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Topic: Esterification


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In the News (Sat 25 Oct 14)

  
  physics - Esterification
Esterification is the general name for a chemical reaction in that an ester is the reaction product.
the Fischer esterification (refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst) in the absence of water with alcohol/phenole
The Fischer esterification of acetic acid in excess ethanol in the presence of sulfuric acid resulting in the ester ethyl acetate.
www.physicsdaily.com /physics/Esterification   (319 words)

  
 Process for esterification in a chromatographic reactor - Patent 6586609
Process for the esterification of organic acids with alcohols in a reactor of the chromatographic type in which the heterogeneous solid phase is capable of acting both as an esterification catalyst and as a means exhibiting preferential adsorption towards one of the reaction products (typically water).
Esterification reactions are limited by a chemical equilibrium and therefore techniques for the industrial preparation of an ester involve two consecutive steps.
In the case of carboxylic acids that are soluble under the esterification reaction conditions, the organic solvent is normally the carboxylic acid; alternatively, in the case of carboxylic acids that are insoluble and alcohols that are soluble under the esterification reaction conditions, the organic solvent is the alcohol
www.freepatentsonline.com /6586609.html   (4529 words)

  
 Esterification process - Patent 6255442
In producing polyalkylene terephthalates by direct esterification, terephthalic acid and an alkylene glycol are reacted in the presence of a catalyst to form a monomer and water.
This example demonstrates the esterification reaction of terephthalic acid with 1,3-propanediol using a combination of n-butylstannoic acid (31 ppm of tin based on TPA) and tetraisopropyl titanate (62 ppm of Ti based on TPA) as the esterification catalyst.
The catalyst concentration used during the esterification reaction is given in the table as the parts per million (ppm) relative to the weight of TPA or as mg catalyst per kg TPA.
www.freepatentsonline.com /6255442.html   (4367 words)

  
 Phosphorous acid catalyzed phenol esterification - Patent 4610825
A phosphorous acid or mixture of phosphorous acids is used as catalyst in the esterification reaction of phenol and carboxylic acids.
Esterification in accord with this invention is effected by introducing at least one phenol compound, at least one organic carboxylic acid, and phosphorous acid compound (as catalyst) into a reaction zone (e.g., a vessel).
For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto-appended claims.
www.freepatentsonline.com /4610825.html   (3550 words)

  
 Fischer esterification - Wikipedia, the free encyclopedia
Fischer esterification is a special type of esterification and the process of forming an ester by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst.
Commonly used catalysts for a Fischer esterification include sulfuric acid or lewis acids such as scandium(III) triflate.
An example of an esterification is in the formation of benzocaine.
en.wikipedia.org /wiki/Fischer_esterification   (336 words)

  
 Microscale Esterification of Peptides and Analysis by MALDI-MS   (Site not responding. Last check: 2007-10-13)
Esterification reactions were carried out with methanol, ethanol, hexanol and benzyl alcohol; ester formation was detected by the appropriate mass shift.
The esterification protocol was applied to the characterization of a novel gonadotropin releasing hormone (GnRH) isolated from cichlid pituitaries (2), since less than 1 pmol of material remained to determine the C-terminus of the peptide.
Esterification with ethanol was carried out in the presence of bombesin free acid as an internal control.
www.salk.edu /LABS/pbl/brukeran1.html   (1244 words)

  
 Organic Chemistry   (Site not responding. Last check: 2007-10-13)
The esterification of long-chain fatty acids such as lauric, stearic, oleic, elaidic, and linoleic acids in excess alcohol was accelerated under high pressure.
The esterification of unsaturated fatty oleic, elaidic, and linoleic acids with methyl alcohol was accelerated by greater compression and activation volume ranged from -27 to -33 cm
With dichloromethane as solvent in the esterification of long-chain fatty acids with methyl alcohol, the reactions were greatly accelerated at high pressure with apparent activation volume from 0.4 MPa to 200 MPa and as much as -80 cm
www.aist.go.jp /NIMC/publication/annual97/06/06_11.html   (142 words)

  
 Effects of Drugs on Cholesterol Esterification in Normal and Niemann-Pick Type C Fibroblasts
Furthermore, in the present study which demonstrated that A Y-9944 and other CADs caused a marked reduction of cholesterol esterification in control fibroblasts and an excessive intracellular accumulation of unesterified cholesterol as in NPC cells, and that this reduction could partially be,corrected by the addition of 2% DMSO to the medium.
Esterification of LDL-derived cholesterol in fibroblasts treated with AY-9944 reduced to 0.5 nmol/mg prot at 24 hours of incubation, and the reduced activity remained almost unchanged during subsequent incubation.
However, the mechanism of the effect of CADs on cholesterol esterification may be related to the alteration of membrane permeability, as imipramine did.
www.dmso.org /articles/niemannpick/effects.htm   (2701 words)

  
 Insulin increases FA uptake and esterification but reduces lipid utilization in isolated contracting muscle -- Dyck et ...
Triacylglycerol esterification (A) and hydrolysis (B) in soleus in the presence and absence of insulin (10 mU/ml).
The stimulatory effect of insulin on FA uptake and esterification was additive to that of contraction.
uptake and esterification to PL and TG and inhibition of TG hydrolysis
ajpendo.physiology.org /cgi/content/full/281/3/E600   (5532 words)

  
 Esterification   (Site not responding. Last check: 2007-10-13)
esterification of a carboxylic acid with an alcohol in the presence of an acid catalyst (Fischer esterification); 2.
This esterification proceeds via the nucleophilic attack of an alcohol on the protonated carbonyl group of a carboxylic acid to yield a tetrahedral intermediate, Scheme I. The ester and water are
Since esterification of primary alcohols is readily reversible, the products are only slightly favored at equilibrium.
www.bradley.edu /las/chm/Course/351/FischerEsterificationA.htm   (680 words)

  
 The Distal Pathway of Lipoprotein-induced Cholesterol Esterification, but Not Sphingomyelinase-induced Cholesterol ...
SMase treatment causes esterification of endogenous plasma membrane cholesterol (24), and thus one might expect similar mechanisms of cholesterol transport to ACAT as that seen in the distal pathway of lipoprotein-induced cholesterol esterification.
The inhibition of cholesterol esterification in energy-depleted cells was not due to increased cellular cholesterol efflux, which was not affected by energy depletion (11.9 ± 1.0% of cellular cholesterol effluxed in control cells versus 11.4 ± 1.6% in energy-depleted cells).
Lipoprotein-induced cholesterol esterification in macrophages is a prominent and important event during atherogenesis (1, 2, 3, 4, 5, 6).
www.jbc.org /cgi/content/full/271/23/13392   (7081 words)

  
 Fischer Esterification   (Site not responding. Last check: 2007-10-13)
Eleven different starting compounds were used to study the effects of substituents on the benzene ring of benzoic acid.
Yields were found to follow trends based on the effect of the substituent on the aromatic carboxylic acid and its position.
The substituent was either electron-withdrawing or electron-donating towards the carboxylic acid functional group.
www.heidelberg.edu /depts/chm/fischer.html   (636 words)

  
 An Intensified Esterification Process of Palm Oil Fatty Acid Distillate Catalyzed by Delipidated Rice Bran Lipase
An intensified esterification process was operated by circulating 10 l of reaction mixtures, consisting of palm oil fatty acid distillate (PFAD) and glycerol in hexane, through a packed-bed reactor (PBR) filled with 10 kg of delipidated rice bran lipase (RBL).
The influence of the process parameters, such as reaction temperature and type of water-removal agent, on the performance of this intensified esterification process were investigated.
The highest degree of esterification (61%) was achieved at a reaction temperature of 65ºC, using silica gels as the water-removal agent.
www.thescientificworld.com /SCIENTIFICWORLDJOURNAL/toc/TSWJ_ArticleLanding.asp?ArticleId=2268&jid=&toggleArticleCloud=1   (331 words)

  
 Esterification of commodity acetates : ethyl acetate and n-butyl acetate by Amberlyst Polymeric Catalysts
Esterification of commodity acetates : ethyl acetate and n-butyl acetate by Amberlyst Polymeric Catalysts
Methyl acetate is used in the United States as a chemical intermediate to produce acetic anhydride.
The traditional method of acetate production is by esterification of acetic acid with alcohol in the presence of sulfuric acid or sulfonic acid catalyst.
www.amberlyst.com /acetates.htm   (208 words)

  
 Esterification : Acrylate esters (MA, EA, BA, MMA, 2-EHA)   (Site not responding. Last check: 2007-10-13)
Acrylic acid and its esters are perhaps some of the most versatile monomers for improving performance characteristics to thousands of polymer formulations.
Speciality acrylate esters are made from isobutanol, isooctyl alcohol and several polyols such as Hydroxyalkyl, alkylalkanolamine and are manufactured in minor quantities to produce specialty polymeric materials.
The direct esterification of alcohol with acrylic acid is the only significant route for the production of esters.
www.rohmhaas.com /ionexchange/IP/acrylate.htm   (288 words)

  
 Esterification process - Patent 6887953
It is further desirable to develop a process for producing 3GT by a continuous esterification of TPA with 3G to produce an oligomer and using the oligomer for polymerization to high molecular weight 3GT polymer that does not exhibit filterability problems during spinning.
The present invention provides a process for direct esterification of a dicarboxylic acid and a glycol to produce an oligomer comprising repeat units derived from the acid and the glycol.
Because such esterification vessel is well known to one skilled in the art, the description of which is omitted for the interest of brevity.
www.freepatentsonline.com /6887953.html   (4852 words)

  
 Interleukin-4 augments acetylated LDL-induced cholesterol esterification in macrophages -- Cornicelli et al. 41 (3): ...
IL-4 augmentation of AcLDL-induced cholesterol esterification is inhibited by fucoidan.
MPM were incubated with 10 ng/ml IL-4 for 48 h prior to incubation in the absence of lipoproteins (basal) or in the presence AcLDL (50 µg/ml).
The anti-SR-A monoclonal antibody, 2F8, attenuates the IL-4 augmentation of AcLDL-induced cholesterol esterification.
www.jlr.org /cgi/content/full/41/3/376   (4399 words)

  
 HSC Online
identify esterification as the reaction between an acid and an alkanol and describe, using equations, examples of esterification  
Esterification is catalysed by the addition of a small amount of acid.
Esterification requires heat for the reaction to reach equilibrium within an hour, rather than after many days.
hsc.csu.edu.au /chemistry/core/acidic/chem935/chem935net.html   (1249 words)

  
 A study esterification reactions resources and help   (Site not responding. Last check: 2007-10-13)
Esterification reactions with C. rugosa lipase and M. javanicus lipase exhibited preferences...www.ejbiotechnology.info/content/ vol3/issue3/full/3/bip/index.html - 23k - Cached - Similar pages Full Text - Immobilization and stability studies of a lipase from...The optimum temperature for esterification reactions was determined to be 60- 65ºC.
Science Project _ A study of esterification reactions - An esterification is a reaction which achieves this.
Alcohol esterification reactions and mechanisms of snake venom 5...
www.kidsexperimentshelp.info /astudyesterificationreactions.html   (2682 words)

  
 BIP - Lipase-catalyzed enantioselective esterification of flurbiprofen with n-butanol
One approach that may be used to obtain a pure enantiomer of flurbiprofen from its racemic mixture is to use lipase in an organic medium to catalyze the esterification of the flurbiprofen with an alcohol, such as n-butanol.
Since the three solvents possess similar physical properties, the explanation for this anomalous behavior might be the effect of the solvent structural characteristics on Crl, since isooctane is the only branched alkane.
The results of this study suggest that the enantioselective esterification of flurbiprofen catalyzed by lipases is significantly influenced by the nature of the solvent, the source of the lipase, and the activity of water in the reaction medium.
www.ejbiotechnology.info /content/vol3/issue3/full/3/bip   (1145 words)

  
 Tackifiers
Improved stability can be developed by several processes such as hydrogenation, disproportionation, and dimerization, followed by esterification of the rosin with glycerol or pentaerythritol.
A particularly exceptional catalyst for esterification is Ciba® IRGAMOD® 195.
Ciba® IRGANOX® B 551 combines the esterification catalyst with a bleaching agent, which is useful in further improving the initial color of rosin esters.
www.cibasc.com /ind-pla-adh-app-tackifiers   (227 words)

  
 Amazon.com: Esterification: Books   (Site not responding. Last check: 2007-10-13)
Esterification: An entry from Thomson Gale's Gale Encyclopedia of Science, 3rd ed.
Esterification does not impair lutein bioavailability in humans: An article from: The Journal of Nutrition by Phyllis E Bowen, Suzanne M Herbst-Espinosa, Erum A Hussain, and Maria Stacewicz-Sapuntzakis (Digital - Dec 31, 2002) - HTML
Esterification equilibria in the gaseous phase, ([Contribution from the Cobb chemical laboratory of the University of Virginia) by Graham Edgar (Unknown Binding - 1924)
www.amazon.com /s?ie=UTF8&keywords=Esterification&tag=httpexplaguid-20&index=books&link_code=qs&page=1   (431 words)

  
 Thermodynamics of Phase and Chemical Equilibrium in a Strongly Nonideal Esterification System
In this study, the reaction equilibrium of the reversible esterification of acetic acid with 1-butanol giving 1-butyl acetate and water was investigated.
In experiments concerning reactive subsystems (subsystems containing both butanol and acetic acid), reaction I cannot be totally avoided using a circulating still because acetic acid catalyzes both the esterification reaction and the hydrolysis of the ester.
On the basis of a comprehensive experimental investigation and literature data, thermodynamic models of both phase and reaction equilibrium of the esterification system containing acetic acid, 1-butanol, 1-butyl acetate, and water were developed.
pubs.acs.org /cgi-bin/sample.cgi/jceaax/2005/50/i01/html/je0498199.html   (4811 words)

  
 Fischer Esterification
The Lewis or Brønstedt acid-catalyzed esterification of carboxylic acids with alcohols to give esters is a typical reaction in which the products and reactants are in equilibrium.
The equilibrium may be influenced by either removing one product from the reaction mixture (for example, removal of the water by azeotropic distillation or absorption by molecular sieves) or by employing an excess of one reactant.
Another pathway for the production of esters is the formation of a carboxylate anion, which then reacts as a nucleophile with an electrophile (similar reactions can be found here).
www.organic-chemistry.org /namedreactions/fischer-esterification.shtm   (273 words)

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