DOCSLIB.ORG

Green Synthesis of Natural Benzaldehyde from Cinnamon Oil Catalyzed By&Nbsp;Hydroxypropyl-Β-Cyclodextrin

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Green Synthesis of Natural Benzaldehyde from Cinnamon Oil Catalyzed By&Nbsp;Hydroxypropyl-Β-Cyclodextrin Tetrahedron 66 (2010) 9888e9893 Contents lists available at ScienceDirect Tetrahedron journal homepage: www.elsevier.com/locate/tet Green synthesis of natural benzaldehyde from cinnamon oil catalyzed by hydroxypropyl-b-cyclodextrin Hongyan Chen a,b, Hongbing Ji a,*, Xiantai Zhou a, Lefu Wang c a School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China b Department of Chemical Engineering, Huizhou University, Huizhou 516007, China c School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China article info abstract Article history: The efficient synthesis of natural benzaldehyde from natural cinnamon oil catalyzed by 2-hydroxypropyl- Received 12 June 2010 b-cyclodextrin (2-HPb-CD) in water under rather mild conditions has been developed. Various analysis Received in revised form 10 October 2010 methods, e.g., DSC, UVevis, 1H NMR, ROESY, and fluorescence measurements had been utilized to Accepted 22 October 2010 demonstrate formation of the 1:1 (molar ratio) complexes between 2-HPb-CD and cinnamaldehyde. The Available online 28 October 2010 À1 inclusion equilibrium constant Ka was 928 M at 298 K. The inclusion complex activated the substrate and promoted the reaction selectivity. The yield for benzaldehyde could reach 70% under the optimized Keywords: conditions (323 K, 5 h, 2% NaOH (w/v), cinnamaldehyde: 2-HPb-CD¼1:1 (molar ratio)). Further 2-Hydroxypropyl-b-cyclodextrin Cinnamaldehyde investigation on kinetics and solubilization revealed that the binding ability between 2-HPb-CD and Natural benzaldehyde cinnamaldehyde is primarily responsible for the catalytic effects. Inclusion complex Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction those methods did not give a high yield for benzaldehyde. Besides, the severe reaction conditions or strong oxidant would unavoidably Natural benzaldehyde, the second largest perfume in the world, decrease the natural essence of benzaldehyde. It is significant to has captivated many researchers’ interest both in organic synthesis develop a new and clean process under mild reaction conditions and industry, as benzaldehyde plays important roles in food, bev- with high selectivity for natural benzaldehyde and the natural erages, cosmetics, and pharmaceutical industries etc.1,2 Moreover, essence of benzaldehyde is well preserved. compared to chemically synthetic benzaldehyde, natural benzal- Supramolecular reactivity has attracted much attention over the e dehyde is more popular and represents a strong market advantage.3 past decade.11 13 As one of the important and nontoxic supramo- Generally natural benzaldehyde is from alkaline hydrolysis of Lae- lecular hosts, cyclodextrin (CD) has been widely introduced into trile catalyzed by enzyme, however, the process need thoroughly various aqueous-phase organic reactions including oxidation, e dispose of the toxic hydrocyanic acid, which results in high cost for reduction, ring opening and hydrolysis etc.14 20 It is able to catalyze production. chemical reactions because of its particular inclusion and kinetic In recent years, natural benzaldehyde can also be produced from properties. Specifically speaking the CDs can selectively form natural cinnamon oil through various clean processes. Yi and her hosteguest inclusion complex with guest molecule, which has group reported ozonization of natural cinnamon oils,4 the reaction appropriate size and polarity in aqueous solution under mild con- conditions were rather harsh (273 K, anhydrous conditions) and ditions, for they own a hollow truncated cylinder-shaped structure the yield of benzaldehyde was 62%. Gao and Lv used near-critical with one hydrophobic internal cavity and two hydrophilic external water (553 K, 15 MPa) as solvent for the conversion of cinna- faces.21,22 maldehyde, and the yield of benzaldehyde was 57%.5 As In this paper, a practical challenge is to explore a water-soluble manufacturing method, alkaline hydrolysis of cinnamaldehyde or and robust catalyst, that is, able to increase reaction selectivity for e natural cinnamon oil is desirable,6 10 but the reaction requires high the hydrolysis of cinnamaldehyde to benzaldehyde under mild temperature (373 e393 K), toxic phase transfer or surfactants cat- reaction conditions efficiently. For this purpose, 2-hydroxypropyl- alysts, and the yield of benzaldehyde was about 50%. Therefore, b-CD (2-HPb-CD) was used to catalyze the hydrolysis of cinna- maldehyde (Scheme 1). HPb-CD is a highly water-soluble derivative of natural b-CD, and is usually produced via a condensation reac- tion between b-CD and propylene oxide in alkaline solution, which * Corresponding author. Tel.: þ86 20 84113658; fax: þ86 20 84113654; e-mail can extend the physicochemical and inclusion properties and address: [email protected] (H. Ji). 0040-4020/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.tet.2010.10.063 H. Chen et al. / Tetrahedron 66 (2010) 9888e9893 9889 catalytic activities of natural b-CD. 2-HPb-CD means hydroxypropyl and 290 nm, the former is attributed to aldehyde group and the substitution only is at the O2 positions. It has been applied more other one is from its aromatic ring; besides, the absorption maxi- frequently than CD in food and pharmaceutical industry because of mum gradually increased at 220 nm and decreased at 290 nm along its relatively more flexible cavity sizes, greater water solubility and with increasing concentration of 2-HPb-CD. These behaviors may lower toxicity than the natural b-CD.23,24 be considered as the proof of cinnamaldehyde incorporating into the HPb-CD cavity, that is, both phenyl ring and aldehyde group of - O OH /H2O O cinnamaldehyde were entrapped into the 2-HPb-CD cavity, because + O the non-polar cavity of HPb-CD provided a smaller polar micro- 2-HPβ-CD environment, which enhanced dissolution of guest molecule, Scheme 1. Alkaline hydrolysis of cinnamaldehyde to benzaldehyde promoted by increased n/p* electron transition of aldehyde group and reduced e 2-HPb-CD. p/p* electron transition of phenyl ring.25 28 In contrast to transition-metal catalysts and organocatalysts, supramolecular catalysts employ non-covalent intermolecular interactions between host and guest molecule. The inclusion behavior of 2-HPb-CD with cinnamaldehyde was investigated by Differential Scanning Calorimetry (DSC), UVevis, 1H NMR, Rotat- ing-frame Overhauser Effect Spectroscopy (ROESY), and Fluores- cence measurement. These characteristic methods served as an aid for better understanding of how weak interactions affect reactivity. In order to get further insight into the catalytic effects of 2-HPb-CD for the alkaline hydrolysis, the solubilization of the CDs for cinna- maldehyde solubility in water was investigated and the reaction activation energy was calculated using the initial concentrations method. It has been found that the reactivity is driven by the binding ability between the host and the guest for the supramo- lecular catalytic system. The reported hydrolysis process in the present paper used green catalyst (2-HPb-CD) and green solvent (water) to realize the clean synthesis of natural benzaldehyde. 2. Results and discussion À Fig. 2. The absorption spectra of cinnamaldehyde (7.5Â10 5 mol/L) in the presence of À 2-HPb-CD with different concentrations (Â10 3 mol/L) at 298 K: (1) 0, (2)0.5, (3) 1.0, 2.1. Characterization of inclusion complex (4) 2.0, (5) 3.0, (6) 4.0, and (7) 5.0. 2.1.1. DSC results. DSC reveals some evidence about complex for- 2.1.3. NMR results. In order to provide a definitive proof of the for- mation between cinnamaldehyde and cyclodextrins. The DSC curves mation of the inclusion complex, 1H NMR spectroscopy was carried of pure components, physical mixture, and the inclusion complex of out using D2O as solvent, since the chemical and electronic envi- cinnamaldehyde/2-HPb-CD were presented in Fig. 1. A typical ther- ronments of protons changed during the inclusion complexation mal curve for pure cinnamaldehyde (curve b) was a broad endo- process, which is reflected by changes of chemical shifts (Dd¼din- thermic peak at 409 K corresponding to its boiling point. For the 29 clusionÀdfree). The comparison of the spectra for the individual physical mixture of cinnamaldehyde/2-HPb-CD, the characteristic components and the cinnamaldehyde/2-HPb-CD inclusion complex thermal profile of cinnamaldehyde (curve c) was distinguishable was shown in Fig. 3. The 1H chemical shift values for free cinna- and shifted to lower temperature of 395 K. The formation of the maldehyde and the complex were reported in Table 1. The spectrum inclusion complex can be strongly evidenced by the disappearance of the complex is significantly different from cinnamaldehyde and of the cinnamaldehyde endothermic peak (curve d). 2-HPb-CD. Cinnamaldehyde has six types of protons: aldehyde fi c hydrogen (1-H), ole nic hydrogens (2-H and 3-H), and aromatic protons (4-H, 40-H, 5-H, 50-H, and 6-H). From Fig. 3, all protons of cinnamaldehyde had clear chemical shifts. Remarkable shift was observed for 1-H, 3-H, 4-H, and 40-H protons in Table 1. It demon- b strates that inclusion complex was formed, and the highly hydro- phobic phenyl ring and unsaturated double bond entered into the d cavity of 2-HPb-CD. a 2D NMR studies revealed some useful information on the nature of the inter- and intra-actions between guest and cyclodextrin in the inclusion complexes.30 The contour map expansion for the inclusion complex with 1:1 cinnamaldehyde/2-HPb-CD (molar ratio) was presented in Fig. 4. The 2D ROESY spectra show corre- 0 50 100 150 200 250 300 o lations between the protons of 2-H (olefinic hydrogen) and 1-H Temperature ( C) (aldehyde hydrogen) in cinnamaldehyde and the protons of the Fig. 1. DSC thermograms of 2-HPb-CD (a), cinnamaldehyde (b), the physical mixture of internal hydrogen (H-3) and methyl hydrogen (CH3) in 2-HPb-CD, 2-HPb-CD and cinnamaldehyde (c), and the inclusion complex (d).
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]