Process for continuously producing ethyl N-cyanoethylimidoate hydrochloride

Abstract

The invention discloses a process for continuously producing ethyl N-cyanoethylimidoate hydrochloride. The process flow is as follows: mixing and reacting according to the mol ratio of ethanol: acetonitrile: hydrogen chloride of 1: 0.8-2.5: 0.8-3.0, separating to obtain the ethyl N-cyanoethylimidoate hydrochloride product and an acetonitrile solution containing hydrogen chloride, and when the ethanol content is less than 1%, separating the ethyl N-cyanoethylimidoate hydrochloride and the acetonitrile solution through a separator to return the acetonitrile solution to the inlet of an absorption reactor. The process has the advantages of reducing investment scale, saving cost, increasing production capacity, saving labor cost, reducing labor intensity and the like while improving synthesis efficiency, and has better industrial application prospects.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a process for the continuous production of N-cyano-ethyl imidate hydrochloride. Background technique [0002] Ethyl imidate hydrochloride is an important intermediate for the preparation of vitamin B1, acetamiprid and other drugs. It is an important basic chemical raw material and is widely used in dyestuffs, pharmaceuticals, pesticides and other industries. [0003] The technique of utilizing acetonitrile, ethanol, hydrogen chloride to synthesize ethyl imidate hydrochloride is the technique usually used at present, and its chemical reaction equation is as follows: [0004] [0005] The main problems of above-mentioned technology are as follows: [0006] (1) In the industry, solvents such as chloroform, carbon tetrachloride, ether, petroleum ether, toluene, nitrobenzene, dioxane, dimethyl cellosolve, hexane and other solvents need to be added. The use of organic s...

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Problems solved by technology

The use of organic solvents requires solvent recovery and loss of solvents, and solvents usually have a certain impact on the environment;

[0007] (2) According to the reaction mechanism of the above synthesis, in order to make the reaction safe and stable, the current production process usually adopts batch reaction, and a production line with an annual output of 2000 tons of ethyl imidate hydrochloride needs 1-5m 3 There are about 30 reaction kettles (including degassing kettles, drying kettles, salt-forming kettles, crystallization kettles, and hydrogen chloride absorption kettles), which not only take up a lot of space, but are also a waste of resources and energy

After the reaction, use suction filtration to separate ethyl imidate hydrochloride crystals from acetonitrile, and a large amount of hydrogen chloride will be decomposed during decompression. In order not to affect the environment, this part of the waste liquid needs to be treated with liquid caustic soda or Lime milk can only meet the requirements of sewage discharge after adjustment, which is not ideal in terms of economy and environmental protection

[0009] (4) Due to the limitation of the drying treatment process, the normal pressure drying device in the production will cause the pyrolysis of N-cyano-ethyl imidate hydrochloride, resulting in product deterioration and decreased purity, which will eventually affect the product the quality of

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