Process for preparing N-phenylamino acetonitrile

A technology of phenylaminoacetonitrile and production method, which is applied in chemical instruments and methods, preparation of carboxylic acid nitrile, preparation of organic compounds, etc., and can solve problems such as large amount of cooling capacity and steam, difficult treatment of cyanide-containing tail gas, and large investment in equipment , achieve the effect of good yield and quality, lower production cost and less investment

Inactive Publication Date: 2004-10-20
四川省天然气化工研究院
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The hydroxyacetonitrile method has long reaction steps, cumbersome operation, difficult treatment of cyanide-containing tail gas, and requires a large amount of cooling capacity and steam, which requires large equipment investment and high cost

Method used

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  • Process for preparing N-phenylamino acetonitrile

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Effect test

Embodiment 1

[0025] Add 1500kg of aniline (industrial product) into the reaction kettle, under stirring, add 800kg of formaldehyde (industrial product) at 10-30°C, adjust the pH to 2-3 with sulfuric acid, and pass gas hydrocyanic acid (gas Hydrocyanic acid percentage concentration is 4~10%, all the other are air and inert gas), when formaldehyde is nearly consumed, then add 518kg formaldehyde, continue to pass into gas hydrocyanic acid simultaneously. At the end of the reaction, put the material into the extraction tank, extract it twice with water, and then put it into the crystallization tank. Add an appropriate amount of water to cool and stir to crystallize, and centrifuge to obtain 2049.2 kg of N-phenylaminoacetonitrile with a content of 98.5% and a yield of 95.2%.

[0026] Wastewater treatment: Combine the water phase, which contains a small amount of hydrocyanic acid, aniline and its derivatives, etc. Bubble air into the water phase to drive out most of the hydrocyanic acid and abs...

Embodiment 2

[0028] Add 1500kg of aniline into the reaction kettle, under stirring, add 1000kg of formaldehyde at 10-15°C, adjust the pH to 1.5-2.5 with phosphoric acid, and feed gaseous hydrocyanic acid at a constant speed at 85-90°C (the percentage concentration of gaseous hydrogencyanic acid is 10- 35%, the rest is air and inert gas), when the formaldehyde is nearly consumed, add 275kg formaldehyde, and continue to feed gaseous hydrocyanic acid at the same time. At the end of the reaction, put the material into the extraction tank, extract it twice with water, and then put it into the crystallization tank. Add an appropriate amount of water to cool and stir to crystallize, and centrifuge to obtain 2060.5 kg of N-phenylaminoacetonitrile with a content of 98.8% and a yield of 95.6%.

[0029] Waste water treatment is the same as embodiment 1.

Embodiment 3

[0031] Add 1500kg of aniline into the reaction kettle, under stirring, add 1250kg of formaldehyde at 50-60°C, adjust the pH to 1-3 with acetic acid, and feed gaseous hydrocyanic acid at a constant speed at 75-90°C (the percentage concentration of gaseous hydrocyanic acid is 35- 45%, the rest is air and inert gas), when the formaldehyde is nearly consumed, add 318kg formaldehyde, and continue to feed gaseous hydrocyanic acid simultaneously. At the end of the reaction, put the material into the extraction tank, extract it twice with water, and then put it into the crystallization tank. Add an appropriate amount of water to cool and stir to crystallize, and centrifuge to obtain 2075.3 kg of N-phenylaminoacetonitrile with a content of 99.6% and a yield of 96.5%.

[0032] Waste water treatment is the same as embodiment 1.

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Abstract

A process for preparing N-phenylamino acetonitrile from aniline, formaldehyde and gas-state hydrocyanic acid in a mole ratio of 1: (0.8-1.2):(0.8-3) and acid catalyst includes such steps as catalytic reation between aniline, 0-80 wt.% of formaldehyde and continuously introduced gas-state hydrocyanic acid at 10-90 deg.C, adding the rest of formaldehyde when the formaldehyde in the reactor is nearly consumed off, adding water after reaction is completed, stirring, crystallizing to obtain product, and treating the waste water by adding air, caustic alkali and oxidant and biochemial treatment. Its advantages are high safety and low cost.

Description

Technical field: [0001] What the present invention relates to is a kind of production method of N-phenylaminoacetonitrile. Background technique: [0002] Synthetic N-phenyl amino acetonitrile, existing method has following several: [0003] 1), sodium cyanide method: Patent Application No. CN971045054.0 discloses a "N-phenylaminoacetate manufacturing process", using aniline, sodium cyanide, formaldehyde, in the presence of magnesium salt (magnesium chloride or magnesium sulfate) Next, N-phenylaminoacetonitrile is generated. [0004] 2), liquid hydrocyanic acid method: German patents DE3,010,511, 2,621,450, 2,621,728, 2,625,935, Japanese patents JP591210,052, JP56,141251, etc. use aniline, formaldehyde, liquid hydrocyanic acid as raw materials, and drop formaldehyde and hydrogen at the same time Cyanic acid, reacted, extracted and crystallized to obtain N-phenylaminoacetonitrile with a yield of 80-95% and a content of 92-98%. [0005] 3), hydroxyacetonitrile method: Britis...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C253/00C07C255/58
Inventor 李明中郑道敏林辉荣刁正坤龙晓钦
Owner 四川省天然气化工研究院
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