Method for preparing aminoacetonitrile sulfate

Abstract

The invention relates to a method for preparing aminoacetonitrile sulfate. The method comprises the following steps of: (1) performing condensation on ammonium chloride, formaldehyde, acetic acid and sodium cyanide which are taken as reaction raw materials to obtain aminoacetonitrile, namely putting ammonium chloride, formaldehyde and water into a reactor, stirring uniformly, cooling to below zero, dripping 30 to 40 weight percent of aqueous solution of sodium cyanide, simultaneously dripping the acetic acid when 40 to 60 percent of aqueous solution of sodium cyanide is dripped, continuing to react below zero for 1 to 2 hours after the dripping is finished, filtering, and centrifuging to obtain the aminoacetonitrile; and (2) reacting the aminoacetonitrile and a methanol solution of sulfuric acid at the temperature of between 30 and 35 DEG C for 1 to 2 hours, cooling to below 5 DEG C, filtering, and centrifuging to obtain the aminoacetonitrile sulfate, wherein the sulfuric acid accounts for less than or equal to 15 percent of the weight of the methanol solution of the sulfuric acid and the water accounts for less than or equal to 1 percent of the weight of the methanol solution of the sulfuric acid. According to the method, the total yield of a target product is high; and the method is easy to operate.

Description

technical field [0001] The invention relates to a preparation method of aminoacetonitrile sulfate. Background technique [0002] In the prior art, aminoacetonitrile sulfate is usually obtained by reacting aminoacetonitrile with sulfuric acid aqueous solution. Because aminoacetonitrile has a more active reaction property and sulfuric acid has oxidizing properties, the salt-forming rate of aminoacetonitrile sulfate 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 sulfate; [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...

AI Technical Summary

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 The hydroxyacetonitrile method has long reaction steps, complicated 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%