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Malononitrile synthesis method

A synthesis method and technology of malononitrile, applied in the field of chemical synthesis and synthesis of malononitrile, can solve the problems of large amount of solvent and adsorbent, difficult separation of by-product phosphoric acid, high safety risk, etc., and achieve few reaction steps and high product quality Good purity and the effect of reducing the amount of three wastes

Inactive Publication Date: 2015-09-30
JINGZHOU HELE IND SCI & TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, at present, this method mainly has problems such as large amount of solvent and adsorbent used and difficult separation of by-product phosphoric acid, so the process technology needs to be further improved and optimized.
[0009] Fourth: Other synthetic methods, such as acetonitrile high-temperature cracking polymerization method, acrylonitrile method, styrene method, aminoacetonitrile method, etc., but these methods are difficult to be used in industrialization because of high cost or high safety risks.

Method used

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Examples

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Embodiment 1

[0035] (1) In a 5000ml four-necked flask, add 3000ml methanol, cool down to -5°C~0°C in an ice-salt bath, feed ammonia gas to saturation, control the temperature at 10~15°C, add 1000g methyl cyanoacetate dropwise, add dropwise After the completion, the reaction was carried out with heat preservation and stirring for 4 hours. Sampling was carried out to control the reaction of methyl cyanoacetate. The reaction of methyl cyanoacetate was basically complete. The ammonia gas was decompressed until the temperature dropped below -10°C. Then, it was filtered by suction and dried to obtain 822g, with a yield of 97.9%.

[0036] (2) In a 1000ml four-neck flask, add 168g cyanoacetamide, 500g1,2-dichloroethane, catalyst and 170g phosphorus oxychloride, heat and reflux for 6 hours, cool down to room temperature, filter with suction, and use 200g1 , washed with 2-dichloroethane, drained, and the filtrate was desolvated to obtain a crude product. Then, 122 g of malononitrile was obtained by v...

Embodiment 2

[0038] (1) In a 5000ml four-neck flask, add 3000ml of methanol, cool down in an ice-salt bath to 0°C-5°C, feed ammonia gas to saturation, control the temperature at 0-5°C, add 1000g of methyl cyanoacetate dropwise, and the dropwise addition is completed Afterwards, heat-preserve and stir for 4 hours, take a sample to control, the reaction of methyl cyanoacetate is basically complete, remove ammonia gas under reduced pressure until the temperature drops below -10°C, filter with suction, and dry to obtain 818g, with a yield of 97.4%.

[0039] (2) In a 1000ml four-neck flask, add 168g cyanoacetamide, 500g cyclohexane, catalyst and 170g phosphorus oxychloride, heat and reflux for 6 hours, cool down to room temperature, filter with suction, and wash the filter cake with 200g cyclohexane , pumped to dryness, and the filtrate was desolvated to obtain a crude product. Then, oil pump vacuum distillation gave 125 g of malononitrile, with a yield of 94.7%.

Embodiment 3

[0041] (1) In a 5000ml four-neck flask, add 3000ml methanol, cool down in an ice-salt bath to 20°C-30°C, feed ammonia gas to saturation, control the temperature at 20-30°C, add 1000g methyl cyanoacetate dropwise, and dropwise complete Afterwards, heat-preserved and stirred for 4 hours to react. Sampling was carried out to control the reaction of methyl cyanoacetate. The reaction of methyl cyanoacetate was basically complete. The ammonia gas was decompressed until the temperature dropped below -10°C. Then, it was filtered by suction and dried to obtain 803g, with a yield of 95.6%.

[0042](2) In a 1000ml four-neck flask, add 168g cyanoacetamide, 500g1,2-dichloroethane, catalyst and 230g phosphorus oxychloride, heat and reflux for 6 hours, cool down to room temperature, filter with suction, and use 200g1 , washed with 2-dichloroethane, drained, and the filtrate was desolvated to obtain a crude product. Then, 123 g of malononitrile was obtained by vacuum distillation with an oil p...

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Abstract

The invention relates to a malononitrile synthesis method and belongs to the technical field of malononitrile synthesis. The malononitrile synthesis method comprises the following steps of 1, adding methanol or ethanol into a reactor, feeding ammonia gas into the reactor at a temperature of -20 to 50 DEG C, dropwisely adding methyl cyanoacetate or ethyl cyanoacetate into the reactor at a temperature of -20 to 50 DEG C, after dropwise addition, carrying out heat-preservation stirring, carrying out reduced pressure degasification until a temperature is reduced to below -10 DEG C and carrying out filtration and drying to obtain cyanoacetamide, and 2, mixing a dehydrant, a catalyst, cyanoacetamide and a solvent, heating the mixture for a reflux reaction lasting for 6h, carrying out cooling and filtration, removing the solvent to obtain a crude product, and carrying out reduced pressure rectification to obtain a malononitrile product. The preparation method has less reaction processes, can be operated simply, has a high yield and good product purity, utilizes cheap and easily available raw materials, greatly reduces a production cost, is free of an adsorbent, has a less phosphorous oxychloride use amount, greatly reduces three wastes, realizes easy recovery and recycle of the solvent, is suitable for industrial production and solves the problems of the existing a malononitrile synthesis method.

Description

technical field [0001] The invention relates to a chemical synthesis method, in particular to a synthesis method of malononitrile, belonging to the technical field of malononitrile synthesis. Background technique [0002] Malononitrile is an important chemical intermediate, which is widely used in the fields of medicine, pesticide and dye materials. In terms of medicine, it can be used to synthesize a series of important drugs such as vitamin B1, aminopterin, and triamterene; 4,5,8-Naphthalene tetracarboxylic acid, Lanzhongwang, etc.; can also be used as an extraction agent for gold. Its structure is a compound shown in formula one: [0003] [0004] (Formula 1) [0005] According to domestic and foreign literature reports, currently malononitrile mainly has the following several synthetic methods. [0006] One: using acetonitrile and cyanogen chloride as raw materials, dehydrochlorination and condensation at high temperature to obtain malononitrile, as disclosed in J...

Claims

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Application Information

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IPC IPC(8): C07C253/20C07C255/04
Inventor 吴清来杨雄
Owner JINGZHOU HELE IND SCI & TECH CO LTD
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