CH₃COOC₂H₅ — Ethyl Acetate

Ethyl acetate, also known as ethyl ethanoate, is one of the most commonly used esters in the chemical industry. It is an organic compound with the molecular formula \(CH_3COOC_2H_5\). This compound is known for its pleasant, fruity smell, reminiscent of pear drops, and is widely used as a solvent in paints, varnishes, adhesives, and nail polish removers. Ethyl acetate naturally occurs in fruits such as bananas, apples, and pears, where it contributes to their characteristic aroma. It is also found in wine as a product of fermentation.

Due to its volatility, low toxicity, and ability to dissolve many organic compounds, ethyl acetate is a preferred solvent in laboratories and industries. It plays a major role in the formulation of coatings, cleaning mixtures, perfumes, and flavorings. Additionally, its biodegradable nature makes it an environmentally safer choice compared to many chlorinated solvents.

The structure of ethyl acetate consists of an acetyl group (CH3CO–) linked to an ethoxy group (C2H5O–) through an ester bond. It can be represented as:

In this molecule, the central carbon atom of the carbonyl group is sp²-hybridized, forming a double bond with oxygen. The C–O bond in the ester group exhibits partial double bond character due to resonance. The polar nature of the carbonyl bond gives ethyl acetate a moderate dipole moment, making it miscible with organic solvents like alcohol and ether, but only partially soluble in water.

Ethyl acetate is primarily synthesized through the esterification reaction between ethanol and acetic acid in the presence of an acid catalyst such as concentrated sulfuric acid:

This reaction is a classic example of Fischer esterification. It is reversible and reaches equilibrium; hence, to drive the reaction toward ester formation, excess ethanol or continuous removal of water is used. Industrially, ethyl acetate is also produced via the Tishchenko reaction from acetaldehyde in the presence of an aluminum alkoxide catalyst:

Ethyl acetate is a colorless, volatile liquid with a sweet, fruity odor. It evaporates quickly and has a relatively low boiling point of 77°C. It is soluble in organic solvents such as acetone, benzene, and ethanol, but only slightly soluble in water (8.7 g/100 mL at 20°C).

Being an ester, ethyl acetate undergoes hydrolysis in the presence of acid or base to yield acetic acid and ethanol:

Under basic conditions, the reaction is known as saponification, which is irreversible and results in the formation of sodium acetate and ethanol when NaOH is used.

• Solvent: Extensively used in paints, coatings, adhesives, and printing inks due to its fast evaporation rate and excellent solvency for resins and polymers.
• Extraction agent: Used in decaffeination of coffee and tea, as well as in the extraction of antibiotics and organic acids.
• Flavoring and fragrance industry: Imparts fruity aroma in perfumes, artificial fruit essences, and confectioneries.
• Laboratory reagent: Common solvent for chromatography, particularly thin-layer chromatography (TLC).
• Pharmaceuticals: Used in drug formulation and purification processes due to its non-toxic residue characteristics.

Ethyl acetate is considered a low-toxicity compound. However, prolonged exposure to high concentrations may cause irritation to the eyes, nose, and throat. It may also cause dizziness or drowsiness due to its anesthetic effect. Because it evaporates rapidly and breaks down easily in the atmosphere, its environmental impact is minimal. It is biodegradable and does not contribute significantly to smog formation or ozone depletion.