CN106496031B - A method of improving dimethyl malenate yield - Google Patents
A method of improving dimethyl malenate yield Download PDFInfo
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- CN106496031B CN106496031B CN201610794002.1A CN201610794002A CN106496031B CN 106496031 B CN106496031 B CN 106496031B CN 201610794002 A CN201610794002 A CN 201610794002A CN 106496031 B CN106496031 B CN 106496031B
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- solution
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- dimethyl malenate
- cyanoacetic acid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/18—Preparation of carboxylic acid esters by conversion of a group containing nitrogen into an ester group
- C07C67/22—Preparation of carboxylic acid esters by conversion of a group containing nitrogen into an ester group from nitriles
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/14—Preparation of carboxylic acid nitriles by reaction of cyanides with halogen-containing compounds with replacement of halogen atoms by cyano groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/32—Separation; Purification; Stabilisation; Use of additives
- C07C253/34—Separation; Purification
Abstract
The present invention provides a kind of method for improving dimethyl malenate yield, includes the following steps 1) acidification reaction: acid or hydrogen chloride gas is added to cyanoacetic acid sodium, reacts and cyanoacetic acid aqueous solution is made；2) distillation and concentration: methyl cyanoacetate being added into cyanoacetic acid aqueous solution, and distillation and concentration to anhydrous outflow removes inorganic salts solid；3) esterification: methanol being added into the solution after step 2 desalination and catalyst carries out esterification, obtains the solution containing methyl cyanoacetate；4) desalination: the inorganic salts solid in solution is removed；5) secondary esterification: a part of reuse is separated from the solution after step 3) desalination to step 2, methanol is added into another part solution, carries out esterification in acid condition, dimethyl malenate is made.The present invention reduces the dosages of sulfuric acid and waste water yield, avoid decomposition of the cyanoacetic acid in concentration removal process, effectively increase the yield of dimethyl malenate.
Description
Technical field
The present invention relates to chemical fields, more particularly to a kind of method for improving dimethyl malenate yield.
Background technique
Dimethyl malenate is the intermediate of medicine, pesticide and dyestuff etc., and production method is more domestic main both at home and abroad at present
Use cyaniding esterification process, i.e., be raw material with monoxone, Cymag and methanol etc., neutralized, cyaniding, acidification and esterification process and obtain
To dimethyl malenate.
Common synthetic method is as follows:
1, cyanoacetic acid direct esterification
This method has the drawback that: the reaction process for synthesizing cyanoacetic acid generates a large amount of inorganic salts sodium chloride, cyanoacetic acid
Esterification is carried out with after the mixture concentration of salt, but is concentrated to later period cyanoacetic acid and easily decomposes, and due to reaction mixture
In have a large amount of sodium chloride, sulfuric acid is reacted with sodium chloride when esterification, is consumed a large amount of sulfuric acid and is generated a large amount of acid waste waters.
2, cyanoacetic acid is hydrolyzed into malonic acid resterification
There is also the disadvantages identical as method 1 for this method.
3, desalination process for cleanly preparing
The mixed solution of cyanoacetic acid and sodium chloride is obtained after acidification reaction, distillation and concentration adds methanol to dissolve cyanogen second
Acid, separates to obtain solid sodium chloride and cyanoacetic acid methanol solution, and enriching sulfuric acid direct esterification in cyanoacetic acid methanol solution is isolated
Dimethyl malenate.The shortcomings that the method, is similar with method 1, i.e. concentration steams the water later period because with the presence of a large amount of inorganic salts, stirs
It is poor to mix and stir heat-transfer effect, it is easy to because hot-spot causes cyanoacetic acid largely to decompose.Also patent report removes using concentration twice
The process of salt reduces the decomposition of cyanoacetic acid: it first the mixed solution of cyanoacetic acid and sodium chloride is concentrated, removes part water,
Desalination is filtered, filtrate is concentrated eliminates water again, and again with methanol dissolves cyanoacetic acid, filters desalination.This method is removed in secondary concentration
The phenomenon that causing cyanoacetic acid to decompose because of local heating's unevenness is still remained during salt.
Detailed description of the invention
Fig. 1 is shown as the process flow chart of the embodiment of the present invention.
Summary of the invention
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide a kind of raising dimethyl malenate receipts
The problems such as method of rate, decomposition for solving cyanoacetic acid in the prior art is serious, dimethyl malenate yield is low.
In order to achieve the above objects and other related objects, the present invention provides a kind of side for improving dimethyl malenate yield
Method includes the following steps:
1) acidification reaction: acid or hydrogen chloride gas is added to cyanoacetic acid sodium, reacts and cyanoacetic acid aqueous solution is made.
2) distillation and concentration: methyl cyanoacetate being added into cyanoacetic acid aqueous solution, and distillation and concentration to anhydrous outflow removes inorganic
Salt solid；It is removed water, improve the dispersion performance of material in reaction system and is heated equal as solvent using methyl cyanoacetate
Even property avoids cyanoacetic acid in the decomposition of concentration removal process, improves product yield.The cyanogen being added into cyanoacetic acid aqueous solution
Methyl acetate can be mixed solution, for example, containing a large amount of methyl cyanoacetate in the solution after step 4) desalination, can also add
Enter into cyanoacetic acid aqueous solution, methyl cyanoacetate improves the dispersion performance and mass-and heat-transfer of material, avoid cyanogen as solvent
Decomposition of the acetic acid in concentration removal process.
3) esterification: methanol being added into the solution after step 2) desalination and catalyst carries out esterification, obtains
To the solution containing methyl cyanoacetate.
4) desalination: the inorganic salts solid in solution is removed.
5) a part of reuse secondary esterification: is separated from the solution after step 4) desalination to step 2), to another portion
Divide in solution and methanol is added, carry out esterification in acid condition, dimethyl malenate is made.
Further, in step 2), distillation and concentration carries out in two times, for the first time by cyanoacetic acid aqueous solution distillation and concentration to surplus
The water of remaining 40wt%~60wt% removes inorganic salts solid, methyl cyanoacetate is added into the cyanoacetic acid aqueous solution after desalination,
Second of distillation and concentration removes inorganic salts solid to anhydrous outflow.
Further, inorganic salts solid is washed using methanol, 3) methanol cleaning solution is entered step or carried out in step 5)
Esterification.Solid is washed using methanol, on the one hand remaining active principle sufficiently in recycling solid, on the other hand, excessive
Methanol, can recycling and reusing by rectification under vacuum after esterification.
Further, in step 3), the catalyst is one of ferric sulfate, iron chloride, zinc chloride or several groups
It closes.
Further, in step 1), the acid is hydrochloric acid；In step 5), the acid condition is by sulfuric acid or hydrogen chloride gas
Body provides.Sulfuric acid should be the concentrated sulfuric acid, and herein, enriching sulfuric acid or hydrogen chloride gas will not bring water into again, can effectively improve product
Yield.
Further, in step 2), distillation and concentration is to carry out under vacuum conditions, and control temperature is lower than 110 DEG C.Cyanoacetic acid
Methyl esters boiling point is 205 DEG C, and therefore, which not will cause methyl cyanoacetate decomposition.
Further, in step 2), the quality that methyl cyanoacetate is added is 0.5-5.0 times of cyanoacetic acid quality.
Further, in step 1), the cyanoacetic acid sodium carries out cyanogenation with Cymag by sodium chloroacetate and is made.
Further, the sodium chloroacetate, which is reacted by monoxone with sodium carbonate, is made.
Further, the molar ratio of sodium chloroacetate and Cymag is 1:(1.0-1.05), reaction carries out at 85-105 DEG C,
After reaction, it is cooled to room temperature, cyanoacetic acid sodium is made.
Further, in step 1), the pH=6.5-7.5 of cyanoacetic acid aqueous solution obtained.
Further, in step 5), the mole of methanol is 1.5 times or more of cyanoacetic acid mole in reaction solution.
Further, in step 3), an esterification reaction temperature is 40-80 DEG C, reaction cyanoacetic acid quality into reaction solution
Content is less than 1%.
Further, in step 5), secondary esterification reaction temperature is 60-100 DEG C, reaction time 1-5h.
Further, further include step 6) extraction split-phase: after secondary esterification, solution being cooled to room temperature, water is added to stir
It mixes, stands split-phase, after organic phase is washed with saturated aqueous sodium carbonate, be transferred to rectifying column, rectification under vacuum obtains malonic acid dimethyl
Ester.
As described above, a kind of method of raising dimethyl malenate yield of the invention, has the advantages that cyanogen second
Acid eliminates the inorganic salts sodium chloride being wherein mixed with by steaming water desalination before esterification, avoid in esterification process sulfuric acid with
Sodium chloride reacts, and reduces the dosage and waste water yield of sulfuric acid, using methyl cyanoacetate as solvent carry out water removal and
Desalination improves the dispersion performance and mass-and heat-transfer of material, avoids decomposition of the cyanoacetic acid in concentration removal process, effectively mentions
The high yield of dimethyl malenate, and be a kind of dimethyl malenate production method of environment-protecting clean.
Specific embodiment
Illustrate embodiments of the present invention below by way of specific specific example, those skilled in the art can be by this specification
Other advantages and efficacy of the present invention can be easily understood for disclosed content.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also based on different viewpoints and application, without departing from
Various modifications or alterations are carried out under spirit of the invention.
Embodiment 1
A kind of preparation method of dimethyl malenate, includes the following steps:
1) neutralization reaction: adding 620kg water stirring and dissolving in 445kg monoxone (mass content 98%, 4.62kmol), uses
Saturated aqueous sodium carbonate is neutralized to pH=6.5-7.0, generates sodium chloroacetate.
2) cyanogenation: the sodium chloroacetate that step 1) is obtained is transferred to cyanogenation kettle, is warming up to 50 DEG C, matter is then added dropwise
The sodium cyanide solution 765kg (Cymag containing 4.68kmol in aqueous solution) that concentration is 30% is measured, when reaction temperature reaches 85-90
After DEG C, stop heating and beginning to cool, when reaction temperature reaches 105 DEG C (later period is strong exothermal reaction), reaction terminates, cooling
To room temperature, the aqueous solution containing cyanoacetic acid sodium is made.
3) acidification reaction: being transferred to acidification reaction kettle for cyanoacetic acid sodium water solution made from step 2), stirring, by 500L (matter
Measure content 31%, density 1.16g/ml, HCl 4.93kmol) hydrochloric acid by measuring tank is slowly added to acidification reaction kettle, and acidification generates
After cyanoacetic acid, it is transferred to steaming water kettle and carries out steaming water.
4) desalination is once concentrated: opening vacuum, control system vacuum degree is greater than -0.09MPa, and starting stirring is opened collet and steamed
Vapour controls steam pressure 0.2-0.25MPa, carries out steaming water for the first time, collects water 1100L, stops steaming water, cools to room temperature, takes out
Filter is made filtrate respectively and filter cake, filter cake (salt) is washed with 450kg methanol.
5) secondary concentration removes water: 1500kg methyl cyanoacetate is added to filtrate, carries out second and steams water, control temperature exists
105 DEG C steam hereinafter, distilling to substantially anhydrous in kettle, reach striking point, and it is molten that the desalinization of soil by flooding or leaching methanol that step 4) obtains then is added
Liquid and 25kg ferric sulfate are transferred to and carry out an esterification.
6) esterification: being warming up to reflux, and reaction, less than 1%, is cooled to room temperature, is filtered to remove to cyanoacetic acid content
Inorganic salts, filter cake (secondary salt) are washed with 450kg methanol, and filtrate separates 1700kg (methyl cyanoacetate mass content 88.2%) work
It steams water jacket for lower batch step 5) to use, remainder and the merging of desalinization of soil by flooding or leaching methanol are transferred to secondary esterification.
7) secondary esterification: the sulphur of mass fraction 98% is added dropwise in steam off when reaction kettle of the esterification is warming up to 40 DEG C
Acid, acid adding control kettle temperature 65-70 DEG C (should suitably open cooling water temperature when necessary) in the process, and time for adding is controlled in 60-
120 minutes, acid adding total amount 300L (excess sulfuric acid)；65-70 DEG C of kettle temperature is controlled after acid adding, keeps the temperature 2 hours, then slowly heating
To 75 DEG C, 3 hours are kept the temperature, esterification terminates, and generates dimethyl malenate, is transferred to extraction split-phase process.
8) it extracts split-phase: after esterification, solution being cooled to room temperature, water 300L is added (to can be used what distillation and concentration obtained
Water, recycling reduce production cost), it stirs 30 minutes, split-phase after standing 40-60 minutes, organic phase saturated sodium carbonate water
It is transferred to rectifying column rectification under vacuum after solution washing, obtains dimethyl malenate 546kg, content 99.3% (GC, internal standard method), yield
89.0% (in terms of monoxone).The methanol that rectification under vacuum is isolated can be with recycling and reusing.
Specifically,
It is wherein mixed in conclusion reactant cyanoacetic acid of the invention is eliminated before esterification by steaming water desalination
Inorganic salts sodium chloride avoids sulfuric acid in esterification process and reacts with sodium chloride, and the dosage and waste water for reducing sulfuric acid generate
Amount carries out water removal and desalination as solvent using methyl cyanoacetate, improves the dispersion performance and mass-and heat-transfer of material, avoid
Decomposition of the cyanoacetic acid in concentration removal process, effectively increases the yield of dimethyl malenate, and be a kind of environment-protecting clean
Dimethyl malenate production method.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology all without departing from the spirit and scope of the present invention, carries out modifications and changes to above-described embodiment.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should be covered by the claims of the present invention.
Claims (9)
1. a kind of method for improving dimethyl malenate yield, which comprises the steps of:
1) acidification reaction: acid or hydrogen chloride gas being added into cyanoacetic acid sodium, react and cyanoacetic acid aqueous solution is made；
2) distillation and concentration: methyl cyanoacetate being added into cyanoacetic acid aqueous solution, and it is solid to remove inorganic salts for distillation and concentration to anhydrous outflow
Body；
3) esterification: methanol being added into the solution after step 2) desalination and catalyst carries out esterification, is contained
There is the solution of methyl cyanoacetate, the catalyst is one of ferric sulfate, iron chloride, zinc chloride or several combinations；
4) desalination: the inorganic salts solid in solution is removed；
5) secondary esterification: separating a part of reuse to step 2) from the solution after step 4) desalination, molten to another part
Methanol is added in liquid, carries out esterification in acid condition, dimethyl malenate is made.
2. the method according to claim 1 for improving dimethyl malenate yield, it is characterised in that: in step 2), distillation
Concentration carries out in two times, for the first time by cyanoacetic acid aqueous solution distillation and concentration to the water of remaining 40wt%~60wt%, removes nothing
Machine salt solid, methyl cyanoacetate is added into the cyanoacetic acid aqueous solution after desalination, and second of distillation and concentration to anhydrous outflow removes
Inorganic salts solid.
3. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: washed using methanol
Inorganic salts solid is washed, 3) methanol cleaning solution enters step or carry out in step 5) esterification.
4. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: in step 1), institute
Stating acid is hydrochloric acid；In step 5), the acid condition is provided by sulfuric acid or hydrogen chloride gas.
5. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: in step 2), steam
Evaporating concentration is to carry out under vacuum conditions, and control temperature is lower than 110 DEG C.
6. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: in step 1), system
The pH=6.5-7.5 of the cyanoacetic acid aqueous solution obtained；In step 2), the quality that methyl cyanoacetate is added is the 0.5- of cyanoacetic acid quality
5.0 again.
7. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: in step 1), institute
Cyanoacetic acid sodium is stated to be made by sodium chloroacetate and Cymag progress cyanogenation.
8. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: in step 3), one
Secondary esterification reaction temperature is 40-80 DEG C, reacts into reaction solution cyanoacetic acid mass content less than 1%；In step 5), secondary esterification
Reaction temperature is 60-100 DEG C, reaction time 1-5h.
9. the method according to claim 1 or 2 for improving dimethyl malenate yield, it is characterised in that: further include step
6) it extracts split-phase: after secondary esterification, solution being cooled to room temperature, is added water and stirred, stand split-phase, organic phase unsaturated carbonate
After sodium water solution washing, it is transferred to rectifying column, rectification under vacuum obtains dimethyl malenate.
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| CN107540543A (en) * | 2017-09-12 | 2018-01-05 | 潍坊滨海石油化工有限公司 | The preparation method of malonate |
| CN111138286A (en) * | 2018-11-01 | 2020-05-12 | 上海凯赛生物技术股份有限公司 | Method for treating mixture containing long-chain dibasic acid |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101270063A (en) * | 2008-01-22 | 2008-09-24 | 天津大学 | Method for preparing high purity solid cyanoacetic acid |
| CN101891610A (en) * | 2010-07-03 | 2010-11-24 | 潍坊市元利化工有限公司 | Continuous esterification production method for mixed dibasic acid dimethyl ester |
| CN103420834A (en) * | 2013-08-12 | 2013-12-04 | 重庆紫光化工股份有限公司 | Environment-friendly clean method for preparing dimethyl malonate |
| CN103724191A (en) * | 2014-01-28 | 2014-04-16 | 重庆紫光化工股份有限公司 | Dimethyl malonate preparation method |
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- 2016-08-31 CN CN201610794002.1A patent/CN106496031B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101270063A (en) * | 2008-01-22 | 2008-09-24 | 天津大学 | Method for preparing high purity solid cyanoacetic acid |
| CN101891610A (en) * | 2010-07-03 | 2010-11-24 | 潍坊市元利化工有限公司 | Continuous esterification production method for mixed dibasic acid dimethyl ester |
| CN103420834A (en) * | 2013-08-12 | 2013-12-04 | 重庆紫光化工股份有限公司 | Environment-friendly clean method for preparing dimethyl malonate |
| CN103724191A (en) * | 2014-01-28 | 2014-04-16 | 重庆紫光化工股份有限公司 | Dimethyl malonate preparation method |
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