Preparation method of ethyl 3-ethoxypropionate

Abstract

The embodiment of the invention discloses a preparation method of ethyl 3-ethoxypropionate, and relates to the technical field of chemical industry synthesis. According to the scheme, low-acidity absolute ethyl alcohol and ethyl acrylate are subjected to an addition reaction under the catalytic action of a strongly basic ion exchange resin to prepare ethyl 3-ethoxypropionate, wherein the acidity of the reactant is within 10ppm and cannot affect the catalyst, so that the conversion rate of the catalyst is high so as to achieve high yield (the conversion rate and the yield of the scheme are morethan 98%). According to the invention, the method has the advantages of simplicity, mild conditions, few side reactions and easy regeneration of the catalyst; and the product easily achieves the purity of more than 99.8%, can be further processed into an electronic grade, can be used in photoelectric industry, greatly simplifies the separation process, and is convenient for continuous production.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a preparation method of ethyl 3-ethoxypropionate. Background technique [0002] Ethyl 3-ethoxypropionate is an important organic solvent and organic synthesis intermediate, widely used in the coating industry, electronics industry and the synthesis of pharmaceutical intermediates. [0003] U.S. Patent No. 5,081,285 uses ethanol and ethyl acrylate to obtain ethyl 3-ethoxy propionate under the catalysis of methanesulfonic acid. The reaction temperature is 120-130 degrees, and the yield is 41%. However, this scheme needs to be reacted under pressure, which is inconvenient production, and the reaction temperature is high, the side reactions are many, and the cost is too high. [0004] Literature [Tetrahedro letters, 46 (19), 3279-3282:2005] adopts aluminum oxide-supported potassium fluoride as a catalyst to synthesize 3-ethoxy ethyl propionate with ethanol and ethyl acryl...

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Problems solved by technology

[0003] U.S. Patent No. 5,081,285 uses ethanol and ethyl acrylate to obtain ethyl 3-ethoxy propionate under the catalysis of methanesulfonic acid. The reaction temperature is 120-130 degrees, and the yield is 41%. However, this scheme needs to be reacted under pressure, which is inconvenient Production, and the reaction temperature is high, the side reactions are many, and the cost is too high

[0004] Literature [Tetrahedro letters, 46 (19), 3279-3282:2005] adopts aluminum oxide-supported potassium fluoride as a catalyst to synthesize 3-ethoxy ethyl propionate with ethanol and ethyl acrylate, and the process uses acetonitrile as Solvent, the yield is 90%, but the product has a large amount of solvent to be recovered, and the reaction time is as long as 20 hours, which affects production efficiency

[0005] Patent CN200810061996.1 uses alkali metals such as sodium metal or alkali metal alkoxides as catalysts to synthesize ethyl 3-ethoxypropionate with absolute ethanol and ethyl acrylate, the reaction time is shortened to less than 3 hours, and the highest yield can reach 96%, but the catalyst is extremely sensitive to acid and water, once it encounters water or acid, it will be destroyed and cannot be regenerated, and the reaction needs to be neutralized with acid to neutralize the system to neutral or even acidic, which increases the separation steps and produces certain Salt-containing wastewater, and the reaction generates organic salts, which increases the difficulty of product purification. The high degree of heat release during the neutralization process increases side reactions. The purity of the product is within 99.8%, which cannot be further processed into electronic grade products, and cannot be used in the optoelectronic industry.

[0006] In addition, it is also reported to use strong basic ion exchange resin to catalyze dehydrated alcohol and ethyl acrylate to obtain ethyl 3-ethoxy propionate, but due to the trace acid content in dehydrated alcohol and ethyl acrylate is generally at 200-500ppm , will neutralize the strong basic ion exchange resin, which will affect the catalytic effect. It is necessary to increase the amount of strong basic ion exchange resin (generally about 20% of the mass of ethyl acrylate), and the strong basic ion exchange resin is expensive. The service life is short, generally it takes 6-8 hours to lose the catalytic effect, and it needs to be regenerated, and it can only be regenerated 7 times at most, and the strong basic ion exchange resin is easily broken and loses its use, and the conversion rate is not high, generally between 70-90%. Strongly basic ion exchange resins will generate a large amount of waste water, which greatly increases the cost of production and cannot be produced continuously on a large scale

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