Preparation method and refining method of ethoxymethylenemalononitrile

Abstract

The invention relates to a preparation method and a refining method of ethoxymethylenemalononitrile. The preparation method comprises the steps as follows: putting malononitrile, triethyl orthoformate and anhydrous lithium chloride in a reaction vessel, stirring the mixture, heating the mixture to the temperature of 78-85 DEG C, after complete reaction, removing ethanol produced in the reaction through distillation, cooling and crystallizing the residual liquid after distillation, and collecting and drying solids to obtain the ethoxymethylenemalononitrile. According to the preparation method, a catalyst is changed into the anhydrous lithium chloride, the full contact of the catalyst with reaction substances is promoted, the ethanol produced in the reaction is directly used as a reaction solvent, and a synthetic reaction is performed at an ethanol backflow temperature, so that the catalytic efficiency, the reaction speed and the reaction efficiency are improved remarkably, the use of a large number of toxic solvents (methylbenzene) is avoided, the environmental protection is facilitated, the reaction operation is simplified, the problem of inconvenience in solvent recovery is solved, the manufacturing cost is reduced remarkably (the cost is reduced by about 40%), and the preparation method is applicable to the industrial production.

Description

Technical field [0001] The invention relates to the technical field of compound preparation, in particular to a preparation method and a refining method of ethoxymethylene malononitrile. Background technique [0002] Ethoxymethylenemalononitrile (Ethoxymethylenemalononitrile, structure shown in formula 1) is also known as ethoxydicyanoethylene, ethoxymethylenemalononitrile, ethoxymethylenemalononitrile, ethoxy Methylalkenylmalononitrile, CAS registration number is 123-06-8, molecular formula is C 6 H 6 N 2 O, the molecular weight is 122.1246. [0003] [0004] Ethoxymethylene malononitrile is white to off-white crystalline powder, insoluble in water, soluble in organic solvents such as methanol, ethanol, melting point 65℃-67℃, boiling point 160℃ (12mmHg), commonly used in the preparation of industrial chemicals , Intermediates of pharmaceutical chemicals, such as intermediates for the preparation of milrinone. [0005] At present, the preparation method of ethoxymethylene malononit...

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Problems solved by technology

[0006] Liu Qiming et al. (Liu Qiming, Su Yuyong, Chen Bangyin, Zhang Hanping. Synthesis and structural identification of phosphodiesterase inhibitor Milrinone [J]. Journal of Huazhong University of Science and Technology (Medical Science), 2005, 34(1): 74-75) published A kind of preparation method of ethoxymethylene malononitrile is proposed, and this method uses poisonous toluene in a large amount as solvent, and used catalyst zinc chloride is insoluble in organic solvent (toluene) and is difficult to fully contact with reaction substance, causes catalytic effect Not ideal, affecting reaction speed and reaction efficiency, and this method also adopts mixed solvent to refine ethoxymethylene malononitrile, so there are defects such as inconvenient product post-processing, unfavorable for environmental protection, high production cost, and difficult solvent recovery

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