Production method for preparing glutaronitrile by aminolysis of ester substances

Abstract

The invention provides a production method for preparing glutaronitrile by aminolysis of ester substances. The production method comprises the following steps: ester aminolysis reaction, amide dehydration nitrile-forming reaction, coarse treatment and refining treatment, and the ester aminolysis reaction is carried out in a microreactor with an umbrella-shaped channel structure by using dimethyl glutarate and ammonia water as raw materials, so that rapid and complete mass transfer reaction of the materials is realized, the conversion efficiency of the raw materials is improved, and the reaction time is greatly shortened. A chemical dehydrating agent is adopted to participate in the reaction, so that the reaction temperature is reduced, the side reaction is inhibited, and the dehydration reaction time is shortened. Through coarse treatment, trace impurities in the material can be removed, product decomposition caused in the subsequent refining process is reduced, according to the production method, the content of the finally prepared glutaronitrile reaches 98.9-99.5%, the color number is 25-30 #, and the quality of the prepared glutaronitrile product is excellent.

Description

technical field [0001] The invention belongs to the technical field of fine chemical synthesis, and in particular relates to a production method for preparing glutaronitrile by aminolysis of esters. Background technique [0002] Glutaronitrile is a fungicide intermediate with very important application value. The preparation of nitriles is usually obtained by the reaction of chlorinated hydrocarbons and cyanide. Glutaronitrile is usually reacted with dibromopropane and sodium cyanide. Sodium cyanide is dissolved in water, and the ethanol solution of dibromopropane is added. Cool, filter off the precipitate, extract the mother liquor with ethyl acetate, wash with water, dry over potassium carbonate, and recover the ethyl acetate. The residue is distilled under reduced pressure, and the fraction at 144-147°C (1.73kPa) is collected as the finished product, with a yield of about 80%. However, this kind of process must use highly toxic sodium cyanide and hydrogen cyanide, which...

AI Technical Summary

Problems solved by technology

However, this kind of process must use highly toxic sodium cyanide and hydrogen cyanide, which has high requirements on the overall equipment conditions. In addition, the reaction temperature is usually high, causing side reactions to occur

[0003] CN107266335B discloses a method for preparing sebaconitrile by one-pot method, which uses sebacic acid and urea as raw materials, conducts condensation reaction at a reaction temperature of 145-205°C, then adds a dehydrating agent for dehydration reaction, and extracts, separates The sebaconitrile product is obtained by liquidation, rectification and other operations, but its reaction temperature is high, and side reactions are prone to occur in the preparation process, which affects the product yield.

[0004] CN201810653383.0 discloses a method for preparing an atorvastatin calcium intermediate. In the preparation process of the pharmaceutical intermediate, under alkaline conditions, the organic ester compound IV and the methanol solution of ammonia undergo aminolysis reaction to obtain the amide compound V , the amide compound V is dehydrated under the action of a dehydrating agent to form a nitrile compound, which realizes the preparation of an organic nitrile compound without the use of highly toxic substances such as hydrocyanic acid and hydrochloride, but its amination reaction time is as long as 16 hours , and the dehydration reaction is carried out under the condition of adding the dehydrating agent thionyl chloride and the basic substance pyridine. The reaction process will release a series of sulfides, which is not suitable for industrial production

Images