http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Wed, 24 Apr 2013 14:16:04 +0000 http://www.hindawi.com/isrn/oc/2013/453682/ A new, efficient method for the synthesis of 2-aryl substituted benzimidazole by using silica supported periodic acid (H5IO6-SiO2) as a catalyst has been developed. The salient feature of the present method includes mild reaction condition, short reaction time, high yield and easy workup procedure. The synthesized benzimidazoles exhibited potent anticancer activity against MCF7 and HL60 cell lines. Vyankat A. Sontakke, Sougata Ghosh, Pravin P. Lawande, Balu A. Chopade, and Vaishali S. Shinde Copyright © 2013 Vyankat A. Sontakke et al. All rights reserved. Sun, 07 Apr 2013 15:42:19 +0000 http://www.hindawi.com/isrn/oc/2013/791591/ Condensation of amine 1 with aldehyde 2 gives Schiff base, N-(4-((benzofuran-2-ylmethylene) amino)phenyl)acetamide 3. Schiff base on N-acylation with different substituted acid chlorides in the presence of triethylamine gives the corresponding benzamides, N-acetyl-N-(4-((benzofuran-2-ylmethylene)amino)phenyl)substitutedbenzamide (NABP) 5a–j. The structures of newly synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR FT-IR, and mass spectral studies. Compounds 3 and 5a–j have been screened for their antimicrobial activity using the disc diffusion and minimum inhibitory concentration (MIC) method against the selected bacterial and fungal strain. Compounds 5a, 5e, 5g, and 5h were found to be more active against all tested strains. The antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging methods. Compounds 5i and 5j showed predominant antioxidant activities among the synthesized analogues. The interaction between NABP and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopic techniques at 298 K under imitated physiological conditions. The results revealed that NABP caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants and the number of binding sites were calculated. The binding distance between the donor (BSA) and acceptor (NABP) was determined based on Forster’s theory. M. K. Prashanth, M. Madaiah, H. D. Revanasiddappa, and K. N. Amruthesh Copyright © 2013 M. K. Prashanth et al. All rights reserved. Thu, 28 Mar 2013 17:12:07 +0000 http://www.hindawi.com/isrn/oc/2013/656185/ Suspensions of graphene, prepared from graphite foil by sonochemical exfoliation, have been treated with new nonpolar pyrenebutyric amides. The assemblies, in suspension and after deposition on solid supports, were characterized by NMR, absorption, and fluorescence spectroscopy and by transmission electron microscopy, where the well-defined shape and size of an appended [60]fulleropyrrolidine unit facilitates TEM detection of the nonstationary molecules. The accumulated evidence, also including direct comparisons of carbon nanotubes treated with pyrene amides under the same conditions, proves the successful noncovalent functionalization of graphene suspended in non-polar solvent with non-polar pyrene derivatives. Wenzhi Yang, Sultan Akhtar, Klaus Leifer, and Helena Grennberg Copyright © 2013 Wenzhi Yang et al. All rights reserved. Mon, 18 Mar 2013 11:58:47 +0000 http://www.hindawi.com/isrn/oc/2013/526173/ The reaction of 5,5-dimethylcyclohexane-1,3-dione with various heteroarylaldehydes afforded the corresponding heteroaryl substituted xanthene derivatives 1(a–f). The reaction proceeds via the initial Knoevenagel, subsequent Michael, and final heterocyclization reactions using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst in aqueous media. The synthesized heteroaryl substituted xanthenes 1(a–f) reacted with malononitrile to obtain different alkylidenes 2(a–f). Short reaction time, environmentally friendly procedure, avoiding of cumbersome apparatus, and excellent yields are the main advantages of this procedure which makes it more economic than the other conventional methods. Pradeep Paliwal, Srinivasa Rao Jetti, Anjna Bhatewara, Tanuja Kadre, and Shubha Jain Copyright © 2013 Pradeep Paliwal et al. All rights reserved. Tue, 05 Mar 2013 10:37:49 +0000 http://www.hindawi.com/isrn/oc/2013/159164/ The synthesis of six thiadiazole nucleoside analogs is reported: 5-diacetylamino-1,2,4-thiadiazol-3-one (1), 5-amino-2- (tetrahydrofuran-2-yl)-1,2,4-thiadiazol-3-one (2), 5-amino-3-[(2′-hydroxyethoxy)methyl]-1,3,4-thiadiazol-2-one (3), 5-amino-3-(4′-hydroxy-2′-hydroxymethyl-butyl)-1,3,4-thiadiazole-2-thione (4), (R)-5-amino-3-(2′,3′-dihydroxypropyl)-1,3,4-thiadiazole-2-thione (5), and (S)-5-amino-3-(2′,3′-dihydroxypropyl)-1,3,4-thiadiazole-2-thione (6). The synthesis, characterization, and properties of these new synthesized thiadiazole derivatives are discussed. A dimerization of 5-amino-3H-1,3,4-thiadiazole-2-thione (14) by sodium nitrite resulting in di-(5-amino-1,3,4-thiadiazol-2-yl) disulfide (19) is also reported. The preliminary in vitro evaluation of these newly synthesized compounds is discussed. Yuxiang Zhao, Peter J. McCarthy, and Cyril Párkányi Copyright © 2013 Yuxiang Zhao et al. All rights reserved. Sun, 09 Dec 2012 11:12:26 +0000 http://www.hindawi.com/isrn/oc/2012/873035/ Reaction(s) of -guanosine monophosphate (GMP) with di- and triorganotin(IV) chloride(s) led to formation of organotin(IV) derivatives of general formulae, [R2Sn(-GMP)·H2O]n and [(R′3Sn)2(-GMP)·H2O]n, where R = Me, n-Bu, and Ph; R′ = Me, i-Pr, n-Bu, and Ph; (-GMP)2− = -guanosine monophosphate. An attempt has been made to prove the structures of the resulting derivatives on the basis of FT-IR, multinuclear 1H, 13C, and 119Sn NMR and 119Sn Mössbauer spectroscopic studies. These investigations suggest that both di- and triorganotin(IV)--guanosine monophosphates are polymeric in which (-GMP)2− is bonded through phosphate group resulting in a distorted trigonal bipyramidal geometry around tin. The ribose conformation in all of the derivatives is C3′-endo, except diphenyltin(IV) and tri-i-propyltin(IV) derivatives where it is C2′-endo. All of the studied derivatives exhibited mild-to-moderate anti-inflammatory activity (~15.64–20.63% inhibition) at 40 mg kg−1 dose and LD50 values > 400 mg kg−1 in albino rats. Mala Nath, Hitendra Singh, George Eng, and Xueqing Song Copyright © 2012 Mala Nath et al. All rights reserved. Wed, 28 Nov 2012 13:15:07 +0000 http://www.hindawi.com/isrn/oc/2012/674629/ Iodine-catalyzed reaction of indoles with ,-bis(arylmethylene)cyclopentanones afforded one diastereomer of the corresponding Michael adducts, namely, E-2-(3-indolylphenylmethyl)-5-phenylmethylenecyclopentanones, in a good yield. The products form a new group of indole derivatives. Rammohan Pal, Arpita Das Gupta, and Asok K. Mallik Copyright © 2012 Rammohan Pal et al. All rights reserved. Thu, 22 Nov 2012 14:42:00 +0000 http://www.hindawi.com/isrn/oc/2012/480989/ An environmentally benign green protocol for the synthesis of 5-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones using Amberlyst 15 DRY as a recyclable catalyst has been developed. The use of resinous, nontoxic, thermally stable, and inexpensive Amberlyst 15 DRY, as a recyclable heterogeneous catalyst, makes the process simple with negligible chemical waste. Among the various solid acid catalysts Amberlyst 15 DRY was found to be the most efficient catalyst with regard to reaction time, yield, and ease of work-up procedure. Srinivasa Rao Jetti, Divya Verma, and Shubha Jain Copyright © 2012 Srinivasa Rao Jetti et al. All rights reserved. Wed, 21 Nov 2012 09:19:28 +0000 http://www.hindawi.com/isrn/oc/2012/873046/ The replacement of petrochemicals by oleochemical feedstocks in many industrial and domestic applications has resulted in an increase in demand for biobased products and as such recognizing and increasing the benefits of using renewable materials. In line with this, the oil extracted from the seed of Hura crepitans was characterized by an iodine value of  g Iodine/100 g and a saponification number of  mg KOH/g with the dominant fatty acid being C18:2 (%). The epoxidised fatty acid methyl esters prepared from the oil were used to synthesise the azidohydrin with a yield of 91.20%. The progress of the reaction was monitored and confirmed using FTIR and NMR. This showed the seed oil of Hura crepitans as a renewable resource that can be used to make valuable industrial and domestic products. Adewale Adewuyi, Andrea Göpfert, Thomas Wolff, B. V. S. K. Rao, and R. B. N. Prasad Copyright © 2012 Adewale Adewuyi et al. All rights reserved. Sun, 18 Nov 2012 08:02:22 +0000 http://www.hindawi.com/isrn/oc/2012/814247/ An efficient La2O3-catalyzed new route for the carbon-carbon bond formation in particular, symmetrical and unsymmetrical biphenyls has been developed, which proceeds through carbon-carbon coupling reaction of aryl iodides with boronic acids. The reaction provided the desired products in moderate-to-good yields with a wide range of functional group tolerance. Payal Malik and Debashis Chakraborty Copyright © 2012 Payal Malik and Debashis Chakraborty. All rights reserved. Wed, 14 Nov 2012 10:03:01 +0000 http://www.hindawi.com/isrn/oc/2012/474626/ Trichloroacetic acid was found to be a convenient catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones and their corresponding 2(1H)-thiones through a one-pot three-component reaction of aldehydes, alkyl acetoacetate, and urea or thiourea at 70°C under solvent-free conditions. Zahed Karimi-Jaberi and Mohammad Sadegh Moaddeli Copyright © 2012 Zahed Karimi-Jaberi and Mohammad Sadegh Moaddeli. All rights reserved. Wed, 14 Nov 2012 09:46:10 +0000 http://www.hindawi.com/isrn/oc/2012/595868/ A new BiCl3-loaded montmorillonite K10 catalyst has been prepared by solid dispersion method and was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and cyclic voltammetry (CV) measurements. BiCl3 loaded K10 (BiCl3-K10) has been used as solid acid catalyst for the synthesis of azine derivatives from benzophenone hydrazone and ketones/aldehydes by simple physical grinding. This BiCl3-K10 gives an excellent yield with short reaction time and is an inexpensive, easily recyclable catalyst for this reaction. K. Ravi, B. Krishnakumar, and M. Swaminathan Copyright © 2012 K. Ravi et al. All rights reserved. Mon, 05 Nov 2012 15:32:29 +0000 http://www.hindawi.com/isrn/oc/2012/274980/ From the treatment of 5-hydroxy-1,4-naphthoquinone (juglone) with acetic anhydride and H2SO4 followed subsequently by treatment with methanolic HCl, 5-hydroxy-3-methoxy-1,4-naphthoquinone (3-methoxy juglone) and 8-hydroxy-4-methoxy-1,2-naphthoquinone were obtained as products rather than the anticipated product 2,5-dihydroxy-1,4-naphthoquinone (2-hydroxy juglone). The reaction and the identification of the products are discussed in terms of NMR and DFT calculations. Bastian Blauenburg, Mikko Metsä-Ketelä, and Karel D. Klika Copyright © 2012 Bastian Blauenburg et al. All rights reserved. Thu, 01 Nov 2012 09:02:50 +0000 http://www.hindawi.com/isrn/oc/2012/906839/ Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area () and Brewster angle microscopy (BAM) observations. Rocío Redón, M. Pilar Carreón-Castro, and F. J. Mendoza-Martínez Copyright © 2012 Rocío Redón et al. All rights reserved. Tue, 30 Oct 2012 09:59:34 +0000 http://www.hindawi.com/isrn/oc/2012/242569/ A simple and efficient protocol is developed for the synthesis of 2-substituted-4,6-diarylpyrimidines from one-pot three-component reaction of 4′-hydroxy-3′,5′-dinitro substituted chalcones, S-benzylthiouronium chloride (SBT), and heterocyclic secondary amines (morpholine/pyrrolidine/piperidine) in the presence of 15 mol% of ZnO as a heterogeneous catalyst. The present methodology offers several advantages such as being a simple procedure as well as providing excellent yields, and short reaction time. The catalyst is inexpensive, stable, and can be easily recycled and reused for several cycles with consistent activity. K. L. Ameta, Biresh Kumar, and Nitu S. Rathore Copyright © 2012 K. L. Ameta et al. All rights reserved. Wed, 17 Oct 2012 13:14:47 +0000 http://www.hindawi.com/isrn/oc/2012/104975/ An efficient one-pot microwave-assisted hydrogenation of codeine was achieved in aqueous solution. This technique is simple, fast, environmentally friendly, and highly efficient. Structure of produced dihydrocodeine was approved by using FT-IR, 1H NMR, 13C NMR, EIMS, and elemental analysis technique. Its purity analysis was performed by using HPLC and assay analysis was performed by using potentiometric titration methods. F. Taktak and I. Bulduk Copyright © 2012 F. Taktak and I. Bulduk. All rights reserved. Mon, 15 Oct 2012 10:13:33 +0000 http://www.hindawi.com/isrn/oc/2012/281642/ Ozonation of N-aryl-cyclic amines in organic solvents gave N-aryl-lactams regioselectively. In particular, 4-(4-aminophenyl)-morpolin-3-one, a key intermediate in the preparation of factor Xa inhibitors, was obtained in fair yields. The method represents an alternative approach for the lactamization of tertiary N-arylic substrates and is based on a “metal-free” introduction of the carbonyl function into the heterocyclic ring. Francesco Saliu, Marco Orlandi, and Maurizio Bruschi Copyright © 2012 Francesco Saliu et al. All rights reserved. Tue, 11 Sep 2012 15:48:41 +0000 http://www.hindawi.com/isrn/oc/2012/760517/ A series of novel 4-amino-5-mercapto-3-[(3-aralkyl amido/imidoalkyl) phenyl]-1,2,4-triazoles (5a-d) were obtained by treating m-(aralkyl amido/imidoalkyl) benzoic acid hydrazides (3a-d) with carbon disulphide in alcoholic KOH and hydrazine hydrate, respectively. These triazole derivatives were employed in the synthesis of 5-[(3′-aralkyl amido/imidoalkyl) phenyl]-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (6a-d). The newly synthesized compounds were evaluated for their antiviral activity against two animal viruses, namely, Japanese encephalitis virus (JEV) strain P20778 and herpes simplex virus-1 (HSV-1) strain 753166. Vinod Kumar Pandey, Zehra Tusi, Sumerah Tusi, and Madhawanand Joshi Copyright © 2012 Vinod Kumar Pandey et al. All rights reserved. Mon, 27 Aug 2012 15:42:08 +0000 http://www.hindawi.com/isrn/oc/2012/635835/ A novel catalytic system consisting of I2-SDS-H2O has been developed which cleaves 2,3-diaza-1,3-butadiene, 1-aza-1,3-butadienes, oximes and in presence of indoles in the medium uses the corresponding aldehyde products to produce bis(indolyl)alkanes in situ. This one pot simple and mild dual catalytic system works in water at room temperature under neutral conditions. Parasa Hazarika, Pallab Pahari, Manash Jyoti Borah, and Dilip Konwar Copyright © 2012 Parasa Hazarika et al. All rights reserved. Wed, 22 Aug 2012 15:48:03 +0000 http://www.hindawi.com/isrn/oc/2012/976178/ Six star-shaped oligomers containing triphenylamine (D1–D3) and benzene unit (D4–D6) as cores have been synthesized by Wittig condensation or Heck coupling reaction using aromatic aldehydes and triphenylphosphonium salts or aromatic halogenated compounds with vinyl triphenylamine. All oligomers have well-defined molecular structure and high purity. Characterization of the oligomers was made by FT-IR, 1H-NMR spectroscopy, UV-Vis, and fluorescence spectroscopy. The electrochemical behavior was studied by cyclic voltammetry (CV). The cyclic voltammograms have revealed that oligomers undergo quasireversible or irreversible redox processes. The irreversible process is associated with electrochemical polymerization of oligomers by dimerization of unsubstituted triphenylamine groups. Thermal characterization was accomplished by TGA and DSC methods and evidenced that all oligomers were stable materials until 250°C and have formed stable molecular glasses after first heating scan. Teofilia Ivan, Loredana Vacareanu, and Mircea Grigoras Copyright © 2012 Teofilia Ivan et al. All rights reserved. Sun, 12 Aug 2012 08:23:55 +0000 http://www.hindawi.com/isrn/oc/2012/342738/ An eco-friendly “on-water” protocol for efficient catalyst-free synthesis of the Hantzsch dihydropyridines from aryl, heteroaryl, alkyl, and vinylogous aldehydes has been developed with minimum auxiliary substances, toxic reagents, organic solvents, and disposal problems. Amit Pramanik, Manabendra Saha, and Sanjay Bhar Copyright © 2012 Amit Pramanik et al. All rights reserved. Wed, 08 Aug 2012 10:11:33 +0000 http://www.hindawi.com/isrn/oc/2012/415645/ An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton’s reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure. Amulrao Borse, Mahesh Patil, Nilesh Patil, and Rohan Shinde Copyright © 2012 Amulrao Borse et al. All rights reserved. Sun, 29 Jul 2012 12:15:00 +0000 http://www.hindawi.com/isrn/oc/2012/963195/ A new, TiCl4-or SnCl4-mediated, solvent-free method was developed for the synthesis of N-Aryl benzamidines and N-phenylpicolinamidines, in moderate-to-good yield, using suitable amines and nitriles as starting materials. Umesh D. Patil and Pramod P. Mahulikar Copyright © 2012 Umesh D. Patil and Pramod P. Mahulikar. All rights reserved. Tue, 17 Jul 2012 18:34:14 +0000 http://www.hindawi.com/isrn/oc/2012/928484/ The combination of chitosan as a renewable heterogeneous catalyst and ionic liquid as a “green” solvent was employed for the Knoevenagel reaction. The chitosan catalyst was characterized by various techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. Excellent conversions were achieved under mild conditions without the need for an inert atmosphere. There was no contribution from leached active species, and conversion was only being possible in the presence of the solid catalyst. The chitosan catalyst as well as the ionic liquid solvent could be recovered in essentially pure form after being used in the reaction, and each of them could be reused several times without a significant degradation in efficiency. Nam T. S. Phan, Ky K. A. Le, Thien V. Nguyen, and Nhan T. H. Le Copyright © 2012 Nam T. S. Phan et al. All rights reserved. Tue, 03 Jul 2012 09:13:25 +0000 http://www.hindawi.com/isrn/oc/2012/526867/ Comparison of ion-molecular reactions of free-phenyl cations generated by tritium β-decay with 2-methyl- and 2-phenylquinolines has been investigated. The reaction of direct nitrogen atom phenylation with the help of nucleogenic phenyl cations has been fulfilled for the first time and a new one-step synthesis of tritium-labeled N-phenyl-2-phenylquinolinium salt—lipophilic radioactive biological marker has been elaborated. Nadezhda E. Shchepina, Viktor V. Avrorin, Gennady A. Badun, Scott B. Lewis, and Sergey N. Shurov Copyright © 2012 Nadezhda E. Shchepina et al. All rights reserved. Wed, 16 May 2012 10:19:19 +0000 http://www.hindawi.com/isrn/oc/2012/810938/ Herein, we describe an efficient one-step synthesis of new fused benzothiadiazepine-1,1-dioxides and macrocyclic sulfamides. The synthesis of these compounds was achieved in moderate yields starting from previously described N,N′-disubstituted symmetric sulfamides and N-tert-butoxycarbonyl, N′-alkyl sulfamide. The chemical structures of all the new compounds reported in this work were confirmed by NMR, IR, and mass spectrometry. These compounds are beneficial building blocks that can be used in deriving new chemical entities that exert a wide spectrum of pharmacological activities. Mohamed Dehamchia and Zine Regainia Copyright © 2012 Mohamed Dehamchia and Zine Regainia. All rights reserved. Wed, 09 May 2012 10:18:18 +0000 http://www.hindawi.com/isrn/oc/2012/404235/ A simple, efficient, and eco-friendly protocol for the N-Boc protection of the amine moiety in a variety of compounds with di-tert-butyl dicarbonate under water-acetone catalyst-free conditions is described. The corresponding monocarbamate is obtained in excellent yields on short reaction times. No competitive side reactions such as isocyanate urea and O-Boc were observed. This method represents a reasonable alternative to the previous reported protection procedures. Zinelaabine Cheraiet, Souad Ouarna, Sihem Hessainia, Malika Berredjem, and Nour-Eddine Aouf Copyright © 2012 Zinelaabine Cheraiet et al. All rights reserved. Thu, 22 Mar 2012 15:06:14 +0000 http://www.hindawi.com/isrn/oc/2012/945893/ Interaction of O-benzoyl-𝛽-aminopropioamidoximes [𝛽-amino group: pyperidin-1-yl; morpholin-1-yl; thiomorpholin-1-yl; 4-phenylpiperazin-1-yl; benzimidazol-1-yl] with Lawesson's reagent was done in tetrahydrofuran at heating to 70∘C during 10 h. New O-thiobenzoyl-𝛽-aminopropioamidoximes were obtained with the outputs 57–96%; they were characterized with the help of physicochemical, IR, and NMR spectra. Lyudmila Kayukova, Kaldubai Praliyev, Ulan Kemelbekov, Asel Abdildanova, and Vanda Gutyar Copyright © 2012 Lyudmila Kayukova et al. All rights reserved. Wed, 08 Feb 2012 08:22:51 +0000 http://www.hindawi.com/isrn/oc/2012/208284/ Two new macrocyclic hydrazone Schiff bases were synthesized by reaction of succindihydrazide and adipdihydrazide with acetylacetone. Hydrazones have been characterized by elemental analyses and IR, mass, 1H NMR, and 13C NMR spectral data. Hydrazones have been studied by liquid-liquid extraction towards the s-metal ions (Li+, Na+, and K+) and d-metal ions (Cu2+ and Cr3+) from aqueous phase to organic phase. The effect of chloroform and dichloromethane as organic solvents over the metal chlorides extraction was investigated at 25 ± 0.1°C by using flame atomic absorption. We found differences between the two solvents in extraction selectivity. Farouk Kandil, Mohamad Khaled Chebani, and Wail Al Zoubi Copyright © 2012 Farouk Kandil et al. All rights reserved. Sun, 13 Nov 2011 13:42:14 +0000 http://www.hindawi.com/isrn/oc/2011/273136/ A simple and economic synthesis of 3,4-dihydropyrimidin-2(1H)-ones using ammonium trifluoroacetate as catalyst and as solid support is accomplished. Easy workup procedure for the synthesis of title compounds is well arrived at and is well documented. Chandran Raju, R. Uma, Kalaipriya Madhaiyan, Radhakrishnan Sridhar, and Seeram Ramakrishna Copyright © 2011 Chandran Raju et al. 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