Ethyl ethanoate
Names Preferred IUPAC name Systematic IUPAC name Other names Identifiers 506104 ChEBI ChEMBL ChemSpider ECHA InfoCard 100.005.001 E number E1504 (additional chemicals) 26306 KEGG RTECS number UNII Properties C4H8O2 Molar mass 88.106 g·mol−1 Appearance Colorless liquid Odor nail polish-like, fruity Density 0.902 g/cm3 Melting point −83.6 °C (−118.5 °F; 189.6 K) Boiling point 77.1 °C (170.8 °F; 350.2 K) 8.3 g/100 mL (at 20 °C) Solubility in ethanol, acetone, diethyl ether, benzene Miscible log P 0.71[1] Vapor pressure 73 mmHg (9.7 kPa) at 20 °C[2] Acidity (pKa) 25 −54.10×10−6 cm3/mol 1.3720 Viscosity 426 μPa·s (0.426 cP) at 25 °C Structure 1.78 D Hazards Occupational safety and health (OHS/OSH): GHS labelling: [3] Danger H225, H319, H336[3] P210, P233, P240, P305+P351+P338, P403+P235[3] NFPA 704 (fire diamond) Flash point −4 °C (25 °F; 269 K) Explosive limits 2.0-11.5%[2] Lethal dose or concentration (LD, LC): 11.3 g/kg, rat 16,000 ppm (rat, 6 h)12,295 ppm (mouse, 2 h)1600 ppm (rat, 8 h)[4] 21 ppm (guinea pig, 1 h)12,330 ppm (mouse, 3 h)[4] NIOSH (US health exposure limits): TWA 400 ppm (1400 mg/m3)[2] TWA 400 ppm (1400 mg/m3)[2] 2000 ppm[2] Related compounds Supplementary data page Ethyl acetate (data page)
Ethyl acetate (commonly abbreviated EtOAc, ETAC or EA) is the organic compound with the formula CH3CO2CH2CH3, simplified to C4H8O2. This flammable, colorless liquid has a characteristic sweet smell (similar to pear drops) and is used in glues, nail polish removers, and the decaffeination process of tea and coffee. Ethyl acetate is the ester of ethanol and acetic acid; it is manufactured on a large scale for use as a solvent.[5]
Ethyl acetate was first synthesized by the Count de Lauraguais in 1759 by distilling a mixture of ethanol and acetic acid.[6]
In 2004, an estimated 1.3 million tonnes were produced worldwide.[5][7] The combined annual production in 1985 of Japan, North America, and Europe was about 400,000 tonnes. The global ethyl acetate market was valued at $3.3 billion in 2018.[8]
Ethyl acetate is produced in industry mainly via the classic Fischer esterification reaction of ethanol and acetic acid. This mixture converts to the ester in about 65% yield at room temperature:
CH3CO2H + CH3CH2OH → CH3CO2CH2CH3 + H2O
The reaction can be accelerated by acid catalysts and the equilibrium can be shifted to the right by removal of water.
It is also prepared in industry using the Tishchenko reaction, by combining two equivalents of acetaldehyde in the presence of an alkoxide catalyst:
2 CH3CHO → CH3CO2CH2CH3
Silicotungstic acid is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene:[9]
C2H4 + CH3CO2H → CH3CO2C2H5
Ethyl acetate is used primarily as a solvent and diluent, being favored because of its low cost, low toxicity, and agreeable odor.[5] For example, it is commonly used to clean circuit boards and in some nail varnish removers (acetone is also used). Coffee beans and tea leaves are decaffeinated with this solvent.[10] It is also used in paints as an activator or hardener. Ethyl acetate is present in confectionery, perfumes, and fruits. In perfumes it evaporates quickly, leaving the scent of the perfume on the skin.
Ethyl acetate is an asphyxiant for use in insect collecting and study.[11] In a killing jar charged with ethyl acetate, the vapors will kill the collected insect quickly without destroying it. Because it is not hygroscopic, ethyl acetate also keeps the insect soft enough to allow proper mounting suitable for a collection. However, ethyl acetate is regarded as potentially doing damage to insect DNA, making specimens processed this way less than ideal for subsequent DNA sequencing.[12]
In the laboratory, mixtures containing ethyl acetate are commonly used in column chromatography and extractions.[13] Ethyl acetate is rarely selected as a reaction solvent because it is prone to hydrolysis, transesterification, and condensations.
Ethyl acetate is the most common ester in wine, being the product of the most common volatile organic acid – acetic acid, and the ethyl alcohol generated during the fermentation. The aroma of ethyl acetate is most vivid in younger wines and contributes towards the general perception of “fruitiness” in the wine. Sensitivity varies, with most people having a perception threshold around 120 mg/L. Excessive amounts of ethyl acetate are considered a wine fault.
Ethyl acetate is only weakly Lewis basic, like a typical carboxylic acid ester.
Ethyl acetate hydrolyses to give acetic acid and ethanol. Bases accelerate the hydrolysis, which is subject to the Fischer equilibrium mentioned above. In the laboratory, and usually for illustrative purposes only, ethyl esters are typically hydrolyzed in a two-step process starting with a stoichiometric amount of a strong base, such as sodium hydroxide. This reaction gives ethanol and sodium acetate, which is unreactive toward ethanol:
CH3CO2C2H5 + NaOH → C2H5OH + CH3CO2Na
In the Claisen condensation, anhydrous ethyl acetate and strong bases react to give ethyl acetoacetate:[14]
Its melting point is −83 °C, with a melting enthalpy of 10.48 kJ/mol. At atmospheric pressure, the compound boils at 77 °C. The vaporization enthalpy at the boiling point is 31.94 kJ/mol. The vapor pressure function follows the Antoine equation
log 10 ( p ) = A − B T + C , {displaystyle log _{10}(p)=A-{frac {B}{T+C}},}
where
p {displaystyle p} is the vapor pressure in bars, T {displaystyle T} is the absolute temperature in kelvins, and A = 4.22809 {displaystyle A=4.22809} , B = 1245.702 {displaystyle B=1245.702} , C = − 55.189 {displaystyle C=-55.189} are constants.
This function is valid within the temperature range of 289 to 349 K (16-76 °C).
The enthalpy of vaporization in kJ/mol is calculated according to the empirical equation by Majer and Svoboda[16]
Δ H vap = A exp ( − β T r ) ( 1 − T r ) β , {displaystyle Delta H_{text{vap}}=Aexp(-beta ,T_{text{r}}),(1-T_{text{r}})^{beta },}
where
T r = T / T c {displaystyle T_{text{r}}=T/T_{text{c}}} is the reduced temperature, and T c {displaystyle T_{text{c}}} = 523.2 K is the critical temperature. A {displaystyle A} = 54.26 kJ/mol and β {displaystyle beta } = 0.2982 are constants.
The following table summarizes the most important thermodynamic properties of ethyl acetate under various conditions.
Compilation of key thermodynamic properties Property Type Value Remarks References Standard enthalpy of formation Δ f H liquid 0 {displaystyle Delta _{f}H_{text{liquid}}^{0}} Δ f H gas 0 {displaystyle Delta _{f}H_{text{gas}}^{0}} −480.57 kJ/mol −445.43 kJ/mol as liquid as gas [17] Standard entropy S liquid 0 {displaystyle S_{text{liquid}}^{0}} S gas 0 {displaystyle S_{text{gas}}^{0}} 259.4 J/(mol·K) 362.75 J/(mol·K) as liquid as gas [18][19] Combustion enthalpy Δ c H liquid 0 {displaystyle Delta _{c}H_{text{liquid}}^{0}} −2235.4 kJ/mol [20] Heat capacity (25 °C) c p {displaystyle c_{p}} 168.94 J/(mol·K) 1.92 J/(g·K) 113.64 J/(mol·K) 1.29 J/(g·K) as liquid as gas [21][19] Critical temperature T c {displaystyle T_{text{c}}} 523.2 K [16] Critical pressure p c {displaystyle p_{text{c}}} 38.82 bar [22] Critical density ρ c {displaystyle rho _{text{c}}} 3.497 mol/L [23] Acentric factor ω c {displaystyle omega _{c}} 0.36641 [24]
The LD50 for rats is 5620 mg/kg,[25] indicating low acute toxicity. Given that the chemical is naturally present in many organisms, there is little risk of toxicity.
World Health Organization(WHO) has assessed the Acceptable Daily Intake (ADI) of Ethyl Acetate at 25mg per kg of body weight.[26] This is similar to the ADI of other artificial sweeteners that are friendly and have been commonly used for a long time.[27][28] According to European Food Safety Authority (EFSA), Ethyl Acetate taken orally is rapidly metabolized and broken down. The half-life in blood after ingestion exposure is known to be approximately 35 seconds.[29]
Overexposure to ethyl acetate may cause irritation of the eyes, nose, and throat. Severe overexposure may cause weakness, drowsiness, and unconsciousness.[30] Humans exposed to a concentration of 400 ppm in 1.4 mg/L ethyl acetate for a short time were affected by nose and throat irritation.[31] Ethyl acetate is an irritant of the conjunctiva and mucous membrane of the respiratory tract. Animal experiments have shown that, at very high concentrations, the ester has central nervous system depressant and lethal effects; at concentrations of 20,000 to 43,000 ppm (2.0-4.3%), there may be pulmonary edema with hemorrhages, symptoms of central nervous system depression, secondary anemia and liver damage. In humans, concentrations of 400 ppm cause irritation of the nose and pharynx; cases have also been known of irritation of the conjunctiva with temporary opacity of the cornea. In rare cases exposure may cause sensitization of the mucous membrane and eruptions of the skin. The irritant effect of ethyl acetate is weaker than that of propyl acetate or butyl acetate.[32]
- https://pubchem.ncbi.nlm.nih.gov/compound/ethyl_acetate#section=Toxicity
- NIOSH Pocket Guide to Chemical Hazards
- International Chemical Safety Cards
- Material safety data (MSDS) for ethyl acetate
- National Pollutant Inventory – Ethyl acetate fact sheet
- Ethyl Acetate: Molecule of the Month
- Purpose of Using Concentrated Sulfuric Acid in Esterification for Catalysis
- Basic facts and contact SEKAB [1] SEKAB ethyl acetate
- A Techno Commercial Profile of Ethyl Acetate in India
- Calculation of vapor pressure, liquid density, dynamic liquid viscosity, surface tension of ethyl acetate
