant azido groups were synthesized by low‐temperature solution polycondensation of PPH‐N3 or different molar ratios of PPH‐N3 and bisphenol‐A (BPA) with aromatic diacid chlorides in dry dichloromethane in the presence of triethylamine (TEA) as a base. The formation of medium to reasonably high‐molecular‐weight (co)polyesters was evidenced from intrinsic viscosity and number‐average molecular‐weight measurements that were in the range 0.52–0.85 dL/g and 16,700–28,200, respectively. Tough, transparent, and flexible films could be cast from chloroform solutions of these (co)polyesters. (Co)polyesters were characterized using FTIR, 1H NMR, 13C NMR spectroscopy, XRD, and TGA. The thermal curing reaction of (co)polyesters involving decomposition of azido groups was studied by DSC analysis. The chemical modification of a representative copolyester containing pendant azido groups was carried out quantitatively using catalyst‐free azide‐maleimide cycloaddition reaction with two maleimides, namely, N‐methylmaleimide and N‐hexylmaleimide. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1516–1526 相似文献
127.
Sharma Pravin O. Barewar Surendra D. Chougule Sandesh S. 《Journal of Thermal Analysis and Calorimetry》2021,143(2):1051-1061
Journal of Thermal Analysis and Calorimetry - The present study aims at investigating the enhancements in thermal properties, CHF and HTC of novel Ag/ZnO hybrid nanofluid at various concentrations.... 相似文献
128.
A stereoselective, route to aza-polycyclic systems related to magellanine, and congeners from simple aromatic precursor is described. Oxidative dearomatization leading to a highly reactive spiroepoxycyclohexa-2,4-dienone, intramolecular inverse demand π4s+π2s cycloaddition and photochemical reactions are key features of our approach. 相似文献
129.
Dr. Pravin Kumar Ankush Jagtap Dr. Sam Asami Claudia Sippel Prof. Dr. Ville R. I. Kaila Prof. Dr. Felix Hausch Prof. Dr. Michael Sattler 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(28):9529-9533
The recently discovered SAFit class of inhibitors against the Hsp90 co‐chaperone FKBP51 show greater than 10 000‐fold selectivity over its closely related paralogue FKBP52. However, the mechanism underlying this selectivity remained unknown. By combining NMR spectroscopy, biophysical and computational methods with mutational analysis, we show that the SAFit molecules bind to a transient pocket in FKBP51. This represents a weakly populated conformation resembling the inhibitor‐bound state of FKBP51, suggesting conformational selection rather than induced fit as the major binding mechanism. The inhibitor‐bound conformation of FKBP51 is stabilized by an allosteric network of residues located away from the inhibitor‐binding site. These residues stabilize the Phe67 side chain in a dynamic outward conformation and are distinct in FKBP52, thus rationalizing the basis for the selectivity of SAFit inhibitors. Our results represent a paradigm for the selective inhibition of transient binding pockets. 相似文献
130.
Vikas Shinde Pravin C. Mhaske Aakriti Singh Dhiman Sarkar Pramod Mahulikar 《Journal of heterocyclic chemistry》2019,56(11):3093-3101
A novel series of 4‐(4‐(1‐benzyl‐1H‐1,2,3‐triazol‐4‐yl)phenyl)‐2‐substitutedthiazole derivatives ( 8a‐l) have been synthesized by [3 + 2] cycloaddition reaction of 4‐(4‐ethynylphenyl)‐2‐substitutedthiazole with substituted benzyl azide in aqueous DMF. Starting compounds 4‐(4‐ethynylphenyl)‐2‐substitutedthiazole ( 6a‐d ) were synthesized by reaction of 4‐(2‐substitutedthiazol‐4‐yl)benzaldehyde with Ohira‐Bestmann reagent in methanol. The structures of these novel triazole‐thiazole clubbed derivatives were confirmed by the spectral analysis. The title compounds ( 8a‐l ) were tested for antimycobacterial activity against Mycobacterium tuberculosis H37Ra active and dormant (MTB, ATCC 25177) and antimicrobial activity against standard Gram‐positive bacteria, Staphylococcus aureus (NCIM 2602) and Bacillus subtilis (NCIM 2162), and Gram‐negative bacteria, Escherichia coli (NCIM 2576) and Pseudomonas flurescence (NCIM 2059). Compounds 8a , 8b , 8c , and 8h reported good activity against B subtilis, compounds 8a , 8b , and 8c showed good activity against S aureus, and compound 8b showed good activity against dormant M tuberculosis H37Rv strain. Compounds 8b and 8c found more potent against Gram positive and dormant M tuberculosis H37Rv strains. These novel triazole‐thiazole clubbed analogues found to be a capable leads for further optimization and development. 相似文献