Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 

Saved Queries

Sign in to use this feature.

Search Filter Reset All

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Subjects Reset
Select Subjects

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Journals Reset
Select Journals

Article Types

remove_circle_outline
remove_circle_outline
Add Article Types Reset
Select Article Types

Countries / Regions

remove_circle_outline
Add Countries / Regions Reset
Select Countries / Regions
Update Search
share announcement

Search Results (8)

Search Parameters:
Authors = Muzaffer Alkan

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
15 pages, 156 KiB  
Article
Synthesis, Acidity and Antioxidant Properties of Some Novel 3,4-disubstituted-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives
by Muzaffer Alkan, Haydar Yüksek, Özlem Gürsoy-Kol and Mustafa Calapoğlu
Molecules 2008, 13(1), 107-121; https://doi.org/10.3390/molecules13010107 - 19 Jan 2008
Cited by 34 | Viewed by 8962
Abstract
3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2a-g reacted with4-diethylaminobenzaldehyde to afford the corresponding 3-alkyl(aryl)-4-(4-diethylaminobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3a-g. The acetylationreactions of compounds 3a-e were investigated and compounds 4a-e were thus obtained.The new compounds were characterized using IR, 1H-NMR, 13C-NMR, UV and MSspectral data. In addition, the newly synthesized compounds [...] Read more.
3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2a-g reacted with4-diethylaminobenzaldehyde to afford the corresponding 3-alkyl(aryl)-4-(4-diethylaminobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3a-g. The acetylationreactions of compounds 3a-e were investigated and compounds 4a-e were thus obtained.The new compounds were characterized using IR, 1H-NMR, 13C-NMR, UV and MSspectral data. In addition, the newly synthesized compounds 3a-g were titratedpotentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents suchas isopropyl alcohol, tert-butyl alcohol, acetone and N,N-dimethylformamide (DMF), andthe half-neutralization potential values and the corresponding pKa values were determinedfor all cases. Moreover, 3 and 4 type compounds were also screened for their antioxidantactivities. Full article
►▼ Show Figures

Figure 1

21 pages, 196 KiB  
Article
Preparation, GIAO NMR Calculations and Acidic Properties of Some Novel 4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives with Their Antioxidant Activities
by Haydar Yüksek, Muzaffer Alkan, Ismail Cakmak, Zafer Ocak, Şule Bahçeci, Mustafa Calapoğlu, Mahfuz Elmastaş, Ali Kolomuç and Havva Aksu
Int. J. Mol. Sci. 2008, 9(1), 12-32; https://doi.org/10.3390/ijms9010012 - 8 Jan 2008
Cited by 12 | Viewed by 11674
Abstract
Six novel 3-alkyl(aryl)-4-(p-nitrobenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f) were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f) with p-nitrobenzoyl chloride and characterized by elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide [...] Read more.
Six novel 3-alkyl(aryl)-4-(p-nitrobenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f) were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f) with p-nitrobenzoyl chloride and characterized by elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as acetone, isopropyl alcohol, tert-butyl alcohol and N,Ndimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, isotropic 1H and 13C nuclear magnetic shielding constants of compounds 2 were obtained by the gauge-including-atomic-orbital (GIAO) method at the B3LYP density functional level. The geometry of each compound has been optimized using the 6-311G basis set. Theoretical values were compared to the experimental data. Furthermore, these new compounds and five recently reported 3-alkyl-4-(2- furoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3a-c,e,f) were screened for their antioxidant activities. Full article
(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)
►▼ Show Figures

12 pages, 149 KiB  
Article
A Study on 4-Acylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones
by Muzaffer Alkan, Haydar Yüksek, Fatih İslamoğlu, Sule Bahçeci, Mustafa Calapoğlu, Mahfuz Elmastaş, Hüseyin Akşit and Mustafa Özdemir
Molecules 2007, 12(8), 1805-1816; https://doi.org/10.3390/12081805 - 13 Aug 2007
Cited by 27 | Viewed by 9646
Abstract
Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, 1HNMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with [...] Read more.
Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, 1HNMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. In addition, these new compounds and five recently reported 3-alkyl-4-(pmethoxybenzoylamino)- 4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were screened for their antioxidant activities. Full article
►▼ Show Figures

Figure 1

2 pages, 132 KiB  
Short Note
Synthesis and acidic properties of new 1-phenylacetyl-3-ethyl-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one
by Haydar Yüksek, Muzaffer Alkan and Şule Bahçeci
Molbank 2006, 2006(1), M463; https://doi.org/10.3390/M463 - 22 Jan 2006
Viewed by 2685
Abstract
It is known that 1,2,4-triazole and 4,5-dihydro-1H-1,2,4-triazol-5-one rings have weak acidic properties, so some 1,2,4-triazole and 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives were titrated potentiometrically with tetrabutylammonium hydroxide in non-aqueous solvents, and the pKa values of the compounds were determined [1,2,3].[...] Full article
2 pages, 130 KiB  
Short Note
Synthesis and acidic properties of novel 3-methyl-4-[(2-amino-1,3,4-thiadiazol-5-il)-thioacetylamino]-4,5-dihydro-1H-1,2,4-triazol-5-one
by Haydar Yüksek, Muzaffer Alkan and Şule Bahçeci
Molbank 2006, 2006(1), M462; https://doi.org/10.3390/M462 - 22 Jan 2006
Cited by 1 | Viewed by 2951
Abstract
A number of studies involving the determination of pKa values of some 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives in non-aqueous solvents has been revealed [1,2,3].[...] Full article
►▼ Show Figures

Figure 1

10 pages, 294 KiB  
Article
Synthesis and Non-Aqueous Medium Titrations of Some New 4-Benzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives
by Haydar Yüksek, Osman Ücüncü, Muzaffer Alkan, Zafer Ocak and Sule Bahceci
Molecules 2005, 10(8), 961-970; https://doi.org/10.3390/10080961 - 31 Aug 2005
Cited by 16 | Viewed by 8554
Abstract
The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described.The acetylation and methylation reactions of the compounds 3 giving compounds of type4 and 5, respectively, were investigated. The newly synthesized compounds werecharacterized using elemental analyses and IR, 1 [...] Read more.
The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described.The acetylation and methylation reactions of the compounds 3 giving compounds of type4 and 5, respectively, were investigated. The newly synthesized compounds werecharacterized using elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data.In addition, to investigate the effects of solvents and molecular structure upon acidity,compounds 3 were titrated potentiometrically with tetrabutylammonium hydroxide infour non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide). The half-neutralization potential values and the corresponding pKavalues were determined for all cases. Full article
►▼ Show Figures

Figure 1

11 pages, 109 KiB  
Article
Synthesis and GIAO NMR Calculations for Some Novel 4-Heteroarylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives: Comparison of Theoretical and Experimental 1Hand 13C- Chemical Shifts
by Haydar Yüksek, Ismail Cakmak, Sibel Sadi, Muzaffer Alkan and Haci Baykara
Int. J. Mol. Sci. 2005, 6(6), 219-229; https://doi.org/10.3390/i6060219 - 25 Aug 2005
Cited by 35 | Viewed by 8521
Abstract
3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) reacted with 5-methylfuran-2-carboxyaldehyde to afford the corresponding 3-alkyl(aryl)-4-(5-methyl-2-furylmethylenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (2). Four newly synthesized compounds have been characterized by elemental analyses, IR, 1H-NMR, 13C-NMR and UV spectral data. In addition, isotropic 1H- and 13C-nuclear magnetic shielding constants of compounds [...] Read more.
3-Alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) reacted with 5-methylfuran-2-carboxyaldehyde to afford the corresponding 3-alkyl(aryl)-4-(5-methyl-2-furylmethylenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (2). Four newly synthesized compounds have been characterized by elemental analyses, IR, 1H-NMR, 13C-NMR and UV spectral data. In addition, isotropic 1H- and 13C-nuclear magnetic shielding constants of compounds 3 were calculated by employing the direct implementation of the gaugeincluding-atomic-orbital (GIAO) method at the B3LYP density functional and HF levels of the theory. The geometry of each compound has been optimized using a 6-311G basis set. Nuclear shielding constants were also calculated by using 6-311G basis set. Theoretical values are compared to the experimental data. Full article
►▼ Show Figures

Figure 1

9 pages, 226 KiB  
Article
Synthesis and Determination of pKa Values of Some New 3,4-Disubstituted-4,5-Dihydro-1H-1,2,4-triazol-5-one Derivatives in Non-aqueous Solvents
by Haydar Yüksek, Zafer Ocak, Muzaffer Alkan, Sule Bahçeci and Mustafa Özdemir
Molecules 2004, 9(4), 232-240; https://doi.org/10.3390/90400232 - 31 Mar 2004
Cited by 27 | Viewed by 10228
Abstract
3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with 2-furoyl chloride and thiophene-2-carbonyl chloride to afford the corresponding 3- alkyl(aryl)-4-(2-furoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) and 3-alkyl(aryl)- 4-(2-thienylcarbonylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (4), respectively. The new compounds synthesized were characterized by using IR, 1H-NMR, 13C-NMR and UV spectral data together with elemental analysis. In addition, to [...] Read more.
3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with 2-furoyl chloride and thiophene-2-carbonyl chloride to afford the corresponding 3- alkyl(aryl)-4-(2-furoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) and 3-alkyl(aryl)- 4-(2-thienylcarbonylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (4), respectively. The new compounds synthesized were characterized by using IR, 1H-NMR, 13C-NMR and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 3 and 4 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide and acetonitrile). The half-neutralization potential values and the corresponding pKa values were determined for all cases. Full article
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 1-50 on page 1 of 1.
Back to TopTop