Ethyl acetate, also known as ethyl acetate, is an organic compound with the chemical formula C4H8O2. It is an ester with functional group coor (double bond between carbon and oxygen). It can produce common reactions of alcoholysis, ammonolysis, transesterification, reduction and other general esters. It is mainly used as a solvent, edible flavor, cleaning and degreasing agent.
Ethyl acetate can produce common ester reactions such as alcoholysis, ammonolysis, transesterification, reduction and so on. In the presence of sodium metal, it condenses automatically to produce 3-hydroxy-2-butanone or ethyl acetoacetate; It reacts with Grignard reagent to produce ketone, and further reacts to obtain tertiary alcohol. Ethyl acetate is relatively stable to heat, and there is no change when heated at 290 ℃ for 8~10 hours. It is decomposed into ethylene and acetic acid when passing through the red hot iron pipe. Zinc powder heated to 300~350 ℃ is decomposed into hydrogen, carbon monoxide, carbon dioxide, acetone and ethylene. Alumina dehydrated at 360 ℃ can be decomposed into water, ethylene, carbon dioxide and acetone. Ethyl acetate is decomposed by ultraviolet radiation to produce 55% carbon monoxide, 14% carbon dioxide, 31% hydrogen or methane and other combustible gases. It reacts with ozone to produce acetaldehyde and acetic acid. Gaseous hydrogen halide reacts with ethyl acetate to produce haloethane and acetic acid. Among them, hydrogen iodide is the easiest to react, and hydrogen chloride needs to be pressurized to decompose at room temperature. It is heated to 150 ℃ with phosphorus pentachloride to produce chloroethane and acetyl chloride. Ethyl acetate and metal salts form various crystalline complexes. These complexes are soluble in absolute ethanol but insoluble in ethyl acetate, and are easily hydrolyzed in water.
Hydrolysis reaction: Ethyl acetate is easy to hydrolyze. When there is water at room temperature, it also gradually hydrolyzes to acetic acid and ethanol. Adding a small amount of acid or base can promote the hydrolysis reaction. The biggest difference between alkaline hydrolysis and acid hydrolysis of ethyl acetate is that alkaline hydrolysis is irreversible, that is, reversible process and irreversible process in the reaction mechanism. Acetic acid reacts reversibly with ethanol to produce ethyl acetate. The reason why the aged wine tastes good is that a small amount of acetic acid in the wine reacts with ethanol to produce ethyl acetate with fruit flavor.
Alcoholysis reaction: CH3COOCH2CH3+CH3OH⇌CH3COOCH3+CH3CH2OH
Ammonolysis reaction: NH3+C2H5OOCCH3=C2H5OH+CH3CONH2
Preparation of ethyl acetoacetate:Ethyl acetoacetate was prepared by Claisen ester condensation with anhydrous ethyl acetate and metallic sodium as raw materials and excess ethyl acetate as solvent.
2CH3COOC2H5(NaOC2H5)→Na+ [CH3COCHCOOC2H5]-(HOAC)→CH3COCH2COOC2H5 +NaOAC
Artificial synthesis of ethyl acetate: it can be prepared by the reaction of acetic acid or its derivatives with ethanol, or by sodium acetate. There are many synthetic methods of acetic acid and acetic acid vinegar, which are used by direct esterification of acetic acid and ethyl alcohol under acid catalysis. It is often synthesized by the reaction of concentrated and haloethane. Among them, the most commonly used method is the push system of the Commission of law, the town and the rear. If the concentrated acid is used as the catalyst, it will be acid, hydrogen chloride, p-methylenephalic acid or strong acid the dosage of Dianli is 0.3% of alcohol.
The reaction is: main reaction:
Side reaction:
The esterification reaction is reversible, and the measures to improve the yield are: - on the one hand, add excess ethanol, on the other hand, continuously evaporate the product and water during the reaction process, so as to promote the direction of equilibrium formation. However, the mixture of ester and water or ethyl acetate is close to that of equine ethyl acetate. In order to base the generated anhydrous water and steam less ethanol as soon as possible, this experiment uses a technically advanced fractionation column for fractionation.
GB 2760-1996 is a permitted edible flavor. A small amount of it can be used for essence such as magnolia, Ylang Ylang Ylang, osmanthus, rabdosia and toilet water, fruit fragrance type, etc. as a head fragrance to enhance the fresh fruit fragrance, especially for perfume essence, which has a mellow effect. Suitable for cherry, peach, apricot, grape, strawberry, raspberry, banana, raw pear, pineapple, lemon, melon and other edible essence. Essence for wine, such as brandy, whisky, rum, yellow rice wine, Baijiu, etc., are also used.
Ethyl acetate is one of the most widely used fatty acid esters. It is a fast drying solvent with excellent solubility. It is an excellent industrial solvent and can also be used as an eluent for column chromatography. It can be used for nitric acid fiber, ethyl fiber, chlorinated rubber and vinyl resin, cellulose acetate, cellulose butyl acetate and synthetic rubber, and can also be used for liquid nitro fiber ink for copiers. It can be used as a solvent for adhesives and a thinner for painting. Ethyl acetate is an efficient solvent for many resins, which is widely used in the production of ink and artificial leather. It is used as analytical reagent, chromatographic reference material and solvent.