Phenols - Esterification
Let us discuss some of our usable daily life things.
We use perfumes which has fragrant odors
This fragrant odor is due to the presence of ester.
Even in the manufacturing of soaps and detergents we use ester
The ester has much application in our life and we prepare ester by the process of esterification
So let us start our discussion with esterification.
Esterification is a process or a general name for a chemical reaction, in which alcohol and acid react to form an ester as the product.
Here carboxylic acid reacts with methyl alcohol to form an ester.
The formula for carboxylic acid esters is RCOOR’ (where R and R’ are any organic combining groups)
Esters can be prepared by carboxylic acid derivatives like acid anhydride, acid chloride etc.
Let us now learn about the preparation of esters using acyl chlorides.
When we add an acyl chloride to alcohol, a vigorous (even violent) reaction at room temperature
occurs producing an ester and clouds of steamy acidic fumes of hydrogen chloride.
For example when we add the liquid ethanoyl chloride to ethanol, hydrogen chloride produced together with the liquid ester ethyl ethanoate.
Similarly, when we treat acid chloride with phenol, we will get Phenyl ethanoate together with hydrogen chloride gas
Let us now discuss the preparation of esters using acid anhydrides.
Let us take ethanol and treat it with ethanoic anhydride.
This reaction gives a mixture of ethyl ethanoate and ethanoic acid.
The reaction with phenol is similar, but will be slower. Phenyl ethanoate is formed along with ethanoic acid.
Similarly, we can prepare aspirin by the esterification.
The introduction of acetyl (
C
H
3
C
O
) group in alcohols or phenols is known as acetylation.
Acetylation of salicylic acid produces aspirin.
Aspirin possesses analgesic, anti- inflammatory and antipyretic properties.
From esterification, we can prepare useful esters like salol (phenyl salicylate), oil of wintergreen (methyl salicylate ).
Phenyl salicylate is used in the manufacture of some polymers, lacquers, adhesives, waxes.
The substance phenyl salicylate is created by a chemical reaction between phenol, an organic compound, and salicylic acid.
It can be synthesized by esterification of salicylic acid with phenol using acid catalyst.
Similarly, we can prepare oil of wintergreen (methyl salicylate) by esterification
Methyl salicylate (oil of wintergreen) is an organic compound with the formula
C
6
H
4
(
O
H
)
(
C
O
2
C
H
3
)
.
It is the methyl ester of salicylic acid. It is a colorless, viscous liquid with a sweet odor.
The reaction involved in the preparation of methyl salicylate is given as;
Let’s revise.
Esterification is a process or a general name for a chemical reaction, in which alcohol and acid react to form an ester as the product.
The formula for carboxylic acid esters is RCOOR’ (where R and R’ are any organic combining groups)
The introduction of acetyl (
C
H
3
C
O
) group in alcohols or phenols is known as acetylation.
From esterification, we can prepare useful esters like salol (phenyl salicylate), oil of wintergreen (methyl salicylate ).