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991.
Venkateswarlu Chimaladenne Ramesh Manda Ashok Reddy Gudipally Krishna Reddy Valluru Pradeep Kumar Brahman 《合成通讯》2020,50(19):2941-2949
Abstract A mild and efficient base promoted, microwave assisted, green synthesis of 2-amino-2-ene-1,4-diones has been described by the decomposition of phenacyl azides followed by treatment with pyridinium salts of phenacyl bromides in aqueous media. A diverse range of substrates bearing electron-releasing and electron-withdrawing substituents were well tolerated and delivered corresponding 2-amino-2-ene-1,4-diones in good yields. Synthesized 2-amino-2-ene-1,4-diones have been further explored in the synthesis of various substituted 4-hydroxypyrrolidin-2-ones. 相似文献
992.
Maheshwara Reddy Nadiveedhi Mahammad Sadik Shaik Suresh Kumar Krishnammagari Suresh Reddy Cirandur 《Journal of heterocyclic chemistry》2021,58(7):1472-1483
Multisubstituted indolylpyrazolopyrimidines were synthesized in good yields with base promoted one-pot multicomponent system from aldehyde, ketone, and indolylpyrazolamine. Milder and cost-effective conditions are the highlights of the present protocol. Among the synthesized compounds ( 4a-j ) 4b , 4c , 4e , and 4f have shown significant better in vitro antioxidant activity compared to standard ascorbic acid. 相似文献
993.
Madasu Madhu Sai Reddy Doda Prem Kumar Begari Krishna Rao Dasari Gangadhar Thalari Sudhakar Kadari Jhillu Singh Yadav 《Journal of heterocyclic chemistry》2021,58(4):942-946
Enantioselective and a highly concise total synthesis of Ambrisentan are described. The chiral auxiliary controlled enantioselective epoxidation (Azerad protocol), photochemical regioselective epoxide opening, and base mediated ester hydrolysis reactions are the key reactions. 相似文献
994.
Chapala Vijaya Lakshmi Katari Naresh Kumar Malavattu Giri Prasad Kerru Nagaraju Reddy Pedavenkatagari Narayana Marisetti Vishnu Murthy 《Russian Journal of General Chemistry》2021,91(5):932-938
Russian Journal of General Chemistry - Large-scale enantioselective synthesis of the chiral amine unit of HCV NS5A inhibitor Elbasvir has been accomplished in six steps, with 55% overall yield. The... 相似文献
995.
996.
This paper reports on solvent-extraction studies of Ni(II) from sulfate solutions with LIX 84I (2-hydroxy-5-nonylacetophenoneoxime) as the extractant. The extraction of metal depends on the equilibrium pH of the aqueous phase and the extractant concentration. The transfer of metal follows a cation exchange-type mechanism: Ni2+ + 2HA --> NiA2 + 2H+. Extraction varies with the nature of the diluents. Temperature has no effect on the extraction of metal. The extraction behavior of associated metals clearly demonstrates the application of LIX 84I as the extractant for the separation of Cu(II), Ni(II) and Zn(II). Based on the results, a flow sheet of the process was developed. 相似文献
997.
998.
Remko Achten Evelien A. W. Smits R. Amaranatha Reddy Marcel Giesbers Antonius T. M. Marcelis Ernst J. R. Sudh lter 《Liquid crystals》2006,33(1):57-65
The synthesis and mesomorphic properties of 30 bent-core compounds with a fluorine substituent in one of the outer rings are reported. The banana-shaped compounds are all derived from resorcinol and contain esters as linking groups between the five aromatic rings. The different mesophases have been characterized by polarizing optical microscopy, differential scanning calorimetry, X-ray diffraction studies and electro-optical investigations. The compounds with the longer terminal chains exhibit an antiferroelectric SmCP phase. Upon introduction of a fluorine substituent the layer spacing increases, as compared with the corresponding unsubstituted compound. The introduction of one terminal vinyl group in the mono-substituted bent-core mesogens has no significant influence on the liquid crystalline properties and the switching remains antiferroelectric. Due to the introduction of the terminal double bond, these banana-shaped compounds are suitable for the preparation of siloxane polymers or attachment to a hydrogen-terminated silicon surface. 相似文献
999.
Fission-track registration characteristics of Lexan solid state nuclear track detectors have been used to measure the fast neutron induced fission cross section of232Th. The fast neutrons (?14.2MeV) were produced with the help of an AN-400 model Van-de-Graaff accelerator at Banaras Hindu University laboratory using3H(2H,n)4He reaction and were used to irradiate the fissile target deposited on the plastic detector. The track densityT, registered on the plastic detector is related to the fission cross sectionσ f, through the relationT=knσ føt wheren is the number of fissile atoms per cm2 in the deposit, ø is the neutron flux,k is fission track registration efficiency andt is the time of irradiation. The fission cross sectionσ f of232Th, relative to the well measured fission cross section of238U, was found to be 0.36±0.04 barn. 相似文献
1000.
The effects of thermal dispersion and thermal stratification on mixed convection about a vertical surface in a porous medium
are studied. The conservation equations that govern the problem are reduced to a system of nonlinear ordinary differential
equations. The resulting equations are solved on the basis of the local similarity approximation. The results indicate that
both dispersion and stratification effects have considerable influence on the heat transfer rate. 相似文献