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Fischer esterification or Fischer–Speier esterification is a special type of esterification by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst. The reaction was first described by Emil Fischer and Arthur Speier in 1895. [ 1 ]
The reaction is slow in the absence of a catalyst. Sulfuric acid is a typical catalyst for this reaction. Many other acids are also used such as polymeric sulfonic acids. Since esterification is highly reversible, the yield of the ester can be improved using Le Chatelier's principle: Using the alcohol in large excess (i.e., as a solvent).
This reaction sequence is thus a condensation reaction since there is a net loss of HCl when the two reactant molecules join. [7] Arrow-pushing mechanism for the Darzens reaction. If the starting halide is an α-halo amide, the product is an α,β-epoxy amide. [8] If an α-halo ketone is used, the product is an α,β-epoxy ketone. [2]
This reaction is exploited in native chemical ligation, a protocol for peptide synthesis. [8] In a related reaction, thioesters can be converted into esters. [9] Thioacetate esters can also be cleaved with methanethiol in the presence of stoichiometric base, as illustrated in the preparation of pent-4-yne-1-thiol: [10]
This reaction is important in the history of organic chemistry because it helped prove the structure of ethers. The general reaction mechanism is as follows: [3] An example is the reaction of sodium ethoxide with chloroethane to form diethyl ether and sodium chloride: C 2 H 5 Cl + C 2 H 5 ONa → C 2 H 5 OC 2 H 5 + NaCl
In acid catalysis and base catalysis, a chemical reaction is catalyzed by an acid or a base. By Brønsted–Lowry acid–base theory, the acid is the proton (hydrogen ion, H +) donor and the base is the proton acceptor. Typical reactions catalyzed by proton transfer are esterifications and aldol reactions.
Strong acids catalyze the reaction by donating a proton to the carbonyl group, thus making it a more potent electrophile. Bases catalyze the reaction by removing a proton from the alcohol, thus making it more nucleophilic. The reaction can also be accomplished with the help of enzymes, particularly lipases (one example is the lipase E.C.3.1.1.3 ...
An esterification reaction is a chemical reaction that creates an ester This category is part of a classification scheme based on the Royal Society of Chemistry RXNO Name Reaction Ontology. Pages in category "Esterification reactions"