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Esterification

Explanation

Esterification : alcohols and phenols react with carboxylic acids, acid chlorides and acid anhydrides to form esters.
`RO - H + R. - COOH overset(H^(+))rarr ROCOR. + H_(2)O`
`RO - H + R.COCl overset("Pyridine")rarr ROCOR. + HCl`
`RO - H + (R.CO_(2))O overset(H^(+))rarr ROCOR. + R.COOH`
The reaction with carboxylic acid or acid anhydride is carried out in presence of a small amount of concentrated sulphuric acid. The reaction is reversible, and therefore, water is removed as soon as it is formed. The reaction with acid chloride is carried out in presence of a base (pyridine) so as to remove HCl. It is also shifts the equilibrium to the right hand side. The introduction of acetyl `(CH_(3)CO-)` group in alcohols or phenols is known as acetylation.