All Topics  
Esterification

 

 
   Email Print
   Bookmark   Link
 

 

Esterification
 
 
  Topics Esterification Topic Home

Esterification is the general name for a chemical reaction
Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
 in which two reactants (typically an alcohol and an acid) form an ester
Ester

An ester is an often Aroma compound organic chemistry or partially organic compound formed by the reaction between an acid and an alcohol or aromatic alcohol with the elimination of water....
 as the reaction product
Product (chemistry)

A product is a substance that forms as a result of a biological- or chemical reaction. While the end product of some chemical reactions may be the result of a relatively rapid reaction, nanoseconds to seconds, chemical equilibrium in complex systems may require years or even centuries to be established....
. Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odor. This leads to their extensive use in the fragrance and flavour industry. Esterification is a reversible reaction. Hydrolysis
Hydrolysis

Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions....
- literally "water splitting" involves adding water and a catalyst (commonly NaOH) to an ester to get the sodium salt of the carboxylic acid and alcohol.






Discussion
Ask a question about 'Esterification'
Start a new discussion about 'Esterification'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Esterification is the general name for a chemical reaction
Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
 in which two reactants (typically an alcohol and an acid) form an ester
Ester

An ester is an often Aroma compound organic chemistry or partially organic compound formed by the reaction between an acid and an alcohol or aromatic alcohol with the elimination of water....
 as the reaction product
Product (chemistry)

A product is a substance that forms as a result of a biological- or chemical reaction. While the end product of some chemical reactions may be the result of a relatively rapid reaction, nanoseconds to seconds, chemical equilibrium in complex systems may require years or even centuries to be established....
. Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odor. This leads to their extensive use in the fragrance and flavour industry. Esterification is a reversible reaction. Hydrolysis
Hydrolysis

Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions....
- literally "water splitting" involves adding water and a catalyst (commonly NaOH) to an ester to get the sodium salt of the carboxylic acid and alcohol. As a result of this reversibility, many esterification reactions are equilibrium reactions and therefore need to be driven to completion according to Le Chatelier's principle
Le Châtelier's principle

In chemistry, Le Chatelier's Principle, also called the Le Chatelier-Braun principle, can be used to predict the effect of a change in conditions on a chemical equilibrium....
. Esterifications are among the simplest and most often performed organic transformations.

Examples


  • Heating to reflux
    Reflux

    Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations....
     an acid
    Organic acid

    An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids whose acidity is associated with their carboxyl group -COOH....
     (usually, but not always a carboxylic acid
    Carboxylic acid

    Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the Chemical formula -COH, usually written -COOH or -CO2H....
    ) and a primary or secondary alcohol
    Alcohol

    In chemistry, an alcohol is any organic compound in which a hydroxyl Functional group is bound to a carbon atom of an alkyl or substituted alkyl group....
     in the presence of a catalyst (commonly H2SO4) forms the ester, with water as a byproduct which can be removed to force the equilibrium in the desired direction. This method is called Fischer esterification
    Fischer esterification

    Fischer esterification or Fischer-Speier 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....
    . For example, esterification of acetic acid
    Acetic acid

    Acetic acid, CH3COOH, also known as ethanoic acid, is an organic acid which gives vinegar its sour taste and pungent smell. Pure, water-free acetic acid is a colourless liquid that absorbs water from the environment , and freezes at 16.7 Celsius to a colourless crystalline solid....
     in excess ethanol
    Ethanol

    Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatility , flammable, colorless liquid....
     (possibly as the solvent
    Solvent

    A solvent is a liquid or gas that dissolves a solid, liquid, or gaseous solute, resulting in a solution.The most common solvent in everyday life is water....
    ) in the presence of concentrated sulfuric acid
    Sulfuric acid

    Sulfuric acid, hydrogen2sulfuroxygen4, is a strong mineral acid. It is soluble in water at all concentrations. Sulfuric acid has many applications, and is one of the top products of the chemical industry....
     as a catalyst results in an ester (ethyl acetate
    Ethyl acetate

    Ethyl acetate is the organic compound with the formula CH3COOCH2CH3. This colorless liquid has a characteristic sweet smell like certain glues or nail polish removers, in which it is used....
    ).


  • The reaction of an alkali carboxylate and an alkyl halide. This is not a reversible reaction and therefore can run to completion naturally. In the case that an alkyl chloride is used, iodide may be added to catalyze the reaction by a halide exchange mechanism. The carboxylate salt may be generated in situ or prior to the reaction. In difficult cases, the silver carboxylate may be used, since the silver ion coordinates to the halide aiding its departure and improving the reaction rate. This reaction can suffer from anion availability problems and therefore can benefit from the addition of phase transfer catalyst
    Phase transfer catalyst

    A phase transfer catalyst or PTC in chemistry is a catalyst which facilitates the migration of a reactant in a heterogeneous system from one phase into another phase where reaction can take place....
    s or highly polar aprotic solvents such as DMF
    DMF

    DMF may be an abbreviation for:*Organic compounds:**N,N-Dimethylformamide, a common solvent.**Dimethyl fumarate, is the methyl ester of fumaric acid, a potent allergen, often used for mold inhibition....
    . As an example, the reaction of sodium acetate
    Sodium acetate

    Sodium acetate, is the sodium Salt of acetic acid. It is an inexpensive chemical produced in industrial quantities for a wide range of uses....
     with ethyl bromide is shown.


  • The reaction of a carboxylic acid halogenide (which is also called acyl halide
    Acyl halide

    An acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.If the acid is a carboxylic acid, the compound contains a ?COX functional group, which consists of a carbonyl group singly bonded to a halogen atom....
    ) with an alcohol/phenol. This reaction is usually very rapid due to the high reactivity of the acyl halide (it is often performed at low temperatures), but for the same reason it tends to be difficult to control, often resulting in a mixture of low purity products and a high percentage of by-products.


  • The reaction of a carboxylic acid anhydride with an alcohol. This method is favored for the synthesis of phenyl esters (for example, it is used in the synthesis of aspirin
    Aspirin

    Aspirin , also known as acetylsalicylic acid , is a salicylate medication, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication....
    ). The anhydride may be generated in situ, and catalysts are usually added (often stoichiometric quantities of amines such as pyridine or triethylamine, which also serve to neutralize the acid formed). This method is very inefficient with respect to the acid (essentially 2 moles are required for each mole of alcohol), so is mainly used either for low molecular weight acids or for very expensive alcohols.


See also


  • Transesterification
    Transesterification

    In organic chemistry, transesterification is the process of exchanging the alcohol group of an ester compound with another alcohol. These reactions are often catalyst by the addition of an acid or base ....
    , a reaction to transform one ester into a different ester.
  • Hydrolysis
    Hydrolysis

    Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions....
    , the cleavage of an ester with water back to a carboxylic acid and alcohol.
  • acetylation
    Acetylation

    Acetylation describes a reaction that introduces an acetyl functional group into an organic compound. Deacetylation is the removal of the acetyl group....
  • acylation
    Acylation

    In chemistry, acylation is the process of adding an acyl group to a compound. The compound providing the acyl group is called the acylating agent....