Esterification is the interaction of an organic acid (RCOOH) with an alcohol (ROH) to produce an ester (RCOOR) and water, or a chemical reaction that has at least one ester product.
RCOOH+R’OH → RCOOR'+H2O
Carboxylic acid reacts with alcohols in the presence of concentrated H2SO4 to form esters, resulting in the loss of water molecules. When ethanoic acid reacts with ethanol, for example, the ethyl ethanoate ester is formed. Because it is fruity, the aroma of ester differs from that of carboxylic acid and alcohol.
CH3COOH + CH3CH2COOH → CH3COOCH2CH3
Step 2: Delocalized Carbocation
Step 3: Transfer of proton
Step 4: Formation of pi-Bond
Step 5: Ester formation