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Methyl acetate 79-20-9
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Methyl acetate, also known as MeOAc, methyl acetate or methyl acetate, is a carboxylic acid ester with the chemical formula CH3COOCH3. It is a flammable liquid with a characteristic pleasant odor reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent and is slightly polar and lipophilic, but its close relative ethyl acetate is a more common solvent, is less toxic and poorly soluble in water. The solubility of methyl acetate in water at room temperature is 25%. Its solubility in water is much higher at elevated temperatures. Methyl acetate is unstable in the presence of strong alkali aqueous solutions or acid aqueous solutions. Methyl acetate is VOC-free.
| describe | Methyl acetate, also known as MeOAc, methyl acetate or methyl acetate, is a carboxylic acid ester with the chemical formula CH3COOCH3. It is a flammable liquid with a characteristic pleasant odor reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent and is slightly polar and lipophilic, but its close relative ethyl acetate is a more common solvent, is less toxic and poorly soluble in water. The solubility of methyl acetate in water at room temperature is 25%. Its solubility in water is much higher at elevated temperatures. Methyl acetate is unstable in the presence of strong alkali aqueous solutions or acid aqueous solutions. Methyl acetate is VOC-free. |
| chemical properties | Methyl acetate has a pleasant fruity aroma and slightly bitter taste. It can be prepared by boiling acetic acid and methanol in the presence of an acid catalyst; or by heating methanol with excess carbon monoxide under pressure in the presence of a catalyst (phosphoric acid, cobalt salt). Methyl acetate occurs naturally at low concentrations in mint, fungi, grapes, bananas, coffee (Furia and Bellanca, 1975), and is a volatile component of nectarines (Takeoka et al., 1988). It is also present in some distilled alcoholic beverages (Shimoda et al., 1993). It is produced industrially by the carbonylation of methanol as a by-product of acetic acid production or by the esterification of acetic acid with methanol in the presence of strong acids such as sulfuric acid. |
| physical properties | Colorless liquid with pleasant odor. Nagata and Takeuchi (1990) reported an odor threshold concentration of 48 ppb v . Cometto-Muñiz and Cain (1991) reported a mean nasal irritation threshold concentration of 112,500 ppm v . |
| occur | It has been reported to be found in apples, bananas, sweet and sour cherries, orange juice, black currants, guava, grapes, melons, peaches, pears, pineapples, strawberries, cabbage, tomatoes, clove sprouts, peppermint oil, vinegar, bread, cheese, Butter, yogurt, beef, beer, brandy, rum, whiskey, cider, sherry, wine, cocoa, coffee, hazelnuts, peanuts, honey, soybeans, olives, passion fruit, fruit brandy, figs, gin, Kiwi, clary sage, arrack and nectarine. |
| use | Methyl acetate is used as a solvent for varnishes, resins, oils, and nitrocellulose; as a paint remover; as a flavoring agent; and in the manufacture of artificial leather. |
| Prepare | Methyl acetate is industrially produced as a by-product of acetic acid through the carbonylation of methanol. Methyl acetate can also be produced by esterification of acetic acid and methanol in the presence of strong acids such as sulfuric acid, a production process known by Eastman and Kodak's enhanced process of reactive distillation. 2-1-Reaction In the presence of a strong base such as sodium hydroxide or a strong acid such as hydrochloric or sulfuric acid, it hydrolyzes back to methanol and acetic acid, especially at elevated temperatures. Conversion of methyl acetate back to its components by acid is a first-order reaction for esters. The reaction of methyl acetate and a base such as sodium hydroxide is a second-order reaction for both reactants. 3-Applications The primary use of methyl acetate is as a volatile, low-toxic solvent in glues, paints, and nail polish removers. Acetic anhydride is produced by the carbonylation of methyl acetate, a process inspired by Monsanto's synthesis of acetic acid. |
| definition | ChEBI: Methyl acetate is an acetate ester obtained by the formal condensation of acetic acid and methanol. It is a low boiling point (57°C) colorless flammable liquid used as a solvent for many resins and oils. It acts as a polar aprotic solvent, fragrance and EC 3.4.19.3 (pyroglutamyl peptidase I) inhibitor. It is an acetate, methyl ester, and volatile organic compound. |
| application | Methyl acetate can be used for the preparation of fatty acid methyl esters and triacetin from rapeseed oil by non-catalyzed transesterification under supercritical conditions. Methyl acetate can be used for the following purposes: as an acyl acceptor in the production of biodiesel. Synthesis of ethanol. In the presence of an acidic catalyst, carry out transesterification reaction with n-butanol to prepare n-butyl acetate. It is also used as a precursor in the synthesis of: Acetic anhydride Methyl acrylate Vinyl acetate Acetamide |
| aroma threshold | Detection: 1.5 to 47 ppm |
| taste threshold | Taste profile at 60 ppm: green, airy, fruity, fresh, rum and whiskey-like. |
| general instructions | Methyl acetate is a clear, colorless liquid with an aromatic odor. Moderately toxic. Flash point 14°F. Vapor is heavier than air. |
| air and water reaction | Highly flammable. water soluble. |
| reactive profile | Methyl acetate can create a fire or explosion hazard when exposed to strong oxidizing agents. Emit irritating and acrid fumes when heated to decompose, [Lewis, 3rd ed., 1993, p. 14] 826]. The reactivity of methyl acetate is consistent with other ester-based compounds. |
| adventure | It is flammable, dangerous fire and explosion hazard, and the explosion limit in air is 3-16%. Irritating to respiratory tract. Headache, dizziness, nausea, eye damage (degeneration of retinal ganglion cells). |
| health hazard | (Very similar to commercial grade methanol, which contains 20% methanol.) Inhalation can cause headaches, fatigue, and drowsiness; high concentrations can produce central nervous system depression and optic nerve damage. Liquids can irritate the eyes and may cause skin degreasing and cracking. Ingestion can cause headache, dizziness, drowsiness, fatigue; may cause serious eye damage. |
| health hazard | Toxic effects of exposure to methyl acetate include eye inflammation, visual and neurological disturbances, chest tightness, drowsiness, and anesthesia. It hydrolyzes into methanol in the body, which may cause optic nerve atrophy. Exposure to 32,000 ppm can kill rats in 4 hours. The compound has low oral and dermal toxicity. The oral LD50 value in rats is approximately 5000 mg/kg. |
| fire hazard | Behavior in Fire: Vapors are heavier than air and may travel considerable distances to the source of fire and backfire. |
| Security overview | Moderately toxic via multiple pathways. Inhalation has a stimulating effect on the human body. Moderately irritating to skin and eyes. Report mutation data. Fire hazard when exposed to heat, flame or oxidizing agents. Moderate explosion hazard when exposed to heat or flame. When heated and decomposed, acrid fumes and fumes are released. See also ester. |
| synthesis | By boiling acetic acid and methanol in the presence of an acid catalyst, or heating methanol with excess carbon monoxide under pressure in the presence of a catalyst (phosphoric acid, cobalt salts). |
| potential contact | Methyl acetate is used as a solvent in varnishes and paint strippers; and as an intermediate in pharmaceutical production. |
| environmental fate | Photolytic. The reaction rate constant of methyl acetate and OH radicals in aqueous solution has been reported to be 2.00 x 10 -13 cm 3 /molecule·second (Wallington et al., 1988b). Chemistry/Physics. Slowly hydrolyzes in water to produce methanol and acetic acid (NIOSH, 1997). In water at 25 °C, pH 7, the hydrolysis half-life is estimated to be 2.5 years (Mabey and Mill, 1978). When the inlet water concentration is 1,030 mg/L, the effluent concentration after GAC treatment is 760 mg/L. The carbon used had an adsorption capacity of 54 mg/g carbon (Guisti et al., 1974). |
| Shipping | UN1231 Methyl acetate, hazard level: 3; label: 3 - Flammable liquid. |
| Purification method | Methanol in methyl acetate can be detected by measuring its solubility in water. At 20°C, the solubility of methyl acetate in water is approximately 35g/100mL, but 1% MeOH is completely miscible. Methanol can be converted into methyl acetate, refluxed with acetic anhydride (85 mL/L) for 6 hours, and then removed by fractional distillation. Acidic impurities can be removed by shaking with anhydrous K2CO3 and distilling. An alternative treatment is to use acetyl chloride, followed by washing with concentrated NaCl and drying with CaO or MgSO4. (Solid CaCl2 cannot be used because it forms crystalline addition compounds.) Distillation of copper stearate destroys the peroxide. Free alcohol or acid in methyl acetate can be eliminated by shaking with concentrated Na2CO3 or K2CO3 aqueous solution (3 times), then with 50% CaCl2 aqueous solution (3 times), saturated aqueous sodium chloride solution (twice), and dried with potassium carbonate , and distilled from phosphorus pentoxide. [Beilstein 2 IV 122. ] |
| Incompatibility | Vapors may form explosive mixtures with air. Strong reducing agent. Incompatible water, acids, nitrates, strong oxidizing agents; bases. Attacks some plastics. Water will corrode many metals. Reacts slowly with water to form acetic acid and methanol. Decomposed by heat; contact with air, alkali, strong oxidants; ultraviolet rays; possible fire and explosion hazard |
| waste disposal | The material is dissolved or mixed with a flammable solvent and burned in a chemical incinerator equipped with an afterburner and scrubber. All federal, state and local environmental regulations must be followed. |
| Methyl acetate upstream and downstream product information |
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