- Synthesis and crystal structure of 1,3-bis(p-nitrophenoxy)propane
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The title compound 1,3-bis(p-nitrophenoxy)propane was synthesized by nucleophilic substitution of p-nitrophenol and 1,3-dibromopropane. Single crystal X-ray diffraction analysis reveals that the molecule in the solid state packs in the monoclinic P2/n spa
- Rafique, Muhammad,Zulfiqar, Sonia,Yap, Glenn P. A.,Shah, Syed Ismat,Sarwar, Muhammad Ilyas
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- Discovery of Diphenoxy Derivatives with Flexible Linkers as Ligands for β-Amyloid Plaques
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The highly rigid and planar scaffolds with π-conjugated systems have been widely considered to be indispensable for β-amyloid (Aβ) binding ligands. In this study, a library of diphenoxy compounds with different types of more flexible linkers as Aβ ligands were synthesized and evaluated. Most of them displayed good affinity (Ki1-42aggregates, and some ligands even showed values of Kiless than 10 nM. Structure-activity relationship analysis revealed that modification on the linkers or substituents tolerated great flexibility, which challenged the long-held belief that rigid and planar structures are exclusively favored for Aβ binding. Three ligands were labeled by iodine-125, and they exhibited good properties in vitro and in vivo, which further supported that this flexible scaffold was potential and promising for the development of Aβ imaging agents.
- Jia, Jianhua,Zhang, Longfei,Song, Jia,Dai, Jiapei,Cui, Mengchao
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p. 4089 - 4100
(2020/12/13)
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- Green synthesis of symmetric aryl ether dinitro compounds in deep eutectic solvents
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A series of symmetric aryl ether dinitro compounds were synthesized by 4Urea/ZnCl2 as green solvent and catalyst, and halogenated aromatic hydrocarbon derivatives and dihydroxy compounds as raw materials. This method has the advantages of easy operation, simple recrystallization, environmental friendliness and biodegradability. The structures of the products were subjected to 1H NMR, and the reaction conditions, reaction mechanism and greening advantages of deep eutectic solvents were discussed at the end of the experiments. We learned from the results of the experiments that both the aliphatic dihydroxy compounds and the aromatic dihydroxy compounds could proceed effectively in Ullmann reaction, and the desired products could be obtained in acceptable yields. When using this methodology, symmetric aryl ether dinitro compounds could be synthesized simply at 80oC in 2 h with high yields (66%~94%). Meanwhile, the DES, called deep eutectic solvent which is composed of 4Urea/ZnCl2, could be recycled at least five times without an obvious decraese in the catalytic activity.
- Jin, Yan,Ding, Yinhao,Hou, Xichao,Dong, Jingjing,Lu, Jianqiang,Feng, Baicheng
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p. 101 - 107
(2020/03/17)
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- Design and characterization of novel bis-benzamide liquid crystalline materials
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A new homologous series of symmetric, bent-shaped bis-benzamide dimers have been prepared. Several 1,n-bis(p-aminophenoxy)alkanes (n = 3, 5, 9,10,11) were employed as spacers and p-hexyloxy tails have been synthesized and appended to the spacers by amide linking groups. Different important parameters were explored using computational analysis by semi empirical method. The experimental results were correlated with theoretical studies and relationship between molecular structure and mesogenic behavior has been established. The mesomorphic properties of the resultant dimers were characterized by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) equipped with a hot stage. Change in mesomorphic properties with change of methylene spacers was observed. Enantiotropic mesogenic behavior was exhibited by D3A6, D10A6 and D11A6 and the needle like and blurred schleiren textures were observed. It was observed that increased methylene spacers chain length decreased the melting temperatures. Thermogravimetric analysis revealed the thermal stability of dimers upto 360 °C.
- Iqbal, Asma,Siddiqi, Humaira Masood,Akhter, Zareen,Qaiser Fatmi, Muhammad
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p. 135 - 141
(2017/09/23)
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- Synthesis and characterization of new optically active poly(amide-imide)s based on n-trimellitimido-l-amino acid and trimethylene units
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Six new optically active poly(amide-imide)s (8a-f) were synthesized through the direct polycondensation reaction of 1,3-bis(4-aminophenoxy) propane (4) with six different derivatives of N-trimellitimido-L-amino acid (7a-f) in a medium consisting of N-meth
- Faghihi, Khalil,Shabanian, Meisam
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scheme or table
p. 97 - 102
(2012/05/20)
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- Synthesis and Thermal Studies of Some Epoxy Systems cured with Aromatic Diamines
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Some aromatic diamines having flexible ether linkages with variable aliphatic and aromatic character were synthesized via Williamson's method and used as curing agents in their solution phase and/or molten state for a commercially available epoxy resin; diglycidyl ether of bisphenol-A (DGEBA) (n = 0.03, epoxy equivalent = 174.5 g/mol). The resulting polymeric systems were characterized by their physical properties and FT-IR-spectral studies. The thermal behaviour of the synthesized epoxy polymers were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). The optimum curing temperature of these polymers was found to be ~ 150°C. The polymers were stable up to 270°C with maximum weight loss at ~ 400°C.
- Khalid, Naila,Khan, Muhammad Saif Ullah,Siddiqi, Humaira Masood,Akhter, Zareen,Iqbal, Naseer
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scheme or table
p. 570 - 577
(2012/01/03)
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- Synthesis of symmetric liquid crystal dimers based on azo and imine groups and investigation of phase behaviour by varying alkoxy terminal chain length
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With the objective to study the effect of alkoxy terminal chain length on mesomorphic properties of liquid crystals, we have synthesized two (Azo and Imine) different series of dimesogens by varying terminal alkoxy chain length (n = 6-12) with a short spacer unit in between two mesogens. Transition temperatures and phase characterization were studied by DSC, POM and XRD analysis. It was found that all the dimers show mesomorphic properties and the change in terminal alkoxy chain length has pronounced effect on the smectic phase window. In the DSC cooling scan, the smectic phase window of azo compounds increased from 6.4°C (2A6) to 16.0°C(2A12), whereas in Schiff base compounds, it increased from 9.2°C (2S6) to 31.0°C(2S12). Further, the 2A11 dimer was found to undergo photo induced configurational changes.
- Kim, Tae Hyeong,Lee, Chang Sin,Ramaraj,Jeon, Hye Jin,Song, Hyun Hoon,Lee, Soo Min,Yoon, Kuk Ro
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experimental part
p. 102 - 116
(2010/03/04)
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- Synthesis, characterization and ion transportation studies of some novel cyclophane amides
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Various novel cyclophane amides with a large cavity have been synthesized. The structures of cyclophane amides 14 and 15 were resolved using XRD studies. Cyclophane amide 28 shows a shift in λmax in the UV/Vis. spectra when treated with Cu (II) ion as well as with Pb (II) ion. Ion transportation studies were carried out with cyclophane amide 14 which proved that the Na+ ion passes through the cavity while K+ ions are retained.
- Rajakumar, Perumal,Rasheed, A. Mohammed Abdul
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p. 5351 - 5362
(2007/10/03)
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- Biological properties of amidinium sulfinic and sulfonic acid derivatives: inhibition of glycolytic enzymes of Trypanosoma brucei and protective effect on cell growth
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The activity of the title compounds has been investigated on two biological targets: cultures of trypanosome and glycolytic enzymes inhibition of the parasite, and on retinal epithelium cells.In both cases, these compounds exhibit a significant activity,
- Willson, M,Perie, JJ,Malecaze, F,Opperdoes, F,Callens, M
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p. 799 - 808
(2007/10/02)
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- Dipole Moments and UV Spectra of some Long-chain Molecules
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About one hundred compounds with long-chain molecular structure have been prepared (most of them are new).The dipole moments of four α,ω-bis(p-methoxyphenylthio)alkanes and five α,ω-bis(p-methoxyphenylsulphonyl)alkanes have been determined to find the effect of chain-length.In the case of sulphones, the observed values are compared with the values calculated for free rotation around all bonds intervening the end dipoles.The uv spectra of some 1,2-(distyrylsulphonyl)ethanes, and a number of α,ω-bis(arylsulphonyl)- and α,ω-bis(aryloxy)alkanes have been recorded to examine the applicability of the principle of chromophore additivity.
- Baliah, V.,Aparajithan, K.
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p. 255 - 259
(2007/10/02)
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- Novel Bis as Antitrypanosomal Agents
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A series of novel 1,1'-(4,1-phenylene)bis was prepared and evaluated for activity against Trypanosoma rhodesiense in mice.The importance of the bis structure and the nature of the spacer between the two phenyl rings for optimal activity have been revealed.The potent parenteral activity of several analogues within this series as well as preliminary indication of oral activity lends encouragement to further development of this structural class.
- Turner, William R.,Werbel, Leslie M.
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p. 1728 - 1740
(2007/10/02)
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