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Wyszukujesz frazę "reaction" wg kryterium: Temat


Tytuł:
One-pot three component (LaCl3•7H2O) catalysed biginelli reaction for the synthesis of 1,2,3,4-tetrahydropyrimidine
Autorzy:
Murugesan, C.
Sihabudeen, M. Mohamed
Ahamed, A. Asrar
Powiązania:
https://bibliotekanauki.pl/articles/1190119.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
2
3
4-tetrahydropyrimidine; one pot synthesis
Multicomponent reaction; Biginelli reaction; 1
Opis:
A Series of tetrahydropyrimidine has been derived by LaCl3•7H2O catalysed one pot three component biginelli reaction. The compounds have synthesised from an aldehyde, ethyl acetoacetate and urea or thiourea in an ethanolic medium using a catalytic amount of (LaCl3•7H2O). This method provides quantitative yield and the catalysis can be easily recovered from the reaction medium and be re-used.
Źródło:
World Scientific News; 2016, 35; 87-99
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nitrogen-doped pyrene as a catalyst for fuel cells
Autorzy:
Chudoba, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1179638.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
DFT
fuel cells
oxygen reduction reaction
Opis:
Density functional theory (DFT) was applied to study nitrogen-doped pyrene as an oxygen reduction reaction (ORR) cathode catalyst for fuel cells. Transition states and energy barriers were calculated to predict the catalytic properties of this substance.
Źródło:
World Scientific News; 2017, 72; 61-68
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterization of fully substituted pyrimidines by using ketene dithioacetal as potent antimicrobial agent
Autorzy:
Khunt, H. R.
Pipaliya, P. P.
Ghelani, S. M.
Babariya, J. S.
Naliapara, Y. T.
Powiązania:
https://bibliotekanauki.pl/articles/412064.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ketene dithioacetal
pyrimidines
guanidine
biginelli reaction
Opis:
Various ketene dithioacetals of acetoacetanilides were reacted with guanidine nitrate in the presence of base to produce the 2-amino-4-isopropyl-6-alkoxy-N-arylpyrimidine-5-carboxamide derivatives with good yields. All the synthesized compounds were characterized by mass, NMR and IR and also evaluated for antimicrobial activity against five different bacterial and fungal strains. The compounds 4i, 4k and 4l has found comparatively good active against all the bacterial strains.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 134-141
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green synthesis of pyrimidine derivative
Autorzy:
Sonawane, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/412470.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
Grindstone chemistry
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is study and synthesis of dihydropyrimidinones efficiently and in high yields under mild, solvent free and eco-friendly conditions by using “Grindstone Chemistry Technique” catalyzed by CuCl2•2H2O and Conc. HCl. The obtained products have been identified by comparison with spectral data & their melting points. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. 3,4-dihydropyrimidin-2-(1H)-ones was synthesized and characterized using IR. The melting points was obtained 203 °C.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 2; 64-68
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Study of Chemical Synthesis of Pyrimidine Derivatives by Using Grindstone Chemistry Technique and Conventional Metod
Autorzy:
Sonawane, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/412505.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
Grindstone chemistry
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is comparative study of chemically synthesis of two DHPMs derivatives by Biginelli Reaction using conventional method and grindstone chemistry technique. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. Two derivative viz. 3,4-dihydropyrimidin-2-(1H)-ones and 3,4-dihydropyrimidin-2-(1H)-thiones were synthesized and characterized using IR. The melting points were obtained are 208 °C and 210 °C respectively. “Grindstone Chemistry Technique” catalyzed by CuCl2•2H2O and Conc. HCl. gave more yield, solvent free and ecofriendly. The obtained products have been identified by comparison with spectral data & their melting points. This study will help to develop easy protocol for the synthesis of many more DHPMs derivative with high field.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 1; 22-27
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A convergent approach for the synthesis of new pyrazolyl bipyridinyl substituted coumarin derivatives as antimicrobials
Autorzy:
Bhila, V. G.
Chovatiya, Y. L.
Patel, C. V.
Giri, R. R.
Brahmbhatt, D. I.
Powiązania:
https://bibliotekanauki.pl/articles/411982.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Coumarin
Bipyridine
Pyrazole
Kröhnke’s reaction
antimicrobial activity
Opis:
Some new 3-[3-(1-phenyl-3-aryl-1H-pyrazol-4-yl)acryloyl]coumarins 3a-f were synthesized (coumarin chalcones) by the condensation of various 3-acetyl coumarins 1 and appropriate 1-phenyl-3-aryl-1H-pyrazole-4-carbaldehyde 2. These coumarin chalcones 3a-f were then employed for the synthesis of pyrazolyl bipyridinyl substituted coumarins 7a-f, 8a-f, and 9a-f under Krohnke’s reaction condition. The characterization of all the synthesized compounds was carried out by elemental analysis, IR, 1H-NMR, 13C-NMR, DEPT-135 and mass spectral analysis. In addition to that, in vitro antimicrobial competency of the title compounds was assessed against selected pathogens. Compounds 3b, 3e, 7b, 8b, 8c and 9b exhibited excellent antimicrobial activity and said to be the most proficient members of the series.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2015, 40; 1-16
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gewald reaction for the synthesis of benzo[4,5]-thieno[2,3-d]pyrimidin-4(3H)-one derivatives and it’s antimicrobial study
Autorzy:
Dhuda, Gautamkumar
Ladwa, Paresh
Modha, Jayesh J.
Powiązania:
https://bibliotekanauki.pl/articles/1031419.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Antimicrobial Study
Benzo[4-5]thienopyrimidines
Gewald Reaction
Opis:
A variety of schiff base of 3-amino-2,7-dimethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one have been synthesized using novel and yield efficient protocol i.e., Gewald condensation reaction by four step processes. The characterization of synthesized diverse molecules was characterized by various spectroscopic methods such as IR, Mass, and NMR. The hybrids of thieno-pyrimidines were utilized to check their efficiency as anti-microbial activity against various Gram-positive (S. aureus, S. pyogenes, MRSA- multi-resistance S. aureus) and Gram negative (E. coli, P. aeruginosa, Klebsiella pneumonia) bacteria, using five anti-microbial agents as reference standard. It was found that 4a (anti-fungal agent) and 4e (anti-bacterial agent) shown best efficiency and which can lead in the area of medicinal field.
Źródło:
World Scientific News; 2021, 151; 110-122
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rice Blast Biology and Reaction of Host to the Disease
Autorzy:
Zewdu, Zelalem
Powiązania:
https://bibliotekanauki.pl/articles/1839725.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Rice
Blast
Magnaporthe grisea
Magnaporthe oryzae
Host Reaction
Opis:
Rice blast (Magnaporthe grisea) is first reported in China and then in Africa in1922. The disease is now the most widespread and devastating rice disease in all rice producing areas of the world. The disease can cause from mild yield reduction to total crop loss as depends on the variety and severity level. The rice blast isolate is closely related to the isolate of other blast like fungus and distinctly described as Magnaporthe grisea. Rice blast fungus starts the infection cycle after a three-celled conidium lands on the rice leaf surface. Thousands of spores can be produced from a single lesion within 15 days after infection. Symptoms on leaves start as small brown necrotic lesions that evolve to larger elliptical or spindle-shaped lesions, colored whitish to gray with darker borders while infected seeds display brown spots, which may result from the infection of the florets as they matured into seeds. The rice blast needs at least a 12-hour period of moderate temperatures (25 to 30 °C), high relative humidity (90-92 %), and high moisture which are conducive for its development. The disease can be managed by using resistant varieties, using integrated disease management options and nutrient managements like application of recommended nitrogen fertilizers and application of silicon fertilizers. The rice plant responds differently for reducing the occurrence and damage of the disease either fungus is incapable causing sporulating lesions on the plant or the plant develop residual resistance that remains when complete resistance has been overcome by the pathogen.
Źródło:
World News of Natural Sciences; 2021, 39; 11-21
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study of chemical synthesis of dihydropyrimidine (DHPMS) derivatives by Biginelli Reaction using microwave irradiation and conventional method
Autorzy:
Sonawane, R.P.
Powiązania:
https://bibliotekanauki.pl/articles/411784.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
dihydropyrimidine derivatives
Biginelli reaction
microwave irradiation
conventional method
Opis:
The majority of the drugs on the market today are entirely chemically synthesized in the laboratory. Several scientists had synthesized dihydropyrimidine (DHPMs) derivatives showing a wide spectrum of biological actions as antibacterials, antivirals as well as antitumor agents. This activity is principally due to presence of steriogenic carbon C4 in their structure. The current investigation is comparative study of chemically synthesis of two DHPMs derivatives by Biginelli Reaction using microwave irradiation and conventional method. The synthesis of DHPMs derivative involves a multicomponent reaction (aldehyde derivative, urea /thiourea and 1,3-dicarbonyl compounds) in presence of HCl / NH4Cl as a catalyst. Two derivative viz. 3,4-dihydropyrimidin-2-(1H)-ones and 3,4-dihydropyrimidin-2-(1H)-thiones were synthesized and characterized using IR. The melting points were obtained are 203 °C and 211 °C respectively. Microwave irradiation was easy and gave more yield than conventional method. This study will help to develop easy protocol for the synthesis of many more DHPMs derivative with high yield.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 5; 7-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiotracer Technique in Study of Strongly Basic Anion Exchange Resins Dowex-SBR LC and Indion-454
Autorzy:
Singare, P. U.
Powiązania:
https://bibliotekanauki.pl/articles/411866.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
anion exchange resins
Indion-454
Dowex-SBR LC
radioisotopes
131I
82Br
ion-isotopic exchange reaction
reaction kinetics
characterization
Opis:
The present paper demonstrates application of isotopic tracer technique in characterization of anion exchange resins Dowex-SBR LC and Indion-454 for which 131I and 82Br radio isotopes were used. The characterization was made based on iodide and bromide ion-isotopic exchange reaction kinetic data obtained for the two resins. It was observed that during iodide ion-isotopic exchange reaction performed at 35.0 °C, 1.000 g of ion exchange resins and 0.002 mol/L labeled iodide ion solution, the values of specific reaction rate (min-1), amount of ion exchanged (mmol), initial rate of ion exchange (mmol/min) and log Kd were 0.379, 0.426, 0.161 and 16.2 respectively for Dowex-SBR LC resin, which was higher than the respective values of 0.156, 0.243, 0.038 and 13.4 as that obtained by using Indion-454 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The results of present investigation also indicate that during the two ion-isotopic exchange reactions, for both the resins, there exists a strong positive linear correlation between amount of ions exchanged and concentration of ionic solution; and strong negative correlation between amount of ions exchanged and temperature of exchanging medium. Based on overall results it appears that under identical experimental conditions, as compared to Indion-454 resins, Dowex-SBR LC resins show superior performance. It is expected here that the present technique can be extended further for characterization of different ion exchange resins which will further help in the selection of those reins for the specific industrial application.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 13; 37-49
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ecofriendly synthesis of Zinc oxide nanoparticles from asthma plant - Euphorbia hirta L.
Autorzy:
Manokari, M.
Shekhawat, Mahipal S.
Powiązania:
https://bibliotekanauki.pl/articles/1182444.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Absorption spectrum
Euphorbia hirta
Reaction mixtures
Zinc oxide nanoparticles
Opis:
The present study states about the biosynthesis and UV-Visible characterization of Zinc oxide (ZnO) nanoparticles using leaf, stem, roots and inflorescence of the medicinal herb Euphorbia hirta. The aqueous extracts of plant parts were acted as capping and reducing agent while Zinc Nitrate Hexahydrate used as precursor. One milliliter of plant extracts mediated the formation of ZnO nanoparticles in solution which were visually confirmed by the development of yellowish color in the reaction mixtures. The optical properties of the reaction mixtures were analyzed by the UV-Visible double beam spectrophotometer. The leaf reaction mixture showed strong absorption band at 302nm, stem reaction mixture at 299nm, and the root and inflorescence reaction mixtures at 310nm. The results indicate that whole Euphorbia hirta plant can be used for the biosynthesis of Zinc oxide nanoparticles.
Źródło:
World Scientific News; 2017, 69; 111-121
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PEG mediated eco-friendly one pot sunthesis of benzylamine coumarin derivatives using multicomponent reactant
Autorzy:
Viradiya, D. J.
Kotadiya, V. C
Khunt, M. D.
Baria, B. H.
Bhoya, U. C.
Powiązania:
https://bibliotekanauki.pl/articles/412545.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
one pot reaction
benzylamine coumarin derivative
green synthesis
PEG-400
Opis:
A green resourceful, eco-friendly and facile protocol was developed for the synthesis of benzylamine coumarin derivatives by the reaction of 4-hydroxy coumarin, secondary amine and aromatic aldehyde in the presence of PEG400 as a solvent as well as catalyst at room temperature. A wide range of functional groups were tolerated in the developed protocol. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis. The target molecules were obtained in good to excellent yield applying this method.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 11, 2; 177-184
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zinc oxide nanoparticles synthesis from Moringa oleifera Lam. Extracts and their characterization
Autorzy:
Manokari, M.
Shekhawat, Mahipal S.
Powiązania:
https://bibliotekanauki.pl/articles/1192606.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Zinc oxide nanoparticles
Moringa oleifera
UV-Visible spectroscopy
Reaction medium
Opis:
The enormous applications of metal nanoparticles urged to find new biologically hazard free methods for huge synthesis. The green synthesis approaches are acknowledged by many scientists due to its cost effective, simple, eco-friendly and resourceful move. The present investigation deals with the bio-production and characterization of zinc oxide (ZnO) nanoparticles using leaf, stem, flowers and fruit pods of the medicinal plant Moringa oleifera. The synthesis of ZnO nanoparticles from the aqueous extracts were mediated by Zinc Nitate Hexahydrate as precursor. Various parameters like time periods, concentration of plant extracts and different temperatures were influenced the synthesis of ZnO nanoparticles. The stability and reduction of zinc ions to ZnO nanoparticles were characterized by UV-Visible spectroscopic analysis. The reaction medium from the leaves and flowers showed strong absorption at 308nm. The stem and fruit pods reaction medium existed absorption peak at 293nm.
Źródło:
World Scientific News; 2016, 55; 252-262
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Inverse Reaction Cross Sections for Some Charged Particles Using the Optical Model Parameters
Autorzy:
Ahmed, Rasha S.
Powiązania:
https://bibliotekanauki.pl/articles/1193016.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Optical reaction cross-sections
charged particles
neutrons
pre-equilibrium models
Opis:
p-nucleus, (_1^2)H-nucleus, (_1^3)H-nucleus, and (_2^4)He-nucleus inverse reaction cross sections have been determined using the optical model potentials in a wide range of target nuclei started from A=1 to A=232 using several incident particle energies ( E = 2, 8, 10, 20, and 40 MeV). In this work, a large number of optical model available parameters were used to calculate the inverse reaction cross section and compared to investigate the effect of the mass number and incident particle energy on the inverse reaction cross section. All the calculations were performed using MATHLAB programming language.
Źródło:
World Scientific News; 2016, 28; 72-83
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Click Reactionat an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers
Autorzy:
Ashaduzzaman, Md.
Kai, S.
Kunitake, M.
Powiązania:
https://bibliotekanauki.pl/articles/412120.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
click reaction
hollow-capsules
oil-water interface
tri-arm polystyrene
copolymer
Opis:
Cu(I)-catalyzed Huisgen click reactions between lipophilic polymer (tri-arm azidofunctionalized polystyrene) and hydrophilic polymer (copolymer of styrene sulfonate sodium and propargyl methacrylate) were investigated and hollow capsules, consisting of composite polymer nanofilms were obtained in chloroform-water biphasic solution. Since the lipophilic polymer, or hydrophilic polymer and copper catalyst were present in the oil or aqueous phase, respectively, the cross-linking reaction proceeded only at the phase interface. The combination of lipophilic and hydrophilic polymers produced hollow capsules consisting of nanofilms with lipophilic core and hydrophilic shell.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 6; 31-39
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł

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