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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]
Standard acid catalysts are sulfuric acid or a mixture of BF 3 and HF. Although the use of acidic ionic liquids for the Koch reaction requires relatively high temperatures and pressures (8 MPa and 430 K in one 2006 study [ 9 ] ), acidic ionic solutions themselves can be reused with only a very slight decrease in yield, and the reactions can be ...
Alcohol oxidation is a collection of oxidation reactions in organic chemistry that convert alcohols to aldehydes, ketones, carboxylic acids, and esters. The reaction mainly applies to primary and secondary alcohols. Secondary alcohols form ketones, while primary alcohols form aldehydes or carboxylic acids. [1] A variety of oxidants can be used.
The classic synthesis is the Fischer esterification, which involves treating a carboxylic acid with an alcohol in the presence of a dehydrating agent: RCO 2 H + R'OH ⇌ RCO 2 R' + H 2 O. The equilibrium constant for such reactions is about 5 for typical esters, e.g., ethyl acetate. [15] The reaction is slow in the absence of a catalyst.
The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester RCO 2 H + R′OH ⇌ RCO 2 R′ + H 2 O. Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water.
The resulting carboxylic acid quickly protonates the alkoxide ion to give a carboxylate ion and an alcohol. [1] Water is often used as a solvent, but the presence of water is not necessary; alcohols may also be used as solvents, with dissolved hydroxide ion performing hydrolysis. [2]
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.
For oxidations to the aldehydes and ketones, two equivalents of chromic acid oxidize three equivalents of the alcohol: 2 HCrO 4 − + 3 RR'C(OH)H + 8 H + + 4 H 2 O → 2 [Cr(H 2 O) 6] 3+ + 3 RR'CO. For oxidation of primary alcohols to carboxylic acids, 4 equivalents of chromic acid oxidize 3 equivalents of the alcohol. The aldehyde is an ...