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Synthesis of Some New Fluorine Substituted Thiobarbituricacid Derivatives as Anti HIV1 and Cyclin-Dependent Kinase 2 (CDK2) for Celltumer Division-Part II  [PDF]
Abdulrahman S. Al-Harbi, Reda M. Abdel-Rahman, Abdullah M. Asiri
International Journal of Organic Chemistry (IJOC) , 2014, DOI: 10.4236/ijoc.2014.42016
Abstract: In search for new potential inhibitors some new fluorine substituted thiobarbituric acid derivatives (2-4, 7, 8) and their fused/isolated heterobicyclic nitrogen systems (5, 6, 9, 10, 11, 12) have been synthesized from heterocyclization of fluorinated 1,3-diketoamine (1) with CS2 followed by ring closure reactions with primary nitrogen reagents. Structures of the targets have been established from elemental analysis and spectral data. Some synthesized systems have been evaluated as anti-HIV-1 and of cyclin-dependent kinase 2 (CDK2) for cell tumor division.
Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold
Nikolay T. Tzvetkov,Harald Euler,Christa E. Müller
Beilstein Journal of Organic Chemistry , 2012, DOI: 10.3762/bjoc.8.181
Abstract: Dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives were prepared by successive N3- and N1-alkylation of hydantoins, followed by regioselective thionation and subsequent cyclization under mild conditions. In a final alkylation step a further substituent may be introduced. The synthetic strategy allows broad structural variation of this new drug-like heterobicyclic scaffold. In addition to extensive NMR and MS analyses, the structure of one derivative was confirmed by X-ray crystallography.
Synthesis of New Fluorinated Fused Heteropolycyclic Nitrogen Systems Containing a Pyrazolotriazine Moiety as Antimicrobial Agents Part I  [PDF]
Layla A. Taib, Sofiyah A. Adibani
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81013
Abstract: A simple route to synthesize novel fluorinated fused hetero-polycyclic nitrogen systems containing a pyrazolotriazine moiety (5,8,11) have been deduced from cyclization of 2-aminothiocarbonyl-5-arylidene-3-phenyl-1,2,4-triazin-6(1H)one (2) with diethoxy-phosphine, diethyl carbonate and/or diethyl oxalate in boil THF followed by cyclo condensation with aryl sulfonic acid hydrazide in EtOH/piperidine and finally fluorination with trifluoroethyl acetate. Structures of the products have been established from their elemental analysis and spectral measurements. The antimicrobial activity of the targets has also been evaluated.
Synthesis and antimicrobial evaluation of some new polyheterocyclic systems containing 1,2,4-triazine moiety  [cached]
Wafaa Ramzy Abdel-Monem
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.3.168-172.29
Abstract: 7-(4-Chloro/3-nitrophenyl)-8-[5,6-diphenyl-4-(1,3-thiazol-2-yl)-1,4-dihydro-1,2,4-triazin-3-yl]-5-oxo-1,5-dihydro[1,2,4]triazolo[1,5-a]pyridine-6-carbonitrile (6a, b) was utilized as a key intermediate for the target polyheterocyclic systems. Reactions of 6a, b with halocarbonyl reagents followed by heterocyclization with bi-nitrogen nucleophiles gave some new nitrogen heterocycles (7-13). Structures of the new compounds were established by elemental analyses and spectral data. The synthesized compounds were screened for their antimicrobial activity.
Synthesis of Novel Fluorine Substituted Isolated and Fused Heterobicyclic Nitrogen Systems Bearing 6-(2’-Phosphorylanilido)-1,2,4-Triazin-5-One Moiety as Potential Inhibitor towards HIV-1 Activity  [PDF]
Reda M. Abdel-Rahman, Mohammed S. T. Makki, Abeer N. Al-Romaizan
International Journal of Organic Chemistry (IJOC) , 2014, DOI: 10.4236/ijoc.2014.44028
Abstract: Novel 6-(5’-fluoro-2’-diphenylphosphorylanilido)-3-hydrazino-1,2,4-trizin-5 (2H) one (3) is achieved from hydrozinolysis of the corresponding 3-thioxo-analoges 2. Compound 2 is also obtained from phosphorylation of 6-(5’-fluoro-2’-aminophenyl)-3-thioxo-1,2,4-triazin-5(2H) one (1). Novel fluorine substituted isolated and/or fused heterobicyclic nitrogen systems bearing and/or containing, 6-phosphoryl anilido-1,2,4-trizin-5 (2H) one moiety (4 - 22) have been synthesized from ring closure reactions of compound 3 with π-acceptors activated carbon compounds in different medium and conditions. Structures of the products are characterized by MS, IR, UV-VIS, CH, N, and 1H/13CNMR spectral data. The new products have been evaluated as potential inhibitors towards HIV-1 activity.
1,2,4-Triazine Chemistry Part II: Synthetic approaches for phosphorus containing 1,2,4-triazine derivatives  [cached]
Reda Mohammady Abdel-Rahman,Magdy Ahmed Ibrahim,Tarik El-Sayed Ali
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.4.388-396.154
Abstract: This review represents the methods developed for the synthesis of phosphorus containing 1,2,4-triazine moieties. These methods depends on the phosphorylation of side functional groups of 1,2,4-triazines and cyclization of side functional groups of 1,2,4-triazines with phosphorus reagents to give isolated and fused phosphorus heterocyclic systems.
1,2,4-Triazine Chemistry Part I: Orientation of cyclization reactions of functionalized 1,2,4-triazine derivatives  [cached]
Reda Mohammady Abdel-Rahman,Mohammed Saleh Tawfik Makki,Tarik El-Sayed Ali,Magdy Ahmed Ibrahim
European Journal of Chemistry , 2010, DOI: 10.5155/eurjchem.1.3.236-245.54
Abstract: Orientation of heterocyclization reactions of functionalized 1,2,4-triazines were studied by effect of substituents in 1,2,4-triazine moieties, type of the solvent used in the reaction and the temperature effect. Also, it was found that cyclization process depended mainly on the chemoselective and regioselectivity states of the parent substrate as well as preferring cite of ring closure.
Structures of Fluorinated Graphenes and Their Signatures  [PDF]
Hasan Sahin,Mehmet Topsakal,Salim Ciraci
Physics , 2011, DOI: 10.1103/PhysRevB.83.115432
Abstract: Recent synthesis of fluorinated graphene introduced interesting stable derivatives of graphene. In particular, fluorographene (CF), namely fully fluorinated chair conformation, is found to display crucial features, such as high mechanical strength, charged surfaces, local magnetic moments due to vacancy defects and a wide band gap rapidly reducing with uniform strain. These properties, as well as structural parameters and electronic densities of states are found to scale with fluorine coverage. However, most of the experimental data reported to date neither for CF, nor for other CnF structures complies with the results obtained from first-principles calculations. In this study, we attempt to clarify the sources of disagreements.
A Facile Synthesis of Pyrido[ , :3,4]pyrazolo[1,5- a ]pyrimidine and Pyrido[ , :3,4]pyrazolo[5,1- c ][1,2,4]triazine Bearing a Thiophene Moiety  [PDF]
Tilal Elsaman,Mohamed Fares,Hatem A. Abdel-Aziz,Mohamed I. Attia,Hazem A. Ghabbour,Kamal M. Dawood
Journal of Chemistry , 2013, DOI: 10.1155/2013/463515
Abstract: Pyridinone derivative 8 was synthesized and transformed into the respective chloropyridine 9, which was allowed to react with hydrazine hydrate to afford pyrazolo[3,4-b]pyridin-3-amine derivative 11. Compound 11 was used as a key intermediate for a facile synthesis of the title compounds 14, 15, 17, 21a,b, and 24a–c where the reaction of 11 with some 1,3-dielecrophiles resulted in the formation of pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidines 14, 15, and 17, whereas diazotization of compound 11 gave the respective diazonium salt 18 which was coupled with some active methylene-containing compounds to give the corresponding hydrazones 19a,b and 22a–c. Cyclization of the latter hydrazones yielded the pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazines 21a,b and 24a–c, respectively. 1. Introduction Thiophene moiety is present in a large number of bioactive molecules having diverse biological activities such as antiinflammatory [1], anticonvulsant [2], antibacterial [3], and antitumor [4] activities. Moreover, thiophene moiety is a well-known isostere for benzene; for example, the replacement of benzene ring of the antidepressant drug, Viloxazine, (I, Figure 1) led to a prolongation of half-life [5]. Figure 1: Chemical structures of Viloxazine ( I), Etazolate ( II), and Glicaramide ( III). On the other hand, several pyrazolo[3,4-b]pyridines revealed interesting biological properties including antimicrobial [6], antiviral [7], antiinflammatory [8], analgesic [9], and antitumor activities [10]. In addition, pyrazolo[3,4-b]pyridines represent the skeleton of pharmaceuticals possessing significant biological activities as represented by Etazolate (II, EHT-0202, Figure 1), an anxiolytic drug, which is now in clinical trials for the treatment of Alzheimer’s disease [11], and by Glicaramide (III, Figure 1), a potent antidiabetic agent [12]. Following a program dealing with the development of bioactive heterocyclic derivatives [13–15], we report herein a facile synthesis of new pyrazolo[3,4-b]pyridines 14, 15, 17, 21a,b, and 24a–c, bearing a thiophene moiety, as new bioactive candidates. 2. Experimental 2.1. General Melting points were determined on a Gallenkamp melting point apparatus and are uncorrected. Infrared (IR) spectra were recorded as KBr disks using the Perkin Elmer FT-IR Spectrum BX apparatus. NMR Spectra were measured in DMSO-d6 on a Jeol-NMR spectrometer operating at 400?MHz for 1H NMR and at 100?MHz for 13C NMR. Chemical shifts are expressed in δ values (ppm) relative to TMS as an internal standard. Coupling constants (J) are expressed in Hz. D2O was added
Convenient synthesis of some new pyrazolo[5,1-c]triazines, isoxazolo[3,4-d] pyrimidine and pyridine derivatives containing benzofuran moiety  [cached]
Abdou Osman Abdelhamid,Abdelgawad Ali Fahmi,Amna Ali Mohamed Alsheflo
European Journal of Chemistry , 2012, DOI: 10.5155/eurjchem.3.2.129-137.579
Abstract: Pyrazolo[5,1-c][1,2,4]triazine, [1,2,4]triazolo[3,4-c][1,2,4]triazine, benzo[4,5]-imidazo[2,1-c][1,2,4]triazine, isoxazole, isoxazolo[3,4-d]pyridazine, pyrazole, pyridine, substituted urea and phenyl carbamate derivatives containing benzofuran moiety were synthesized via reaction of sodium salt of 5-hydroxy-l-benzofuran-2-ylpropenone or 1-(benzofuran-2-yl)-3-(dimethylamino)prop-2-en-1-one with diazotized heterocyclic amines, hydroximoyl chlorides and active methylene compounds. The structures of all the newly synthesized compounds were confirmed by elemental analyses, spectral data, and alternative synthetic routes, whenever possible.
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