DOCSLIB.ORG

Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using Cuxznyo Mixed Metal Oxide Nanoparticles

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using Cuxznyo Mixed Metal Oxide Nanoparticles catalysts Article Selective Catalytic Oxidation of Toluene to Benzaldehyde: Effect of Aging Time and Calcination Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles Khadijah H. Alharbi 1,*, Ali Alsalme 2 , Ahmed Bader A. Aloumi 2 and Mohammed Rafiq H. Siddiqui 2,* 1 Department of Chemistry, Science and Arts College, Rabigh Campus, King Abdulaziz University, Jeddah 21911, Saudi Arabia 2 Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; [email protected] (A.A.); [email protected] (A.B.A.A.) * Correspondence: [email protected] (K.H.A.); rafi[email protected] (M.R.H.S.); Tel.: +966-563180807 (K.H.A.); +966-(0)114676082 (M.R.H.S.) Abstract: Oxidation is an important organic transformation, and several catalysts have been reported for this conversion. In this study, we report the synthesis of mixed metal oxide CuxZnyO, which is prepared by a coprecipitation method by varying the molar ratio of Cu and Zn in the catalytic system. The prepared mixed metal oxide CuxZnyO was evaluated for catalytic performance for toluene oxidation. Various parameters of the catalytic evaluation were studied in order to ascertain the optimum condition for the best catalytic performance. The results indicate that aging time, calcination temperature, reaction temperature, and feed rate influence catalytic performance. It was found that the catalyst interfaces apparently enhanced catalytic activity for toluene oxidation. The Citation: Alharbi, K.H.; Alsalme, A.; XRD diffractograms reveal the crystalline nature of the mixed metal oxide formed and also confirm Aloumi, A.B.A.; Siddiqui, M.R.H. the coexistence of hexagonal and monoclinic crystalline phases. The catalyst prepared by aging for 4 h Selective Catalytic Oxidation of and calcined at 450 ◦C was found to be the best for the conversion of toluene to benzaldehyde while Toluene to Benzaldehyde: Effect of the reactor temperature was maintained at 250 ◦C with toluene fed into the reactor at 0.01 mL/min. Aging Time and Calcination The catalyst was active for about 13 h. Temperature Using CuxZnyO Mixed Metal Oxide Nanoparticles. Catalysts 2021, 11, 354. https://doi.org/ Keywords: oxidation of toluene; mixed metal oxide; heterogeneous catalysis 10.3390/catal11030354 Academic Editor: Sónia Carabineiro 1. Introduction Received: 26 January 2021 Toluene, an aromatic hydrocarbon, is a solvent that is an important industrial feed- Accepted: 5 March 2021 stock. Moreover, it is also an important starting material for the preparation of benzalde- Published: 9 March 2021 hyde and benzyl alcohol. However, this transformation has intrigued scientists for a long time as this oxidation is difficult because of the over oxidation of benzaldehyde into ben- Publisher’s Note: MDPI stays neutral zoic acid. Hence, the benzoic acid production is carried out by the oxidation of toluene, with regard to jurisdictional claims in while the chlorination of toluene is employed for the production of benzaldehyde and published maps and institutional affil- benzyl alcohol, which raises serious ecological issues [1–3]. A variety of transition metal iations. catalysts have been reported for the synthesis of benzaldehyde using a variety of substrates as starting materials such as benzyl chloride, benzyl alcohol, and toluene, as mentioned earlier (Scheme1)[ 4,5]. However, the preparation of benzaldehyde from toluene oxidation is more efficient for industrial production, and hence it is widely studied. Copyright: © 2021 by the authors. Various noble-metal-based catalysts such as Au, Pd, Pt, Ru, and Ag, along with their Licensee MDPI, Basel, Switzerland. alloys, have been utilized for the oxidation of toluene by oxygen [6–10]. However, in most This article is an open access article cases, the selectivity towards benzaldehyde is compromised; moreover, these catalysts are distributed under the terms and not cost-effective for use in large-scale production. Hence, it can be said that a cheap and conditions of the Creative Commons efficient catalytic system for high toluene conversion is yet to be identified. Attribution (CC BY) license (https:// In order to replace the noble metals, cheaper alternatives are being probed by replacing creativecommons.org/licenses/by/ these noble metals with cheaper transition metals for a variety of chemical reactions [11–14]. 4.0/). Catalysts 2021, 11, 354. https://doi.org/10.3390/catal11030354 https://www.mdpi.com/journal/catalysts Catalysts 2021, 11, 354 2 of 14 One such transition metal is Zn, and zinc-based catalysts have been widely used for various conversions such as decomposition of nitrous oxide [15], oxidation of water [16], hydrocarbon oxidation [17], dye degradation [18], and preparation of alcohols [19–22]. Catalysts 2021, 11, x FOR PEER REVIEWOn the other hand, copper-based catalysts have also been broadly employed for several 2 of 14 conversions, such as CO oxidation [23], benzene oxidation [24], and the hydroxylation of benzene [25]. Scheme 1. Schematic representation of oxidation of toluene. Scheme 1. Schematic representation of oxidation of toluene. Mixed metal oxides have also attracted attention for other catalytic reactions such as oxidation, dehydrogenation, and various coupling reactions [26–29]. However, one suchIn mixed order metal to replace oxide, zinc–copper the noble mixedmetals, oxide cheaper catalyst, alternatives has gained attention are being due probed by replac- ingto these its use noble in a plethora metals of catalyticwith cheaper processes, transition particularly metals for methanol for a synthesisvariety [of30], chemical reactions [11CO–14] oxidation. One such [31,32 ],transition methanol oxidation metal is [33 Zn], primary, and z alcoholsinc-based [34], catalyst and reductions have of been widely used 4-nitrophenol [35]. However, to the best of our knowledge, it has not been employed for forthe various conversion conve of toluenersions to benzaldehyde.such as decomposition of nitrous oxide [15], oxidation of water [16], hydrocarbonHence, based on theoxidation above literature [17], reportsdye degradation and in continuation [18] of, ourand studies preparation towards of alcohols [19– 22]preparation. On the other of various hand catalysts, copper for different-based conversion catalysts reactions have also [36– 42been], in thebroadly present employed for sev- work we report the synthesis of CuxZnyO mixed oxide by coprecipitation with varied eralaging conversions time and calcination, such as temperature. CO oxidation The prepared[23], benzene catalysts oxidation were characterized [24], and by the hydroxylation of variousbenzene techniques [25]. such as XRD, XPS, FT-IR, TGA, SEM, and TEM. The catalysts obtained wereM studiedixed metal for the oxides optimization have of also reaction attracted conditions attention for the conversionfor other ofcatalytic toluene reactions such as to benzaldehyde. oxidation, dehydrogenation, and various coupling reactions [26–29]. However, one such mixed2. Results metal oxide, zinc–copper mixed oxide catalyst, has gained attention due to its use in 2.1.a plethora XRD Analysis of catalytic processes, particularly for methanol synthesis [30], CO oxidation [31,32]The, methanol CuxZnyO mixed oxidation metal oxide [33] nanoparticles, primary werealcohols synthesized [34], byand the coprecipita-reduction of 4-nitrophenol tion method and subjected to calcination at different temperatures, namely 350, 450, and [35]550. However,◦C. The XRD to pattern the ofbest the of samples our knowledge calcined at different, it has temperatures not been is employed presented in for the conversion of Figuretoluene1. No to observable benzaldehyde. difference was found among the three XRD patterns observed. HenceA comparison, based of XRDon the patterns above obtained literature for CuxZn reportsyO mixed and metal in oxide continuation nanoparticles of our studies to- calcined at 450 ◦C with standard peaks is displayed in Figure2. The high-intensity sharp wardspeak confirmedpreparation the highly of crystallinevarious naturecatalysts of the material.for different The peaks conversion observed completely reactions [36–42], in the presentmatched work those reportedwe report in the databasethe synthesis for CuO (JCPDSof Cu 48-1548)xZnyO andmixed ZnO (JCPDSoxide 36-1451). by coprecipitation with variedThe XRD aging pattern time obtained and indicatedcalcination the absence temperature. of any other The molecules prepared of Znand catalyst Cu, sinces were characterized there were no additional peaks observed in the XRD pattern. The pattern observed in the byZnO various diffractogram techniques at 31.83(100), such 34.45(002),as XRD, 36.30(101),XPS, FT- 47.57(012),IR, TGA, 56.65(110), SEM, and 62.90(013), TEM. The catalysts ob- tained66.28(200), were 68.03(112), studied 69.11(201), for the optimization 72.47(004), and 76.97(202)of reaction confirmed conditions the formation for the of conversion of tol- uehexagonalne to benzaldehyde. structure like wurtzite (space group: P63mc, lattice parameters: a = 3.2533 Å and c = 5.2073 Å) [22]. Similarly, the remaining signals at 32.64(110), 35.56(11-1), 38.75(111), 46.26(−112), 48.78(20-2), 53.49(020), 56.63(021), 58.38(202), 61.55(−113), 65.85(022), 2. 66.28(Results31-1), 68.03(113), 72.45(311), and 75.20(22-2) were confirmed to be of CuO in tenorite crystal with monoclinic crystal structure (space group: C1c1, lattice parameters: a = 4.6893 Å, 2.1.b =XRD 3.4268 A Å,nalysisc = 5.1321 Å, and b = 99.653◦)[22]. The CuxZnyO mixed metal oxide nanoparticles were synthesized by the coprecipita- tion method and subjected to calcination at different temperatures, namely 350, 450, and 550 °C. The XRD pattern of the samples calcined at different temperatures is presented in Figure 1. No observable difference was found among the three XRD patterns observed. CatalystsCatalysts 2021,2021 11,, x11 FOR, 354 PEER REVIEW 3 of 14 3 of 14 Catalysts 2021, 11, x FOR PEER REVIEW 4 of 14 ◦ Figure 1. XRD patterns of CuxZnyO mixed metal oxide nanoparticles calcined at 350, 450, and 550 C. Figure 1. XRD patterns of CuxZnyO mixed metal oxide nanoparticles calcined at 350, 450, and 550 °C .
Load more

Recommended publications
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • New Insights Into the Mechanism of Schiff Base Synthesis from Aromatic
    A peer-reviewed version of this preprint was published in PeerJ on 15 December 2020. View the peer-reviewed version (peerj.com/articles/ochem-4), which is the preferred citable publication unless you specifically need to cite this preprint. Silva PJ. 2020. New insights into the mechanism of Schiff base synthesis from aromatic amines in the absence of acid catalyst or polar solvents. PeerJ Organic Chemistry 2:e4 https://doi.org/10.7717/peerj-ochem.4 New insights into the mechanism of Schiff base synthesis from aromatic amines in the absence of acid catalyst or polar solvents Pedro J Silva Corresp. 1 1 FP-ENAS/Fac. de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal Corresponding Author: Pedro J Silva Email address: [email protected] 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 delocalisation and enable sufficient transition state stabilisation. These insights cannot, however, be applied to the understanding of the reaction pathway in apolar solvents due their inability to form extensive hidrogen-bonding networks. In this work, we perform the first computational studies of this reaction in apolar 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 an additional molecule of amine may provide enough stabilization of the first transition state even in the absence of a hydrogen bonding network. Our computations also show that the second reaction step cannot take place unless an extra proton is added to the system but, crucially, that reaction rate is so high that even picomolar amounts of protonated base are enough to achieve realistic rates.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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-
    [Show full text]
  • 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).
    [Show full text]
  • Convenient Reductive Amination of Aldehydes by Nabh4/Cation Exchange Resin
    J. Mex. Chem. Soc. 2014, 58(1), 22-26 Article22 J. Mex. Chem. Soc. 2014, 58(1) Davood© Setamdideh2014, Sociedad and FarhadQuímica Sepehraddin de México ISSN 1870-249X Convenient Reductive Amination of Aldehydes by NaBH4/Cation Exchange Resin Davood Setamdideh* and Farhad Sepehraddin Department of Chemistry, College of Sciences, Mahabad Branch, Islamic Azad University, Mahabad, Iran. [email protected]; [email protected] Received June 10th, 2013; Accepted September 18th, 2013 Abstract. Different secondary amines have been synthesized by re- Resumen. Se sintetizaron diversas aminas secundarias por aminación ductive amination a variety of aldehydes and anilines with NaBH4/ reductiva de una variedad de aldehidos y anilinas empleando como DOWEX(R)50WX8 as reducing system in THF at room temperature sistema reductor NaBH4/DOWEX(R)50WX8 en THF a temperatura in high to excellent yields of products (85-93%). ambiente con rendimientos de altos a excelentes. Key words: NaBH4, DOWEX(R)50WX8, Reductive amination, Car- Palabras clave: NaBH4, DOWEX(R)50WX8, aminación reductiva, bonyl compounds. aminas secundarias. Introduction Results and Discussion Amines are important in drugs and in active pharmaceuti- Recently, we have reported that the DOWEX(R)50WX4 (low cal intermediates. Amines can be achieved by reduction of price cation exchange resin, strong acid) can be used as recy- nitro, cyano, azide, carboxamide derivatives or alkylation of clable catalyst for the regioselective synthesis of Oximes by amines (using alkyl halides or sulfonates). On the other hand, NH2OH.HCl/DOWEX(R)50WX4 system [31], reduction of a direct reductive amination (DRA) is other approach which of- variety of carbonyl compounds such as aldehydes, ketones, α- fers significant advantages.
    [Show full text]
  • Catalytic Oxidation of Toluene with Molecular Oxygen Over Manganese Tetraphenylporphyrin Supported on Chitosan
    Available online at www.sciencedirect.com Applied Catalysis A: General 338 (2008) 83–86 www.elsevier.com/locate/apcata Catalytic oxidation of toluene with molecular oxygen over manganese tetraphenylporphyrin supported on chitosan Guan Huang a,*, Jin Luo a, Cao Cheng Deng b, Yong An Guo a, Shu Kai Zhao a, Hong Zhou a, Shan Wei a a College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, PR China b Guangxi Traditional Chinese Medical University, Nanning 530001, PR China Received 13 September 2007; received in revised form 18 December 2007; accepted 23 December 2007 Available online 8 January 2008 Abstract Catalysis by simple manganese tetraphenylporphyrin [Mn TPP] supported on chitosan [CTS] for liquid phase aerobic oxidation of toluene has been investigated. The toluene conversion depends on the reaction temperature, the air pressure and the amount of catalyst, but the selectivity for aldehyde and alcohol is little affected by these three parameters. Using the Mn TPP/CTS containing 2 mg of Mn TPP as a catalyst, the aerobic oxidation of toluene under the optimum conditions of 195 8C and 0.6 MPa produced benzaldehyde and benzyl alcohol at 96% selectivity with 5.9% conversion of toluene. The catalyst can be reused once. Chitosan played an important role in the catalytic oxidation of toluene. # 2008 Elsevier B.V. All rights reserved. Keywords: Chitosan; Manganese tetraphenylporphyrin; Toluene oxidation; Air 1. Introduction catalysts have great advantages because of their easy separation and recovery from the reaction mixture, widespread application At present, stringent ecological standards require extensive and effectiveness in environmentally friendly conditions [19,20].
    [Show full text]
  • Regular Article Studies on Synthesis of Aldimines: Part
    Recent Research in Science and Technology 2018, 10: 23-27 doi: 10.25081/rrst.2018.10.3489 http://updatepublishing.com/journal/index.php/rrst/ ISSN: 2076-5061 R E G U L A R A RTICLE STUDIES ON SYNTHESIS OF ALDIMINES: PART-I. SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF ALDIMINES FROM BENZALDEHYDE WITH VARIEDLY SUBSTITUTED ANILINES C. J. PATIL1*, MANISHA C. PATIL2, MRUNMAYEE C. PATIL3 1Organic Chemistry Research Laboratory, Department of Chemistry, Smt. G. G. Khadse College, Muktainagar, Dist-Jalgaon-425 306, M.S., India 2Department of Zoology, Dr. A. G. D. Bendale Mahila College, Jalgaon, Dist-Jalgaon-425 001, M.S., India. 3Department of Pharmaceutical Science and Technology, Nathalal Parekh Marg, Institute of Chemical Technology, Matunga, Mumbai-400 019, M.S., India ABSTRACT A conventional condensation reaction of an aromatic aldehyde, Benzaldehyde with seven different aromatic amines viz. Aniline, 2-Choro-aniline, 3-Choro-aniline, 4-Choro-aniline, 2-Nitro-aniline, 3-Nitro-aniline and 4-Nitro-aniline and reacted efficiently to synthesize a series of Aldmines, I to VII, in moderate to high yield and high purity. The reaction was monitored and the products were analyzed by employing the TLC technique. All the products obtained were characterized by their colour, physical constant, TLC, elemental analysis and spectral (UV-Vis and FTIR) method. The synthesized Aldimines were subjected to in vitro biological activity. Keywords: Aldimines or Schiff bases, Benzaldehyde, Conventional, TLC, UV-Vis, FTIR and biological activity INTRODUCTION concentration with ciprofloxacin as standard drug and 10% DMSO as control sample. From this laboratory, the synthesis of aldimines viz. of Schiff bases from Benzaldehyde and Anisaldehyde reacted In the present study we have putforth a conventional with aniline, p-bromo-aniline and p-methoxy-aniline by condensation reaction of an aromatic aldehyde viz.
    [Show full text]
  • Organic Chemistry, 5E (Bruice) Chapter 17: Carbonyl Compounds II
    Organic Chemistry, 5e (Bruice) Chapter 17: Carbonyl Compounds II 1) Which of the following compounds is an aldehyde? A) I B) II C) III D) IV E) V Answer: D Type: MC Section: 17-1 2) Which of the following compounds is a ketone? A) I B) II C) III D) IV E) V Answer: B Type: MC Section: 17-1 3) What is the common name for the following compound? A) chloroaldehyde B) α-chloroacetaldehyde C) β-chloroacetaldehyde D) 2-chloroethanal E) α-chloroethanal Answer: B Type: MC Section: 17-1 4) Which of the following compounds is acetone? A) B) C) D) E) Answer: A Type: MC Section: 17-1 5) What is the IUPAC name for the following compound? A) 2-bromobutanal B) α-bromobutanal C) 3-bromobutanal D) β-bromobutyraldehyde E) 3-bromobutanone Answer: C Type: MC Section: 17-1 6) Which of the following compounds is benzaldehyde? A) I B) II C) III D) IV E) V Answer: D Type: MC Section: 17-1 7) What is the IUPAC name for the following compound? A) 5-chloro-3-methylhexanone B) 1-chloro-1,3-dimethyl-4-pentanone C) 5-chloro-3,5-dimethyl-2-pentanone D) 5-chloro-3-methyl-2-hexanone E) 2-chloro-4-methyl-5-hexanone Answer: D Type: MC Section: 17-1 8) Which of the following is cyclohexanone? A) I B) II C) III D) IV E) V Answer: E Type: MC Section: 17-1 9) Provide the proper IUPAC name for PhCH 2CH(CH 3)CH 2CH 2CHO. Answer: 4-methyl-5-phenylpentanal Type: SA Section: 17-1 10) Provide the proper IUPAC name for CH 3CHOHCH 2COCH 2C(CH 3)2CH 2CH 3.
    [Show full text]
  • Alcohol Oxidations – Beyond Labz Virtual Chemlab Activity
    Alcohol Oxidations – Beyond Labz Virtual ChemLab Activity Purpose: In this virtual experiment, you will be performing two oxidation reactions of benzyl alcohol, a primary alcohol. Primary alcohols can be oxidized to aldehydes or carboxylic acids, depending on the reagents used. You will be setting up oxidation reactions using chromic acid (H2CrO4) and pyridinium chlorochromate (PCC), and comparing the products of the two reactions. You will be monitoring the reactions using thin-layer chromatography (TLC) and analyzing IR and NMR spectra of the reactants and products. O further O OH oxidation oxidation H OH benzyl alcohol benzaldehyde benzoic acid Figure 1. Oxidation reactions of benzyl alcohol Introduction: Primary alcohols can be oxidized to aldehydes or carboxylic acids, depending on the reagents used. For many years, chromium reagents were commonly used for alcohol oxidations. Because of the toxicity of chromium-based reagents, many safer oxidizing agents have been developed and are more commonly used. As this lab is virtual, we can safely explore the reactivity trends for the older, chromium-based reagents. The two reaction conditions we will be exploring in this virtual experiment are: • Jones oxidation: This reaction uses chromic acid (H2CrO4) as the oxidizing agent. Chromic acid can be formed by dissolving sodium dichromate (Na2Cr2O7) or chromium trioxide (CrO3) in aqueous sulfuric acid (H2SO4). • PCC oxidation: This reaction uses pyridinium chlorochromate (PCC) in an anhydrous solvent, typically dichloromethane (CH2Cl2). The virtual lab does not give us CH2Cl2 as an option for a solvent, so we will substitute diethyl ether (CH3CH2OCH2CH3, or Et2O). Once your two virtual experiments are complete, you will decide which set of conditions oxidizes primary alcohols to aldehydes, and which oxidizes primary alcohols to carboxylic acids.
    [Show full text]