Synthesis method of ethyl acetate

Abstract

The invention relates to a synthesis method of ethyl acetate and belongs to the technical field of organic chemistry and pharmaceutical synthesis. The synthesis method comprises the following steps: firstly, immersing macroporous type cation exchange resin by acetic acid, sodium hydroxide and the acetic acid in sequence, then washing with water, enabling the pH (Potential of Hydrogen) value of theresin to be neutral, then filtering and removing water adhered to the surface of the macroporous type cation exchange resin to obtain pre-treated resin; adding the acetic acid and the pre-treated resin into toluene, carrying out an esterification reaction under a state that organic acid ethyl ester is dropwise added, filtering after the reaction is finished and separating the resin; cooling a toluene solution, and then filtering the toluene solution so as to leach unreacted acetic acid; washing an ethyl acetate toluene solution with water, then decompressing and carrying out condensation, andrecycling solvent, and then distilling to obtain the ethyl acetate. The synthesis method involved in the invention has the advantages of high yield, convenience for post-treatment, no pollution and capability of repeatedly regenerating and utilizing the ethyl acetate; and the resin can be directly reused, and the solvent can be recycled and reused, so that not only are resources saved, but also environmental friendliness is realized.

Description

technical field [0001] The invention belongs to the technical field of organic chemistry and medicine synthesis, in particular to a method for synthesizing ethyl acetate. Background technique [0002] Ethyl acetate is a white or slightly pink crystalline solid at room temperature. Melting point: 28~29°C, boiling point: 285°C (760mmHg), refractive index: n 20 D 1.4390, relative density: 0.986. Insoluble in water, easily soluble in alcohol, ether and other organic solvents. Ethyl acetate and its derivatives, as a class of important organic intermediates, are widely used in the technical field of pharmaceutical synthesis. [0003] At present, domestic related synthesis methods have disadvantages such as difficult control of the amount of reactants, many side reactions, low yield, and troublesome post-treatment. At the same time, the catalysts used include concentrated sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, triethylamine, and methanol. Sodium and liquid c...

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Problems solved by technology

[0003] At present, domestic related synthesis methods have disadvantages such as difficult control of the amount of reactants, many side reactions, low yield, and troublesome post-treatment. At the same time, the catalysts used include concentrated sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, triethylamine, and methanol. Sodium and liquid caustic soda all have disadvantages such as easy to corrode equipment, pollute the environment, consume a large amount and are not suitable for recycling, and easily cause secondary pollution of the target product.

[0004] Chinese invention patent application publication number CN102351691A discloses a kind of synthetic method of ethyl acetate, and the preparation method of this patent scheme is identical with the above-mentioned second synthetic method, generates acetic anhydride by acetic acid under the catalysis of concentrated sulfuric acid as catalyst, and then Acetic acid and ethanol undergo alcoholysis reaction to obtain ethyl acetate, but due to the unstable chemical properties of acetic anhydride, it needs to be prepared and used immediately (i.e. ready-to-use), and the preparation of acetic anhydride requires a large amount of concentrated sulfuric acid, which is also easy to corrode equipment and pollute Environmental and other disadvantages