bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave‐assisted synthesis of new regioisomeric 6,7‐dihydroindeno[1,2‐e]pyrimido[4,5‐b][1,4]diazepin‐5(5aH)‐ones
Authors: Insuasty Braulio , Orozco Fabián , Garcia Angélica , Quiroga Jairo , Abonia Rodrigo , Nogueras M. , Cobo Justo 
Published: March 2009

Abstractmagnified imageNovel 11‐amino‐6‐aryl‐6,7‐dihydroindeno[1,2‐e] pyrimido[4,5‐b][1,4]diazepin‐5(5aH)‐ones 4a‐f were prepared regioselectively by the tricomponent reaction of 4,5,6‐triaminopyrimidine 1, 1,3‐indandione 2 and aromatic aldehydes 3a‐f. The bicomponent approach, using 2,4,5,6‐tetraaminopyrimidine 5 and 2‐aryl‐ideneindandiones 6a‐f as reagents, afforded 9,11‐diamino‐6‐aryl‐6,7‐dihydroindeno[1,2‐e]pyrimido[4,5‐b]‐[1,4]diazepin‐5(5aH)‐ones 7a‐f in good yields and the regioisomeric 8,10‐diamino derivatives 8a‐c in lower yields. Both, bi‐ and tricomponent approaches were performed by microwave irradiation and all products were fully characterized by detailed NMR measurements.
1,3,2‐(2H)‐dioxaborine polymethine dyes on the base of dehydroacetic acid — effective fluorescent amine probes
Authors: Gerasov Andriy O. , Shandura Mykola P. , Kovtun Yuriy P. , Vlasenko Yuriy G. , Gorchev Vasyliy F. 
Published: March 2009

Abstractmagnified imageA number of new polymethine dyes based on the boron difluoride complexes of dehydroacetic acid and 3‐acetyl‐4‐hydroxypyridone has been synthesized. Their spectral‐luminescent properties have been investigated. The reaction of obtained merocyanines with primary and secondary amines has been studied. These low fluorescent dyes gave highly fluorescent open chain products, which on further heating cyclized to weakly fluorescent pyridone dyes.
A facile one pot synthesis of 2, 4‐diamino‐6‐substituted s‐triazine derivatives
Authors: Sathunuru Ramadas , Melendez Victor , Kozar Michael P. , Lin Ai J. 
Published: March 2009

Abstractmagnified imageA novel and facile one‐pot procedure for the preparation of 2,4‐diamino‐6‐substituted‐s‐triazine derivatives (IIa‐n) was reported. The scope of its application was demonstrated with a number of examples. The new procedure involved treatment of proguanil or chloroproguanil with acyl chloride or alky chlorooxoacetate in pyridine at ice cold temperature followed by reflux overnight to give good yields of the desired products.
Ring closure reactions of 5‐azidopyrido[2,3‐d]pyrimidinetriones to isoxazolo‐ and oxadiazolopyrido[2,3‐d]pyrimidinetriones
Authors: Van Tinh Dang , Stadlbauer Wolfgang 
Published: March 2009

Abstractmagnified imageThermal decomposition of 5‐azidopyrido[2,3‐d]pyrimidines 2 and 7 having reactive ortho‐substituents such as a formyl or a nitro group yielded isoxazolo[3′,4′:4,5]pyrido[2,3‐d]pyrimidines 3 or oxadiazolo‐[3′,4′:4,5]pyrido[2,3‐d]pyrimidines 9. The reaction conditions of the azide decomposition were studied by differential scanning calorimetry (DSC). In addition, desoxygenation of N‐oxides 9 to oxadiazoles 10 and regioselective reduction of azides 7 to amines 8 were studied.
Application of the acetate of baylis‐hillman adducts of salicylaldehydes in the synthesis of methyl 2‐oxo‐2,3‐dihydrobenzo[b]oxepine‐4‐carboxylates
Authors: Ahn Sang‐Hyun , Lim Hee Nam , Lee Kee‐Jung 
Published: March 2009

Abstractmagnified imageA simple synthesis of several methyl 2‐oxo‐2,3‐dihydrobenzo[b]oxepine‐4‐carboxylates from Baylis‐Hillman adducts of O‐benzyl protected 2‐hydroxybenzadehydes has been described through the acetylation, cyanation, debenzylation, as well as acid assisted Pinner cyclization.
Synthesis of new 1‐[4‐methane(amino)sulfonylphenyl)]‐5‐[4‐(aminophenyl)]‐3‐trifluoromethyl‐1H‐pyrazoles
Authors: Abdellatif Khaled R. A. , Chowdhury Morshed A. , Knaus Edward E. 
Published: March 2009

Abstractmagnified imageA regiospecific cyclization‐dehydration reaction of a 1‐[(4‐(N‐alkyl‐N‐(tert‐butyloxycarbony)amino)‐phenyl]‐4,4,4‐trifluorobutane‐1,3‐done with a 4‐aminosulfonyl‐, or 4‐methylsulfonyl‐, phenylhydrazine hydrochloride in refluxing ethanol proceeded with simultaneous loss of the N‐tert‐butyloxycarbonyl protecting group to afford a group of 1‐(4‐methanesulfonylphenyl or 4‐aminosulfonylphenyl)‐5‐[4‐(N‐alkylaminophenyl)]‐3‐(trifluoromethyl)‐11H‐pyrazoles(6). Subsequent reaction of the pyrazole 6 (R1 = R2 = Me) with nitric oxide (40 psi) proceeded via a N‐methylamino‐N‐diazen‐1‐ium‐1,2‐diolate intermediate that undergoes protonation of the more basic diazen‐1‐ium‐1,2‐diolate N2‐nitrogen and then loss of a nitroxyl (HNO) species to furnish the N‐nitroso product 7.
Studies in synthesis of furoflavones possessing anti‐cancer activity
Authors: Patel Jagdish M. , Soman Shubhangi S. 
Published: March 2009

Abstractmagnified imageSeveral new furoflavanones (3a‐3I) have been synthesized from the in‐situ generated chalcones by the reaction of ortho‐hydroxy acetyl benzofuran and aryl aldehyde in presence of piperidine. Ethanolic sodium hydroxide (1%) gave chalcones (2a‐2I) as the exclusive product. Flavindogenides (3‐arylidene flavanones) (5a‐5d) have been isolated as the co‐product along with chalcones and flavanones in cases where excess of aryl aldehyde was used. The stereochemistry of 3‐arylidene flavanones has been established by the preparation of both Z (6) and E (5a‐5d) diastereomers. Single crystal X‐ray diffraction data shows the flavanone ring to exist in quasi chair conformation with phenyl ring equatorial. Furoflavanones were finally dehydrogenated to furoflavones (4a‐4I) using DDQ (2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone). The compounds have been screened for in‐vitro cytotoxicity against human cancer cell lines.
Gas‐phase pyrolysis in organic synthesis: New route for synthesis of functionally substituted imidazoles
Authors: El‐Dusouqui Osman M. E. , Al‐Awadi Nouria A. , Elnagdi Mohamed H. , Abdelkhalik Mervat M. 
Published: March 2009

Abstractmagnified image1,2,3‐Triazolylpropanone was prepared and coupled with aryldiazonium salts yielding the corresponding arylhydrazones. Gas‐phase pyrolysis of the hydrazono derivative produced N‐arylamino‐2‐acetylimidazole as well as 2‐acetylimidazole. The latter is the product of further pyrolysis of the former.
Synthesis and biological activities of novel chiral fluorinated β‐carboline derivatives
Authors: Ding Jin Chang , Huang Xiao Bo , Wu Hua Yue , Chen Jie Zhi , Cai Ming Tiao , Liu Miao Chang 
Published: March 2009

Abstractmagnified imageA series of unreported chiral β‐carbolines 4 with trifluoromethyl group at position‐1 and chiral carboxamide chains or amino acid ester chains at position‐3 has been designed and synthesized. The results of bioassay in vitro show that compounds 4e, 4i and 4k show 78.8%, 84.0% and 78.9% inhibition on monoamine oxidase, in 1 mmol/L, respectively, and compound 4e also exhibit 60.9% inhibitory activity on tumor lung cell A‐549 in 10−5 mmol/L. In view of different configuration, the inhibitory activity on monoamine oxidase of S‐enantiomer of the target compound is better than that of R‐enantiomer.
Formation of aryl‐bis (6‐amino‐1,3‐dimethyluracil‐5‐yl) methanes by reaction of 6‐amino‐1, 3‐dimethyluracil with aromatic aldehydes
Authors: Bansal Ranju , Kumar R. Sunil , Kumar Gulshan , Thota Sridhar , Thamotharan S. , Parthasarathi V. , Linden Anthony 
Published: March 2009

Abstractmagnified imageThe synthesis of aryl‐bis(6‐amino‐1,3‐dimethyluracil‐5‐yl)‐methanes 3a‐m by condensation of 6‐amino‐1,3‐dimethyluracil (1) with aromatic aldehydes 2a‐m at room temperature is reported. The structures of the compounds were established using various spectroscopic analyses and X‐ray crystallography. The crystal structures of two aryl‐bis (6‐amino‐1,3‐dimethyluracil‐5‐yl) methanes are presented.
An efficient synthesis of quinoxaline derivatives mediated by stannous chloride
Authors: Shi Da‐Qing , Dou Guo‐Lan , Ni Sai‐Nan , Shi Jing‐Wen , Li Xiao‐Yue 
Published: March 2009

Abstractmagnified imageVarious biologically important quinoxaline derivatives were efficiently synthesized in excellent yields by the reaction of 1,2‐diketones and 2‐nitroaniline, benzofuroxan or 1,2‐dinitrobenzene promoted by SnCl22H2O. The role of stannous chloride is acting as both reductive agent and catalyst in this synthesis. This new method has the advantages of accessible starting materials, convenient manipulation, short reaction time and high yields.
Synthesis of the indole core structures of conophylline
Authors: Ando Shin , Okamoto Yoshinari , Otsuka Masami , Umezawa Kazuo 
Published: March 2009

Abstractmagnified imageConophylline is a bisindole alkaloid of unique structure that shows anti‐cancer and anti‐diabetic activities. Two indole core structures of conophylline, namely 6,7‐dimethoxy‐5‐methoxymethoxy‐1H‐indole (1), and N‐benzoyl‐N‐[2‐(6‐methoxymethoxy‐2‐vinyl‐1H‐indol‐3‐yl)ethyl]amine (2) has been synthesized starting with substituted benzene derivatives.
N‐Arylation of N‐H heterocycles with aryl bromides and aryl iodides using cui and kf/Al2O3
Authors: Hosseinzadeh Rahman , Tajbakhsh Mahmood , Alikarami Mohammad , Mohadjerani Maryam 
Published: March 2009

Abstractmagnified imageCopper‐catalyzed system for N‐arylation of N‐H group in heterocycles such as indole, pyrrole and carbazole with aryl iodides and aryl bromides using potassium fluoride supported on alumina as a base is described. This is a simple and efficient method for the coupling of aryl iodides and bromides with N‐H heterocycles. Different functionalized iodo and bromo arenes were coupled with N‐H heterocycles using this system.
Solvent‐free one‐pot approach for synthesis of substituted 2‐aminochromenes
Authors: Zhou Dong , Ren Zhongjiao , Chen Jie , Cao Weiguo , Deng Hongmei 
Published: March 2009

Abstractmagnified imageA solvent‐free one‐pot approach for the preparation of 2‐aminochromenes in the presence of NaHCO3 by grinding was described. Its advantages are easy work‐up, mild reaction condition, high yield and environmental compatibility.
Vicarious nucleophilic amination of nitroquinolines by 1,1,1‐trimethylhydrazinium iodide
Authors: Grzegożek Maria 
Published: March 2009

Abstractmagnified imageThe amination of 3‐, 5‐, 6‐, 7‐ and 8‐nitroquinoline via the vicarious nucleophilic substitution of hydrogen (VNS) with 1,1,1‐trimethylhydrazinium iodide (TMHI) in the presence of t‐BuOK in DMSO was studied. The amination occurs regioselectively giving ortho or ortho and para isomers relative to the nitro group with a high yield (95‐86%). 2‐Nitroquinoline does not undergo vicarious amination but displacement of the labile nitro group by an amino group occurs and then transformation to an imine compound and hydrolysis gives2(1H)‐quinolinone.
Synthesis and DNA‐binding properties of 1,10‐phenanthroline analogues as intercalating‐crosslinkers
Authors: Higashi Toshinori , Inami Keiko , Mochizuki Masataka 
Published: March 2009

Abstractmagnified imageWe synthesized a series of bis(bromomethyl)‐1,10‐phenanthrolines as novel anticancer lead compounds and examined their DNA‐binding properties. 5,6‐Bis(bromomethyl)‐1,10‐phenanthroline showed DNA intercalating activity and DNA crosslinking activity, furthermore it is stable in aqueous solution.
Post‐offence characteristics of 19th‐century American parricides: An archival exploration
Authors: Shon Phillip C. , Roberts Michael A. 
Published: March 2009

AbstractUsing archival records from the New York Times and the Chicago Tribune, 1851–1899, the current project examines the post‐offence characteristics of 19th‐century American parricides. Post‐offence behaviours of 100 parricide offenders were gathered. Results indicate that post‐offence behaviours of parricide offenders can be thematically classified into those that reflect a continuity of violence, attempts to cover up the crime, and unusual behaviours. The implications of post‐offence behaviours of parricide offenders in the context of law, mental illness, and criminological theory are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and evaluation of two uncharged 99mTc‐labeled derivatives of thioflavin‐T as potential tracer agents for fibrillar brain amyloid
Authors: Serdons K. , Vanderghinste D. , Van Eeckhoudt M. , Cleynhens J. , de Groot T. , Bormans G. , Verbruggen A. 
Published: March 2009

AbstractThioflavin‐T is a fluorescent dye for in vitro detection of fibrillar amyloid β, a protein found in the brain of patients suffering from Alzheimer's disease. We synthesized and biologically evaluated two uncharged 99mTc‐labeled derivatives of thioflavin‐T. The precursors for labeling were synthesized by coupling an S,S′‐bis‐triphenylmethyl‐N‐tert‐butoxycarbonyl bis‐amino‐bis‐thiol tetradentate ligand via a propoxy spacer to 2‐(4′‐aminophenyl)‐1,3‐benzothiazole at the 6‐position or the 2′‐position. Deprotection and labeling with 99mTc were done via a one‐pot procedure (15% yield) after which the labeled compound was isolated by high performance liquid chromatography (LC). LC in combination with mass spectrometry (MS) was used for identity confirmation of the labeled compounds. Results of electrophoresis and log P determination supported the assumption that the radiolabeled compounds could cross the blood–brain barrier by passive diffusion. However, in normal mice both compounds showed a low brain uptake 2 min post injection. They were mainly excreted through the hepatobiliary system, with some accumulation in the stomach. Sixty minutes after intravenous injection, 37% of the 99mTc‐activity in the blood corresponded to the original compound. In view of the low brain uptake, it is concluded that the studied 99mTc‐labeled derivatives of thioflavin‐T are not suitable as tracer agents for in vivo visualization of amyloid in brain. Copyright © 2009 John Wiley & Sons, Ltd.
Syntheses of deuterium labelled atropine and scopolamine
Authors: Balssa Frédéric , Bonnaire Yves 
Published: March 2009

AbstractEasy preparative scale syntheses of deuterium labelled atropine and scopolamine are described. [2H3]‐atropine and [2H3]‐scopolamine are obtained in good yield and good isotopic purity in two steps starting from the unlabelled alkaloids. Copyright © 2009 John Wiley & Sons, Ltd.
Recognition and palaeoclimatic implications of late Quaternary niche glaciation in eastern Lesotho
Authors: Mills Stephanie C. , Grab Stefan W. , Carr Simon J. 
Published: March 2009

AbstractGeomorphic evidence of former glaciation in the high Drakensberg of southern Africa has proven controversial, with conflicting glacial and non‐glacial interpretations suggested for many landforms. This paper presents new geomorphological, sedimentological and micromorphological data, and glacier mass‐balance modelling for a site in the Leqooa Valley, eastern Lesotho, preserving what are considered to be moraines of a former niche glacier that existed during the Last Glacial Maximum (LGM). The geomorphology and macro‐sedimentology of the deposits display characteristics of both active and passive transport by glacial processes. However, micromorphological analyses indicate a more complex history of glacial deposition and subsequent reworking by mass movement processes. The application of a glacier reconstruction technique to determine whether this site could have supported a glacier indicates a reconstructed glacier equilibrium line altitude (ELA) of 3136 m a.s.l. and palaeoglacier mass balance characteristics comparable with modern analogues, reflecting viable, if marginal glaciation. Radiocarbon dates obtained from organic sediment within the moraines indicate that these are of LGM age. The reconstructed palaeoclimatic conditions during the LGM suggest that snow accumulation in the Drakensberg was significantly higher than considered by other studies, and has substantial relevance for tuning regional climate models for southern Africa during the last glacial cycle. Copyright © 2009 John Wiley & Sons, Ltd.
Oligoagarose‐Graft‐Polycaprolactone Copolymers: Synthesis and Characterization
Authors: Bhaw‐Luximon Archana , Jhurry Dhanjay , Booluck Mooneerah Heerah , Correc Gaëlle , Génicot Sabine , Helbert William 
Published: March 2009

AbstractIn this paper, we combine hydrophilic oligoagarose (DPn = 10–15), issued from enzymatic degradation of the natural biopolymer agarose, with polycaprolactone, a synthetic biodegradable and hydrophobic polyester. To synthesize these amphiphilic graft copolymers, we use partially acetylated oligoagarose as macroinitiator in combination with tin (II) octanoate for the bulk polymerization of ε‐caprolactone. The grafting was confirmed by NMR and SEC which showed a monomodal distribution. After removal of the acetyl protecting groups, copolymers with 30–60% free hydroxyl groups were soluble in water and insoluble in chloroform, thus indicating that they probably adopt micelle‐like structures in aqueous solution with a PCL hydrophobic core and spherical oligoagarose side chains.
Rheological Hybrid Effect and its Conditions in Filled Polymer Melts
Authors: He Jiasong 
Published: March 2009

AbstractIn contrast to usually increased viscosity of filled polymer melts with increasing filler content, some filled polymer melts showed decreased melt viscosity in the presence of thermotropic (main chain) liquid crystalline polymer (LCP) with increasing filler content. This phenomenon was termed as rheological hybrid effect and found correlated well with the fibrillation of LCP melt droplets. Investigation of this LCP fibrillation in matrix polymers, with fillers of various shapes at micro‐ and nano‐meter scales, showed that LCP fibrillation was promoted by the filler addition, depending upon thermodynamic and hydrodynamic driving forces involved.
Vibrational Dynamics, Phonon Dispersion and Specific Heat in Gas Permeable Poly(4‐Methyl‐2‐Pentyne)
Authors: Kumar Anuj , Pathak Sapna , Singh Mahendra , Tandon Poonam , Gupta V. D. 
Published: March 2009

AbstractPoly(4‐methyl‐2‐pentyne) (PMP) is an amorphous glassy disubstituted acetylene based polymer. The excellent gas‐separation and mechanical properties of these polymers have stipulated their use as membrane material for vapor and gas separation. PMP is among the hydrocarbon disubstituted polyacetylenes which have been synthesized to date. This polymer combines excellent gas and vapor permeability with good resistance to organic solvents. As was shown recently, PMP offers promise in the manufacture of nanocomposite membranes for the separation of various hydrocarbon mixtures. It is also of importance as its monomer, 4‐methyl‐ 2‐pentyne, can be easily derived from commercial compounds, 4‐methyl‐2‐pentene or methyl isobutyl ketone, produced on a large scale. It is known that PMP exists in cis and trans configurations. Synthetic conditions, e.g., the used catalyst, temperature, solvent etc., of substituted polyacetylenes decide percentage of different configurations (cis or trans). Different geometries of macromolecules can influence the supramolecular structure of the polymer, which primarily defines its properties, such as solubility, permeability, sorption, etc. Qualitative assignments of few bands of IR spectra are reported earlier. We present here, complete normal mode analysis and dispersion curves for PMP using Wilson GF matrix method modified by Higgs using Urey‐Bradley force field. Dispersion curves for PMP are drawn and salient features are discussed. Predicted values of specific heat via density‐of‐states are also reported.
Synthesis and Characterization of Polysulfide Rubber Using Phase Transfer Catalyst
Authors: Kalaee M. R. , Famili M. H. N. , Mahdavi H. 
Published: March 2009

AbstractSummary: Poly(alkyltetrasulfide) is prepared via reaction of ethylene dichloride with sodium tetrasulfide (Na2S4) in the presence of methyl tributyl ammonium chloride as phase transfer catalyst (PTC). The polysulfide polymer is characterized by CHN analysis, FT‐IR, TGA, DTA and DSC techniques.
Growth and Thermal, Electrical, Structural Characterization of Mixed Hydrated Single Crystal
Authors: Naware S. P. , Kelkar D. S. 
Published: March 2009

AbstractMixed single crystal was made by mixing saturated aqueous solutions of NiSO4 · 6H2O and CuSO4 · 5H2O by volume (80:20) and the mixture was kept to form the crystals at room temperature by slow evaporation process. After some days, big pieces of greenish blue, dark colored crystals were grown. To determine the weight of NiSO4 · 6H2O and CuSO4 · 5H2O in the crystal, Ni‐DMG complexiometrical and EDTA gravimetrical analysis was done respectively. From this analysis it was concluded that 5.8 molecules of water of crystallization is present in the mixed single crystal. The crystals were characterized by UV‐Visible, FTIR and single crystal X‐ray diffraction studies. From single crystal XRD lattice parameters have been calculated. All these structural analysis confirms formation of new single crystal. Further, DTA‐TGA, dc electrical conductivity and dielectric constant studies were done from the room temperature to 400 °C.From DTA studies it was observed that 5.8 molecules of water of crystallization get dehydrated in four major steps at temperature 115 °C, 150 °C, 240 °C and 325 °C respectively corresponding to the detachment of 1 mole, 3 moles, 1 mole and 0.8 mole of water of crystallization. DC electrical conductivity and dielectric constant studies also show close agreement to the dehydration steps. The observed peaks in the conductivity verses temperature graph have been explained on the basis of release of water molecules and subsequent dissociation of these released water molecules into H+ and OH− ions.
Photophysical and Electrochemical Investigations on Photoconducting Poly(6‐tert‐butyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine)
Authors: Dhanya R. , Kishore V. C. , Sreekumar K. , Kartha C. Sudha , Joseph Rani 
Published: March 2009

AbstractPoly(6‐tert‐butyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine) was synthesized by thermally activated cationic ring opening polymerization. The structure of the polymer was confirmed by spectral and thermal studies. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were estimated using cyclic voltammetry and optical absorption. Modulated photocurrent measurement technique was employed to study the spectral and field dependence of photocurrent. Photocurrent of the order of 1.5 µA/m2 was obtained for polymer at a biasing electric field of 40 V/µm.
Modification of Polypropylene/Glass Fiber Composites with Nanosilica
Authors: Jacob Sinto , Suma K. K. , Mendaz Jude Martin , George Abhilash , George K. E. 
Published: March 2009

AbstractPoly(propylene) (PP) reinforced with short glass fiber was modified with precipitated nanosilica (pnS) by melt mixing. The weight of the glass fiber was varied by keeping the pnS at optimum level. The properties of the composites were studied using universal testing machine, dynamic mechanic analyser (DMA), differential Scanning calorimetry (DSC) and thermo gravimetric analyser (TGA). The amount of the glass fiber required for a particular modulus could be reduced by the addition of nanosilica.
Paint Formulation Using Water Based Binder and Property Studies
Authors: Suma K. K. , Jacob Sinto , Joseph Rani 
Published: March 2009

AbstractVinyl acetate – Butyl acrylate (VAc‐BuA) copolymer latices of various compositions were prepared by semicontinuous emulsion polymerization. The copolymer formed after removing the homopolymers was characterized by FTIR spectroscopy. Mechanical properties were studied by Universal Testing machine. Differential scanning calorimetry (DSC) study of copolymer showed single glass transition temperature (Tg) value confirming the absensce of graft and block copolymer. These copolymer latices were used as the binder in water based latex paint formulation. The paint prepared using 85/15 wt.% of VAc‐BuA was found to give a better paint properties. Water based paints are generally easier to apply and clean up. The surface properties found to be superior compared to commercially used paint.