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1.
Nehal M. Elwan 《Journal of heterocyclic chemistry》2004,41(2):281-284
Reaction of 1‐amino‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (1) with dimethylformamide‐dimethylacetal (DMF‐DMA) gave 1 ‐[N,N‐(dimethylaminomethylene)amino]‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (2). Compounds (1) reacted with triethylorthoformate yielding 1‐[N‐(ethoxymethylene)amino]‐3‐arylpyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile (3). 3‐Amino‐4‐imino‐5‐aryl‐6‐cyanopyrimido[5′,4′:5,6]pyrido[1,2‐α] benzimidazole (4) was synthesized via condensation of either (2) or (3) with hydrazine hydrate. Reactions of (4) with acetic anhydride, ethyl chloroformate or aryl isothiocyanate yielded the respective derivative of the new ring system namely 1,2,4‐triazolo[2″,3″:6′,1′]pyrimido[4′,5′:2,3]pyrido[1,2‐a]benzimidazole (5–7). 相似文献
2.
EnasM. Awad NehalM. Elwan HamdiM. Hassaneen Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2002,85(1):320-332
Treatment of 6,7‐diethoxy‐3,4‐dihydroisoquinoline ( 8 ) and its 1‐methyl derivative 12 with hydrazonoyl halides 10 in the presence of Et3N in THF under reflux afforded the corresponding 5,6‐dihydro‐1,2,4‐triazolo[3,4‐a]isoquinolines 11 and 13 , respectively, in high yield (Schemes 2 and 3). The products are formed via regioselective 1,3‐dipolar cycloaddition of the intermediate nitrilimines 9 with the isoquinoline C=N bond. Reaction of 6,7‐diethoxy‐3,4‐dihydroisoquinoline‐1‐acetonitrile ( 4a ) with ethyl α‐cyanocinnamates 15 in the presence of piperidine in refluxing MeCN yielded benzo[a]quinolizin‐4‐ones 16 (Scheme 4). Under the same conditions, 12 and arylidene malononitriles 19 reacted to give benzo[a]quinolizin‐4‐imines 20 (Scheme 5). Instead of 15 and 19 , mixtures of an aromatic aldehyde, and ethyl cyanoacetate or malononitrile, respectively, can be used in a one‐pot reaction. 相似文献
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4.
Anthony Linden Enas M. Awad Nehal M. Elwan Hamdi M. Hassaneen Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o122-o124
Crystals of the title compound, C23H17ClN4O2·2.5H2O, contain channels filled with highly disordered water molecules. The best structure refinement was obtained by removing the solvent contribution from the intensity data and refining against a solvent‐free model. The central six‐membered ring of the quinolizine molecule has a slightly distorted screw‐boat conformation. 相似文献
5.
Alsaif Nawaf A. Elwan Alaa Alanazi Mohammed M. Obaidullah Ahmad J. Alanazi Wael A. Alasmari Abdullah F. Albassam Hussam Mahdy Hazem A. Taghour Mohammed S. 《Molecular diversity》2022,26(4):1915-1932
Molecular Diversity - Vascular endothelial growth factor receptor-2 (VEGFR-2) is critically involved in cancer angiogenesis. Blocking of VEGFR-2 signaling pathway proved effective suppression of... 相似文献
6.
A. E. Fekry N. M. El-Bieh K. M. Elwan S. A. Mangood 《Journal of Radioanalytical and Nuclear Chemistry》2003,257(1):75-82
This study was carried out to verify the therapeutic role of Prussian Blue (PB) in removing internal [137Cs] contamination from rats and to evaluate any side effects caused by chronic consumption of this compound on hematological (RBCs, Hb) parameters, serum biochemical contents (total proteins, albumin, globulins, A/G ratio, urea, urea nitrogen, creatinine, cholesterol, calcium, sALT and sAST enzymatic activity, bilirubin) and thyroid function (T4 and T3). PB administration before or at the time of irradiation could eliminate the decreased or increased effects of [137Cs]-gamma irradiation on: RBCs, Hb, total proteins, globulins, creatinine, urea, urea nitrogen, SAT, T3, T4. However, PB administration, one or seven days post irradiation eliminated [137Cs]-gamma irradiation effects on: cholesterol, calcium, bilirubin in both of growing and adult rats. 相似文献
7.
EnasM. Awad NehalM. Elwan HamdiM. Hassaneen Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2001,84(5):1172-1180
The synthesis of 2‐(6,7‐diethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile ( 1 ) has been performed by ring closure of the corresponding amide according to the Bischler‐Napieralski method (Scheme 1). Based on spectroscopic data, the tautomeric 2‐(tetrahydroisoquinolin‐1‐ylidene)acetonitrile is the actual compound. The reactions of 1 with α‐oxohydrazonoyl halides 4 in the presence of Et3N led to 2‐(aryldiazenyl)pyrrolo[2,1‐a]isoquinoline derivatives 8 (Scheme 2), whereas with C‐(ethoxycarbonyl)hydrazonoyl chlorides 14 , 2‐(arylhydrazono)pyrrolo[2,1‐a]isoquinoline‐1‐carbonitriles 16 were formed (Scheme 4). The structures of the products were established from their analytical and spectroscopic data and, in the case of 8b , by X‐ray crystallography. 相似文献
8.
SiO2–PbO–Bi2O3 glasses having the composition of 35SiO2–xPbO–(65 ? x)Bi2O3 (where x = 5, 20 and 45; in mol%) have been prepared using the conventional melting and annealing method. Differential scanning calorimetry (DSC) was employed to characterize the thermal behavior of the prepared glasses in order to determine their crystallization temperatures (Tcr). It has been found that Tcr decreases with the decrease of Bi2O3 content. The amorphous nature of the prepared glasses as well as the crystallinity of the produced glass–ceramics were confirmed by X-ray powder diffraction (XRD) analysis. SiPbBi2O6 glass nano-composites, comprising bismuth oxides nano-crystallites, were obtained by controlled heat-treatment of the glasses at their (Tcr) for 10 h. Transmission electron microscopy (TEM) of the glass nano-crystal composites demonstrates the presence of cubic Bi2O3 nano-crystallites in the SiPbBi2O6 glass matrix. Nano-crystallites mean size has been determined from XRD line width analysis using Scherrer's equation as well as from TEM; and the sizes obtained from both analyses are in good agreement. These sizes varied from about 15 to 170 nm depending on the chemical compositions of parent glasses and, consequently, their structure. Interestingly, replacement of the Bi2O3 by PbO in the glass compositions has pronounced effect on the nature, morphology and size of the formed nano-crystallites. Decrease of the Bi2O3 content increases the size of the nano-crystallites, and at the lowest Bi2O3 extreme, namely 20 mol%, introduces minority of the monoclinic Bi2O4 in addition to the cubic Bi2O3. The crystallization mechanism is suggested to involve a diffusion controlled growth of the bismuth oxide nano-crystallites in the SiPbBi2O6 glass matrix with the zero nucleation rate. 相似文献
9.
Hamdi M. Hassaneen Rifaat H. Hilal Nehal M. Elwan Abdelhamid Harhash Ahmad S. Shawali 《Journal of heterocyclic chemistry》1984,21(4):1013-1016
The 1,3-cycloaddition of the nitrile imines 2a-e to the carbon-carbon double bond in benzalacetophenone leads to the formation of 4-phenyl-5-benzoylpyrazolines 3a-e which were converted into 4-phenyl-5-benzoylpyrazoles 5a-e upon treatment with chloranil in xylene. However, the cycloaddition of 2a-e to the carbon-carbon double bond in the enol tautomer of dibenzoylmethane gives the regioisomers 5-phenyl-5-hydroxy-4-benzoylpyrazolines which loose elements of water to yield 4-benzoyl-5-phenylpyrazoles 6a-e . The orientations in these reactions are interpretted in terms of the Frontier Molecular Orbital theory. The structures of the products 3 , 5 and 6 were substantiated by their chemical reactions and alternate synthesis wherever possible. 相似文献
10.
Reda G. Yousef Wagdy M. Eldehna Alaa Elwan Abdelaziz S. Abdelaziz Ahmed B. M. Mehany Ibraheem M. M. Gobaara Bshra A. Alsfouk Eslam B. Elkaeed Ahmed M. Metwaly Ibrahim H. Eissa 《Molecules (Basel, Switzerland)》2022,27(13)
VEGFR-2, the subtype receptor tyrosine kinase (RTK) responsible for angiogenesis, is expressed in various cancer cells. Thus, VEGFER-2 inhibition is an efficient approach for the discovery of new anticancer agents. Accordingly, a new set of nicotinamide derivatives were designed and synthesized to be VEGFR-2 inhibitors. The chemical structures were confirmed using IR, 1H-NMR, and 13C-NMR spectroscopy. The obtained compounds were examined for their anti-proliferative activities against the human cancer cell lines (HCT-116 and HepG2). VEGFR-2 inhibitory activities were determined for the titled compounds. Compound 8 exhibited the strongest anti-proliferative activities with IC50 values of 5.4 and 7.1 µM against HCT-116 and HepG2, respectively. Interestingly, compound 8 was the most potent VEGFR-2 inhibitor with an IC50 value of 77.02 nM (compare to sorafenib: IC50 = 53.65 nM). Treatment of HCT-116 cells with compound 8 produced arrest of the cell cycle at the G0–G1 phase and a total apoptosis increase from 3.05 to 19.82%—6.5-fold in comparison to the negative control. In addition, compound 8 caused significant increases in the expression levels of caspase-8 (9.4-fold) and Bax (9.2-fold), and a significant decrease in the Bcl-2 expression level (3-fold). The effects of compound 8 on the levels of the immunomodulatory proteins (TNF-α and IL-6) were examined. There was a marked decrease in the level of TNF-α (92.37%) compared to the control (82.47%) and a non-significant reduction in the level of IL-6. In silico docking, molecular dynamics simulations, and MM-PBSA studies revealed the high affinity, the correct binding, and the optimum dynamics of compound 8 inside the active site of VEGFR-2. Finally, in silico ADMET and toxicity studies indicated acceptable values of drug-likeness. In conclusion, compound 8 has emerged as a promising anti-proliferative agent targeting VEGFR-2 with significant apoptotic and immunomodulatory effects. 相似文献