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Full-Text Articles in Physical Sciences and Mathematics
A Simple And Efficient Procedure For Synthesis Of Optically Active 1,3,4-Oxadiazole Derivatives Containing L-Amino Acid Moieties, Naser Foroughifar, Akbar Mobinikhaledi, Sattar Ebrahimi
A Simple And Efficient Procedure For Synthesis Of Optically Active 1,3,4-Oxadiazole Derivatives Containing L-Amino Acid Moieties, Naser Foroughifar, Akbar Mobinikhaledi, Sattar Ebrahimi
Turkish Journal of Chemistry
Some new unsymmetrical and optically active 2,5-disubstituted 1,3,4-oxadiazoles 5a-j were efficiently synthesized by cyclization reaction of diacylhydrazides 4a-j. The synthesis of the title compounds was achieved by the reaction of acyl hydrazides 3a-b and N-phetaloyl-L-amino acids 1a-e in the presence of the phosphoroxy chloride (POCl_3) as an anhydrous reagent.
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Turkish Journal of Chemistry
An efficient one-pot method for the synthesis of 1,4-dihydropyridines from \beta-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 °C), reusable, and efficiently used under reaction conditions.
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Turkish Journal of Chemistry
Compounds 2 were synthesised via the reaction of 4-amino-5-thiophen-2-yl-methyl-2,4-dihydro-[1,2,4]-triazol-3-one (1) with aldehydes. Compounds 3 and 4 were obtained from compounds 2 with bromo acetophenone and ethyl bromoacetate, respectively. The synthesis of compounds 2, 3, and 4 and crystal structure of compound 2a are being reported. The molecular structures were identified by IR, ^1H-NMR, ^{13}C-NMR, MS, and elemental analyses. Compound 2a crystallises in the monoclinic P 2_1/n space group, with a = 6.565(5) Å, b = 18.278(5) Å, c = 13.8166(18) Å, \beta = 96.227(5)°, V = 1553.6(14) Å^3, Z = 4. The newly compounds synthesised were screened for their antibacterial …
Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal
Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal
Turkish Journal of Chemistry
The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the density functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied molecules was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the experimental and the calculated acidity constants, …
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-{3-(4-Substitutedbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl}-N'-(aryl-methylene)acetohydrazides (5a-g), 4-amino-2-{-(4-substitutedbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(arylmethylene)acetohydrazides (6a,b), and 4-[2-(1H-indol- 3-yl)ethyl]-5-(4-substitutedbenzyl)-2-{5-(phenylamino)-1,3,4-thiadiazol- 2-yl]methyl}-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a,b) were synthesized starting from 4-alkyl-5-(4-substitutedbenzyl)-2,4-dihydro- 3H-1,2,4-triazol-3-ones (2a-c) by several steps and their structures were well characterized by elemental analyses, IR, ^1H-NMR, ^{13}C-NMR, and mass spectral studies. They were also screened for their microbial activities. The obtained antimicrobial activity results revealed that 12 among the 24 compounds tested displayed variable growth inhibition effects on the tested gram-positive and gram-negative bacterial strains. None of the compounds showed antifungal activity against yeast-like fungi.
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Turkish Journal of Chemistry
The synthesis of 4-amino-2-[(5-mercapto-1,3,4-oxadiazol-2- yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2) and 4-amino-2-[(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)methyl]- 5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (5) was performed starting from 2-[4-amino-3-(4-methylphenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl]acetohydrazide (1). The treatment of 2 and 5 with 4-fluorobenzaldehyde (for 8) or salicylaldehyde (for 6) afforded the corresponding Schiff bases (6 and 8). The condensation of 5 with phenacyl bromide produced 4-amino-5-(4-methylphenyl)-2- [(6-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)methyl]- 2,4-dihydro-3H-1,2,4-triazol-3-one (7). The alkylation of 2 and 8 was carried out by using methyl iodide in basic media. Compounds 3 and 10a,b were prepared by aminoalkylation of 2 and 8 with 4-fluorophenyl piperazine, morpholine, or 4-methyl piperazine in the presence of formaldehyde. The synthesized compounds were screened for their antimicrobial activities …
Heterocyclic Synthesis Using Nitrilimines: Part 14. Synthesis Of New Pyrazole Derivatives, Hany Dalloul
Heterocyclic Synthesis Using Nitrilimines: Part 14. Synthesis Of New Pyrazole Derivatives, Hany Dalloul
Turkish Journal of Chemistry
A new series of 1,3,4,5-tetrasubstituted pyrazoles have been synthesized by the 1,3-dipolar cycloaddition of suitable nitrilimines to 3-propylidene and 3-benzylidene-phthalide. Both analytical and spectroscopic data of all the synthesized compounds are in full agreement with the proposed structures.
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-(4-Amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H-1,2,4-triazol- 1-yl)-N'-[(2,6-dihalogenophenyl)-methylene]acetohydrazides (3a,b) was obtained via the formation of 2-(4-amino-3-(4-chlorophenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl)acetohydrazide (2), which was obtained starting from 4-amino-5-(4-chlo\-rophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (1) in 2 steps. 2-{[4-amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H- 1,2,4-triazol-1-yl]acetyl}-N-phenylhydra-zine carbothioamide (4), which was prepared starting from 2, was converted to the corresponding 1,3,4-thiadiazole derivative (5) in acidic media. Moreover, the basic treatment of 4 resulted in the formation of 4-amino-5-(4-chlorophenyl)- 2-[(4-phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4- dihydro-3H-1,2,4-triazol-3-one (7). The reactions of compounds 5 and 7 with methyl iodide in the presence of sodium ethoxide afforded the corresponding N-methyl (6) and S-methyl (8) derivatives, respectively. The synthesis of Mannich bases (10a and 10b) was performed from the reaction of 7 with …
Synthesis And Characterization Of Novel Triazol Compounds Containing A Thiophen Ring As Potential Antifungal Agents And The Structure Of 2-(2-Hydroxy-2-P-Tolyethyl)-5-(Thiophen-2-Ylmethyl)- 4-(4h-1,2,4-Triazol-4-Yl)-2h-1,2,4-Triazol-3(4h)-One, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Reşat Ustabaş
Synthesis And Characterization Of Novel Triazol Compounds Containing A Thiophen Ring As Potential Antifungal Agents And The Structure Of 2-(2-Hydroxy-2-P-Tolyethyl)-5-(Thiophen-2-Ylmethyl)- 4-(4h-1,2,4-Triazol-4-Yl)-2h-1,2,4-Triazol-3(4h)-One, Yasemi̇n Ünver, Esra Düğdü, Kemal Sancak, Mustafa Er, Reşat Ustabaş
Turkish Journal of Chemistry
A series of new 4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)- 5-(thiophen-2-yl-methyl)-2H-1,2,4-triazol-3(4H)-ones (3a-c) were obtained by reaction N'-1-ethoxy-2-thiophen-2-yl-ethylydene hydrazino carboxylic acid ethyl ester (1) and 4-amino-4H-1,2,4-triazoles (2). 4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)-2-(2-oxo-2-arylethyl)-5- (thiophen-2-yl-methyl)-2H-1,2,4-triazol-3(4H)-ones (4a-e) and ethyl 2-(4-(3,5-disubstitue-4H-1,2,4-triazol-4-yl)-5-oxo-3-(thiophen-2-ylmethyl)- 4,5-dihydro-1,2,4-triazol-1-yl)acetates (6a-c) were obtained by reaction of compounds 3 and bromoacetophenon derivatives and bromo ethylacetate, respectively. Compounds 5a-e were synthesized from the reaction of corresponding compounds 4a-e with NaBH_4. Compounds 7a-c were obtained by the reaction compounds 6 and LiAlH_4. Seventeen new compounds were synthesized and characterized by elemental analyses, IR, ^1H-NMR, and ^{13}C-NMR spectral data. The structure of compound 5d was inferred through IR, ^1H-, ^{13}C-NMR, elemental analyses, and X-ray spectral techniques. …
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
The synthesis of ethyl [3-(cyanomethyl)-5-alkyl-4H-1,2,4-triazol- 4-yl]carbamates (2a-d) was performed starting from ethyl 2-[ethoxy(4- (aryl)methylene]hydrazinecarboxylates (1a, 1b). The treatment of 2a with thiosemicarbazide afforded ethyl [3-[(5-amino-1,3,4-thiadiazol- 2-yl)methyl]-5-(4-nitrophenyl)-4H-1,2,4-triazol-4-yl]carbamates (3a), whereas compound 2b produced 5-{[4-amino-5-(4-methylphenyl)- 4H-1,2,4-triazol-3-yl]methyl}-1,3,4-thiadiazol-2-amine (3b) in the same reaction conditions. The treatment of tert-butyl 2-[2-(4-chlorophenyl)-1-ethoxyethylidene]hydrazinecarboxylate (5) with malonohydrazide or cyanoacethydrazide gave the corresponding 1,2,4-triazol-ylcarbamate derivatives (6 or 9); then the hydrolysis of these compounds resulted in the formation of 3-{[4-amino-5-(4- chlorobenzyl)-4H-1,2,4-triazol-3-yl]methyl}-5-(4-chlorobenzyl)-4H- 1,2,4-triazol-4-amine (7) and [4-amino-5-(4-chlorobenzyl)-4H- 1,2,4-triazole-3-yl]acetonitrile (10), respectively. The synthesis of the Schiff base derivatives 3-(4-chlorobenzyl)-5-{[5-(4-chloroben- zyl)-4-[(2-hydroxyphenyl-methylene)amino]-4H-1,2,4-triazol-3-yl]methyl} -N-(2-hydroxyphenylmethylene)-4H-1,2,4-triazol-4-amine (8), and (5-(4-chlorobenzyl)-4-{[(2,6-dichlorophenyl)methylene]amino}-4H-1,2,4- triazol-3-yl)acetonitrile (12) was performed from the reaction of compounds 7 …