Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Thirunarayanan, G." wg kryterium: Autor


Tytuł:
IR and NMR spectral studies of some 4-(6-methoxy-2-naphthyl)-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines: Assessment of substituent effects
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412242.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Oxazine-2-amines
IR spectra
NMR spectra
Hammett correlation
Substituent constans
Opis:
A series containing thirteen title compounds were synthesized and recorded IR and NMR spectra. The infrared νNH, C=N(cm-1)stretches, 1H NMR δNH, 13C NMR δC=N(ppm) chemical shifts of synthesized oxazine amines were assigned and correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses, the effect of substituents on the above spectral frequencies can be discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 109-116
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pharmacological and insect antifeedant activities of some 3-(2,4-dichloro-5-fluorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412405.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Halo aryl 4,5-dihydro-1H-pyrazole-1-carbothioamides
antibacterial activity
antifungal activity
antioxidant activity
insect antifeedant activity
Opis:
A series containing twelve titled compounds were synthesized by solvent-free method and their purities were examined by literature procedure. These compounds were subjected to study the pharmacological effects such as antibacterial, antifungal and antioxidant activities and the insect antifeedant activities using Bauer-Kirby disc diffusion method with their bacterial and fungal strains, DPPH radical scavenging and leaf disc bio-assay method with 4th instar larvae Achoea janata L.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 18; 47-56
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solvent-free synthesis, antimicrobial and insect antifeedant potentials of some 4(4-chloro-1-naphthyl)-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1075725.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
3-oxazine-2-amines
4-(4-chloro-1-naphthyl)-5
6-dihydro-6-(substituted phenyl)-4H-1
SiO2-H3PO4
antimicrobial potentials
insect antifeedant activity
solvent-free synthesis
Opis:
More than 85% yields of thirteen 4-(4-chloro-1-naphthyl)-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines weer synthesised by SiO2-H3PO4 catalyzed solvent-free cyclization of substituted styryl4-chloro-1-naphthyl ketones and urea under microwave irradiation. The synthesized oxazine amines have been characterized by analytical and spectroscopic techniques. The antimicrobial activities of these 4-(4-chloro-1-naphthyl)-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines have been appraised by means of Bauer-Kirby technique. The insect antifeedant activities of these oxazine-2-amines were assessed by Dethler’s technique using 4th instar larvae Achoea janata L.
Źródło:
World Scientific News; 2019, 118; 1-16
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Hammett equation on IR and NMR spectral data of (5-bromothiophen-2-yl) (3-(4-methoxyphenyl)bicyclo[2.2.1]hept-5-en-2-yl)methanones
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1182868.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
(5-bromothiophen-2-yl)(3-substituted phenyl)bicyclo[2.2.1]hept-5-en-2-yl)methanones
ir and nmr spectra
hammett equation
hammett substituent constants
regression analysis
electronic effects
Opis:
More than 60% yield of the titled compounds, (5-bromothiophen-2-yl)(3-substituted phenyl) bicyclo[2.2.1]hept-5-en-2-yl)methanones were prepared and examined their purities by literature method. The characteristic infrared spectral frequencies (cm-1) and NMR chemical shifts (ppm) of these ketones were assigned. These spectral data were applied to Hammett equation with Hammett substituent constants for prediction of effects substituent using single and multi-regression analysis. From the results of statistical analysis, the electronic effect of substituents on the spectral data has been studied.
Źródło:
World Scientific News; 2016, 53, 3; 138-156
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral LFER in some aryl azine derivatives
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1191375.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Aryl hydrazines
Hammett correlations
IR spectra
NMR spectra
Swain-Lupton’s parameters
Opis:
About ten (Z)-1-(1-(substitutedphenyl)ethylidene)-2-(diphenylmethylene)hydrazines were prepared and their purities were examined by literature method. The infrared and NMR spectra of these hydrazines were recorded. The characteristics C=N and N-N stretches (ν, cm-1) and the chemical shifts (δ, ppm) of methyl protons and carbons were assigned. These spectral have been correlated with Hammett substituent constants, F, R and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses, the effects of substituent on the spectral data have been studied.
Źródło:
World Scientific News; 2016, 33; 79-95
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solvent-free synthesis and assessment of substituent effects from IR & NMR spectra of some substituted benzylidene-5-ethyl-1,3,4-thiadiazole-2-amines
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/411670.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Benzylidene-5-ethyl-1
3
4-thiadiazole-2-amines
solvent-free synthesis
SiO2
H3PO4
IR spectra
NMR spectra
Hammett correlation
Opis:
A series containing ten titled compounds were synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of substituted benzaldehydes and 2-amino-5-ethyl-1,3,4-thiadiazole under microwave irradiation. The yields of prepared amines are more than 90 %. The synthesized amines were characterized by their physical constants and spectroscopic data reported in literature earlier for known compounds. The assigned spectral group frequencies such as infrared νC=N, C-S-C, N-N (cm-1) and NMR chemical shifts (δ, ppm) of CH, C=N have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analyses, the effects of substituent on the above spectral data have been discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 89-98
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
IR & NMR spectral studies of some 7-substituted 9H-fluorenacyl bromides: Assessment of substituent effects
Autorzy:
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412017.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
9H-Fluorenacyl bromides
IR and NMR spectra
Hammett substituent constants
Correlation analysis
Opis:
A series of some 2-bromo-1-(2-substituted 9H-fluorene-7-yl)ethanones have been prepared. The purities of these ethanones have been checked by their physical constants and spectroscopic data. The spectral group frequencies of these enones have been assigned and correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses, the effects of substituent have been discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 2; 152-161
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NMR Spectral correlations in some Tröger’s bases
Autorzy:
Thirunarayanan, G
Suresh, M.
Powiązania:
https://bibliotekanauki.pl/articles/412650.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
tröger’s bases
NMR spectra
hammett correlations
substituent effects
Opis:
Some Tröger’s bases have been synthesised from substituted anilines and paraformaldehyde in presence of Lewis acid catalyst such as anhydrous AlCl3, through electrophilic substitution reaction. The purities of these Tröger’s bases have been checked by their physical constants and spectroscopic data published earlier in the literature. The NMR chemical shift (δ, ppm) of methylene protons and carbon were assigned. The assigned methylene protons and carbon chemical shifts (δ, ppm) of synthesised Tröger’s bases have been correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituent on methylene protons and carbon were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 1-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and validation of reversed phase gradient HPLC method for the simultaneous estimation of olmesartan medoxomil and chlorthalidone in dosage forms
Autorzy:
Manikandan, S.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1194011.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Accuracy
Acetonitrile
Buffer pH 3.0
Chlorthalidone
Forced degradation
Linearity
Olmesartan medoxomil
Precision
RP-gradient HPLC
Robustness
Simultaneous estimation
Opis:
The main objective of the proposed study is to develop and validate a new stability indicating reverse phase HPLC gradient method for the simultaneous estimation of olmesartan medoxomil and chlorthalidone in combined dosage form. The method is optimized by using zorbax phenyl column (250 x 4.6 mm, 5 μ). For pump-A, ammonium dihydrogen orthophosphate and pump-B, acetonitrile: are used. Phosphate buffer pH was adjusted with orthophosphoric acid to 3.0. Water and acetonitrile (45:50) are used as diluent. The flow rate is 1.5 ml/min and the elutant is monitored at 220 nm with uv detector. The retention time of olmesatran medoxomil and chlorthalidone are 10.70 ±0.1 mins and 4.8 ± 0.1 mins respectively. Precision shows that % Relative standard deviation of olmesartan medoxomil and chlorthalidone is about 0.23 and 0.56 respectively. The percentage recoveries of both the drugs olmesartan medoxomil and chlorthalidone from the dosage formulation are 100.3% and 99.20% respectively. Linearity of olmesartan medoxomil and chlorthalidone is in the range of 10.0 to 60.0 μg/ml and 6.25 μg/ml respectively. Calibration curve shows good linearity and range. The correlation coefficient of olmesartan medoxomil and chlorthalidone is 0.999. And the results obtained for Robustness and Ruggedness are well within the acceptance criteria. The proposed method is found to be simple, rapid, accurate and precise. It is found to be economical and suitable for simultaneous determination of olmesartan medoxomil and chlorthalidone in pharmaceutical dosage form.
Źródło:
World Scientific News; 2015, 9; 101-123
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and validation of dissolution method for levocetirizine dihydrochloride by isocratic reverse phase HPLC
Autorzy:
Thirunarayanan, G.
Manikandan, S.
Powiązania:
https://bibliotekanauki.pl/articles/1194036.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Accuracy
Buffer
Levocetirizine hydrochloride
Precision
Reverse Phase HPLC
Ruggedness
pH
Opis:
Levocetirizine hydrochloride is an orally active, non-sedative antihistamine used in the symptomatic relief of seasonal and perennial allergic rhinitis. The main objective of the proposed study is to develop and validate a dissolution method of Levocetirizine hydrochloride dosage form by reverse phase HPLC isocratic method. The method is optimized by various filteration methods such as centrifuge and whatman 42. The filteration methods are evaluated by reverse phase isocratic HPLC method using column- Phenomenex Luna - C 18 (250 mm x 4.6 mm; 5 µ), mobile phase – mixture of buffer and acetonitrile (580:420), adjusted pH to 6.0 with 10 % sodium hydroxide. buffer - 4.08 g Potassium dihydrogen orthophosphate in 600 mL of water. The flow rate is 1.0 mL/min and the elutant is monitored at 230 nm with UV detector. The retention time of levocetirizine hydrochloride is 5.5. Precision shows that % relative standard deviation is about 1.1%. The percentage recovery of the levocetirizine from the dosage formulation is 99.6%. The results obtained for robustness and ruggedness of levocetirizine hydrochloride are well within the acceptance criteria. The proposed method is found to be simple, rapid, accurate and precise. The proposed methods are validated as per ICH guidelines and successfully applied for the determination of Levocetirizine tablet.
Źródło:
World Scientific News; 2015, 11; 1-17
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bioactive 3-methyl-2,6-diarylpiperidin-4-one, oxime and its copper(II) complex
Autorzy:
Thirunarayanan, G.
Lakshmanan, K.
Powiązania:
https://bibliotekanauki.pl/articles/1070862.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Antimicrobial activities
Copper(II) complex
Disc diffusion
Drug dilution
Piperidine-4-one
Piperidine-4-oneoxime
Opis:
namely 3-methyl-2,6-diphenylpiperidin-4-oneoxime and copper(II) complex of this oxime was prepared by literature procedure. The purities of these ketone, oxime and copper complex was analyzed by physico-chemical and spectroscopic methods reported in the literature. The physicochemical analysis results confirmed that the structure of the complex was distorted octahedral. The antimicrobial activities of these substrates such as ketone, oxime and its copper complex were investigated using Bauer-Kirby disc diffusion technique against several antimicrobes by measuring the mm of zones of inhibitions. Further these activities were concluded using drug dilution method. From the analysis report, the copper (II) complex of the oxime shows significant antimicrobial activities against their antimicrobial stains. The oxime shows moderate antimicrobial activity. The ketone shows satisfactory antibacterial and antifungal activities against their stains in both disc diffusion and drug dilution methods.
Źródło:
World Scientific News; 2019, 123; 124-140
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterization of copper(II) complex of 3-methyl-2,6-diphenylpiperidin-4-one oxime
Autorzy:
Thirunarayanan, G.
Lakshmanan, K.
Powiązania:
https://bibliotekanauki.pl/articles/1076144.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Complexation
Copper chloride
Piperidine-4-one
Piperidine-4-oneoxime
UV and IR spectra
Opis:
A novel six membered heterocyclic oxime namely 3-methyl-2,6-diphenylpiperidin-4-oneoxime was prepared from the condensation of 3-methyl-2,6-diphenylpiperidin-4-one and hydroxylamine hydrochloride. The obtained oxime was characterized by their physical, analytical and spectroscopic data. This oxime was utilized as ligand for preparation of the copper complex. The oxime belongs to bidentate ligand nature. The copper complex of this oxime was prepared by the conventional heating of ethanolic solution of this oxime and copper chloride pentahydrate. The obtained copper complex was analyzed by their physical constants, analytical, pH measurements, UV and IR spectral data. These physicochemical analysis results confirmed, the structure of the complex was octahedral.
Źródło:
World Scientific News; 2019, 116; 102-114
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectral (FT-IR, 1H and 13C NMR) and antimicrobial studies some of (E)-2-(2-((aryl)(phenyl)methylene)hydrazinyl)benzo[d] thiazole
Autorzy:
Manikandan, S.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1177421.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Aryl hydrazone
IR and NMR spectra
antibacterial and antifungal activities
Opis:
A series of (E)-2-(2-((aryl)(phenyl)methylene)hydrazinyl)benzo[d] thiazole compounds by condensation of substituted benzophenone with 2-hydrazinobenzothizol in the presence acetic acid. The synthesized compounds 1-6 were characterized by elemental, FT-IR, 1H and 13C NMR spectral data. From the IR and NMR spectra, the characteristic frequencies were assigned and the data used for confirmation of the formation hydrazones 1-6. All compounds were screened for their preliminary antibacterial and antifungal activities. The methoxy substituted compound 6 shows good antibacterial activity against their bacterial strains within the agreed mm of zone of inhibition. The methyl (5) and methoxy (6) substituted hydrazones show good antifungal activities against their fungal strains.
Źródło:
World Scientific News; 2018, 103; 1-18
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectral correlation study of some 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones
Autorzy:
Thirunarayanan, G.
Ravi, K.
Powiązania:
https://bibliotekanauki.pl/articles/412390.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solvent-free cyclization cum acetylation
N-acetyl pyrazoles
IR spectra
NMR spectra
Hammett correlations
Opis:
Some N-acetyl pyrazoles including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones including substituted styryl 3,4-dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: H2SO4 catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75 %. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νC=N and C=O (cm-1) frequencies, NMR chemical shifts (δ, ppm) of Ha, Hb, Hc, CH3 protons, C=N, C=O and CH3 carbons of 1-(3-(3,4-dichlorophenyl)-5-(substitutedphenyl)-4,5-dihydro-1H-pyrazole-1-yl) ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 14; 44-57
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preheated fly-ash catalyzed cyclization ofchalcones: Synthesis of some substituted pyrazole-1-carbothioamides and spectral correlations in 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1 carbothioamides
Autorzy:
Thirunarayanan, G.
Sekar, K. G.
Powiązania:
https://bibliotekanauki.pl/articles/412612.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Pre-heated fly-ash
solvent-free synthesis
Hammett correlations
3-(3, 4-dichlorophenyl)-5-(substituted phenyl)-4
5-dihydro-1H-pyrazole-1-carbothioamides
Opis:
Some substituted 1-thiocarbomyl pyrazolines including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides using solvent-free preheated fly-ash catalyzed cyclization between chalcones and thiosemicarbazide microwave irradiation. The yields of these thiocarbomyl pyrazolines are more than 80 %. The purities of these synthesised pyrazoline derivatives are checked by their physical constants and spectral data earlier reported in the literature The spectral data of these 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides had been correlated, using single and multi-linear regression analysis.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 1; 18-34
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies