CN111978181A - High-yield preparation method of ethyl chrysanthemate - Google Patents
High-yield preparation method of ethyl chrysanthemate Download PDFInfo
- Publication number
- CN111978181A CN111978181A CN202011023444.9A CN202011023444A CN111978181A CN 111978181 A CN111978181 A CN 111978181A CN 202011023444 A CN202011023444 A CN 202011023444A CN 111978181 A CN111978181 A CN 111978181A
- Authority
- CN
- China
- Prior art keywords
- valve
- dimethyl
- distillation
- hexadiene
- kettle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
- C07C67/333—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton
- C07C67/343—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/06—Halogens; Compounds thereof
- B01J27/08—Halides
- B01J27/122—Halides of copper
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C245/00—Compounds containing chains of at least two nitrogen atoms with at least one nitrogen-to-nitrogen multiple bond
- C07C245/20—Diazonium compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/48—Separation; Purification; Stabilisation; Use of additives
- C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
- C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2601/00—Systems containing only non-condensed rings
- C07C2601/02—Systems containing only non-condensed rings with a three-membered ring
Abstract
The invention belongs to the technical field of chemical processes, and particularly relates to a preparation method of ethyl chrysanthemate with high yield, which comprises the following steps: (1) diazotization: adding water, glycine ethyl ester hydrochloride, glacial acetic acid and dimethyl carbonate serving as solvents into a diazotization kettle, then dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, and obtaining a diazotization solution after the reaction is finished; (2) cyclization: adding 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, adopting cuprous chloride as a catalyst, and obtaining a cyclization solution after complete reaction; (3) desolventizing: sending the cyclized solution into a high-yield desolventizing tower to remove the solvent to obtain a crude product of ethyl chrysanthemate; (4) and (3) distillation: and putting the crude ethyl chrysanthemate into a distillation kettle for vacuum distillation to obtain high-purity ethyl chrysanthemate. The invention has the beneficial effects that: when dimethyl carbonate is used as a solvent, diazotization reaction can be carried out more completely, the loss of raw materials is reduced, and the yield of ethyl chrysanthemate in subsequent cyclization reaction can be improved.
Description
Technical Field
The invention belongs to the technical field of chemical processes, and particularly relates to a preparation method of ethyl chrysanthemate with high yield.
Background
The ethyl chrysanthemate is also an important intermediate of pyrethroids like methyl chrysanthemate, and can be used for preparing various sanitary pyrethroids including permethrin, tetramethrin, phenothrin, propynethrin and other insecticides. The reaction of ethyl diazoacetate and 2, 5-dimethyl-2, 4-hexadiene is one of the most important synthetic routes with the most industrial application value. Ethyl diazoacetate and 2, 5-dimethyl-2, 4-hexadiene are used as raw materials to prepare ethyl chrysanthemate, copper powder is usually used as a catalyst, and toluene or halogenated hydrocarbon is used as a solvent, but the problem of low chemical yield exists.
Disclosure of Invention
The invention aims to provide a method for preparing ethyl chrysanthemate with high yield, which has the effects of high reaction rate, high ethyl chrysanthemate yield and stable reaction process.
The technical purpose of the invention is realized by the following technical scheme: (1) diazotization: adding water, glycine ethyl ester hydrochloride and glacial acetic acid into a diazotization kettle, stirring to dissolve solids, then adding dimethyl carbonate serving as a solvent into the diazotization kettle, starting freezing to reduce the temperature of diazotization kettle materials to 20-25 ℃, then dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, standing and layering after the reaction is finished, and discharging a lower water layer to a waste liquid collecting tank to obtain a diazotization liquid;
(2) cyclization: adding 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, using cuprous chloride as a catalyst, opening and stirring, heating to 90-95 ℃, then beginning to drip heavy nitrogen liquid, continuing to perform heat preservation reaction after dripping the heavy nitrogen liquid, and cooling to 45-60 ℃ after completely reacting, thus obtaining a cyclization liquid;
(3) desolventizing: after the cyclized liquid is sent into a high-yield desolventizing tower, a stirrer and a jacket steam feed pipe are started, the temperature is raised and the reflux is started, the dimethyl carbonate and the 2, 5-dimethyl-2, 4-hexadiene are removed, and a cyclized liquid solvent is removed to obtain a crude ethyl chrysanthemate;
(4) and (3) distillation: and putting the crude ethyl chrysanthemate into a distillation kettle for vacuum distillation to obtain high-purity ethyl chrysanthemate.
The invention is further provided with: in the step (1), glacial acetic acid is adopted to keep the pH value of diazotization reaction between 3.5-4.5.
The invention is further provided with: in the step (1), the diazotization raw materials comprise, by mass, 600-700 parts of water, 470-490 parts of glycine ethyl acetate, 35-37 parts of glacial acetic acid, 260-265 parts of sodium nitrite and 800 parts of dimethyl carbonate solvent.
The invention is further provided with: in the step (1), the dropping time of the sodium nitrite is controlled to be 4-5 h, and the temperature is kept for 30-60 min after the dropping.
The invention is further provided with: the cyclized raw materials in the step (2) comprise, by mass, 1100 parts of the entire batch of diazo liquid in the step (1), 1100 parts of 2, 5-dimethyl-2, 4-hexadiene and 2-5 parts of cuprous chloride.
The invention is further provided with: in the step (2), the dropping time of the diazo liquid is 10-12 h, the dropping speed is less than or equal to 100L/h, and the heat preservation is continued for 60-90 min after the diazo liquid is dropped.
The invention is further provided with: the desolventizing step (3) comprises the following steps:
s1, opening a cyclizing liquid feed valve and a vacuum pipe valve of the efficient desolventizing tower, vacuumizing the efficient desolventizing tower to pump a certain amount of cyclizing liquid, opening a manual emptying pipe emptying valve to return the inside of the efficient desolventizing tower to normal pressure, opening a stirrer of the efficient desolventizing tower, a jacketed steam feed pipe and a condensed water discharge pipe, and starting to heat and reflux;
s2, after refluxing for 20-40 min, opening a dimethyl carbonate receiving tank, a dimethyl carbonate feeding valve and a vacuum valve on the upper part of the dimethyl carbonate receiving tank for vacuum distillation, observing the temperature trend balance, adjusting the reflux ratio, keeping the temperature at the top of the tower below 90 ℃, and continuously steaming out dimethyl carbonate;
s3, when the dimethyl carbonate is recovered to 75-85%, closing a toluene feeding valve of a dimethyl carbonate receiving tank and a vacuum valve at the upper part of the toluene feeding valve, stopping receiving the dimethyl carbonate, opening a 2, 5-dimethyl-2, 4-hexadiene receiving tank 2, 5-dimethyl-2, 4-hexadiene feeding valve, and beginning to remove the 2, 5-dimethyl-2, 4-hexadiene;
s4, wherein the first stage is the previous stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is atmospheric distillation, and the overhead temperature of the stage is 60-135 ℃; the second stage is a stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is normal pressure distillation, and the temperature at the top of the stage is 135-138 ℃; the third stage is a stage of removing the 2, 5-dimethyl-2, 4-hexadiene in vacuum, wherein the pressure in the tower is more than or equal to 0.07Mpa at the temperature of 115-;
and S5, closing a steam feed valve, a condensate water discharge valve and a vacuum valve of a 2, 5-dimethyl-2, 4-hexadiene receiving groove of the efficient desolventizing tower after the removal of the 2, 5-dimethyl-2, 4-hexadiene is finished, opening jacket circulating water of the efficient desolventizing tower to start cooling, and opening a discharge valve at the lower part of the efficient desolventizing tower to start barreling and weighing after the temperature of materials in the efficient desolventizing tower is reduced to 50-70 ℃ to obtain crude ethyl chrysanthemate.
The invention is further provided with: in the step (2), the dropping time of the diazo liquid is 10-12 h, the dropping speed is less than or equal to 100L/h, and the heat preservation is continued for 60-90 min after the diazo liquid is dropped.
The invention is further provided with: and the 2, 5-dimethyl-2, 4-hexadiene removed in the step S4 is recycled as a raw material for cyclization.
The invention is further provided with: the desolventizing step (4) comprises the following steps:
s1, opening a crude ethyl chrysanthemate feeding valve and a vacuum pipe valve of a distillation kettle, pumping the crude ethyl chrysanthemate into the distillation kettle in vacuum, closing the crude ethyl chrysanthemate feeding valve and the vacuum pipe valve, and opening a manual emptying pipe emptying valve to return the distillation kettle to normal pressure;
s2, opening a gas phase feed valve, a liquid phase discharge valve, a circulating water inlet and outlet valve, a front distillate receiving tank feed valve and an upper vacuum valve of the front distillate receiving tank feed valve of the distillation kettle condenser, and opening a high vacuum system when the pressure in the distillation kettle reaches a vacuum degree of more than or equal to 0.08 MPa;
s3, controlling the vacuum degree to be stable, starting a stirrer of the distillation kettle, opening a steam feed valve and a condensate water discharge valve of a jacket of the distillation kettle, and starting heating to distill front distillate, wherein the distillation temperature is about 103-107 ℃;
s4, when the temperature in the distillation still rises obviously, ending the front distillate distillation process, closing the feed valve of the front distillate receiving tank and the vacuum valve at the upper part of the feed valve, opening the feed valve of the main distillate receiving tank and the vacuum valve at the upper part of the feed valve, and opening the steam feed valve of the distillation still jacket to ensure that the temperature in the distillation still reaches about 110-115 ℃, and beginning to distill out the main distillate;
s5, when the temperature in the distillation kettle is obviously reduced, the distillation process of the main distillate is finished
The invention is further provided with: and a DCS (distributed control System) interlocking control system is adopted to control the preparation process of the ethyl chrysanthemate.
The invention has the beneficial effects that:
1. dimethyl carbonate is an organic solvent with low toxicity and excellent environmental protection performance, can replace solvents with high toxicity such as halogenated hydrocarbon, toluene and the like, and reduces the accidents such as poisoning and the like caused by misoperation of operators. .
2. Dimethyl carbonate has good dispersion and stabilization effects on diazoacetic ether which is a heavy nitridation reaction product, and in a dimethyl carbonate solvent, the diazoacetic ether can be kept stable at a higher temperature and is not easy to decompose, so that the stability of a diazo reaction can be greatly improved.
3. When dimethyl carbonate is used as a solvent, the diazotization reaction temperature can reach 20-25 ℃, so that the diazotization reaction can be carried out more completely, the loss of raw materials is reduced, the content of ethyl diazoacetate in a diazotization solution is improved, the yield of ethyl chrysanthemate in a subsequent cyclization reaction can be improved, and the content of ethyl chrysanthemate in the cyclization solution can reach more than 15%.
4. Cuprous chloride can be used as a catalyst for cyclization reaction, has better catalytic effect compared with copper powder, can obviously improve the cyclization reaction rate, and can improve the yield of the ethyl chrysanthemate, the yield of the ethyl chrysanthemate is only 60-70% under the condition that the copper powder is used as the catalyst, and the yield of the ethyl chrysanthemate can reach more than 85% by using the cuprous chloride as the catalyst; the cuprous chloride has a good inhibition effect on polymerization of hexadiene in a dimethyl carbonate environment, the cuprous chloride can play a role in inhibiting polymerization through charge transfer, methoxy groups in the dimethyl carbonate can act with free radicals in the hexadiene to form non-free-radical substances, chain polymerization of the free radicals can be effectively inhibited, polymerization of the 2, 5-dimethyl-2, 4-hexadiene in a cyclization reaction process can be avoided, the utilization rate of the 2, 5-dimethyl-2, 4-hexadiene can be improved, the amount of high-temperature polymers in a distillation kettle is reduced, and coking at the bottom of the distillation kettle can be avoided.
5. The boiling point of the dimethyl carbonate is low, the difference between the boiling point of the dimethyl carbonate and the boiling point of the 2, 5-dimethyl-2, 4-hexadiene is large, the dimethyl carbonate is used as a solvent, the dimethyl carbonate is favorably separated from the 2, 5-dimethyl-2, 4-hexadiene, the recovery purity of the solvent and the 2, 5-dimethyl-2, 4-hexadiene is higher, and the utilization rate of raw materials can be improved.
The removal of the 2, 5-dimethyl-2, 4-hexadiene is divided into three stages, the 2, 5-dimethyl-2, 4-hexadiene can be separated from a cyclizing solution to the maximum extent to obtain the 2, 5-dimethyl-2, 4-hexadiene with higher purity, the recovery rate of the 2, 5-dimethyl-2, 4-hexadiene is improved, the content of the 2, 5-dimethyl-2, 4-hexadiene in ethyl chrysanthemate can be reduced, and the subsequent purification of crude ethyl chrysanthemate is facilitated.
7. The removed 2, 5-dimethyl-2, 4-hexadiene can be recycled to a cyclization reaction kettle, the purity of the 2, 5-dimethyl-2, 4-hexadiene has great influence on the yield of the ethyl chrysanthemate, the 2, 5-dimethyl-2, 4-hexadiene subjected to three-stage desolventizing has low impurity content and high quality, can be directly recycled, and can greatly improve the yield of the ethyl chrysanthemate compared with the conventional desolventizing.
Detailed Description
The technical solutions in the examples will be clearly and completely described below. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.
Example 1
A preparation method of ethyl chrysanthemate with high yield comprises the following steps:
(1) diazotization: adding 600 parts of water, 490 parts of glycine ethyl ester salt and 35 parts of glacial acetic acid into a diazotization kettle, stirring to dissolve solids, keeping the pH value of diazotization reaction between 3.5 and 4.5 by adopting glacial acetic acid, adding 800 parts of dimethyl carbonate serving as a solvent into the diazotization kettle, starting to freeze, cooling the material of the diazotization kettle to 20 to 25 ℃, dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, controlling the dropwise adding time of the sodium nitrite to be 4 to 5 hours, keeping the temperature for 60min after dropwise adding is finished, standing and layering after the reaction is finished, and discharging a lower water layer to a waste liquid collecting tank to obtain a diazotization liquid;
(2) cyclization: putting 1100 parts of 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, taking 2 parts of cuprous chloride as a catalyst, stirring, heating to 90-95 ℃, then starting to dropwise add the whole batch of diazo liquid in the step (1), wherein the dropwise adding time of the diazo liquid is 10-12 h, the dropwise adding speed is less than or equal to 100L/h, continuing to keep the temperature for 90min after dropwise adding the diazo liquid, and cooling the cyclization kettle to 45-60 ℃ after complete reaction to obtain a cyclization liquid;
(3) desolventizing: s1, opening a cyclizing liquid feed valve and a vacuum pipe valve of the efficient desolventizing tower, vacuumizing the efficient desolventizing tower to pump a certain amount of cyclizing liquid, opening a manual emptying pipe emptying valve to return the inside of the efficient desolventizing tower to normal pressure, opening a stirrer of the efficient desolventizing tower, a jacketed steam feed pipe and a condensed water discharge pipe, and starting to heat and reflux;
s2, after refluxing for 20min, opening a dimethyl carbonate receiving tank, a dimethyl carbonate feeding valve and a vacuum valve on the upper part of the dimethyl carbonate receiving tank for vacuum distillation, observing the temperature trend balance, adjusting the reflux ratio, keeping the temperature at the top of the tower below 90 ℃, and continuously steaming out dimethyl carbonate;
s3, when the dimethyl carbonate is recovered to 80%, closing a toluene feeding valve of a dimethyl carbonate receiving tank and a vacuum valve at the upper part of the toluene feeding valve, stopping receiving the dimethyl carbonate, opening a 2, 5-dimethyl-2, 4-hexadiene receiving tank 2, 5-dimethyl-2, 4-hexadiene feeding valve, and beginning to remove the 2, 5-dimethyl-2, 4-hexadiene;
s4, wherein the first stage is the previous stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is atmospheric distillation, and the overhead temperature of the stage is 60-135 ℃; the second stage is a stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is normal pressure distillation, and the temperature at the top of the stage is 135-138 ℃; the third stage is a stage of removing the 2, 5-dimethyl-2, 4-hexadiene in vacuum, wherein the pressure in the tower is more than or equal to 0.07Mpa at the temperature of 115-; s5, closing a steam feed valve, a condensate water discharge valve and a vacuum valve of a 2, 5-dimethyl-2, 4-hexadiene receiving groove of the efficient desolventizing tower after the removal of the 2, 5-dimethyl-2, 4-hexadiene is finished, opening jacket circulating water of the efficient desolventizing tower to start cooling, and opening a discharge valve at the lower part of the efficient desolventizing tower to start barreling and weighing after the temperature of materials in the efficient desolventizing tower is reduced to 50-70 ℃ to obtain crude ethyl chrysanthemate;
(4) and (3) distillation: s1, opening a crude ethyl chrysanthemate feeding valve and a vacuum pipe valve of a distillation kettle, pumping the crude ethyl chrysanthemate into the distillation kettle in vacuum, closing the crude ethyl chrysanthemate feeding valve and the vacuum pipe valve, and opening a manual emptying pipe emptying valve to return the distillation kettle to normal pressure;
s2, opening a gas phase feed valve, a liquid phase discharge valve, a circulating water inlet and outlet valve, a front distillate receiving tank feed valve and an upper vacuum valve of the front distillate receiving tank feed valve of the distillation kettle condenser, and opening a high vacuum system when the pressure in the distillation kettle reaches a vacuum degree of more than or equal to 0.08 MPa;
s3, controlling the vacuum degree to be stable, starting a stirrer of the distillation kettle, opening a steam feed valve and a condensate water discharge valve of a jacket of the distillation kettle, and starting heating to distill front distillate, wherein the distillation temperature is about 105 ℃;
s4, when the temperature in the distillation still rises obviously, ending the front distillate distillation process, closing the feed valve of the front distillate receiving tank and the vacuum valve at the upper part thereof, opening the feed valve of the main distillate receiving tank and the vacuum valve at the upper part thereof, and opening the steam feed valve of the distillation still jacket to ensure that the temperature in the distillation still reaches about 113 ℃, and beginning to distill out the main distillate;
s5, when the temperature in the distillation kettle is obviously reduced, ending the distillation process of the main distillate;
and a DCS (distributed control System) interlocking control system is adopted to control the preparation process of the ethyl chrysanthemate.
Example 2
Example 2 differs from example 1 in that:
(1) diazotization: putting 500 parts of water, 480 parts of glycine ethyl ester salt and 36 parts of glacial acetic acid into a diazotization kettle, stirring to dissolve a solid, keeping the pH value of diazotization reaction between 3.5 and 4.5 by adopting glacial acetic acid, putting 800 parts of dimethyl carbonate into the diazotization kettle as a solvent, starting to freeze, cooling the material temperature of the diazotization kettle to 20 to 25 ℃, dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, controlling the dropwise adding time of the sodium nitrite to be 4 to 5 hours, keeping the temperature for 45min after dropwise adding is finished, standing and layering after the reaction is finished, and discharging a lower water layer to a waste liquid collecting tank to obtain a diazotization liquid;
(2) cyclization: adding 1100 parts of 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, taking 3.5 parts of cuprous chloride as a catalyst, stirring, heating to 90-95 ℃, then starting to dropwise add the whole batch of diazo liquid obtained in the step (1), wherein the dropwise adding time of the diazo liquid is 10-12 h, the dropwise adding speed is less than or equal to 100L/h, continuing to keep the temperature for 70min after dropwise adding the diazo liquid, and cooling water introduced into the cyclization kettle to 45-60 ℃ after complete reaction to obtain the cyclization liquid.
Example 3
Example 3 differs from example 1 in that:
(1) diazotization: putting 700 parts of water, 470 parts of glycine ethyl ester salt and 37 parts of glacial acetic acid into a diazotization kettle, stirring to dissolve solids, keeping the pH value of diazotization reaction between 3.5 and 4.5 by adopting glacial acetic acid, putting 800 parts of dimethyl carbonate into the diazotization kettle as a solvent, starting to freeze, cooling the material temperature of the diazotization kettle to 20 to 25 ℃, dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, controlling the dropwise adding time of the sodium nitrite to be 4 to 5 hours, keeping the temperature for 60min after dropwise adding is finished, standing and layering after the reaction is finished, and discharging a lower water layer to a waste liquid collecting tank to obtain a diazotization liquid;
(2) cyclization: and (2) putting 1100 parts of 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, taking 2-5 parts of cuprous chloride as a catalyst, stirring, heating to 90-95 ℃, then starting to dropwise add the whole batch of diazo liquid obtained in the step (1), wherein the dropwise adding time of the diazo liquid is 10-12 h, the dropwise adding speed is less than or equal to 100L/h, continuing to keep the temperature for 60min after dropwise adding the diazo liquid, and cooling water introduced into the cyclization kettle to 45-60 ℃ after complete reaction to obtain the cyclization liquid.
Example 4
Example 4 differs from example 2 in that dichloroethane is used as solvent in the diazotization step (1).
Example 5
Example 5 differs from example 2 in that copper powder is used as a catalyst in the cyclization in step (2).
Example 6
Example 6 differs from example 2 in that in the step (3) of desolventizing, 2, 5-dimethyl-2, 4-hexadiene was removed by atmospheric distillation at an overhead temperature of 135 ℃ and 138 ℃.
Procedure of the test
Preparing ethyl chrysanthemate by adopting the scheme of the embodiment 1-6, taking the diazo liquid, the cyclized liquid, the 2, 5-dimethyl-2, 4-hexadiene obtained in the high-efficiency desolventizing tower and the finished product ethyl chrysanthemate in each embodiment to prepare samples, and measuring the content of ethyl chrysanthemate in the cyclized liquid, the purity of the 2, 5-dimethyl-2, 4-hexadiene obtained by desolventizing, the residue amount in a distillation kettle and the yield of the finished product ethyl chrysanthemate according to a standard method.
(1) And (3) measuring the content of ethyl chrysanthemate: and (4) measuring by gas chromatography.
(2)2, 5-dimethyl-2, 4-hexadiene content determination:
quantitative analysis by gas chromatography
Reagent: dichloromethane, m-xylene (internal standard), 2, 5-dimethyl-2, 4-hexadiene samples
The instrument comprises the following steps: SC-6 gas chromatograph, hydrogen flame ionization detector and column head sample injection.
The method comprises the following steps: accurately weighing 5 2, 5-dimethyl-2, 4-hexadiene standard samples and internal standard substances in different weight ratios, adding a proper amount of solvent for dissolving, fully shaking up, and then carrying out sample injection on a chromatograph one by one to obtain a standard curve; accurately weighing a 2, 5-dimethyl-2, 4-hexadiene sample and an internal standard substance, adding a proper amount of solvent, fully shaking uniformly, then injecting samples on a chromatograph, and calculating the obtained data in a human-carrying standard curve to obtain the content of the 2, 5-dimethyl-2, 4-hexadiene sample in the 2, 5-dimethyl-2, 4-hexadiene sample.
(3) Yield of finished product ethyl chrysanthemate:
the yield (amount of starting material to form the objective product/amount of starting material fed) × 100%
The yield of the ethyl chrysanthemate is calculated according to the 2, 5-dimethyl-2, 4-hexadiene.
Test results
The test results for examples 1-6 are shown in table 1 below:
TABLE 1 preparation of Ethyl chrysanthemate test results
It can be seen from table 1 that the use of dimethyl carbonate as solvent and cuprous chloride as catalyst can greatly increase the content of ethyl chrysanthemate and the yield of ethyl chrysanthemate (in terms of hexadiene) in the cyclized solution, reduce the amount of residue in the distillation still, and obtain high-purity 2, 5-dimethyl-2, 4-hexadiene by three-stage rectification and desolventization, thereby further increasing the yield of ethyl chrysanthemate.
Claims (10)
1. The preparation method of the ethyl chrysanthemate with high yield is characterized by comprising the following steps:
(1) diazotization: adding water, glycine ethyl ester hydrochloride and glacial acetic acid into a diazotization kettle, stirring to dissolve the solid, then adding dimethyl carbonate as a solvent into the diazotization kettle,
starting freezing, cooling the diazotization kettle material to 20-25 ℃, then dropwise adding a sodium nitrite aqueous solution into the diazotization kettle, standing and layering after the reaction is finished, and discharging a lower water layer to a waste liquid collecting tank to obtain a diazotization liquid;
(2) cyclization: adding 2, 5-dimethyl-2, 4-hexadiene into a cyclization kettle, using cuprous chloride as a catalyst, opening and stirring, heating to 90-95 ℃, then beginning to drip heavy nitrogen liquid, continuing to perform heat preservation reaction after dripping the heavy nitrogen liquid, and cooling to 45-60 ℃ after completely reacting, thus obtaining a cyclization liquid;
(3) desolventizing: after the cyclized liquid is sent into a high-yield desolventizing tower, a stirrer and a jacket steam feed pipe are started, the temperature is raised and the reflux is started, the dimethyl carbonate and the 2, 5-dimethyl-2, 4-hexadiene are removed, and a cyclized liquid solvent is removed to obtain a crude ethyl chrysanthemate;
(4) and (3) distillation: and putting the crude ethyl chrysanthemate into a distillation kettle for vacuum distillation to obtain high-purity ethyl chrysanthemate.
2. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: in the step (1), glacial acetic acid is adopted to keep the pH value of diazotization reaction between 3.5-4.5.
3. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: in the step (1), the diazotization raw materials comprise, by mass, 600-700 parts of water, 470-490 parts of glycine ethyl acetate, 35-37 parts of glacial acetic acid, 260-265 parts of sodium nitrite and 800 parts of dimethyl carbonate solvent.
4. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: in the step (1), the dropping time of the sodium nitrite is controlled to be 4-5 h, and the temperature is kept for 30-60 min after the dropping.
5. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: the cyclized raw materials in the step (2) comprise, by mass, 1100 parts of the entire batch of diazo liquid in the step (1), 1100 parts of 2, 5-dimethyl-2, 4-hexadiene and 2-5 parts of cuprous chloride.
6. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: in the step (2), the dropping time of the diazo liquid is 10-12 h, the dropping speed is less than or equal to 100L/h, and the heat preservation is continued for 60-90 min after the diazo liquid is dropped.
7. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: the desolventizing step (3) comprises the following steps:
s1, opening a cyclizing liquid feed valve and a vacuum pipe valve of the efficient desolventizing tower, vacuumizing the efficient desolventizing tower to pump a certain amount of cyclizing liquid, opening a manual emptying pipe emptying valve to return the inside of the efficient desolventizing tower to normal pressure, opening a stirrer of the efficient desolventizing tower, a jacketed steam feed pipe and a condensed water discharge pipe, and starting to heat and reflux;
s2, after refluxing for 20-40 min, opening a dimethyl carbonate receiving tank, a dimethyl carbonate feeding valve and a vacuum valve on the upper part of the dimethyl carbonate receiving tank for vacuum distillation, observing the temperature trend balance, adjusting the reflux ratio, keeping the temperature at the top of the tower below 90 ℃, and continuously steaming out dimethyl carbonate;
s3, when the dimethyl carbonate is recovered to 75-85%, closing a toluene feeding valve of a dimethyl carbonate receiving tank and a vacuum valve at the upper part of the toluene feeding valve, stopping receiving the dimethyl carbonate, opening a 2, 5-dimethyl-2, 4-hexadiene receiving tank 2, 5-dimethyl-2, 4-hexadiene feeding valve, and beginning to remove the 2, 5-dimethyl-2, 4-hexadiene;
s4, wherein the first stage is the previous stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is atmospheric distillation, and the overhead temperature of the stage is 60-135 ℃; the second stage is a stage of removing 2, 5-dimethyl-2, 4-hexadiene, the stage is normal pressure distillation, and the temperature at the top of the stage is 135-138 ℃; the third stage is a stage of removing the 2, 5-dimethyl-2, 4-hexadiene in vacuum, wherein the pressure in the tower is more than or equal to 0.07Mpa at the temperature of 115-;
and S5, closing a steam feed valve, a condensate water discharge valve and a vacuum valve of a 2, 5-dimethyl-2, 4-hexadiene receiving groove of the efficient desolventizing tower after the removal of the 2, 5-dimethyl-2, 4-hexadiene is finished, opening jacket circulating water of the efficient desolventizing tower to start cooling, and opening a discharge valve at the lower part of the efficient desolventizing tower to start barreling and weighing after the temperature of materials in the efficient desolventizing tower is reduced to 50-70 ℃ to obtain crude ethyl chrysanthemate.
8. The method for preparing ethyl chrysanthemate with high yield according to claim 7, wherein the method comprises the following steps: and the 2, 5-dimethyl-2, 4-hexadiene removed in the step S4 is recycled as a raw material for cyclization.
9. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: the desolventizing step (4) comprises the following steps:
s1, opening a crude ethyl chrysanthemate feeding valve and a vacuum pipe valve of a distillation kettle, pumping the crude ethyl chrysanthemate into the distillation kettle in vacuum, closing the crude ethyl chrysanthemate feeding valve and the vacuum pipe valve, and opening a manual emptying pipe emptying valve to return the distillation kettle to normal pressure;
s2, opening a gas phase feed valve, a liquid phase discharge valve, a circulating water inlet and outlet valve, a front distillate receiving tank feed valve and an upper vacuum valve of the front distillate receiving tank feed valve of the distillation kettle condenser, and opening a high vacuum system when the pressure in the distillation kettle reaches a vacuum degree of more than or equal to 0.08 MPa;
s3, controlling the vacuum degree to be stable, starting a stirrer of the distillation kettle, opening a steam feed valve and a condensate water discharge valve of a jacket of the distillation kettle, and starting heating to distill front distillate, wherein the distillation temperature is about 103-107 ℃;
s4, when the temperature in the distillation still rises obviously, ending the front distillate distillation process, closing the feed valve of the front distillate receiving tank and the vacuum valve at the upper part of the feed valve, opening the feed valve of the main distillate receiving tank and the vacuum valve at the upper part of the feed valve, and opening the steam feed valve of the distillation still jacket to ensure that the temperature in the distillation still reaches about 110-115 ℃, and beginning to distill out the main distillate;
s5, when the temperature in the distillation kettle is obviously reduced, the distillation process of the main distillate is finished.
10. The method for preparing ethyl chrysanthemate with high yield according to claim 1, wherein the method comprises the following steps: and a DCS (distributed control System) interlocking control system is adopted to control the preparation process of the ethyl chrysanthemate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011023444.9A CN111978181B (en) | 2020-09-25 | 2020-09-25 | High-yield preparation method of ethyl chrysanthemate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011023444.9A CN111978181B (en) | 2020-09-25 | 2020-09-25 | High-yield preparation method of ethyl chrysanthemate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111978181A true CN111978181A (en) | 2020-11-24 |
| CN111978181B CN111978181B (en) | 2022-11-15 |
Family
ID=73450468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011023444.9A Active CN111978181B (en) | 2020-09-25 | 2020-09-25 | High-yield preparation method of ethyl chrysanthemate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111978181B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114933523A (en) * | 2022-05-23 | 2022-08-23 | 南通雅本化学有限公司 | Process for the preparation of caronic acid and its derivatives |
| CN114933580A (en) * | 2022-05-23 | 2022-08-23 | 南通雅本化学有限公司 | Process for the preparation of caronic anhydride |
| CN115028527A (en) * | 2022-05-28 | 2022-09-09 | 汉瑞药业(荆门)有限公司 | Preparation method of 3-hydroxymethyl-2, 2-dimethylcyclopropanecarboxylic acid |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB740014A (en) * | 1953-04-23 | 1955-11-09 | Ici Ltd | Manufacture of ethyl chrysanthemate |
| US3897478A (en) * | 1970-05-21 | 1975-07-29 | Stauffer Chemical Co | Continuous process for the manufacture of alkyl chrysanthemate esters |
| GB1459285A (en) * | 1974-12-03 | 1976-12-22 | Ici Ltd | Process for the preparation of cyclopropane carboxylic acid esters |
| WO2002060812A2 (en) * | 2001-01-29 | 2002-08-08 | William Marsh Rice University | Process for derivatizing carbon nanotubes with diazonium species and compositions thereof |
| CN102976945A (en) * | 2012-12-29 | 2013-03-20 | 贵阳柏丝特化工有限公司 | Method for synthetizing ethyl chrysanthemumate compound by microreactor |
| CN106316845A (en) * | 2016-08-24 | 2017-01-11 | 江苏优普生物化学科技股份有限公司 | Preparing method of cis, trans-ethyl 2, 2-dimethyl-3-(1-isobutenyl)cyclopropane-1-carboxylate |
-
2020
- 2020-09-25 CN CN202011023444.9A patent/CN111978181B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB740014A (en) * | 1953-04-23 | 1955-11-09 | Ici Ltd | Manufacture of ethyl chrysanthemate |
| US3897478A (en) * | 1970-05-21 | 1975-07-29 | Stauffer Chemical Co | Continuous process for the manufacture of alkyl chrysanthemate esters |
| GB1459285A (en) * | 1974-12-03 | 1976-12-22 | Ici Ltd | Process for the preparation of cyclopropane carboxylic acid esters |
| WO2002060812A2 (en) * | 2001-01-29 | 2002-08-08 | William Marsh Rice University | Process for derivatizing carbon nanotubes with diazonium species and compositions thereof |
| CN102976945A (en) * | 2012-12-29 | 2013-03-20 | 贵阳柏丝特化工有限公司 | Method for synthetizing ethyl chrysanthemumate compound by microreactor |
| CN106316845A (en) * | 2016-08-24 | 2017-01-11 | 江苏优普生物化学科技股份有限公司 | Preparing method of cis, trans-ethyl 2, 2-dimethyl-3-(1-isobutenyl)cyclopropane-1-carboxylate |
Non-Patent Citations (2)
| Title |
|---|
| 李进军等: "《绿色化学导论》", 31 August 2015, 武汉：武汉大学出版社 * |
| 赵林: "菊酸乙酯工段重氮化反应工艺的改进", 《江苏化工》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114933523A (en) * | 2022-05-23 | 2022-08-23 | 南通雅本化学有限公司 | Process for the preparation of caronic acid and its derivatives |
| CN114933580A (en) * | 2022-05-23 | 2022-08-23 | 南通雅本化学有限公司 | Process for the preparation of caronic anhydride |
| WO2023226331A1 (en) * | 2022-05-23 | 2023-11-30 | 南通雅本化学有限公司 | Method for preparing caronic acid and derivative thereof |
| CN115028527A (en) * | 2022-05-28 | 2022-09-09 | 汉瑞药业(荆门)有限公司 | Preparation method of 3-hydroxymethyl-2, 2-dimethylcyclopropanecarboxylic acid |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111978181B (en) | 2022-11-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111978181B (en) | High-yield preparation method of ethyl chrysanthemate | |
| CN111440160A (en) | Preparation method and application of topramezone | |
| CN106589017B (en) | The preparation method of 3 ', 4 ', 7- troxerutin | |
| CN101693649A (en) | Process for preparing 1.3.5-trimethoxybenzene | |
| CN106854157B (en) | The method of cyclopropane ester is synthesized in low-alcohols solubility solvent | |
| CN112624923A (en) | Preparation method of 4-methoxy methyl acetoacetate | |
| CN111777506A (en) | Green chemical synthesis method of organic bromoacetic acid and ester | |
| CN112142597B (en) | Preparation method of ethyl chrysanthemate | |
| CN101875649A (en) | Synthesis process for industrially producing daidzein | |
| CN104649862A (en) | Method and equipment for producing ethanol product by taking ethyl acetate as raw material | |
| CN113135889A (en) | Process for purifying crude cyclic esters | |
| CN103319309A (en) | Interrupted extraction, rectification and separation method of methanol-nitromethane azeotrope | |
| CN109485564B (en) | Novel method for preparing bifenthrin | |
| CN111454292A (en) | Preparation method of triphenylphosphine | |
| CN112409174A (en) | Preparation device and method of 3, 3-methyl dimethacrylate | |
| CN113185467B (en) | Preparation method of saflufenacil | |
| CN115850184A (en) | Preparation method of iprodione intermediate hydantoin | |
| CN112430205B (en) | Preparation method of arylpyrrole compound | |
| CN112125864B (en) | Synthesis method of 1,1 '-diamino-5, 5' -bitetrazole | |
| CN107522649A (en) | A kind of 7 ethyl tryptophol method for continuously synthesizing of microwave assisted | |
| CN112194655B (en) | Preparation method of engelizin | |
| CN117263799A (en) | Production method of 3, 3-dimethyl-4-methyl pentenoate | |
| CN115819336A (en) | Preparation method of 6-fluoro-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline | |
| CN217173591U (en) | Production system of benzoylpyrazole | |
| CN117924112A (en) | Dark blue esterified liquid and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |