http://www.sciforum.net/conf/ecsoc-13 The 13th International Electronic Conference on Synthetic Organic Chemistry The 13th International Electronic Conference on Synthetic Organic Chemistry http://www.sciforum.net/presentation/253 Claudio Santi wrote: Concerning the topics of your communication I suggest to consider also this really close examples: Tiecco et al. Eur Joc 1999, 797 Landais Tet. Lett 1995, 2987 Landais Synlett 1995, 1191 Kahan JACS 1987, 109 “Organoselenium Chemistry: Modern Developments in Organic Synthesis”: Tiecco, M. Top. Curr. Chem. 2000, pag32 for asymmetric version 2009-11-11 2009-11-11T18:23:13Z http://www.sciforum.net/presentation/257 An AM1 semiempirical method (Gaussian 03) was used to perform molecular structure optimizations in gas phase of two tail-to-tail bile acid-based dimers by an isophthalic acid bridge. The method was also used to study the interactions with the potential guest ibuprofen with the idea of applicative results. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/258 The binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of complexes between adamantyl derivatives and a β-cyclodextrin dimer. It is concluded that, within experimental error, the two cyclodextrin residues in the dimer behave independent to each other when complexing the adamantyl derivatives. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/231 Cellulose was modified with citric acid in high temperature. Investigations of its absorption of heavy metal ions (such as Pb2+ and Cd2+) showed that modified cellulose in conditions 120°C and 12 h and in mass ratio of cellulose :citric acid=1:3 had highest absorption capacity. Absorption capacity of modified cellulose increased in accordance with increase of concentrations of ions. Structure of modified cellulose was confirmed by IR spectra and SEM pictures. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/259 The binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of inclusion complexes between 3α,7α,12α- trihydroxy-5β-cholan-24-amine, C24NH2, and β-cyclodextrin and γ-cyclodextrin. The stoichiometry of both complexes is 1:1 in agreement with previously reported results for other trihydroxy bile salts. The equilibrium constant values for the formation of the inclusion complex are similar as well. The structure of the C24NH2/γ-cyclodextrin complex was studied by ROESY experiments. These results suggest that B, C and Drings of the steroid skeleton, as well as the side chain, interact with the cyclodextrin cavity, while the A ring of the steroid nucleus remains outside the cavity. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/256 New dimeric steroid-based surfactants derived from 3α,7α,12α-trihydroxy-5β- cholan-24-amine (steroid residue) and isophthalic acid, 5,5'-biisobenzofuran-1,1',3,3'- carboxylic acid and succinic acid (spacers) were synthesized and structurally characterized by NMR techniques. The first spacer was also employed to synthesize the dimer corresponding to the 3α,12α-dihydroxy-5β-cholan-24-amine residue. In all cases the steroid residues are tail-to-tail linked through amide bonds with the spacers. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/229 Liquid crystal monomers and polymers containing fluorinated alkyl chain have been prepared. The polymerization initiated by [Rh(nbd)Cl]2 has afforded the products in moderate to high yields. The molecular weight of polymers has been measured with gel permeation chromatography (GPC), the results show that the transition metal catalyst in THF/Et3N solvent system gives the best results for the polymerization. Monomers and polymers are characterized by IR and 1HNMR, and the liquid crystalline properties are evaluated by using POM, DSC and TGA. The results show that the monomers with fluorinated chain and polymers show SmA phase. The fluorinated polymers possess higher clearing points and broader mesophases than the alkyl chain polymers. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/230 Cellulose from cotton was modified through reaction of sodium carboxymethyl cellulose (NaCMC) with diethanolamine and an epichlorohydrinethylendiamine system in molar ratios of 1:1.5:1.5; 1:2:2; 1:3:3 and 1:4:4, respectively. The modification with epichlorohydrin-ethylendiamine was carried out in two steps: in the first step, NaCMC was reacted with epichlorohydrin, and in the second step, oxiran-2-ylmethyl carboxy-methylcellulose reacted with ethylendiamine gave cellulose-g-epichlorohydrin/ ethylendiamine. The surfaces of the obtained products have been investigated by SEM images. Their adsorption capability for Pb2+, Cd2+ and Mn2+ ions (at concentrations of 10,000, 2,000, 1,000, 600, 400 and 100 ppm) have been investigated. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/232 Cellulose was modified by reaction with (N‐butyl‐N‐chloropropyl‐N,N‐dimethyl) ammonium bromide (BCDMAB). The optimum reaction conditions were as follows: temperature 55°C, reaction time 3.2 h and mass ratio of cellulose:BCDMAB=1:2.5. Equilibrium adsorption capacity of modified cellulose for arsenate ion has been estimated. It’s shown that this capacity increased with concentrations of arsenate ion. Structure of modified cellulose was confirmed by IR and SEM images. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/233 In this paper we wish to report our results on investigation of the kind and the concentration of the hydroperoxides initiators on the polymerization rate. Four kinds of peroxides with different concentration have been examined such as), tert-butyl hydroperoxide (TBHP), cumene hydroperoxide (CHP), methyl ethyl ketone hydroperoxide (MEKP) and benzoyl peroxide (BP). Results show that the rate of the reaction depends on the type and percentage of initiators. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/234 Cyclodextrins (CDs) are natural‐occurring oligomers with a hydrophobic cavity which allow them to form inclusion complexes in water with a variety of organic molecules. These complexes are generally stabilized by van der Waals and hydrophobic interactions, although specific host‐guest interactions can also play an important role.[1] In addition, geometrical and orientational requirements of both the guest and the host may control the association process, whereas the dissociation rate is determined by the strength of the interactions.[2] Therefore, a change of the cavity size or the rigidity of the host has dramatic effects on both the association and the dissociation rate constants and in consequence on the stability of the complexes.[3] Moreover, for a certain guest, stoichiometry and geometry of the inclusion complexes may also be much dependent on the host cavity size.[4] In this work we study the effects of CD cavity size on the stoichiometry, stability and structure of the complexes formed between the synthetic organic probe Dapoxyl and three natural cyclodextrins (α‐CD, β‐CD and γ‐CD) differing in the size of their inner cavity, using steady‐state and time‐resolved fluorescence techniques. The ditopic structure of this fluorophore together with its high sensitivity to the surroundings make it a useful model molecule to study the geometrical effects on the complexation. Complexation provokes strong changes in the fluorescent properties of Dapoxyl with a large blue shift of its emission spectrum and a great increase of the fluorescence quantum yield. The differences observed for the three CDs regarding stoichiometry, stability and fluorescence properties of the complexes are discussed on the basis of a size‐selective complexation of the Dapoxyl. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/254 In this study the extract of the Iraqi herb Avena sativa L. (Gramineae) was done by using of 70% ethanol as a solvent, then study the antimicrobil activity of the extract (in vitro) on gram positive bacteria (Staphylococcus aureus), and gram negative bacteria (E. coli, Proteus vulgaris, Pseudomonas aerugiuosa, and Klebsiella), A. niger, and Candida extrat showed considerable activity against all bacteria and fungal. 2009-11-05 2009-11-05T00:00:00Z http://www.sciforum.net/presentation/253   Studies on the stereoselective phenylselenoetherification of (Z)- and (E)-hex-4-en-ols is described. (Z)-Alkenol is envisage to facilitate the 5-exo favored cyclization, while (E)-izomer facilitate the 6-endo favored cyclization. Diastereomeric ratio of the cyclic products depends on counterion and reaction temperature. We found that external additives, such as pyridine and some Lewis acids coordinating to the electrophilic species are used to control the course of cyclizations with high degrees of efficiency and improve the level of stereoinduction. The course of cyclization can be directed as desired by the choice of the electrophile and the additives used in the reaction. 2009-11-04 2009-11-04T00:00:00Z http://www.sciforum.net/presentation/240 Thiiranium heterocycles play an important role in a biocatalytic processes of cells. Usually formation of thiiranium ions are known to proceed by the electrophilic additions of sulfenylhalides to a substituted olefins. We focused attention on the electrophilic addition reaction of methylsulfenyl chloride to the propene. In our work this reaction have been modeled using Ab-initio methods at the MP2/6-31+G(d,f) level of theory to look into the mechanism of the reaction and to explain how the regioselectivity of the reaction is controlled. Calculations of the intrinsic reaction coordinate on the minimum energy pathway revealed the stepwise mechanism for the addition reaction. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/250 Complexes formed by anions and substituted molecular bowls were studied by means of computational calculations with density functional theory methods. An empirical dispersion term was included to correct the well known flaws of common functionals to describe dispersion interactions. The modified bowls consisted of corannulene molecules substituted with five or ten F, Cl, or CN units, whereas Cl-, Br- and BF4 - where the anions considered. Substitution with F, Cl and CN produces an inversion of the molecular electrostatic potential of the bowls, which become positive over the two faces of the bowl, therefore interacting favorably with anions. Three different structures were found for each of the complexes, corresponding to one arrangement with the anion interacting with the concave side of the bowl and two different arrangements with the anions interacting with the convex side of the bowl. The strength of the interaction roughly follows the values of molecular electrostatic potential, being more stable as more positive is the potential. However, the role of dispersion arises as essential for having a correct order of stabilities. In fact, when dispersion is included, most complexes are more stable by the concave face, where the closer proximity of the atoms allows for a larger dispersion effect. Also, it is dispersion which makes the complexes formed with a larger anion as BF4 - as stable as those formed with Cl- or Br-. The results suggest the possibility of employing these substituted molecular bowls as receptors for anions with a preferential concave complexation, specially for structured anions where dispersion effects will be larger. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/251 The dependences of differential spectral parameters (Δδi H) in spectra NMR 1H of monosubstituted benzenes C6H5X on substituent constants (σ) were investigated. The best correlation was founded for set of para-Brown's constants (σ+). 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/241 Optimized geometry and the corresponding electronic structure and thermodynamic properties of cyclopropylmethoxychlorocarbene (cpmcc), 3-cyclopropylmethoxy-3- chlorodiazirine and their -N2 and –CO elimination and consequent rearrangement products, cyclopropylmethoxyfluorocarbene (cpmfc), 3-cyclopropylmethoxy-3-fluorodiazirine and its transition state and cyclopropylmethoxyhydrocarbene (cpmhc), 3-cyclopropylmethoxy-3- hydrodiazirine and its transition state have been calculated using ab initio methods DFTB3LYP with 6-311++G** basis set. The effect of substitutions was investigated on thermodynamic properties of conversion of 3-cyclopropylmethoxy-3-chloro (flouro or hydro) diazirine to different products. Also, nuclear magnetic resonance chemical shifts have been calculated for reactant, transition state and product with various substitutions. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/249 not available 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/248 A comprehensive MP2/6-311+G(d,p) and B3LYP/6-311+G(d,p) study of the aromatic character of phospholes, Pn(CH)4-nPH with n = 0-4 was conducted. For this purpose, the structures for these compounds were optimized at both theoretical levels and different magnetic properties (magnetic susceptibility, χ, magnetic susceptibility anisotropy, χanis, and the nucleus-independent chemical shifts, NICS) were evaluated. For comparison, these magnetic properties were also calculated in the optimized structures with planarity constraints. We have also applied the ACID (anisotropy of the current-induced density) method in this analysis. The main conclusions are the aromatic character of these compounds, the relationship between aromaticity and planarity and the importance of other factors in this aromaticity. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/244 The present communication-reports a study on the variation of some structural and electronic properties related with electron conduction for the series of compounds represented by the formula Ph-(C2+nN4-nHn)-Ph, n=0-4. Properties such as planarity, aromaticity, band gap, and adiabatic electron affinity were analyzed from a theoretical perspective as a function of the number of nitrogen atoms in the molecular structure. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/245 Different partial charge distribution methodologies (Mulliken, Löwdin, Hirshfeld, Natural Population Analysis, Merz–Kollman Electrostatic Potential) were used for charge determination in manganese and zinc Schiff base complexes that are isostructural analogs. Chemical reliable clusters were chosen on the ground of experimental X-ray data. Packing effect on charges was found to be negligible. All calculation employed non hybrid ab-initio GGA PBE density functional method with conjunction of different basis sets to show small influence of basis set incompleteness. On the ground of chemical bonding theory Hishfeld partial charge definition was found to be most reliable in different situation – different spin states, H–bonding, molecular crystal and clusters. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/246 The reaction of substituted furans a-c and Danishefsky's diene which yield 5-benzofuranol derivatives has been studied using the hardness, the polarizability and the electrophilicity of the corresponding D-A primary adducts as global reactivity indexes. The main objective of this work is to investigate the power of these global indexes in predicting the major regioisomer. It has been demonstrated that both the hardness as well as the electrophilicity power of the adducts are appropriate descriptors for predicting the major product of the reactions at least in the cases study here. The maximum hardness principle and the minimun electropilicity principle are obeyed in these regiospecific Diels–Alder reactions. The stereoselectivity of the D-A reactions has also been studied. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/247 not available 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/243 The reaction pathways for the addition of OH- ion to cyclobutane-1,2-dione I are calculated by density functional theory procedures [B3LYP/6-31+G(d,p)]. Initially, I undergoes attack of the nucleophile, in this case OH- ion, at one of the two equivalent carbonyl carbon atoms leading to formation of a tetrahedral intermediate followed by rearrangement reactions. Density functional theory method (B3LYP) with basis set (6-31+G (d,p) are used to investigate the addition of OH- (hydrated) to the hydrated species of I. The most likely pathway consists in a ring contraction of the tetrahedral intermediate, formed from addition of OH– to I, leading to 1-cyclopropan-1-carboxylic acid. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/237 Classification algorithms are proposed based on information entropy. It is studied the molecular classification of anti-human immunodeficiency virus thiocarbamates. The 62 thiocarbamates (TCs) are classified by their structural chemical properties. Many classification algorithms are based on information entropy. An excessive number of results appear compatible with the data and suffer combinatorial explosion. However, after the equipartition conjecture one has a selection criterion. According to this conjecture, the best configuration of a flowsheet is that in which entropy production is most uniformly distributed. The structural elements of an inhibitor can be ranked according to their inhibitory activity in the order: B1/2 > R > R1 > R2 substitution. In TC 17, B1/2 = B1, R = 4-CH3 and R1 = R2 = H; its associated vector is unary. The TC 17 is selected as a reference. In some TCs B1/2 = B1, in some others B1/2 = B2. The analysis is in qualitative agreement with other classification taken as good based on k-means clustering. Program MolClas is a simple, reliable, efficient and fast procedure for molecular classification, based on the equipartition conjecture of entropy production. The structural elements allow the periodic classification of the TCs. A validation is performed with an external property, cytoprotection activity, not used in the development of the table. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/238 Optimized geometry and the corresponding electronic structure, vibrational frequencies and thermodynamic properties of cyclopropylmethoxychlorocarbene (cpmcc), 3- cyclopropylmethoxy-3-chlorodiazirine have been calculated using ab initio methods DFTB3LYP with 6-311++G** basis set. Results show that cpmcc is transition state with a first order TS saddle point. The displacement matrix of the negative mode of vibration of the TS specie shows that the reaction path follows in the direction of the elimination of the CO group which is consistent with the mechanism proposed upon experimental data. Calculations were also carried out for reactants and products at the same levels of theory. Nuclear quadrupole coupling constants (NQCC), χ, and asymmetry parameter, η, of the 2H, 35Cl nuclei have been calculated for reactants, transition states and products. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/239 There are many enantioselective reactions of organolithium to imines described in a very different conditions. In this work, we constructed from experimental outcomes large Complex Network, which may be used to perform datamining and quantitatively describe changes in reaction variables that determine the enantiomeric excess and configuration of the stereogenic centre formed in product. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/252 An efficient and controlled Pd−catalyzed synthesis of attached-ring bis(dihydropyran) fused cyclobutenes via alkyne dimerization followed by double [2+2] cyclization of the resulting bis(allenyne) in a domino sequence has been accomplished. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/214 The preparation of 3-O-methyl-1,2-O-(S)-trichloroethylidene-α-D-xylo-furanuronic acid and 3-O-methyl-1,2-O-(R)-trichloroethylidene-α-D-xylo-furanuronic acid starting from β-chloralose and α-chloralose are described. All new products were characterized by 1H NMR, 13C NMR and FTIR. Antibacterial potency of the product (6b) was determined in term of inhibition zone diameter and results showed that this compound showed moderate activity against the tested microorganisms with inhibition zones ranging from 10 to 22 mm. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/224 Chalcones and their heterocyclic analogues are known to possess a broad spectrum of biological effects. The present study is devoted to the synthesis of 3,4- Dimethoxy-2’-Hydroxy-5’-methyl chalcone and its derived products i.e. flavanone, flavonol, flavone, aurone, isoxazoline, chalconeimine and acetoxy chalcone. These newly synthesized compounds were screened for their antibacterial and anti-fungal activities. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/235 Quantitative structure-affinity relationships were applied to a series of 27 disperse dyes by partial least squares (PLS) analysis and compared to previously published MLR (multiple linear regression), MTD (minimum steric difference) and CoMFA (comparative molecular field analysis) results. Calculated 0D, 1D and 2D structural dye features were correlated to their affinity for cellulose by PLS. A robust model (R2X(cum) = 0.617, R2Y(cum) = 0.959, Q2(cum) = 0.953) with predictive power was obtained from these correlations. Better statistical results were achieved in the PLS model, in comparison to the previous MLR, MTD and CoMFA results, but the three-dimensional models obtained by CoMFA gave more information on the dye-cellulose specific interactions. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/226 Enantiomerically pure substituted 1,4-dioxanes have been prepared from vinyl phenyl selenones and the commercially available enantiopure 1,2-diols in the presence of sodium hydride. This simple and novel one step procedure is an example of the Michael initiated ring closure reactions (MIRC) and involves a conjugate addition of the alkoxide anions derived from the 1,2-diols to the vinyl phenyl selenones. The carbanions thus generated then suffer a proton transfer to give the alkoxide ions which effect the intramolecular displacement of the PhSeO2 group affording the substituted 1,4-dioxanes as the result of a ring closure reaction. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/227 3 equivalents of ammonium persulfate in a 3:1 mixture of MeCN and water slowly convert alkynes into the corresponding 1,2-dicarbonyl compounds. The oxidation rate is enhanced by the presence of diphenyl diselenide that form in situ the electrophilic PhSeOSO3H able to promote a “one pot” hydroxyselenenyilation-deselenenylation reaction. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/236 not available 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/225 A great deal of work has been done on the synthesis of oxazolones. We have obtained 5(4H)-oxazolones by condensing anthracene-10-carbaldehyde & furan-2- carbaldehyde with a number of substituted benzoyl glycines, and tried to design new and effective anti-bacterial agents. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/228 Microwave assisted formation of C-Te bonds is applied to the preparation of p-methoxyphenyltellurium trichloride in a fast, direct and simple way. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/215 Objectives: NL197 is a derivative from 4(3H)- quinazolinon and it has been reported to possess central and peripheral effect as well as learning and memory enhancing effect in vivo test. In this present study, we focus on the anticonvulsant effect of NL197 on pentylentetrazol or strychnine induced- seizure mice. Methods: The anticonvulsive activity of NL197 is investigated in experimental seizure models in mice inducing by chemo-convulsant such as pentylenetetrazole (PTZ) 100 mg/kg, SC or strychnine (STN) 2 mg/kg, SC. The anticonvulsive potent of NL197 is also made comparison with that of diazepam 5 mg/kg, PO. Results: In PTZ induced- seizure model, anticonvulsant activity of NL197 NL was determined at the dose of 50 mg/kg, 73.2 mg/kg, and 100 mg/kg. In strychnine induced- seizure model, NL 197 had anticonvulsant activity at dose of 50mg/kg, 73.2mg/kg. No effect was determined with NL197 at dose of 37mg/kg. The protective potent of NL197 againsts PTZ- or STN induced seizures is equal to that of diazepam 5mg/kg, PO at the dose of 73.2 mg/kg and 50 mg/kg, SC, respectively. Conclusions: These present results provided evidence that NL197 has potential anticonvulsant activity in pentylentetrazol or strychnine induced-seizure model in mice as well as diazepam, a standard antiepileptic drug. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/213 This paper describes the unexpected outcome of the lithium hydroxide hydrolysis of the NXO-compound Boc-NPheO-OMe (1) and an independent synthesis of the product thus obtained, as well as the synthesis of 1,2,5 triazine-3,4,7- trione from 1. We submit these results for discussion to ECSOC 13 and hope to receive constructive comments and suggestions. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/212 A series of halogen containing 1,4-naphthoquinon derivatives (1-4,5a-f) were synthesized and studied for their antifungal activities against C. albicans ATCC10231, C. albicans 955, T. mentagrophytes and M. gypseum. The results indicate that compound 2-hydroxy-3-chloro-1,4-naphthoquinone (2), 2-(N-acetyl)- acetamido-3-chloro- 1,4-napthoquinone (3) and 2-(N-acetyl)-acetamido-3-chloro- 1,4- napthoquinone (4) have potent antifungal activity. Among these promising antifungal candidates, 2 and 4 showed better activity than that of clinically antifungal drug clotrimazole (MIC = 8 μg/ml) with MIC = 1 μg/ml and 4 μg/ml, respectively against C.albicans ATCC10231. Compound 2 also exhibited an extremely potent activity (MIC = 0.25 μg/ml) against C.albicans 955 strain compared with clotrimazole (MIC = 16 μg/ml). Structure and activity relationship (SAR) study demonstrated that replacing of 3-position in 1,4- naphthoquinon by a Cl group is essential for antifungal activity. Meanwhile, antifungal activity was decreased considerably when the hydrogen atom at position-2 in naphthoquinone structure were replaced by a bulky group (e.g. diacetyl of phenyl group). 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/200 A combinatorial library of alpha ketoamines was generated by the Ugi four component reaction on tertiary carboxylic acid. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/221 The present work shows the syntheses, characterizations and investigations of the thermal-oxidative properties by TG-DTG of two phosphorus compounds derived from Cashew Nut Shell Liquid (CNSL). The phosphorus compounds obtained show significant thermal stability resistance: Ti (compound 1, main degradation step) = 202 °C and Ti (compound 2) = 231 °C. The degradation of lubricant commences at 91 °C, and after synthesized compounds incorporation, the degradation commences at 152 and 156 °C, respectively. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/220 With the aim to find out the structural features for the MAO inhibitory activity and selectivity, in the present communication we report the design, synthesis and pharmacological evaluation of a new series of 8-bromo-6-methyl-3-phenylcoumarin derivatives without substituent and with different number of methoxy substituent in the 3-phenyl ring. The substituent in this new scaffold was introduced in the 3’, 4’ and/or 5’ positions of the 3-phenyl ring of the coumarin moiety. The synthesized compounds 3-6 were evaluated as MAO A and B inhibitors using R-(-)-deprenyl (selegiline) and Iproniazide as reference inhibitors, showing, most of them, MAO-B inhibitory activities in the nanomolar range. Compounds 3 (11.05±0.81 nM), 4 (3.23±0.49 nM) and 5 (7.12±0.01 nM) show higher activity than selegiline (IC50 = 19.60 nM), and high MAO-B selectivity with 9,050- fold, 30,960-fold and 14,045-fold inhibition levels, with respect to the MAO-A isoform. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/223 We report the improved synthesis of the antiviral 6-fluoro-3-hydroxy-pyrazine-2-carboxamide (T-705). 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/216 Background: Abelmoschus esculentus L. Malvaceae is used for a long time as a daily food in many countries because of its nourishing components. Extracts from Abelmoschus esculentus have been known to ameliorate not only hyperglycemia but also hyperlipidemia in diabetic mice induced by alloxan and streptozocin. However, its hypolipidemic activity has not yet been studied clearly. Objective: Hypolipidemic activity of the extracts from total plant by dichloromethan (AE1), methanol (AE2) and from fruit by dichloromethan (AE3) and methanol (AE4) was studied and compared to that of simvastatin (Zocor®). Methods: Hyperlipidemia in mice was induced by single intra-peritoneal injection of 300 mg/kg of Tyloxapol. Studied extracts were orally administered at dose equivalent to 30g of dry extract/kg immediately after Tyloxapol injection. Results: Cholesterol levels decreased 56.45(percent), 55.65(percent), 41.13(percent), 40.50(percent) and 53.63(percent) respectively in groups orally administered AE1, AE2, AE3, AE4 and simvastatin as compared to the tyloxapol injected group. Triglycerids levels in treated groups had no significant difference as compared to simvastatine group except methanolic extract from fruit (AE4) administered group. Conclusion: Abelmoschus esculentus is also useful in diminishing cholesterol and triglycerids levels in hyperlipidemic mice. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/218 Several fluorescent benzo[a]phenoxazinium chlorides possessing undecylamino chains with non-functionalised (methyl group) or functionalised terminals (hydroxyl, carboxylic acid and the ester group) as substituents at the 5-position of the heterocycles were used in photophysical studies with DNA. It was found that the functionalised terminal has a dramatic influence on the type of interaction with the hydroxyl group promoting intercalation, while the ester group promotes groove binding. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/219 A series of five chrysin derivatives was synthesized and examinated for their antiinflammatory activities. The in vivo anti-inflammatory activity of synthetic compounds was carried out using the model of carrageenan induced mice paw edema. The results showed that methylation of 5,7- dihydroxyl groups of chrysin resulted to increase the in vivo bioactivity in comparison with the corresponding chrysin derivatives having two free hydroxyl groups. The introduction two halide groups into B ring at 6 and 8 positions of chrysin did not to improve any significant increase positive effect on the in vivo bioactivity. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/201 Polymorphism of active pharmaceutical ingredients (APIs) gets increasing attention as an important physico-chemical parameter influencing bioavailability and stability of API and pharmaceuticals. Co-crystals of API with common pharmaceutical excipients become very important as a tool to tune up solubility and absorption. Bisphosphonates (e.g. alendronate, risedronate, ibandronate) are widely used in clinical practice. They are indicated for the treatment and prevention of osteoporosis. They are powerful inhibitors of bone resorption, but their gastrointestinal adsorption is only about 1(percent) due to their high hydrophilicity. Some experiments were designed to prepare co-crystals of ibandronate. In the present study various mixtures of ibandronate and excipients were prepared. All the prepared mixtures (solid compounds) and/or new entities were analyzed by means of FT-NIR spectroscopy. The absorption of potential new co-crystals was investigated by means of the PAMPA experiments. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/217 Five benzo[a]phenoxazinium dyes containing alkyl chains with twenty carbon atoms on 5- or 9-positions of the tetracyclic ring were efficiently synthesised and characterised by UV/Visible and fluorescence spectroscopy. The absorption and emission maxima in ethanol lie in the range 627-641 nm and 645-676 nm, respectively, with quantum yields varying from 0.14 to 0.38. Preliminary photophysical studies in zwitterionic (2,3-bis(palmitoyloxy)propyl 2- (trimethylammonio)ethyl phosphate, DPPC) and cationic (N,N-dimethyl-Noctadecyloctadecan- 1-aminium bromide, DODAB) vesicles are reported showing that these molecules are able to detect the gel to liquid-crystalline lipid phase transition through variations either in H-aggregation extent or in an acid-base equilibrium. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/209 The synthesis of a new disazo dyes containing 4,4’-diaminostilbene-2,2’-disulfonic acid as middle component is presented. The synthesized dye was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and HPLC technique. The structure was elucidated by FT/IR and 13CNMR spectroscopy. The colouristic evaluation of the synthesized dye indicates that this dye could be ranged as a direct dye, suitable for application on cellulosic substrates. Further, an in vivo imagistic skin study was performed in order to evaluate the individual human skin tolerance for this new disazo dye. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/210 Skin penetration enhancers are used to allow formulation of transdermal delivery systems for drugs that are otherwise insufficiently skin-permeable. The series of seven esters of 6-(2,5-dioxopyrrolidin-1-yl)-2-(morpholin-4-yl)hexanoic acid as potential transdermal penetration enhancers was formed by multistep synthesis. The general synthetic approach of all newly synthesized compounds is presented. Structure confirmation of all generated compounds was accomplished by IR, 1H, 13C NMR and HR-MS spectroscopy. All the prepared compounds were analyzed using RP-HPLC method for the lipophilicity measurement and their lipophilicity (log k) was determined. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/202 5-BromoVerongamine has been successfully synthesized in 2 steps in good yield from readily available starting materials. Structural elucidation has been confirmed through direct comparison with spectroscopic data of isolated natural product. 5-BromoVerongamine has been shown to have moderate bacteriacidal activity against MRSA. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/222 Background: Epilepsy is one of the most common neurological disorders, affecting about 1% of the world’s population. The currently available anticonvulsants are effective in reducing the severity and number of seizures in less than 70% of patients. Moreover, their usage is associated with undesirable side effects ranging from cosmetic (gingival hyperplasia) to life threatening (hepatotoxicity, megaloblastic anemia). Therefore, the continued search for the safer and more effective antiepileptic drugs is urgently necessary. Literature survey reveals that various derivatives of quinazolinone, thienopyrimidine and pyridopyrimidine shown very promising anticonvulsant activity along with other pharmacological activities. So we concentrate our aim to screen novel quinazolinone fused with thienopyrimidine/pyridopyrimidine. Result: A novel series of 1,2,9,11-tetrasubstituted-7H-thieno[2',3':4,5]pyrimido[6,1-b]-quinazolin-7-ones (1–15) and 1,3,10,12- tetrasubstituted-8H-pyrido[2',3':4,5]pyrimido[6,1-b]quinazolin-8-ones (16-36) were synthesized by reported method. The anticonvulsant activity of all the new compounds (1-15 and 16-36) was evaluated against Maximum Electroshock (MES) induced seizures and against subcutaneous pentylenetetrazole (scPTZ) induced seizures model in mice. The neurotoxicity was assessed using the Rotorod procedure. All the compounds tested were administered intraperitoneally at a various dose levels ranging from 15-175 mg/Kg body weight and the median toxic dose (TD50) and the protection index (PI) values were determined. All test compounds exhibited good activity. The structure–activity relationships based on the results obtained for these series were also studied. Conclusion: The present study indicates that fused quinazolinones shown very good anticonvulsant agents. In both series, electronwithdrawing substitutions showed more activity. Among all the tested compounds, 10,12-dibromo-1-(4-chloro-phenyl)-3-(4-tolyl)- 8H-pyrido[2’,3’:4,5]pyrimido[6,1-b]quinazolin-8-one 29 and 10,12-dibromo-3-(4-chloro-phenyl)-1-phenyl-8H-pyrido[2’,3’:4,5] pyrimido[6,1-b]quinazolin-8-one 25 were found to be most potent. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/208 A library of 19 novel 4-(4-phenylpiperazine-1-yl)benzamidines has been synthesized and evaluated in vitro against Pneumocystis carinii. Among these compounds, N-ethyl and Nhexyl 4-(4-phenylpiperazine-1-yl)benzamidines emerged as the most promising compounds with inhibition percentages at 0.1μg/ml of 61(percent) and 56(percent) respectively. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/211 A concise approach towards trisubstituted optically active azetidines, including a study of the scope and limitations of the synthetic sequence, is reported. The synthesis comprises the L-proline organocatalyzed three component reaction between substituted benzaldehydes, anilines and an enolizable aldehyde, followed by the in situ reduction of the resulting β-aminoaldehydes to the corresponding β-aminoalcohols and final intramolecular cyclization of the latter by way of the intermediate tosylates. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/204 In this study, a series of five ring-substituted 2-styrylquinazolin-4(3H)-one and five ring-substituted 4-chloro-2-styrylquinazoline derivatives were prepared. The procedures for synthesis of the compounds are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains. Several compounds showed biological activity comparable with or higher than the standard isoniazid. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed, as well as their structure-activity relationships (SAR). 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/203 The association constants Kb of three receptors (I-III), designed to have both enhanced hydrogen bonding donor strength and conformational preorganization, with biotin analogues (1-5) are reported. 1H-NMR titrations using the saturation conditions have been employed to determine the association constants Kb. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/205 Experimental–theoretical works explain the energetics of the packing of a virus with deoxyribonucleic acid (DNA) and the injection of the DNA into a cell. Washing has a limited effect on enteric viruses in food. Alternatives are needed to acidic matrixes. Feline calicivirus is not a good control model. Various protocols are being prepared. New challenges are: new methods, impact of new technologies, significance of detection, new virus models and emergent–re-emergent viruses. The forthcoming step is to re-develop the virus to direct it and contain the most common contaminants in food: salmonella, listeria, staphylococcus and Mycobacterium tuberculosis. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/207 This study describes a promising one-pot synthesis of [2-(5-benzyl-4-phenyl-4H- [1,2,4]triazol-3-thio)-acetyl]-amino acid methyl esters 6a-h and dipeptides 10a-e were successfully synthesized starting from amino acid esters 5a-h, 9a-e and azides 4, 8a,b respectively. On the other hand, azide 4 underwent Curtius rearrangement to the corresponding isocyanate which subsequently reacted with selected aliphatic and/or aniline derivatives to give the corresponding urea derivatives 11 and 12a, b. Also reaction of isocyanate with secondary amines gave amide derivatives 13a, b. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/206 The synthesis and the physicochemical characterization of a new contrast agent for magnetic resonance imaging (MRI), Gd-C4-thyroxin-DTPA, which has a high affinity for human serum albumin (HSA), are reported. The results show that this chelate is characterized by a relatively high relaxivity, which increases moreover with the concentration. This reflects an aggregation of the molecules in solution. It is also characterized by a better stability versus the transmetallation with the zinc ion than the parent compound, the Gd-DTPA (Magnevist®, Bayer Healthcare). The study of its interaction with human serum albumin was performed by the proton relaxometry technique, which has revealed a relatively high affinity (Ka of the order of 10000 M-1, with 2 binding sites). Finally, competition experiments with ibuprofen and salicylate, of which the binding sites on HSA are known, were performed by the NMR diffusometry method. The results suggest that the chelate shares one of the binding site of ibuprofen. 2009-11-01 2009-11-01T00:00:00Z http://www.sciforum.net/presentation/196 We describe herein a novel synthetical application of shikimic acid, which consist of its transformation into (3R,4S,5R,7S)-7-(hydroxymethyl)azepane-3,4,5-triol. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/199 Evaluation of a new proton sponge, bis-1,1,8,8-(tetramethylguanidino)naphtalene (TMGN), in substituted phenols O-alkylation by methyl iodide in DMF has been studied. Kinetic measurements were performed in N,N-dimethylformamide-d7 and followed by 1H NMR using stoichiometric amounts of reagents. Plot of the results shows that the reaction follows an almost perfect second order rate law. However the Hammett plots for substituted phenols are not linear but bell shaped. In order to separate the deprotonation and alkylation contribution to the kinetics, deprotonation of phenols by TMGN has been investigated by quantitative 13C NMR. By combining these data a linear Hammett plot with a negative slope was obtained for the alkylation step and substituted phenol acidity constants in DMF, not accessible by NMR measurements, were determined which are in agreement with literature data. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/198 A new proton sponge 1,8-bis(tetramethylguanidino)naphthalene (TMGN) was utilized for the alkylation of benzoic acid by iodomethane in a continuous flow microsystem. Using this set-up, kinetics of the reaction was determined in different mixing strategies and the Hammett reaction constant was measured. Good performance and efficiency of this procedure were confirmed through several preparative studies. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/197 A one- pot three-component reaction of 2-aminobenzothiazole, 2-naphthol, and aldehydes has efficiently been carried out in the presence of Wells-Dawson heteropolyacid (H6P2W18O62 _ 24H2O) in water at 60 °C to form the corresponding 2'-aminobenzothiazolomethylnaphthols in high yields. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/194 It was found that tetraethylammonium hydroxide reacts with N-hydroxyphthalimide as a nucleophile rather than a base to afford tetraethylammonium 2-(hydroxycarbamoyl)benzoate (TEAHCB). The TEAHCB was found to be able to efficiently catalyze the cyanosilylation of a wide range of carbonyl compounds as a bifunctional organocatalyst at very low catalyst loading (0.2 mol(percent)). 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/191 The first hydroxilated series of coumarin-chalcone derivatives has been synthesize starting from the corresponding salicyl aldehyde and β-ketoester precursors by a Knoevenagel reaction in order to obtain the methoxy derivatives which have been further hydrolyzed with a Lewis acid. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/190 2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine (H3L) was obtained with high purity by Schiff’s condensation between 5-bromosalicyaldehyde and triethylenetetramine. Its recrystallisation in methanol yields single crystals suitable for X-ray diffraction studies. H3L crystallises in the monoclinic system, space group P21/c, with a = 21.641(3) Å, b = 11.1217(14) Å, c = 11.4156(15) Å and β = 90.016 º. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/192 Phase transfer catalysis (PTC) is an important modern synthetic method where reagents are located in different phases. Generally, it is transfer of inorganic reagent (base or nucleophile) from aqueous medium or solid phase to organic phase. Current catalysts for „classic” PTC are –onium salts (N, P, S), macrocyclic polyesters (crown-ethers), aza- -macrobicyclic ethers (cryptands), polyethylenglycols (PEGs) and their dimethylethers. Both in laboratory and industry, the most widely used catalysts are ammonium salts for their good price and availability. The other trend which is implementing within the frame of „Chemistry for sustainable development” are supported catalysts. Generally catalyst is bound on inorganic or organic polymer support and the system is insoluble in water and organic solvents as well. Supported catalyst can be easily separated from the reaction mixture and it can be reused again. Piperazine (A) as secondary cyclic 1,4-diamine offers two functional centers on its nitrogen atoms – one for preparation of quaternary catalytical place and second for immobilization on solid support, organic polymer. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/193 A novel approach based on combinations of various water compatible Lewis acids and L-proline cocatalysts has been evaluated for the direct asymmetric aldol reaction. From this screening zinc (II) chloride salts lead to the highest stereoselectivities. Optimized catalytic conditions (Catalytic system : L-proline : 20 (percent) / ZnCl2 : 10 (percent) - Solvent mixture : DMSO/H2O – 8 : 2) give anti aldol product with improved enantioselectivity (>99 (percent) e.e.) compared to a moderately stereoselective procedure based on proline activation only. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/195 porphyrins were prepared inside the large pores of the zeolite NaY by a process of sequential introduction of components followed by assembly inside the void space of the zeolite. The appropriate process chosen for the porphyrin synthesis was using the propionic acid solvent for reaction between pyrrole and benzaldehyde and this solvent was not destructive for zeolite. The resulting materials were purified by Soxhlet extractor. The zeolite-included porphyrins were identified for studies using UV-Vis and FTIR Spectroscopy and SEM techniques. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/182 We have developed a new catalytic asymmetric method for the synthesis of highly functionalized non-racemic chiral alkyl halides using Kharasch addition in good yields and moderate enantioselectivities. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/185 The silylcupration of allene has emerged as a useful tool for the synthesis of functionalized allylsilanes which have been used in the synthesis of different-sized carbocycles. We now described the preparation of allylsilane-allylcuprate intermediates by homologation reaction with iodomethylzinc iodide and their reaction with different electrophiles. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/179 An efficient strereocontrolled synthesis of substituted oxazolidin-2-one synthon 11 as the key intermediate in the synthesis of FTY720 analogues starting from the highly functionalized furanose scaffold 21 is reported. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/178 A series of novel bi-heterocyclic ethers, containing 4H-pyrido[1,2-a]pyrimidin-4-one along with other five and six-membered heterocyclic rings, was obtained utilizing ethyl [(4- oxo-4H-pyrido[1,2-a]pyrimidin-2-yl)oxy]acetate (1), [(4-oxo-4H-pyrido[1,2-a]pyrimidin-2- yl)oxy]-acetic acid (2) and/or [(4-oxo-4H-pyrido[1,2-a]pyrimidin-2-yl)oxy]acetohydrazide (3). Reaction of ester 1 with some ortho-hydroxy aldehydes furnished the corresponding pyridopyrimidyloxypyrones. Reaction of ester 1 or acid 2 with 1,2-diamines led to some imidazoles. Also, some pyrazole, triazole, and oxadiazoline derivatives have been prepared from hydrazide 3. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/184 Fluorescent benzo[a]phenoxazinium chlorides with dipropyl-, dioctyl- didecyl- and didodecyl-chains as the amino substituents of the 9-positions of the tetracyclic system were synthesised in moderate to good yields. All the compounds absorbed in the wavelength range of 638-641 nm and emitted at 673 or 676 nm with quantum yields of 0.17-0.19 in ethanol. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/183 Three hexadentate Schiff base ligands were obtained by condensation of 3-ethoxy-2-hydroxybenzaldehyde and different diamines (1,2-diaminoethane, 1,2-diaminopropane, 1,2-diamino-2-metylpropane) to yield H2Ln (H2L1, H2L2 and H2L3, respectively). The ligands have been characterised by elemental analysis, IR, and 1H and 13C NMR spectroscopic techniques, mass spectrometry (ES) and X-ray diffraction. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/188 Oxidative deprotection of benzylic silyl ethers has been carried out using nitrogen dioxide gas to the corresponding aldehydes and ketones in quantitative yields. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/180 A series of N-substituted-3,4,5,6-tetrachlorophthalimides were prepared by a novel sequential reaction of trichloroacetimidate 3 with C-nucleophiles in the presence of TMSOTf. The nucleophiles include arenes, alkenes and active methylene to give the imidomethylation product of 3,4,5,6-tetrachlorophthalimide 5, 7, 9 and 11, respectively. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/181 A combination of tetrachlorosilane (TCS) and phenol in dichloromethane was found to be an efficient reagent for hydrochlorination of α,β- unsaturated ketones to afford the corresponding β-chloroketones in good yield at ambient temperature. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/189 Mono-Boc-protection of bispidine was achieved using equimolar amounts of TFA and Boc2O with iodine as catalyst. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/166 Flexible routes for the stereoselective synthesis of a variety of structurally diverse 1-, 3- or 4-alkyl and aryl-tetrahydrobenzo[c]azepines have been developed. The key steps are the highly diastereoselective 1,2-addition process or metallation/alkylation sequence applied to stereopure hydrazones. Subsequent cyclomethylenation or ringclosing metathesis reaction to secure the formation of the seven-membered azaheterocycle ring system complete the assembly of the targeted titled compounds. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/172 Estra-1,3,5(10),16-tetraene was converted to an estra-1',3',5'(10')- trieno(16',17':4,5)isoxazoline. The isoxazoline was transformed to a substituted 1- formylphenanthrene by the action of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/173 Platelet, tubular and herring-bone carbon nanofibres were doped with Pd under various conditions. The catalysts were analysed as to the Pd-content and as to the size distribution of the Pd particles. The Pd-doped carbon nanofibres were screened for their catalytic activity in the Suzuki-Miyaura cross coupling and in the Heck reaction. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/174 The reaction of enantiopure 3-azido-4-oxoazetidine-2-carbaldehyde with acetone was catalyzed by L-proline, to give the corresponding aldol adduct. This product was stereocontrolled cyclized by using intramolecular reductive amination achieving a new 4-hydroxypipecolic acid analogue with a bicyclic b-lactam structure. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/177 0.2CuO/MgO solids prepared by impregnation method was calcined at 350 and 450 ºC. The effects of γ-rays (0.2-1.6 MGy) on its structure, surface and catalytic properties were investigated by using XRD, N2–adsorption at -196ºC and catalytic conversion of iso-propanol at 150-275 ºC using a flow technique. The results revealed that the investigated solids consisted of nano-sized MgO as a major phase beside CuO and trace amount of Cu2O. γ- Irradiation of the solids investigated exerted measurable changes on their surface and catalytic properties. These changes are dependent on the calcination temperature and dose of irradiation. The catalysts investigated acted as active dehydrogenation solids. The five yearsageing of different solids showed a limited influence on surface and catalytic properties indicating a good catalytic stability of the prepared solids. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/171 Cyano functionalized 6-methoxyquinolin-2-ones were synthesized from malonic acid derivatives and p-anisidines in multistep reactions via 4-chloro-6-methoxyquinolin-2-ones. Introduction of cyano substituents resulted in 3,4-dicyano-6-methoxyquinolin-2-ones or 4- cyano-6-methoxyquinolin-2-ones, depending on the substituents in position 3 and 1. The study of the fluorescence properties of 3,4-dicyano-6-methoxyquinolone showed emission values up to 550 nm (black curve) combined with large Stoke's shifts , whereas 4-cyano-6- methoxyquinolones gave lower values (e.g. blue curve) comparable to earlier findings. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/163 A fluorescent pyrenylmethyl moiety was coupled to the N-terminus of a series of catecholamines. The behaviour of the corresponding fluorescent conjugates towards photocleavage was evaluated by irradiation in MeOH/HEPES buffer (80:20) solution, in a photochemical reactor at different wavelengths (254, 300, 350 and 419 nm), followed by HPLC/UV monitoring. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/170 We wish to report reaction of various carbamates and oxazolidinones with carboxylic acid anhydrides in the presence of Wells-Dawson heteropolyacid catalysis. The N-acylation was carried out in presence heteropolyacid catalyst and gave the corresponding N-acyl products in good yields under solvent-free, green conditions. In this acylation used of Carboxylic acids and anhydride as acylating agents. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/168 A new homologous series of mesogen, 6-ethoxy-2-(4- alkanoyloxybenzylideneamino)benzothiazoles with even number of carbons (n = 6, 8, 10, 12, 14, 16, 18) at terminal ester chain have been successfully synthesized and isolated. The structure of the title compound was confirmed using elemental analysis and various spectroscopic techniques including FT-IR, 1H NMR and 13C NMR and EI-MS. Phase transition temperatures and thermal data were determined using differential scanning calorimetry. The textures of mesophases were observed under optical polarizing microscope attached with a Linkam hotstage. All the compounds are enantiotropic liquid crystals. While n-hexanoyloxy and n-octanoyloxy derivatives exhibited nematic, ndecanoyloxy to n-octadecanoyloxy derivatives showed smectic C and nematic phases. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/169 With of reaction of 5-amino-pyrazole-4-carbonitrile derivative and using from supported Preyssler heteropolyacid catalyst in a series from reactions prepared a several new pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4-e][1,4]diazepine, pyrazolo[3,4- d][1,2,3]triazine and pyrolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/167 The development of an unprecedented methodology based upon direct photolysis of N,N-disubstituted hydrazides to secure N-N bond cleavage and to trigger off the formation of NH free lactams has been disclosed. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/165 2-nitrobenzofuran is studied in Diels-Alder reactions under thermal conditions. A concise synthesis of dibenzofurans has been developed via cycloaddition reactions. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/160 Microwave irradiation of N-[2-(phenylmethyl)phenyl]benzamide with potassium tert-butoxide leads to a 1:1 ratio of the expected product from Madelung’s reaction and 9H-Dibenzo[a,c]carbazole. This one seems to come from a competitive reaction pathway rather than from thermal conrotatory electrocyclic of 2,3-diphenyl- 3H-Indole. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/161 Three steps synthesis of neoflavonoid skeleton (4 hydroxybenzophenone imine was carried out in good yield. The key step is a microwave assisted solventless Knoevenagel condens decarboxylation is involved. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/162 The improved synthesis of metal (copper, nickel, zinc) 5,9,14,18,23,27,32,36- octabutoxynaphthalocyanines using modified microwave oven described. The comparison with conventional synthesis was made. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/164 We wish to report synthesis carbamates using Preyssler heteropolyacid, in absence of solvent and at room temperature, in green conditions.This synthesis was in mild conditions, ecofrienly and environmentally friendly, clean and with a easy work-up. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/159 Enzymatic hydrolysis of potato starch by γ-amylase was investigated to reveal the potential coupling mechanism of MIECC. The MIECC effect on increasing initial reaction rate ~2.5 times was observed in case of low viscous reaction system i.e. low substrate concentration. Up to now amylases were known as microwave sensitive enzymes, that are strongly deactivated when placed in microwave filed. Conducted experiments testifies on γ-amylase specific activation done by microwaves. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/158 We report the cross-coupling of n-hexanol and aryl iodides using Cu(I) catalysis under microwave reaction conditions. The aryl ethers were obtained in good yield. The use of 1,10-phenanthroline as the ligand was found effective in these reactions. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/155 N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)‐N’‐(thiazol‐2’‐yl)thioureas have been synthesized from corresponding 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl isothiocyanate and the substituted derivatives of 2‐aminothiazoles executing in domestic microwave oven. The 1H and 13CNMR spectra of some derivatives of N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)‐N’‐(4’‐arylthiazole‐2’‐ yl)thiourea have been recorded. The magnetic signals in their NMR spectra show the relationships between the structure and positions of the substituted groups. It’s also indicated that the substitution in the thiazole ring influenced on the chemical shift of proton on thiourea group. 2‐Iminothiazolidin‐4‐ones have been synthesized from ethyl bromoacetate and substituted N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐Dglucopyranosyl)‐ N’‐(phenylthiazole‐2’‐yl)thioureas. The presence of 2‐iminothiazolidin‐4‐one isomers were confirmed by NMR spectroscopies. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/156 A summary of detailed studies of influence of microwave irradiation on the kinetics of Knoevenagel condensation was presented. General conclusions were outlined. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/157 A fast and efficient method has been developed for the synthesis of Thiocarbamic acid [(thiophene-2-yl) ethylidene]hydrazide, [TTEH], under microwave irradiation. This compound has been characterized by FT-IR, 1H-NMR, 13C-NMR. 2009-10-31 2009-10-31T00:00:00Z http://www.sciforum.net/presentation/176 A commercial cordierite sample showed a small catalytic activity in iso-propanol conversion carried out at 150-350 °C and no measurable activity in CO oxidation by O2. On the other hand, supporting NiO on Al2O3–modified cordierite resulted in the formation of an active solid that having good catalytic activity in iso-propanol conversion and CO oxidation by O2. These two reactions were carried out at 150-350 and 200 °C, respectively. The results revealed that the catalyst containing 5wt (percent) NiO showed the biggest activity in the alcohol conversion and acted as selective dehydration catalyst. The catalyst sample containing 20wt (percent) NiO exhibited a good activity in CO oxidation by O2 which decreased progressively by increasing its calcination temperature within 350-600 °C. Al2O3–treated cordierite dissolved a portion of NiO in its lattice which increased by increasing the calcination temperature within 350-600 °C. 2009-10-31 2009-10-31T00:00:00Z