Esterification
Encyclopedia : E : ES : EST : Esterification
Esterification is the general name for a chemical reaction in which two chemicals (typically an alcohol and an acid) form an ester as the reaction product. These are commonly used as fragrance or flavour agents.
Examples of esterification reactions include:
- Heating to reflux an acid (usually, but not always a carboxylic acid) and an alcohol in the presence of an catalyst forms the ester and water byproduct which can be removed to force the equibilibrium across to the desired products. This method is called Fischer esterification
- For example, esterification of acetic acid in excess ethanol in the presence of sulfuric acid results in an ester (ethyl acetate).
H3C-COOH + HO-CH2-CH3 → H3C-COO-CH2-CH3 + H2O (with the presence of conc.sulfuric acid)
- the reaction of an alkali carboxylate and an alcohol. For example, the reaction of sodium acetate with ethanol.
H3C-COO- Na+ + HO-CH2-CH3 + H+ → H3C-COO-CH2-CH3 + H2O + Na+
- The reaction of a silver carboxylate with a halogenoalkane (presumably driven by the insolubility of the silver halide).
H3C-CO2-Ag+ + Cl-CH2-CH3 → H3C-COO-CH2-CH3 + AgCl
- The reaction of a carboxylic acid halogenide (which is also called acyl halide) with an alcohol/phenol.
H3C-COCl + HO-CH2-CH3 → H3C-COO-CH2-CH3 + H-Cl
- The reaction of a carboxylic acid anhydride with an alcohol. (This method is used to synthesize aspirin)
H3C-CO-O-CO-CH3 + HO-CH2-CH3 → H3C-COO-CH2-CH3 + H3C-COOH
See also
- Transesterification, a reaction to transform one ester into a different ester.
- Hydrolysis, the cleavage of an ester with water back to a carboxylic acid and alcohol.
- acetylation
- acylation
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.