Preparation method of aminoacetonitrile hydrochloride

Abstract

The invention relates to a preparation method of aminoacetonitrile hydrochloride, which comprises the following steps: (1) carrying out condensation reaction by using ammonium chloride, formaldehyde, acetic acid and sodium cyanide as reaction raw materials to generate aminoacetonitrile: adding the ammonium chloride, formaldehyde and water into a reactor, uniformly stirring, cooling to below 0 DEG C, dropwisely adding 30-40 wt% sodium cyanide aqueous solution, starting to dropwisely add the acetic acid when 40-60% sodium cyanide aqueous solution is dropwisely added in the reactor, continuing the reaction at below 0 DEG C for 1-2 hours, filtering, and centrifugalizing to obtain the aminoacetonitrile; and (2) mixing the aminoacetonitrile with hydrogen chloride methanol solution, reacting at 45-50 DEG C for 1-2 hours, cooling to below 5 DEG C, filtering, and centrifugalizing to obtain the aminoacetonitrile hydrochloride, wherein in the hydrogen chloride methanol solution, the content of hydrogen chloride is 30-50 wt%, and the water content is less than or equal to 1%. According to the method provided by the invention, the total yield of the target product is high, and the operation is simple.

Description

technical field [0001] The invention relates to a preparation method of aminoacetonitrile hydrochloride. Background technique [0002] In the prior art, aminoacetonitrile hydrochloride is usually obtained by reacting aminoacetonitrile with hydrochloric acid, and the salt-forming yield of aminoacetonitrile hydrochloride is not high. [0003] In addition, the existing method of synthesizing aminoacetonitrile mainly contains following several kinds: [0004] Sodium cyanide method: use amine, sodium cyanide, formaldehyde, react and synthesize in the presence of magnesium salts such as magnesium chloride or magnesium hydrochloride; [0005] Liquid hydrocyanic acid method: use amine, formaldehyde, and liquid hydrocyanic acid as raw materials, add formaldehyde and hydrocyanic acid dropwise at the same time, react, extract and crystallize to obtain aminoacetonitrile, with a yield of 80-95% and a content of 92-98%; [0006] Hydroxyacetonitrile method: Use hydrocyanic acid and forma...

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Problems solved by technology

[0007] Among the above methods, although the liquid hydrocyanic acid method has a higher yield, the operation is dangerous. In order to obtain liquid hydrocyanic acid, a refrigeration system and equipment investment are required large, high cost, and uneconomical; while the hydroxyacetonitrile method has long reaction steps, cumbersome operation, large equipment investment, and high cost; the sodium cyanide method has the advantage of simple operation, but the yield is low, only about 50%