CN109265368A - Ethyl cyanoacetate synthesis technology - Google Patents
Ethyl cyanoacetate synthesis technology Download PDFInfo
- Publication number
- CN109265368A CN109265368A CN201811034356.1A CN201811034356A CN109265368A CN 109265368 A CN109265368 A CN 109265368A CN 201811034356 A CN201811034356 A CN 201811034356A CN 109265368 A CN109265368 A CN 109265368A
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- CN
- China
- Prior art keywords
- sulfuric acid
- level
- reaction
- sulfur trioxide
- absorption tower
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Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/30—Preparation of carboxylic acid nitriles by reactions not involving the formation of cyano groups
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/69—Sulfur trioxide; Sulfuric acid
- C01B17/74—Preparation
- C01B17/76—Preparation by contact processes
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
- C01D5/02—Preparation of sulfates from alkali metal salts and sulfuric acid or bisulfates; Preparation of bisulfates
Abstract
The invention belongs to technical field of organic synthesis, provide a kind of ethyl cyanoacetate synthesis technology.The present invention in esterification reaction process by being slowly introducing sulfur trioxide, the water for generating sulfur trioxide with esterification, which reacts, generates sulfuric acid, on the one hand it is carried out to the right as catalyst reaction, on the other hand the water in consumption product prevents side reaction, and the generation of side reaction is reduced while improving product yield；Tail gas absorbs sulfur trioxide using two-level absorption tower, and the first stage tower production concentrated sulfuric acid realizes the reuse of catalyst, and second level tower by-product sodium sulphate realizes the value promotion of tail gas.
Description
Technical field
The invention belongs to technical field of organic synthesis, and in particular to a kind of ethyl cyanoacetate synthesis technology.
Background technique
Ethyl cyanoacetate is the intermediate of the fine chemical products such as medicine, dyestuff, for synthesizing ester, amides, acids,
Nitrile compounds.Japan is mainly used as the intermediate of cyanoacrylate Instant cement, assembles for auto parts, household electrical appliance
In addition the bonding of part is also used to the fields such as vitamin B6, synthetic dyestuffs.Ethyl cyanoacetate and methoxy ethylacetoacetone and ammonium hydroxide ring
5- cyano -6- hydroxyl -4- methoxyl methyl -2- picoline can be made in conjunction.3- amino-can be obtained through nitrification, chlorination, catalytic hydrogenation
5- aminomethyl -4- methoxyl methyl -2- picoline.Further diazotising, hydrolysis, at salt can obtain micro-element B6.
Synthesis ethyl cyanoacetate is mainly using cyanoacetic acid as raw material at present, and ethyl alcohol simultaneously participates in reaction as solvent, dense
The lower generation esterification of sulfuric acid catalyst effect obtains ethyl cyanoacetate, obtains finished product through filtering, air-distillation, rectification under vacuum.?
In synthesis process, there are problems that following two: 1) since esterification is reversible reaction, reaction process conversion ratio is relatively low,
Cause to bring certain difficulty to separation, separation costs increase containing a large amount of unreacting materials in product.2) esterification is raw
At water can slowly generate carboxylic acid under effect of sulfuric acid with the cyano in ethyl cyanoacetate, cause side reaction to increase.
Summary of the invention
The problem of for current ethyl cyanoacetate esterification reaction process, the present invention provide a kind of ethyl cyanoacetate conjunction
At technique, by being slowly introducing sulfur trioxide during the reaction, the water for generating sulfur trioxide with esterification, which reacts, generates sulfuric acid,
On the one hand it is carried out to the right as catalyst reaction, the water on the other hand consumed in product prevents side reaction, improves and produces
The generation of side reaction is reduced while product yield.
Technical solution of the present invention:
A kind of ethyl cyanoacetate synthesis technology, device used in the ethyl cyanoacetate synthesis technology include sulfur trioxide buffering
Tank, reaction kettle, first-stage condenser, level-one sulfuric acid absorption tower, second level lye absorption tower and secondary condenser；
Cyanoacetic acid addition ethyl alcohol is dissolved, the molar ratio for controlling cyanoacetic acid and ethyl alcohol is 1:2~3, is shifted after dissolution
Into reaction kettle；It stirs, under room temperature, is slowly added to the 98wt.% concentrated sulfuric acid into reactor from addition funnel, control cyanogen second
The mass ratio of acid and sulfuric acid is 1:0.1~0.15, controlled at 60 DEG C, after being added dropwise, increases system temperature to 80 DEG C, drips
Enriching sulfuric acid is at the uniform velocity passed through sulfur trioxide into feed liquid simultaneously, and sulfur trioxide surge tank is connected with the air inlet of reaction kettle, leads to
The control valve crossed on pipeline realizes being precisely controlled for flow and pressure, and the molar ratio for controlling cyanoacetic acid and sulfur trioxide is 1:0.3-
0.8；Reaction kettle is connected to condenser, and the alcohol vapor in reaction kettle is entered by first-stage condenser entrance, in first-stage condenser
The lower condensation of effect, alcohol reflux continue to participate in reaction into reaction kettle, and reacting after the 4h that flows back terminates；In 45~85 DEG C of temperature conditions
Under, air-distillation goes out ethanol component in reaction system, and 12wt.% ammonium hydroxide is added dropwise into reaction kettle and is neutralized, and control temperature exists
70~90 DEG C, material liquid pH is transferred to 7-8, separates organic phase ethyl cyanoacetate crude product；Ethyl cyanoacetate crude product is dropped in rectifying column
Interior rectification under vacuum, obtains ethyl cyanoacetate；
Reaction is passed through during sulfur trioxide, and first-stage condenser tail gas enters secondary condenser deep cooling, is collected few in tail gas
Uncooled ethyl alcohol is measured, secondary condenser offgas outlet is connected with level-one sulfuric acid absorption tower, and sulfur trioxide tail gas enters level-one sulfuric acid
In absorption tower；Level-one sulfuric acid absorption column overhead is passed through 90wt.%-98wt.% sulfuric acid, and tail gas obtains after level-one sulfuric acid absorption tower
To the concentrated sulfuric acid, concentrated sulfuric acid a part of formation is collected, and another part is passed through through outlet to continuing to participate in reaction in reaction kettle；Level-one
Tail gas of sulfuric acid absorption tower is passed through to second level lye absorption tower, behind second level lye absorption tower, harmless direct emission, and the sulfuric acid of generation
Sodium solution is collected.
Beneficial effects of the present invention: the present invention makes three oxidations by being slowly introducing sulfur trioxide in esterification reaction process
Sulphur is reacted with the water that esterification generates generates sulfuric acid, on the one hand carries out to the right as catalyst reaction, on the other hand consumption produces
Water in object prevents side reaction, and the generation of side reaction is reduced while improving product yield；Tail gas is absorbed using second level
Tower absorbs sulfur trioxide, and the first stage tower production concentrated sulfuric acid realizes the reuse of catalyst, and second level tower by-product sodium sulphate realizes tail gas
Value promotion.
Detailed description of the invention
Attached drawing 1 is ethyl cyanoacetate synthesis system structural schematic diagram.
Specific embodiment
Below in conjunction with attached drawing and technical solution, a specific embodiment of the invention is further illustrated.
Technical solution of the present invention production technology and its equipment are simple, and product yield is high, low in cost, non-environmental-pollution,
For green production process, it is easy to accomplish industrialized production.
Embodiment 1
Cyanoacetic acid addition ethyl alcohol is dissolved, the molar ratio for controlling cyanoacetic acid and ethyl alcohol is 1:3, is transferred to after dissolution anti-
It answers in kettle.It stirs, under room temperature, is slowly added to 98% concentrated sulfuric acid into reactor from addition funnel, control cyanoacetic acid and sulphur
The mass ratio of acid is 1:0.1, controls temperature 60 C, and system temperature control is increased after being added dropwise at 80 DEG C, it is same that the concentrated sulfuric acid is added dropwise
When be at the uniform velocity passed through sulfur trioxide into feed liquid, the molar ratio for controlling cyanoacetic acid and sulfur trioxide is 1:0.3, reacts knot after the 4h that flows back
Beam；At 80 DEG C, air-distillation goes out ethanol component in reaction system, and 12% ammonium hydroxide is added dropwise into system and is neutralized, and controls temperature
At 70 DEG C, material liquid pH is transferred to 8.Separate organic phase cyanoacetate crude product.The rectification under vacuum in rectifying column of ethyl cyanoacetate crude product,
Obtain ethyl cyanoacetate, purity 99.9%, total yield of products 92.1%.
Embodiment 2
Cyanoacetic acid addition ethyl alcohol is dissolved, the molar ratio for controlling cyanoacetic acid and ethyl alcohol is 1:2, is transferred to after dissolution anti-
It answers in kettle；Stirring, under room temperature, is slowly added to the 98wt.% concentrated sulfuric acid from addition funnel into reactor, control cyanoacetic acid with
The mass ratio of sulfuric acid is 1:0.15, controlled at 60 DEG C, after being added dropwise, increases system temperature to 80 DEG C, the concentrated sulfuric acid is added dropwise
Sulfur trioxide is at the uniform velocity passed through into feed liquid simultaneously, the molar ratio for controlling cyanoacetic acid and sulfur trioxide is 1:0.8, is reacted after the 4h that flows back
Terminate；Under the conditions of 85 DEG C of temperature, air-distillation goes out ethanol component in reaction system, and 12wt.% ammonia is added dropwise into reaction system
Water is neutralized, and controls temperature at 90 DEG C, material liquid pH is transferred to 7.5, separates organic phase ethyl cyanoacetate crude product；By ethyl cyanoacetate
Crude product is dropped in rectification under vacuum in rectifying column, obtains ethyl cyanoacetate, purity 99.9%, total yield of products 93.6%.
Embodiment 3
Cyanoacetic acid addition ethyl alcohol is dissolved, the molar ratio for controlling cyanoacetic acid and ethyl alcohol is 1:2.5, is transferred to after dissolution
In reaction kettle；It stirs, under room temperature, is slowly added to the 98wt.% concentrated sulfuric acid into reactor from addition funnel, control cyanoacetic acid
Mass ratio with sulfuric acid is 1:0.12, controlled at 60 DEG C, after being added dropwise, increases system temperature to 80 DEG C, dense sulphur is added dropwise
Acid is at the uniform velocity passed through sulfur trioxide into feed liquid simultaneously, and the molar ratio for controlling cyanoacetic acid and sulfur trioxide is 1:0.5, anti-after the 4h that flows back
It should terminate；Under the conditions of 80 DEG C of temperature, air-distillation goes out ethanol component in reaction system, and 12wt.% is added dropwise into reaction system
Ammonium hydroxide is neutralized, and controls temperature at 70 DEG C, material liquid pH is transferred to 7, separates organic phase ethyl cyanoacetate crude product；By ethyl cyanoacetate
Crude product is dropped in rectification under vacuum in rectifying column, obtains ethyl cyanoacetate, purity 99.9%, total yield of products 92.8%.
Claims (1)
1. a kind of ethyl cyanoacetate synthesis technology, which is characterized in that device used in the ethyl cyanoacetate synthesis technology includes three
Sulfur oxide surge tank, reaction kettle, first-stage condenser, level-one sulfuric acid absorption tower, second level lye absorption tower and secondary condenser；
Cyanoacetic acid addition ethyl alcohol is dissolved, the molar ratio for controlling cyanoacetic acid and ethyl alcohol is 1:2~3, is transferred to after dissolution anti-
It answers in kettle；Stirring, under room temperature, is slowly added to the 98wt.% concentrated sulfuric acid from addition funnel into reactor, control cyanoacetic acid with
The mass ratio of sulfuric acid is 1:0.1~0.15, controlled at 60 DEG C, after being added dropwise, increases system temperature to 80 DEG C, is added dropwise dense
Sulfuric acid is at the uniform velocity passed through sulfur trioxide into feed liquid simultaneously, and sulfur trioxide surge tank is connected with the air inlet of reaction kettle, passes through pipe
The control valve realization flow of road and being precisely controlled for pressure, the molar ratio for controlling cyanoacetic acid and sulfur trioxide is 1:0.3-0.8；
Reaction kettle is connected to condenser, and the alcohol vapor in reaction kettle is entered by first-stage condenser entrance, in the effect of first-stage condenser
Lower condensation, alcohol reflux continue to participate in reaction into reaction kettle, and reacting after the 4h that flows back terminates；Under the conditions of 45~85 DEG C of temperature,
Air-distillation goes out ethanol component in reaction system, and 12wt.% ammonium hydroxide is added dropwise into reaction kettle and is neutralized, control temperature 70~
90 DEG C, material liquid pH is transferred to 7-8, separates organic phase ethyl cyanoacetate crude product；Ethyl cyanoacetate crude product is dropped in rectifying column and is subtracted
Rectifying is pressed, ethyl cyanoacetate is obtained；
Reaction is passed through during sulfur trioxide, and first-stage condenser tail gas enters secondary condenser deep cooling, collect in tail gas it is a small amount of not
Ethyl alcohol is condensed, secondary condenser offgas outlet is connected with level-one sulfuric acid absorption tower, and sulfur trioxide tail gas enters level-one sulfuric acid absorption
In tower；Level-one sulfuric acid absorption column overhead is passed through 90wt.%-98wt.% sulfuric acid, and tail gas obtains dense after level-one sulfuric acid absorption tower
Sulfuric acid, concentrated sulfuric acid a part of formation are collected, and another part is passed through through outlet to continuing to participate in reaction in reaction kettle；Level-one sulfuric acid
The tail gas on absorption tower is passed through to second level lye absorption tower, behind second level lye absorption tower, harmless direct emission, and the sodium sulphate of generation
Solution is collected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811034356.1A CN109265368A (en) | 2018-09-06 | 2018-09-06 | Ethyl cyanoacetate synthesis technology |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811034356.1A CN109265368A (en) | 2018-09-06 | 2018-09-06 | Ethyl cyanoacetate synthesis technology |
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| Publication Number | Publication Date |
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| CN109265368A true CN109265368A (en) | 2019-01-25 |
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| CN201811034356.1A Pending CN109265368A (en) | 2018-09-06 | 2018-09-06 | Ethyl cyanoacetate synthesis technology |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04124168A (en) * | 1990-09-13 | 1992-04-24 | Taoka Chem Co Ltd | Production of alpha-cyanoacrylate |
| CN102276463A (en) * | 2011-08-01 | 2011-12-14 | 海门瑞一医药科技有限公司 | Process for producing ethyl trifluoroacetate |
| CN107827779A (en) * | 2017-10-30 | 2018-03-23 | 烟台国邦化工机械科技有限公司 | Batch reactive distillation production cyanoacetate compound, malonate compound device and its production technology |
| CN209052604U (en) * | 2018-09-06 | 2019-07-02 | 营创三征(营口)精细化工有限公司 | Ethyl cyanoacetate synthesis system |
-
2018
- 2018-09-06 CN CN201811034356.1A patent/CN109265368A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04124168A (en) * | 1990-09-13 | 1992-04-24 | Taoka Chem Co Ltd | Production of alpha-cyanoacrylate |
| CN102276463A (en) * | 2011-08-01 | 2011-12-14 | 海门瑞一医药科技有限公司 | Process for producing ethyl trifluoroacetate |
| CN107827779A (en) * | 2017-10-30 | 2018-03-23 | 烟台国邦化工机械科技有限公司 | Batch reactive distillation production cyanoacetate compound, malonate compound device and its production technology |
| CN209052604U (en) * | 2018-09-06 | 2019-07-02 | 营创三征(营口)精细化工有限公司 | Ethyl cyanoacetate synthesis system |
Non-Patent Citations (1)
| Title |
|---|
| 刘旭，等: "一种氰乙酸乙酯合成的新方法", 《精细与专用化妆品》 * |
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Application publication date: 20190125 |