However, as with any equilibrium process, the reaction can be driven in one direction by changing the concentration, pressure, temperature, or volume of the reagents. When the concentration of one of the reactants is increased, the equilibrium shifts in the direction that will decrease its concentration.
Thus, by increasing the concentration of one reactant, the equilibrium produces more of the product, thereby resulting in a higher yield of the ester product. One common method utilized in organic chemistry labs is to provide an excess of one of the reagents, typically the alcohol. As mentioned earlier, Fisher esterification can utilize sulfuric acid as a catalyst.
However, one of the other functions of sulfuric acid is to act as a dehydrating agent, sequestering water molecules away from the reaction. This increases the yield of the ester formed. To learn more about our GDPR policies click here. If you want more info regarding data storage, please contact gdpr jove. Your access has now expired. Provide feedback to your librarian. If you have any questions, please do not hesitate to reach out to our customer success team.
Login processing Esterification Reaction Esters are formed from an esterification reaction, with simple esters being formed through Fisher esterification. Reference Streitwieser, A. Introduction to Organic Chemistry. Please enter your institutional email to check if you have access to this content. Please create an account to get access. Forgot Password? Please enter your email address so we may send you a link to reset your password. To request a trial, please fill out the form below. A JoVE representative will be in touch with you shortly.
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In order to begin, please login. Please click here to activate your free hour trial. If you do not wish to begin your trial now, you can log back into JoVE at any time to begin. Phenyl ethanoate forms along with hydrogen chloride gas. The -COCl group attaches itself directly to a benzene ring. Benzoyl chloride is much less reactive than acyl chlorides such as ethanoyl chloride.
The phenol first converts into the ionic compound sodium phenoxide sodium phenate through dissolving it in sodium hydroxide solution. The phenoxide ion thus reacts more rapidly with benzoyl chloride as compared to the reaction of the original phenol. However, one has to shake it along with benzoyl chloride for about 15 minutes to get solid phenyl benzoate. This is a reaction that is useful to make esters from phenols and alcohols again.
Though the reactions are slower as against the corresponding reactions with an acid chloride, they usually warm the mixture as per their requirement. In the case of Amphenol, it reacts with the sodium hydrochloride solution initially to produce the more reactive phenoxide ion.
One can take ethanol to react with ethanoic anhydride which is the typical reaction involving alcohol, it is a slow reaction which is at room temperature. However, there is no visible change to be seen in these colorless liquids, but a mixture of ethanoic acid and ethyl ethanoate is formed.
The reaction with phenol is similar but slower. Phenyl ethanoate is formed together with ethanoic acid. This reaction is unimportant itself, but a very similar esterification reaction example is the manufacture of aspirin.
If the phenol is initially converted into sodium phenoxide by mixing with sodium hydroxide solution, then the reaction is much faster. Phenyl ethanoate is formed again, but this time the other product is sodium ethanoate and not ethanoic acid. This method is useful for converting alcohol into esters. However, this method does not work with phenols or compounds where the -OH group is attached to the benzene ring.
Since phenols react very slowly with carboxylic acids this reaction is not usable for the purpose of preparation. When carboxylic acids are heated with alcohols in the presence of a catalyst which is acid at such time esters are produced.
The catalyst is usually concentrated sulfuric acid. The esterification reaction is very slow and reversible. So, for example, the equation of ethyl ethanoate made from ethanoic acid and ethanol would be:.
An ester gets its name from the carboxylic acid that is used in the esterification reaction. Esters have a pleasant smell. They are highly useful in the perfume and food industries. They are organic compounds usually found in fats and oils. Some common uses of esters are as follows. Esters are fragrant and so are highly useful in perfumes cosmetics and food flavorings. They are useful as an organic solvent.
An ester Nitroglycerin is known and famous for its explosive properties. They are useful in the manufacturing of surfactants like soaps and detergents.
They have present in pheromones if they occur naturally. Phosphoesters from the backbone of DNA molecules.
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