CN106496031A - A kind of method for improving dimethyl malenate yield - Google Patents
A kind of method for improving dimethyl malenate yield Download PDFInfo
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- CN106496031A CN106496031A CN201610794002.1A CN201610794002A CN106496031A CN 106496031 A CN106496031 A CN 106496031A CN 201610794002 A CN201610794002 A CN 201610794002A CN 106496031 A CN106496031 A CN 106496031A
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- Prior art keywords
- dimethyl malenate
- solution
- cyanoacetic acid
- esterification
- 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, comprises the steps 1）Acidification reaction：Add acid or hydrogen chloride gas, reaction that cyanoacetic acid aqueous solution is obtained to cyanoacetic acid sodium；2）Distillation and concentration：To in cyanoacetic acid aqueous solution, add methyl cyanoacetate, distillation and concentration to anhydrous outflow to remove inorganic salt solid；3）Esterification：To step 2）Add methanol and catalyst to carry out esterification in solution after desalination, obtain the solution containing methyl cyanoacetate；4）Desalination：Remove the inorganic salt solid in solution；5）Secondary esterification：From step 3）A part of reuse is separated in solution after desalination to step 2）, methanol being added in another part solution, carrying out esterification in acid condition, dimethyl malenate is obtained.The present invention reduces the consumption of sulphuric acid and waste water yield, it is to avoid decomposition of the cyanoacetic acid in concentration removal process, the yield of dimethyl malenate is effectively increased.
Description
Technical field
The present invention relates to chemical field, more particularly to a kind of method for improving dimethyl malenate yield.
Background technology
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, Cyanogran. and methanol etc., neutralized, cyaniding, acidifying and esterification process and obtain
Arrive dimethyl malenate.
Common synthetic method is as follows：
1st, cyanoacetic acid direct esterification
The method has the drawback that：The course of reaction of synthesis cyanoacetic acid produces substantial amounts of inorganic salt sodium chloride, cyanoacetic acid
Esterification is carried out with after the mixture concentration of salt, but is concentrated to later stage cyanoacetic acid and is easily decomposed, and due to reactant mixture
In have substantial amounts of sodium chloride, during esterification, sulphuric acid and sodium chloride react, and consume substantial amounts of sulphuric acid and simultaneously produce a large amount of acid waste waters.
2nd, cyanoacetic acid is hydrolyzed into malonic acid resterification
The method there is also and 1 identical shortcoming of method.
3rd, desalination process for cleanly preparing
The mixed solution of cyanoacetic acid and sodium chloride, distillation and concentration, plus methanol dissolving cyanogen second is obtained after acidification reaction terminates
Acid, separates to obtain solid sodium chloride and cyanoacetic acid methanol solution, and in cyanoacetic acid methanol solution, the direct esterification of enriching sulphuric acid, isolated
Dimethyl malenate.The shortcoming of the method is similar with method 1, i.e. concentration steams the water later stage because with the presence of substantial amounts of inorganic salt, stirring
Mix and stir heat-transfer effect poor, it is easy to because hot-spot causes cyanoacetic acid to decompose in a large number.Also patent report removes using concentration twice
The process of salt is reducing the decomposition of cyanoacetic acid：First the mixed solution of cyanoacetic acid and sodium chloride is concentrated, part water is removed,
Desalination is filtered, filtrate concentrates again and eliminates water, again with methanol dissolves cyanoacetic acid, filter desalination.This method is removed in secondary concentration
Still existing during salt causes the phenomenon of cyanoacetic acid decomposition because of local heating's inequality.
Description of the drawings
Fig. 1 is shown as the process chart of the embodiment of the present invention.
Content of the invention
The shortcoming of prior art in view of the above, it is an object of the invention to provide a kind of dimethyl malenate that improves is received
The method of rate, the low problem of the yield for decomposing serious, dimethyl malenate for solving cyanoacetic acid in prior art.
For achieving the above object and other related purposes, the present invention provides a kind of side for improving dimethyl malenate yield
Method, comprises the steps：
1) acidification reaction：Add acid or hydrogen chloride gas, reaction that cyanoacetic acid aqueous solution is obtained to cyanoacetic acid sodium.
2) distillation and concentration：To in cyanoacetic acid aqueous solution, add methyl cyanoacetate, distillation and concentration to anhydrous outflow to remove inorganic
Salt solid；Eliminating water is carried out as solvent using methyl cyanoacetate, the dispersive property of material is improved in reaction system and is heated
Even property, it is to avoid cyanoacetic acid improves product yield in the decomposition of concentration removal process.The cyanogen added in cyanoacetic acid aqueous solution
Methyl acetate can be mixed solution, for example, step 4) contain substantial amounts of methyl cyanoacetate in solution after desalination, it is also possible to plus
Enter in cyanoacetic acid aqueous solution, methyl cyanoacetate improves the dispersive property and mass-and heat-transfer of material as solvent, it is to avoid cyanogen
Decomposition of the acetic acid in concentration removal process.
3) esterification：To step 2) add methanol and catalyst to carry out esterification in solution after desalination, obtain
Arrive the solution containing methyl cyanoacetate.
4) desalination：Remove the inorganic salt solid in solution.
5) secondary esterification：From step 4) a part of reuse is separated to step 2 in solution after desalination), to another portion
Divide in solution and add methanol, carry out esterification in acid condition, dimethyl malenate is obtained.
Further, step 2) in, distillation and concentration is carried out in two times, for the first time by cyanoacetic acid aqueous solution distillation and concentration to surplus
The water yield of remaining 40wt%～60wt%, removes inorganic salt solid, in the cyanoacetic acid aqueous solution after desalination adds methyl cyanoacetate,
Second distillation and concentration removes inorganic salt solid to anhydrous outflow.
Further, using methanol wash inorganic salt solid, methanol cleaning mixture enter step 3) or step 5) in carry out
Esterification.Solid is washed using methanol, the active substance remained in solid is on the one hand fully reclaimed, on the other hand, excessive
Methanol, can recycling by rectification under vacuum after esterification terminates.
Further, step 3) in, the catalyst is iron sulfate, iron chloride, one or several groups in zinc chloride
Close.
Further, step 1) in, the acid is hydrochloric acid；Step 5) in, the acid condition is by sulphuric acid or hydrogen chloride gas
Body is provided.Sulphuric acid should be concentrated sulphuric acid, and herein, enriching sulphuric acid or hydrogen chloride gas will not be brought water into again, can effectively improve product
Yield.
Further, step 2) in, distillation and concentration is to carry out under vacuum, and control temperature is less than 110 DEG C.Cyanoacetic acid
Methyl ester boiling point is 205 DEG C, and therefore, the steaming coolant-temperature gage does not result in methyl cyanoacetate decomposition.
Further, step 2) in, the quality for adding methyl cyanoacetate is 0.5-5.0 times of cyanoacetic acid quality.
Further, step 1) in, the cyanoacetic acid sodium carries out cyanogenation by sodium chloroacetate and Cyanogran. and is obtained.
Further, the sodium chloroacetate is obtained with sodium carbonate reaction by monoxone.
Further, sodium chloroacetate is 1 with the mol ratio of Cyanogran.:(1.0-1.05), reaction is carried out at 85-105 DEG C,
After reaction terminates, room temperature is cooled to, cyanoacetic acid sodium is obtained.
Further, step 1) in, the pH=6.5-7.5 of obtained cyanoacetic acid aqueous solution.
Further, step 5) in, more than 1.5 times for cyanoacetic acid mole of the mole of methanol in reactant liquor.
Further, step 3) in, one time esterification reaction temperature is 40-80 DEG C, cyanoacetic acid quality in reacting to reactant liquor
Content is less than 1%.
Further, step 5) in, secondary esterification reaction temperature is 60-100 DEG C, response time 1-5h.
Further, also include step 6) extraction split-phase：After secondary esterification terminates, solution is cooled to room temperature, is added water and is stirred
Mix, stand split-phase, after organic faciess are washed with saturated aqueous sodium carbonate, proceed 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 present invention, has the advantages that：Cyanogen second
Acid eliminates the inorganic salt sodium chloride being wherein mixed with by steaming water desalination before esterification, it is to avoid in esterification process sulphuric acid and
Sodium chloride reacts, and reduces the consumption and waste water yield of sulphuric acid, using methyl cyanoacetate as solvent carry out eliminating water and
Desalination, improve the dispersive property and mass-and heat-transfer of material, it is to avoid decomposition of the cyanoacetic acid in concentration removal process, effectively carries
The high yield of dimethyl malenate, and be a kind of dimethyl malenate production method of environment-protecting clean.
Specific embodiment
Embodiments of the present invention are described below by way of specific instantiation, those skilled in the art can be by this specification
Disclosed content understands other advantages and effect of the present invention easily.The present invention can also pass through in addition different concrete realities
The mode of applying is carried out or applies, and the every details in this specification can also be based on different viewpoints and application, without departing from
Various modifications and changes are carried out under the spirit of the present invention.
Embodiment 1
A kind of preparation method of dimethyl malenate, comprises the steps：
1) neutralization reaction：Add 620kg water stirring and dissolving in 445kg monoxones (mass content 98%, 4.62kmol), use
Saturated aqueous sodium carbonate is neutralized to pH=6.5-7.0, generates sodium chloroacetate.
2) cyanogenation：By step 1) sodium chloroacetate that obtains proceeds to cyanogenation kettle, is warming up to 50 DEG C, then Deca matter
Amount concentration is 30% sodium cyanide solution 765kg (Cyanogran. containing 4.68kmol in aqueous solution), when reaction temperature reaches 85-90
After DEG C, stop heating and beginning to cool down, when reaction temperature reaches 105 DEG C (later stage is strong exothermal reaction), reaction terminates, cooling
To room temperature, the aqueous solution containing cyanoacetic acid sodium is obtained.
3) acidification reaction：By step 2) obtained in cyanoacetic acid sodium water solution proceed to acidification reaction kettle, stir, by 500L (matter
Amount content 31%, density 1.16g/ml, HCl 4.93kmol) hydrochloric acid is slowly added to acidification reaction kettle by measuring tank, and acidifying is generated
After cyanoacetic acid, proceeding to steaming water kettle carries out steaming water.
4) once concentration desalination：Vacuum is opened, control system vacuum starts stirring more than -0.09MPa, open chuck and steam
Vapour, controls steam pressure 0.2-0.25MPa, carries out steaming water for the first time, collects water 1100L, stops steaming water, cool to room temperature, take out
Filter, is obtained filtrate and filter cake respectively, and filter cake (salt) is washed with 450kg methanol.
5) secondary concentration eliminating water：1500kg methyl cyanoacetates are added to filtrate, second steaming water is carried out, control temperature exists
Less than 105 DEG C, distilling and steam to substantially anhydrous in kettle, reach striking point, be subsequently adding step 4) desalinization of soil by flooding or leaching methanol that obtains is molten
Liquid and 25kg iron sulfate, proceeding to carries out an esterification.
6) esterification：Backflow is warming up to, is reacted to cyanoacetic acid content less than 1%, is cooled to room temperature, is filtered to remove
Inorganic salt, filter cake (secondary salt) are washed with 450kg methanol, and filtrate separates 1700kg (methyl cyanoacetate mass content 88.2%) works
For lower batch step 5) water jacket use is steamed, remainder and the merging of desalinization of soil by flooding or leaching methanol proceed to secondary esterification.
7) secondary esterification：Steam off when reaction kettle of the esterification is warming up to 40 DEG C, the sulfur of Deca mass fraction 98%
Acid, during acid adding, 65-70 DEG C (should suitably open cooling water temperature if necessary), time for adding is controlled in 60- control kettle temperature
120 minutes, acid adding total amount 300L (excess sulfuric acid)；Acid adding controls kettle temperature 65-70 DEG C after finishing, and is incubated 2 hours, then slow intensification
To 75 DEG C, 3 hours are incubated, esterification terminates, generate dimethyl malenate, proceed to extraction split-phase operation.
8) split-phase is extracted：After esterification terminates, solution is cooled to room temperature, the 300L that adds water (can be obtained using distillation and concentration
Water, recycling reduce production cost), stir 30 minutes, split-phase after standing 40-60 minutes, organic faciess saturated sodium carbonate water
Rectifying column rectification under vacuum is proceeded to after solution washing, dimethyl malenate 546kg, content 99.3% (GC, internal standard method), yield is obtained
89.0% (in terms of monoxone).The methanol that rectification under vacuum is isolated can be with recycling.
Specifically,
In sum, reactant cyanoacetic acid of the invention is eliminated by steaming water desalination before esterification and to be wherein mixed with
Inorganic salt sodium chloride, it is to avoid sulphuric acid is reacted with sodium chloride in esterification process, the consumption and waste water for reducing sulphuric acid are produced
Amount, carries out eliminating water and desalination using methyl cyanoacetate as solvent, improves the dispersive property and mass-and heat-transfer of material, it is to avoid
Decomposition of the cyanoacetic acid in concentration removal process, effectively increases the yield of dimethyl malenate, and is a kind of environment-protecting clean
Dimethyl malenate production method.
The principle and its effect of above-described embodiment only illustrative present invention, of the invention not for limiting.Any ripe
The personage for knowing this technology all can carry out modifications and changes to above-described embodiment under the spirit and the scope without prejudice to the present invention.Cause
This, those of ordinary skill in the art is complete with institute under technological thought without departing from disclosed spirit such as
Into all equivalent modifications or change, should by the present invention claim be covered.
Claims (10)
1. a kind of improve dimethyl malenate yield method, it is characterised in that comprise the steps：
1) acidification reaction：To in cyanoacetic acid sodium, add acid or hydrogen chloride gas, reaction that cyanoacetic acid aqueous solution is obtained；
2) distillation and concentration：To in cyanoacetic acid aqueous solution, add methyl cyanoacetate, distillation and concentration to anhydrous outflow to remove inorganic salt solid
Body；
3) esterification：To step 2) add methanol and catalyst to carry out esterification in solution after desalination, contained
There is the solution of methyl cyanoacetate；
4) desalination：Remove the inorganic salt solid in solution；
5) secondary esterification：From step 4) a part of reuse is separated to step 2 in solution after desalination), molten to another part
Methanol is added in liquid, esterification is carried out in acid condition, dimethyl malenate is obtained.
2. according to claim 1 improve dimethyl malenate yield method, it is characterised in that：Step 2) in, distillation
Concentration is carried out in two times, for the first time by the water yield of cyanoacetic acid aqueous solution distillation and concentration to remaining 40wt%～60wt%, removes nothing
Machine salt solid, adds methyl cyanoacetate, second distillation and concentration to anhydrous outflow to remove in the cyanoacetic acid aqueous solution after desalination
Inorganic salt solid.
3. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Washed using methanol
Wash inorganic salt solid, methanol cleaning mixture enters step 3) or step 5) in carry out esterification.
4. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 3) in, institute
Catalyst is stated for one or several combinations in iron sulfate, iron chloride, zinc chloride.
5. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 1) in, institute
Acid is stated for hydrochloric acid；Step 5) in, the acid condition is provided by sulphuric acid or hydrogen chloride gas.
6. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 2) in, steam
It is to carry out under vacuum to evaporate concentration, and control temperature is less than 110 DEG C.
7. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 1) in, system
The pH=6.5-7.5 of the cyanoacetic acid aqueous solution for obtaining；Step 2) in, the quality of methyl cyanoacetate is added for the 0.5- of cyanoacetic acid quality
5.0 again.
8. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 1) in, institute
State cyanoacetic acid sodium cyanogenation is carried out by sodium chloroacetate and Cyanogran. and be obtained.
9. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Step 3) in, one
Secondary esterification reaction temperature is 40-80 DEG C, and in reacting to reactant liquor, cyanoacetic acid mass content is less than 1%；Step 5) in, secondary esterification
Reaction temperature is 60-100 DEG C, response time 1-5h.
10. according to claim 1 and 2 improve dimethyl malenate yield method, it is characterised in that：Also include step
6) split-phase is extracted：After secondary esterification terminates, solution is cooled to room temperature, add water stirring, stands split-phase, organic faciess unsaturated carbonate
After sodium water solution washing, rectifying column is proceeded to, rectification under vacuum obtains dimethyl malenate.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
-
2016
- 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 |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
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Granted publication date: 20190322 Termination date: 20200831 |