New Insights Into the Mechanism of Schiff Base Synthesis from Aromatic
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Fluorescent Aminal Linked Porous Organic Polymer for Reversible Iodine Capture and Sensing Muhammad A
www.nature.com/scientificreports OPEN Fluorescent aminal linked porous organic polymer for reversible iodine capture and sensing Muhammad A. Sabri1, Mohammad H. Al‑Sayah2, Susan Sen2, Taleb H. Ibrahim1 & Oussama M. El‑Kadri2* A novel triazene-anthracene-based fuorescent aminal linked porous organic polymer (TALPOP) was prepared via metal free-Schif base polycondensation reaction of 9,10-bis-(4,6-diamino-S‑triazin‑ 2-yl)anthracene and 2-furaldehyde. The polymer has exceptional chemical and thermal stabilities and exhibit good porosity with Brunauer–Emmett–Teller surface area of 401 m2g−1. The combination of such porosity along with the highly conjugated heteroatom-rich framework enabled the polymer to exhibit exceptional iodine vapor uptake of up to 314 wt % and reversible iodine adsorption in solution. Because of the inclusion of the anthracene moieties, the TALPOP exhibited excellent 3 −1 detection sensitivity towards iodine via forescence quenching with Ksv value of 2.9 × 10 L mol . The cost efective TALPOP along with its high uptake and sensing of iodine, make it an ideal material for environmental remediation. Nuclear energy is becoming one of the most feasible alternative sources to meet the ever-increasing energy demand and minimize the emission of greenhouse gases because of its high-density energy, minimal carbon footprints, and low operation cost1–4. Despite such advantages, the potential emissions of radioactive material 129 131 3 14 85 (such as I and I, H, CO2, and Kr) from nuclear energy power plants is a major drawback of this tech- nology due to the serious environmental and health efect of these materials4,5. -
Zr-Modified Zno for the Selective Oxidation of Cinnamaldehyde to Benzaldehyde
catalysts Article Zr-Modified ZnO for the Selective Oxidation of Cinnamaldehyde to Benzaldehyde Pengju Du 1, Tongming Su 1, Xuan Luo 1, Xinling Xie 1, Zuzeng Qin 1,* and Hongbing Ji 1,2 1 School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China 2 School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China * Correspondence: [email protected]; Tel.: +86-771-323-3718 Received: 31 July 2019; Accepted: 21 August 2019; Published: 25 August 2019 Abstract: ZnO and Zr-modified ZnO were prepared using a precipitation method and used for the selective oxidation of cinnamaldehyde to benzaldehyde in the present study. The results showed that physicochemical properties of ZnO were significantly affected by the calcination temperature, and calcination of ZnO at 400 ◦C demonstrated the optimum catalytic activity for the selective oxidation of cinnamaldehyde to benzaldehyde. With 0.01 g ZnO calcined at 400 ◦C for 2 h as a catalyst, 8.0 g ethanol and 2.0 g cinnamaldehyde reacted at an oxygen pressure of 1.0 MPa and 70 ◦C for 60 min, resulting in benzaldehyde selectivity of 69.2% and cinnamaldehyde conversion of 16.1%. Zr was the optimal modifier for ZnO: when Zr-modified ZnO was used as the catalyst, benzaldehyde selectivity reached 86.2%, and cinnamaldehyde conversion was 17.6%. The X-ray diffractometer and N2 adsorption–desorption characterization indicated that doping with Zr could reduce the crystallite size of ZnO (101) and increase the specific surface area of the catalyst, which provided more active sites for the reaction. X-ray photoelectron spectrometer results showed that Zr-doping could exchange the electrons with ZnO and reduce the electron density in the outer layer of Zn, which would further affect benzaldehyde selectivity. -
REGISTRY Database Summary Sheet (DBSS)
SM REGISTRY/ZREGISTRY (CAS REGISTRY ) Subject • All types of inorganic and organic substances, including alloys, coordination Coverage compounds, minerals, mixtures, polymers, salts, high throughput screening (HTS) compounds as well as nucleic acid and protein sequences • Substances included in REGISTRY meet the following criteria: - Identified by CAS as coming from a reputable source, including but not limited to patents, journals, chemical catalogs, and selected substance collections on the web - Described in largely unambiguous terms - Characterized by physical methods or described in a patent document example or claim - Consistent with the laws of atomic covalent organization • Experimental and predicted property data and tags and spectra data File Type Numeric, Structure Features Alerts (SDIs) Biweekly In addition, SMARTracker, an automatic crossfile current-awareness search, (SDI XFILE) using a REGISTRY search profile in CA, HCA, ZCA, CAplus, HCAplus or ZCAplus may be run weekly or biweekly (weekly is the default). CAS Registry Keep & Share SLART Number® Identifiers ® Learning Database STN Easy Structures Record • CAS Registry Numbers • Experimental and predicted property Content • CA index names and commonly used data and tags chemical names and trade names • Spectra • Molecular formulas • List of databases and regulatory listings • Structure diagrams containing information on the substances • Sequence data • Super roles and document type SM • Alloy composition tables information from CAplus • Classes for polymers • Displayable information for 10 most recent references for substances • Ring analysis data File Size More than 140 million organic and inorganic substances; more than 71.1 million sequences (4/18) Coverage Early 1800s to the present Updates Daily Language English Database Chemical Abstracts Service Producer 2540 Olentangy River Road P.O. -
Research Journal of Pharmaceutical, Biological and Chemical Sciences
ISSN: 0975-8585 Research Journal of Pharmaceutical, Biological and Chemical Sciences Metal Complexes of Schiff's Bases Containing Sulfonamides Nucleus: A Review. Zainab Hussain1, Majid Khalaf2, Hadeel Adil2, Dheaa Zageer2, 3, Firas Hassan2, Salam Mohammed4, and Emad Yousif1*. 1Department of Chemistry, College of Science, Misan University, Misan, Iraq . 2Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq. 3Forensic DNA Center for Research and Training, Al-Nahrain University, Baghdad, Iraq. 4College of Engineering and Architecture, University of Nizwa, Birkat Almouz, 616 Nizwa, Oman. ABSTRACT Schiff's bases are versatile ligands which are synthesized from the condensation of primary amines with carbonyl groups. Schiff's bases play an important role in Inorganic chemistry due to formation of very stable complexes with various transition and inner-Transition Metals. Transition metal complexes derived from the Schiff base ligands have widly applications. This review summarizes some metal complexes of schiff's bases derived from sulfonamide derivatives and reviewed the applications of Schiff's bases chelates in quantitative analysis. Keywords: Schiff bases, Metal complexes, Quantitative analysis. *Corresponding author September – October 2016 RJPBCS 7(5) Page No. 1008 ISSN: 0975-8585 Overview of of Schiff's bases A Schiff's base is a nitrogen analog of an aldehyde or ketone in which the C=O group is replaced by C=N-R group. It is usually formed by condensation of an aldehyde or ketone with a primary amine according to the following scheme (Scheme 1): Scheme 1: Formation of Schiff's bases. Where R, may be an alkyl or an aryl group. Schiff's bases that contain aryl substituents are substantially more stable and more readily synthesized, while those which contain alkyl substituents are relatively unstable. -
Synthesis of Aniline and Benzaldehyde Derivatives From
Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2011 Supporting Information Fe2O3-supported nano-gold catalyzed one-pot synthesis of N-alkylated anilines from nitroarenes and alcohols * Qiling Peng, Yan Zhang, Feng Shi , Youquan Deng Centre for Green Chemistry and Catalysis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, China *corresponding author: Tel.: +86-931-4968142; Fax: +86-931-4968116; E-mail: [email protected] 1. Materials and Methods 2. Chlorine concentration measurement 3. Catalyst preparation 4. Table S2. ICP-AES and BET data of various catalysts 5. General procedure for the reaction of nitrobenzene with d7-benzyl alcohol 6. General procedure for the H-D exchange reaction between aniline and D2O 7. Fig. S2. XRD patterns of the catalysts in the experiments. 8. XPS spectra of catalyst samples 9. HRTEM images of the catalyst samples 10.GC-MS spectra of compounds observed by GC-MS 11. Compounds characterization and NMR spectra Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2011 1. Materials and Methods All solvent and chemicals were obtained commercially and were used as received. NMR spectra were measured using a Bruker ARX 400 or ARX 100 spectrometer at 400 MHz (1H) and 100 MHz 13 ( C). All spectra were recorded in CDCl3 and chemical shifts (δ) are reported in ppm relative to tetramethylsilane referenced to the residual solvent peaks. Mass spectra were in general recorded on an HP 6890/5973 GC-MS. High-resolution TEM analysis was carried out on a JEM 2010 operating at 200 KeV. -
Synthesis and Characterization of Polymeric Schiff Bases
SYNTHESIS AND CHARACTERIZATION OF POLYMERIC SCHIFF BASES FROM 2,5-DIFORMYLFURAN A Thesis Present to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Master of Science Tengfei Xiang December, 2012 SYNTHESIS AND CHARACTERIZATION OF POLYMERIC SCHIFF BASES FROM 2,5-DIFORMYLFURAN Tengfei Xiang Thesis Approved: Accepted: Advisor Dean of the College Dr. Yi Pang Dr. Chand Midha Co-Advisor Dean of the Graduate School Dr. Ping Yi Dr. George R. Newkome Department Chair Date Dr. Kim C. Calvo ii ABSTRACT Furan derivatives have the potential to be an alternative resource since it can be obtained from biomass in large scale. Many monomers derived from furfural and 5-hydroxymethylfurfural (HMF), have been used in polymerization investigation in recent years. However, few studies in using 2,5-diformylfuran(DFF) as monomer has been reported, probably due to the limited availability of monmer. Polymeric Schiff bases (or polyimines) is a class of materials containing –CH=N structural unit, which exhibit good thermal stability, useful mechanical properties. In this work, the polymeric Schiff bases obtained from polycondensation of DFF and aromatic, aliphatic diamines, and more comprehensive characterization study has been carried out. FT-IR and 13C Solid NMR study of products confirmed the formation of – CH=N structural unit. And MALDI-TOF mass spectrum showed a typical polymer pattern, providing further understanding on the polymerization process. Thermal Analysis had also been carried out for both alphatic and aromatic polymeric Schiff Bases. iii DEDICATION I would like to dedicate this thesis to my mother, Yumei Jiang, for her love, patience and understanding. -
Reactions of Aromatic Compounds Just Like an Alkene, Benzene Has Clouds of Electrons Above and Below Its Sigma Bond Framework
Reactions of Aromatic Compounds Just like an alkene, benzene has clouds of electrons above and below its sigma bond framework. Although the electrons are in a stable aromatic system, they are still available for reaction with strong electrophiles. This generates a carbocation which is resonance stabilized (but not aromatic). This cation is called a sigma complex because the electrophile is joined to the benzene ring through a new sigma bond. The sigma complex (also called an arenium ion) is not aromatic since it contains an sp3 carbon (which disrupts the required loop of p orbitals). Ch17 Reactions of Aromatic Compounds (landscape).docx Page1 The loss of aromaticity required to form the sigma complex explains the highly endothermic nature of the first step. (That is why we require strong electrophiles for reaction). The sigma complex wishes to regain its aromaticity, and it may do so by either a reversal of the first step (i.e. regenerate the starting material) or by loss of the proton on the sp3 carbon (leading to a substitution product). When a reaction proceeds this way, it is electrophilic aromatic substitution. There are a wide variety of electrophiles that can be introduced into a benzene ring in this way, and so electrophilic aromatic substitution is a very important method for the synthesis of substituted aromatic compounds. Ch17 Reactions of Aromatic Compounds (landscape).docx Page2 Bromination of Benzene Bromination follows the same general mechanism for the electrophilic aromatic substitution (EAS). Bromine itself is not electrophilic enough to react with benzene. But the addition of a strong Lewis acid (electron pair acceptor), such as FeBr3, catalyses the reaction, and leads to the substitution product. -
Synthesis of Some Imines and Investigation of Their Biological Activity
ISSN: 0973-4945; CODEN ECJHAO E-Journal of Chemistry http://www.e-journals.net 2009, 6(3), 629-632 Synthesis of Some Imines and Investigation of their Biological Activity MAJED M. HANIA Chemistry Department, The Islamic University, Gaza P.O.Box 108, Gaza, Palestine. [email protected] Received 12 December 2008; Accepted 5 February 2009 Abstract : Some N-benzylidene aniline derivatives have been synthesized and tested as antibacterial agents. The results of the in vitro tests showed that most of the synthesized compounds were antibacterial inactive against E.coli. Keywords: Synthesis, Imines, Investigation, Antibacterial activity. Introduction Schiff bases such as substituted N-benzylidene aniline are a class of important compounds in medicinal and pharmaceutical field. They show biological activities including antibacterial 1-4, antifungal 5-6, anticancer 7-10 , and herbicidal 11 activities . In view of the above observations, the synthesis of N-benzylidene aniline derivatives have been developed starting from various substituted benzylidene anilines with the aim of investigating their antibacterial activities. Experimental Melting points were determined in open capillaries and are uncorrected. IR spectra were recorded in KBr on Perkin-Elmer 883 spectrometer. The UV spectra were obtained by using UV-vis spectrophotometer instrument, Perkin-Elmer Lambda 20.1 nm. All the compounds gave satisfactory analysis. Benzaldehyde, 4-methylbenzaldehyde, 4-methoxylbenzaldehyde, 4-nitobenzaldehyde and 4-chlorobenzaldehyde were obtained from Sigma- -
New Insights Into the Mechanism of Schiff Base Synthesis from Aromatic Amines in the Absence of Acid Catalyst Or Polar Solvents
New insights into the mechanism of Schiff base synthesis from aromatic amines in the absence of acid catalyst or polar solvents Pedro J. Silva1,2 1 FP-ENAS/Fac. de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal 2 UCIBIO@REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal ABSTRACT Extensive computational studies of the imine synthesis from amines and aldehydes in water have shown that the large-scale structure of water is needed to afford appropriate charge delocalization and enable sufficient transition state stabilization. These insights cannot, however, be applied to the understanding of the reaction pathway in apolar solvents due their inability to form extensive hydrogen-bonding networks. In this work, we perform the first computational studies of this reaction in nonpolar conditions. This density-functional study of the reaction of benzaldehyde with four closely related aromatic amines (aniline, o-toluidine, m-toluidine and p-toluidine) shows that, although an additional molecule of amine may provide some stabilization of the first transition state even in the absence of a hydrogen bonding network, this is insufficient to achieve high reaction rates. Our computations also show that when an extra proton is added to the spectator amine, the activation energies become so low that even picomolar amounts of protonated base are enough to achieve realistic rates. Additional computations show that those minute amounts of protonated base may be obtained under reaction conditions without the addition of extraneous acid through the auto-protolysis of the amines themselves. To our knowledge, this is the first report of a role for the auto-protolysis of anilines in their extensive reactional repertoire. -
Mannich Reaction
1. Introduction 1.1- Mannich Reaction The Mannich reaction is three component condensation in which a compound containing an active hydrogen atom is allowed to react with formaldehyde and an NH-amine derivative . Secondary amines rather than primary amines and ammonia are employed , the resulting product (Mannich Base ) is an amine compound having the N atom linked to the R substrate through a methylene group 1,2. The aminoalkylation of CH-acidic compounds was described by several authors as early as the 19th. century. However, it was Carl Mannich who was the first to recognize the enormous significance of this reaction , and it was he who extended the chemistry into a broad based synthetic methodology through systematic research. Since then this reaction that now carries his name has developed into one of the most important C-C bond-forming reactions in organic chemistry3,4. The Mannich reaction is a classical method for the preparation of β -aminoketones and aldehydes (Mannich bases) and, as such, is one of the most important basic reaction types in organic chemistry. It is the key step in the synthesis of numerous pharmaceuticals and natural products3,4. 1 The Mannich reaction can be presented by the following equation: The essential feature of the reaction is the replacement of the active hydrogen atom by an aminomethyl or substituted aminomethyl group. The symbolizes the active hydrogen component which includes ketones, aldehydes, acids, esters, phenols, acetylenes, picolines, nitroalkanes and quinolines1,2. 1.2- Mechanism of the Mannich reaction The mechanism of the Mannich reaction has been well investigated, the condensation reaction occurs in two steps: first, the amine reacts with formaldehyde to give condensation product (5 ), (6), ( 7) (step I) which then attacks the substrate R-H (step II) .The reaction does not normally follow the other possible route (step III and IV) ; however, some successful reaction between hydroxymethyl derivatives (8) and alkylamines to give Mannich bases (9) should be mentioned . -
Chapter 19 the Chemistry of Aldehydes and Ketones. Addition Reactions
Instructor Supplemental Solutions to Problems © 2010 Roberts and Company Publishers Chapter 19 The Chemistry of Aldehydes and Ketones. Addition Reactions Solutions to In-Text Problems 19.1 (b) (d) (e) (g) 19.2 (a) 2-Propanone (d) (E)-3-Ethoxy-2-propenal (f) 4,4-Dimethyl-2,5-cyclohexadienone 19.3 (b) 2-Cyclohexenone has a lower carbonyl stretching frequency because its two double bonds are conjugated. 19.4 (b) The compound is 2-butanone: (c) The high frequency of the carbonyl absorption suggests a strained ring. (See Eq. 19.4, text p. 897.) In fact, cyclobutanone matches the IR stretching frequency perfectly and the NMR fits as well: 19.6 The structure and CMR assignments of 2-ethylbutanal are shown below. The two methyl groups are chemically equivalent, and the two methylene groups are chemically equivalent; all carbons with different CMR chemical shifts are chemically nonequivalent. INSTRUCTOR SUPPLEMENTAL SOLUTIONS TO PROBLEMS • CHAPTER 19 2 19.7 (a) The double bonds in 2-cyclohexenone are conjugated, but the double bonds in 3-cyclohexenone are not. Consequently, 2-cyclohexenone has the UV spectrum with the greater lmax. 19.9 Compound A, vanillin, should have a p T p* absorption at a greater lmax when dissolved in NaOH solution because the resulting phenolate can delocalize into the carboxaldehyde group; the resulting phenolate from compound B, isovanillin, on the other hand, can only delocalize in the aromatic ring. 19.11 The mass spectrum of 2-heptanone should have major peaks at m/z = 43 (from a-cleavage), 71 (from inductive cleavage), and 58 (from McLafferty rearrangement). -
Synthesis and Characterization of Some Novel Mannich Base Compounds
Synthesis and Characterization of Some Novel Mannich Base Compounds Dr. P. Sounthari Dr. P. R. Sivakumar Dr. P. Sounthari Dr. P.R. Sivakumar Assistant Professor, PG & Research Department of Department of Chemistry, Chemistry, PSG College of Arts and Government Arts Science, Coimbatore- College (Autonomous), 641 014. Coimbatore - 641 018, Tamil Nadu, India. ISBN 978-93-89631-02-9 ISBN 978-93-89631-04-3 (eBook) https://doi.org/10.34256/ioriip196 © IOR INTERNATIONAL PRESS. This book is an open access publication. Open Access This book is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. The images or other third party material in this book are included in the book’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the book’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication.