bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion and Adsorbing Colloid Flotation of Auramine
Authors: Lu Chung‐Shin , Chen Chiing‐Chang 
Published: May 2015

AbstractAuramine, a cationic dye, was removed from synthetic wastewater by ion flotation of auramine‐sodium lauryl sulfate complex. Over 98% of auramine was removed from the solution in 15 min. A stoichiometric amount of surfactant (1 mol of surfactant to 1 mol of dye) was found to be most effective for auramine removal. The rate of separation and ultimate removal of auramine increased with increasing the rate of air flow and decreased with increasing concentration of NaNO3. Auramine was also removed by adsorbing colloid flotation technique using ferric hydroxide as the coagulant. Sodium lauryl sulfate was used as the collector, and over 95% of auramine was removed in 10 min. The separation efficiency decreased with increasing ionic strength of the solution. The deleterious effect of neutral salt was compensated somewhat with the aid of aluminum ions as the activator. Both ion flotation and adsorbing colloid flotation are promising approaches for the removal of cationic dye from wastewater.
Spectroscopic and Chromatographic Identification of Hydrocarbon Group Types in Pakistani Crude Oils
Authors: Ishaq M. , Ahmed Imtiaz , Saeed Khalid , Ismail M. , Bahader Ali 
Published: May 2015

AbstractTwo crude oil samples collected from Paniro and Tangri (Sindh) southern Pakistan. The distillate fractions of both crude oil samples were analysed by U.V‐visible spectrophotometer and column chromatography for hydrocarbon group types. It was found from the physico‐chemical study of these crude oils that Tangri crude oil contains mostly paraffinic contents while Paniro crude oil samples are rich in aromatics. It was concluded from all the experiments that Tangri crude oil is paraffinic in nature; while Paniro crude oil is naphthenic in nature, further it was observed that Tangri crude oil processing would be environmentally friendly compared to Paniro crude oil, because Paniro crude contains a high amount of polyaromatics.
Characterization of Zinc Ion Transport Via Dialysis Process
Authors: Madaeni S. S. , Godini H. R. 
Published: May 2015

AbstractTreatment of metal ions' wastes is getting more interest due to the tight regulations for environmental protection. Dialysis, a membrane based process with the concentration difference as the driving force, may be used for separation of metal ions from wastewater.In this study membranes with different pore sizes including Accurel, Celgard, GVHP, PM30 and PTHK membranes were employed to characterise the transport of zinc ion in various (0.01, 0.1, 0.5, 1, 5 and 10 w/v percent) initial feed concentrations.The results show that low initial feed concentration causes less passage of ions through the membrane due to low driving force, i.e. concentration gradient across the membrane. This result is expected. However the effect of membrane pore size is somehow unexpected. It was found that the large pore size membranes provide less penetration of the metal ions through the membrane. This reproducible result has been explained based on the transport mechanism. Two types of mechanisms, i.e. extensive and intensive mechanisms, have been suggested for metal ion transport through different pore size membranes.
CeCl3/Sm Promoted Pinacolic Coupling of Aromatic Aldehydes and Ketones
Authors: Li Xue , Zhang Songlin , Zhang Xinying , Wang Xiaoyang 
Published: May 2015

AbstractThe pinacolic coupling of aromatic aldehydes and ketone was performed with cerium trichloride and samarium in THF at room temperature to afford the corresponding 1,2‐diols in good yields.
Diastereoselective Epoxidation of Camphor N‐Enoylpyrazolidinones
Authors: Fan Chai Ling , Reddy Gondi Sudershan , Chen Kwunmin 
Published: May 2015

AbstractReaction of camphor N‐enoylpyrazolidinones (1a‐j) with various oxidants, in particular UHP/TFAA afford chiral epoxides with a wide range of stereoselectivities (up to > 90% de).
Nitriles in Heterocyclic Synthesis: Reactivity of 2‐(Benzothiazol‐2‐ylmethyl)‐1,3‐thiazol‐4(5H)‐one towards α,β‐Unsaturated Nitriles
Authors: Sayed S. M. 
Published: May 2015

AbstractThe reaction of 2‐(benzothiazol‐2‐ylmethyl)‐1,3‐thiazol‐4(5H)‐one 1 with α,β‐cinnamonitrile derivatives 2a‐n have been reported.
Two Cerebrosides and One Acylglycosyl Sterol from Monochoria Vaginalis
Authors: Row Lie‐Ching , Chen Chiu‐Ming , Ho Jiau‐Ching 
Published: May 2015

AbstractThree new compounds have been isolated from the whole plant of Monochoria vaginalis and characterized as: (2S,3R,4E,8E,2′R)‐1‐O‐(β‐D‐glucopyranosyl)‐N‐(2′‐hydroxyicosanoyl)‐4,8‐sphingadienine, (2S,3R,4E,8E,2′R)‐1‐O‐(β‐D‐glucopyranosyl)‐N‐(2′‐hydroxyoctadecanoyl)‐4,8‐sphingadienine and 7‐oxostigmasteryl‐3‐O‐(6′‐hexadecanoyl)‐β‐D‐glucopyranoside. Their structures were established by spectral and chemical evidence.
The Efficient Synthesis of the Optically Active β‐Hydroxyl‐γ‐Butyrolactone Derivatives
Authors: Wang Jin Xin , Li Ying , Zhang Chao Xin 
Published: May 2015

AbstractThe optically active β‐hydroxyl‐γ‐butyrolactones were synthesized from nonchiral starting material by employing reductive cleavage reaction, sharpless asymmetric epoxidation and dihydroxylation, and Lewis acid‐catalysed cyclization as key steps. This strategy can be used to prepare many chiral β‐hydroxyl‐γ‐butyrolactone analogues.
Study on the Color Reaction of Silver with 2‐(2‐Quinolylazo)‐5‐Dimethylaminoaniline and its Application
Authors: Hu Qiu‐Fen , Yang Guang‐Yu , Huang Zhang‐Jie , Yin Jia‐Yuan 
Published: May 2015

AbstractA new chromogenic reagent, 2‐(2‐quinolylazo)‐5‐dimethylaminoaniline (QADMAA) was synthesized. A highly sensitive, selective and rapid method for the determination of silver based on the rapid reaction of silver(I) with QADMAA was developed. In the presence of pH = 6.5 sodium citrate‐sodium hydroxide buffer solution and sodium dodecyl sulfonate (SDS) medium, QADMAA reacts with silver to form a violet complex of a molar ratio 1:2 (silver to QADMAA). The molar absorptivity of the complex is 1.26 × 105 L. mol−1.cm−1 at 570 nm. Beer's law is obeyed in the range of 0.01–0.6 μg/mL. The relative standard deviation for eleven replicate samples of 0.2 μg/mL silver is 1.76%. This method was applied to the determination of silver in water with good results.
Synthesis of Some New Heterocycles of Pharmaceutical Interest: Pyridinyl and Isoxazolyl Quinoxaline Derivatives
Authors: Moustafa Osama S. 
Published: May 2015

Abstract3‐(p‐Acetyl‐anilinomethyl)quinoxalin‐2(1H)‐one (3) was prepared by the reaction of 3‐bromomethyl‐quinoxalin‐2(1H)‐one (1) with p‐aminoacetophenone (2) in pyridine. Reaction of p‐acetylcompound (3) with aromatic aldehydes yield the corresponding chalcones (4a‐c). Condensation of latter chalcones with malononitrile afforded cyanopyridines (5a‐c). Also, the reaction of chalcones (4a‐c) with hydroxylamine hydrochloride furnished isoxazoles (6a‐c). The reaction of bromo compound (1) with p‐aminobenzophenone yield (8) which was condenced with hydrazine hydrate to get the corresponding hydrazone derivatives (9). Some of the synthesized compounds have been screened for their antimicrobial activity against various strains of bacteria and fungi.
The Study on Synthesis of Some New 1,2,3‐Triazolylurea and Carbonyl Amide Derivatives
Authors: Dong Heng‐Shan , Liu Shi‐Qiang 
Published: May 2015

AbstractThe study on syntheses of some N‐substituted‐N′‐[5‐methyl‐1‐(4‐chlorophenyl)‐1,2,3‐triazol‐4‐yl]‐urea 6a‐e and N‐substituted‐[5‐methyl‐1‐(4‐chlorophenyl)‐1,2,3‐triazol‐4‐yl]carbonyl amide 6f‐l derivatives were reported in this paper. The yielded products 6a‐l were confirmed by elemental analyses, NMR, MS and IR spectra.
Factors Influence Complexing Selectivity of Lariat Crown Ethers Toward Alkali Metal Ions in Electrospray Ionization Mass Spectrometry
Authors: Cheng Sheng‐Fan , Hung Huan‐Yi , Liu Lilian Kao 
Published: May 2015

AbstractThe selectivity of eight lariat crown ethers in the sym‐dibenzo‐16‐crown‐5 series toward alkali metal ions was studied with electrospray ionization mass spectrometry under different conditions. With the exception of 2g, which is equally selective toward Na+ and Li+, all other lariat crown ethers show the best selectivity toward Li+ in methanol. Factors that influence the selectivity include the water content, counterions, nature of the side arms, and the externally added cations. Iodide gives the best Na+ selectivity with RI > RBr > RCl. Increased water content profoundly increases the Na+ selectivity when the side arm is hydrophilic and the steric hindrance is small. Externally added cations (Cs+ and/or Rb+) enhance the Na+ selectivity by exchanging the smaller Li+ from the cavity.
Probing the Effects of Reagent Gas Pressure and Ion Source Temperature for Dimethyl Ether Chemical Ionization of Tricyclic Antidepressants in an External Source Ion Trap Mass Spectrometer
Authors: Wu Hui‐Fen , Lin Pei‐Yi 
Published: May 2015

AbstractThis study examines the reagent gas pressure and ion source temperature dependence for dimethyl ether chemical ionization (DME CI) mass spectra recorded with an external source ion trap mass spectrometer (ITMS). Information for better controls of the reagent gas pressure in order to obtain fair CI spectra is provided. The origin of M+• ions observed in DME CIMS is discussed in detail. Furthermore, the ion source temperature effect on the DME CI is also investigated.
Synthesis, Reactivity, and Crystal Structure of the η2‐Thiocarbamoyl Palladium Complex [Pd(PPh3)2(η2‐SCNMe2)][PF6]
Authors: Yih Kuang‐Hway , Lee Gene‐Hsiang , Wang Yu 
Published: May 2015

AbstractThe η1‐thiocarbamoyl palladium complexes [Pd(PPh3)(η1‐SCNMe2)(η2‐S2R)] (R = P(OEt)2, 2; CNEt2, 3) and trans‐[Pd(PPh3)2(η1‐SCNMe2)(η1‐Spy)], 4, (pyS: pyridine‐2‐thionate) are prepared by reacting the η2‐thiocarbamoyl palladium complex [Pd(PPh3)2(η2‐SCNMe2)][PF6], 1 with (EtO)2PS2NH4, Et2NCS2Na, and pySK in methanol at room temperature, respectively. Treatment of 1 with dppm (dppm: bis(diphenylphosphino)methane) in dichloromethane at room temperature gives complex [Pd(PPh3)(η1‐SCNMe2)(η2‐dppm)] [PF6], 5. All of the complexes are identified by spectroscopic methods and complex 1 is determined by single‐crystal X‐ray diffraction.
Mixed Cationic‐nonionic Surfactants and pH Adjustment Route to Synthesize High‐quality MCM‐48
Authors: Zhai Shang‐Ru , Gong Yan‐Jun , Zhang Ye , Deng Feng , Luo Qing , Wu Dong , Sun Yu‐Han 
Published: May 2015

AbstractUsing the mixture of cetyltrimethylammonium bromide (CTAB) and p‐Octyl polyethylene glycol phenyl ether (OP‐10) as templates, siliceous MCM‐48 materials can be synthesized with low molar ratio of CTAB to silica (0.139:1) and low concentration of mixed surfactants (ca.5%) and within a wide range of OP‐10/CTAB ratio (0.08˜0.25). The materials were characterized by X‐ray powder diffraction, N2 adsorption/desorption isotherm, TEM, TG‐DSC and 29Si MAS NMR. Measurements indicated that the use of mixed surfactants allowed better condensation and higher ordering of the cubic mesostructure; at the same time, some properties of these materials were sensitive to the OP‐10/CTAB ratio. It was also found that the reduced pH of the gel which had been crystallized for a certain time gave a highly reproducible synthesis with a high silica yield (about 95%). Furthermore, the reaction mechanism of the synthesis is discussed in detail.
Thermodynamic‐Dependent Size‐Selection of ZnSe Nanoparticles in Amphiphilic Triblock Copolymer Systems
Authors: Yang Chung‐Sung , Ku Kuo‐Lung 
Published: May 2015

AbstractZnSe colloidal nanoparticles prepared by the air‐insensitive starting reagents, zinc chloride and selenium powder, have been size‐selected in the Pluronic amphiphilic triblock copolymer [(EO)x(PO)y(EO)x] systems. The size‐selection mechanism between the ZnSe nanoparticles and the triblock copolymers systems is a thermodynamic‐dependent effect. We observe that nanoparticles with special volume (Vs) are trapped first by the triblock copolymers due to the faster entropic depletion interaction arising from the addition of surfactant‐template (micelles) to colloidal nanoparticles. On the other hand, nanoparticles with sizes larger or smaller than Vs will not interact with the surfactant‐templates. They either precipitate quickly by gravity (larger than Vs) or still retain their thermal motion in the aqueous phase (smaller than Vs) when Vs nanoparticles are caught by the surfactant‐templates.
Spectrofluorimetric Determination of Trace Amounts of Copper
Authors: Liu Jian‐Ning , Zhang Bing , Wu Bo‐Wan , Yu Xin‐Qiao 
Published: May 2015

AbstractA fluorescent reagent, 2,4‐dihydroxyacetophenone‐4‐hydroxybenzoylhydrazone (2,4‐DH‐AP‐4‐H‐BH) was studied on its fluorescent reaction with copper using the spectrofluorimetric method. In a water‐ethanol solution at pH 12.0, a chelating reaction occurs between copper and 2,4‐DH‐AP‐4‐H‐BH. The molar ratio of copper to the reagent is 1:2. This reaction causes characteristic changes of spectra of fluorescence with excitation and emission maxima at 342.4 and 419.2 nm, respectively. This method can quantitate the amount of copper in the reaction. It detects as little as 0.2 ppb of copper with a linear range between 0.2 to 120 ppb. It has been successfully applied to detect copper in mineral water, tea, and hair.
Synthesis of 3‐[4‐Acyl‐2‐(1‐methoxy‐1‐methylethyl)morpholin‐3‐yl]‐benzonitriles as Novel Potassium Channel Openers
Authors: Lin Mei‐Shan , Hsin Ling‐Wei , Cheng Chen‐Yu 
Published: May 2015

AbstractPotassium channel openers (KCO's) have been demonstrated to possess potent relaxant‐activity on smooth muscle. Tissue‐selective KCO's may find use in the treatment of a variety of diseases, such as hypertension, asthma, and urinary incontinence. We have previously reported a series of 1,9‐dioxa‐4‐aza‐phenanthrene‐6‐carbonitriles, including compounds 2 & 3, as bladder‐selective KCO's. As a continuation of our efforts, we have designed 3‐[4‐acyl‐2‐(1‐methoxy‐1‐methylethyl)morpholin‐3‐yl]‐benzonitriles as ring‐opened analogs of compounds 2 & 3. In this report, we describe the efficient construction of the novel 2,3‐disubstituted morpholine structure, as represented by the synthesis of compounds 4‐7. Compounds 4‐7 showed potent and selective relaxant‐activity on rat bladder detrusor strip preparation. In this series, the most potent derivatives are Boc‐substituted analogs 4 & 6 (IC50 = 3.9 and 2.9 μM, respectively).
Octasilsesquioxane Chemistry II. Hydrosilylation Reaction of Octa(hydrido)silsesquioxane with Unsaturated Substrates and Product Properties
Authors: Liu Ling‐Kang , Dare Enock O. 
Published: May 2015

AbstractThe hydrosilylation reaction of octa(hydrido)silsesquioxane with ω‐halo‐1‐alkenes and other unsaturated substrates allows attachment of 8 long‐chain functionalized alkyls on the cubic Si8O12 skeleton. Pt/C and H2PtCl6 have been adopted as the catalysts, the yields being 74–98% for compounds 2–9. For terminal alkenes, the hydrosilylation follows the anti‐Markonikov's rule. The morphological state of 2–9 ranges from viscous liquid to crystalline materials. The pyrolysis results indicate that 7, a material of hard spherical core and soft flexible shell, may likely act as nanometer‐size ball bearings up to more than 400 °C. The X‐ray structure of 9 reveals that the molecule is required to possess a center of symmetry crystallographically. The linear arms on 9, except for two of them, are virtually all‐trans in conformation, not counting the ω‐C‐Cl bond.
Flavone Glycosides from Strobilanthes Formosanus
Authors: Kao Kuo‐Ching , Ho Yu‐Ling , Lin I‐Hsin , Ho Li‐Kang , Chang Yuan‐Shiun 
Published: May 2015

AbstractTwo new flavone glycosides, 3′‐hydroxy‐5,7‐dimethoxyflavone 4′‐O‐β‐D‐apiofuranoside (1), and 5,7‐dimethoxyflavone 4′‐O‐[β‐D‐apiofuranosyl(1→5)‐ β‐D‐glucopyranoside] (2) along with four known compounds, 4′‐hydroxy‐5,7‐dimethoxyflavone (3), 2,6‐dimethoxy‐1,4‐benzoquinone (4), lupeol (5) and betulin (6) were isolated from the stem and roots of Strobilanthes formosanus. Their structures were elucidated on the basis of their spectroscopic evidence.
Enthalpy Change of Allosteric Transition in Human Haemoglobin A
Authors: Amire Olasoji A. , Masoudy J. , Saboury A. A. , Moosavi‐Movahedi A. A. , Ogunmola G. B. 
Published: May 2015

AbstractOxygen equilibria of haemoglobin were analysed according to a binding isotherm proposed by Amire (Bull. Chem. Soc. Jpn. 1994, 67, 7)1 to obtain the intrinsic oxygen association constants to the molecule. Two sets of binding sites in haemoglobin were identified, which were ascribed to R2 and T forms of the molecule. The average intrinsic association constants determined as a function of temperature gave a heat of oxygenation of‐76 ± 4 kJ mol−;1 (tetramer). A microcalorimetrically determined heat of deoxygenation of oxyhaemoglobin by dithionite gave −267 ± 10 kJ mol−1 (tetramer). From these results, the heat of allostery of −234 ± 24 kJ mol−1 for haemoglobin tetramer was obtained, yielding allosteric energy per salt bridge of‐29 ± 3 kJ. This result suggests that salt‐bridge may, in fact, be thermochemically equivalent to hydrogen bonds.
One Alkenylphenol and Steroids from the Aquatic Plant Monochoria Vaginalis
Authors: Row Lie‐Ching , Chen Chiu‐Ming , Ho Jiau‐Ching 
Published: May 2015

AbstractTwo new compounds have been isolated from the whole plant of Monochoria vaginalis and characterized as: (10Z)‐1‐(2,6‐dihydroxyphenyl)octadec‐10‐en‐1‐one (1) (20R, 24R)‐campest‐5‐ene‐3β, 4β‐diol (2) together with nine known ones. The structures of these compounds were elucidated on the basis of spectral data and chemical evidence.
Ultrasonic and Volumetric Studies of Molecular Interactions in Acetonitrile + 1‐Alkanol (C6, C8, C10) Binary Liquid Mixtures at Different Temperatures
Authors: Ali Anwar , Nain Anil Kumar , Abida  
Published: May 2015

AbstractThe densities, ρ, and ultrasonic speeds, u, have been measured in the binary liquid mixtures of acetonitrile (ACN) with 1‐hexanol, 1‐octanol and 1‐decanol, and in the pure components, as a function of composition at 25, 30, 35, 40 and 45 °C. The deviations in isentropic compressibility, Δκs, excess molar volume, VE, deviations in ultrasonic speed, Δu, apparent molar compressibility, Kϕ2, apparent molar volume, Vϕ2, partial molar compressibility,\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm \bar K}^\circ _{\phi,2} $\end{document}, and partial molar volume,\documentclass{article}\pagestyle{empty}\begin{document}$ {\rm \bar V}^\circ _2 $\end{document}, of 1‐alkanols in ACN have been calculated from the experimental data of densities and ultrasonic speeds. The variations of these parameters with composition of the mixtures indicate that the structure‐breaking effect dominates over that of the hydrogen‐bonding effect between unlike molecules, suggesting that ACN‐alkanol interaction is weaker than ACN‐ACN and alkanol‐alkanol interactions, and that the interaction (ACN‐alkanol) follows the order: 1‐hexanol > 1‐octanol > 1‐decanol. The excess molar volume data have been analysed by using Flory and Prigogine‐Flory‐Patterson theories. Further, the ultrasonic speeds in these mixtures were theoretically calculated with the help of several theories and empirical relations using the pure component data. The validity and relative merits of these theories and relations have been discussed.
Kinetic Spectrophotometric Determination of Ranitidine
Authors: Walash Mohammed Ibrahim , Sharaf‐El‐Din Mohie Khalid , Metwally Mohammed El‐Sayed , Shabana Mostafa Reda 
Published: May 2015

AbstractTwo spectrophotometric methods were developed for the determination of ranitidine. The first method was a kinetic spectrophotometric method based on the catalytic effect of ranitidine on the reaction between sodium azide and iodine in an aqueous solution. The calibration graph was linear from 4–24 μg/mL. The drug was determined by measuring the decrease in the absorbance of iodine at 348 nm using a fixed time method. The decrease in the absorbance after 1 minute from the initiation of the reaction was related to the concentration of drug. The detection limit of the procedure was 0.76 μg/mL. The proposed procedure was successfully utilized in the determination of the drug in pharmaceutical preparations with mean recovery in the range of 99.83 ‒ 101.16%.The second method is a colorimetric method, which depends on the measurement of absorbances of tris (o‐phenanthroline) iron(II) [method 2A] and tris (bipyridyl) iron(II) [method 2B] complexes at 512 nm. The complexes obeyed Beer's law over the concentration range of 2–16 μg/mL and 4–40 μg/mL for methods 2A and 2B, respectively. The developed method has been successfully applied for the determination of ranitidine in bulk drugs and pharmaceutical formulations. The common excipients and additives did not interfere in its determination.
Fast Multi‐residue Screening for 84 Pesticides in Tea by Gas Chromatography with Dual‐tower Auto‐sampler, Dual‐column and Dual Detectors
Authors: Li Hong‐Ping , Li Gwo‐Chen , Jen Jen‐Fon 
Published: May 2015

AbstractA fast multi‐residue screening method for determining pesticides in tea is described. Pesticides are extracted from tea with acetone and methylene chloride, then enriched and cleaned up with solid phase extraction (SPE) prior to gas chromatographic determination. The fast screening is achieved by a gas chromatograph system equipped with dual‐column, dual‐tower auto‐sampler and both electron capture detector (ECD) and flame photometric detector (FPD). Optimal conditions are investigated for the prospective pesticides including column selection, detection mode, the retention behaviors, quantitative calibration, as well as the recoveries and repeatability of pesticides from tea samples. Under the optimal conditions, with the FPD‐P detector accompanied CP‐SIL 13CB column, 48 pesticides can be separated well and detected within 38 min; and with a DB‐5 column, 35 ECD‐detectable pesticides can be separated and detected within 46 min. The recoveries of 84 pesticides in tea samples are 65–120% with 0.34–16% RSD for spiking 0.02–3.0 mg/kg standard species. Because of the thermal instability of most pesticides, direct cold extraction of pesticides from a tea sample is recommended. The proposed method provided a very fast and efficient procedure to screen 84 pesticides from a complicated tea sample matrix.
Facile Synthesis of (±)‐Parahigginone Methyl Ether and (±)‐Curcuphenol
Authors: Du Zhen‐Ting , Li An‐Pai , Peng Kun , Wu Tong‐Xing , Pan Xin‐Fu 
Published: May 2015

AbstractUsing Grinard coupling as a key step, a facile synthetic approach to (±)‐parahigginone methyl ether 1 and (±)‐curcuphenol 2 has been achieved by five steps with 42.3% and 58.6% overall yield, respectively.
New Approach to N‐substituted‐1,2,3,6‐tetrahydro‐pyridine‐4‐carbaldehyde, a Precursor for Synthesizing Aricept®, Isoguvacine, and Deethylibophyllidine
Authors: Tsai Min‐Ruei , Sun Pei‐Pei , Chang Meng‐Yang , Changa Nein‐Chen 
Published: May 2015

AbstractA new route towards the synthesis of N‐substituted‐4‐formylpiperidine using N‐benzyl or tryptaminyl‐sulfonylacetamide and α,β‐unsaturated ester as starting materials is described. Formal synthesis of Aricept®, deethylibophyllidine, and isoguvacine, which have potential biological activities, were synthesized via this strategy.
Kinetics and Mechanism of Oxidation of Chromium(III)‐guanosine 5‐Monophosphate Complex by Periodate
Authors: Ewais Hassan A. , Ahmed Samah A. , Abdel‐Khalek Ahmed A. 
Published: May 2015

AbstractThe kinetics of oxidation of the chromium(III)‐guanosine 5‐monophosphate complex, [CrIII(L)(H2O)4]3+(L = guanosine 5‐monophosphate) by periodate in aqueous solution to CrVI have been studied spectrophotometrically over the 25–45 °C range. The reaction is first order with respect to both [IO4−] and [CrIII], and increases with pH over the 2.38–3.68 range. Thermodynamic activation parameters have been calculated. It is proposed that electron transfer proceeds through an inner‐sphere mechanism via coordination of IO4− to chromium(III).