CN113563173A - Preparation method of citral - Google Patents
Preparation method of citral Download PDFInfo
- Publication number
- CN113563173A CN113563173A CN202110885534.7A CN202110885534A CN113563173A CN 113563173 A CN113563173 A CN 113563173A CN 202110885534 A CN202110885534 A CN 202110885534A CN 113563173 A CN113563173 A CN 113563173A
- Authority
- CN
- China
- Prior art keywords
- citral
- phosphate
- acetal
- hydrogen phosphate
- reaction
- 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
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
- C07C45/511—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups
- C07C45/513—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups the singly bound functional group being an etherified hydroxyl group
-
- 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
- B01J27/14—Phosphorus; Compounds thereof
- B01J27/16—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr
- B01J27/18—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr with metals other than Al or Zr
- B01J27/1802—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates
- B01J27/1806—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates with alkaline or alkaline earth metals
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A method for preparing citral comprises: (1) 3-methyl-2-butenal diisopentenyl acetal is subjected to cracking reaction under the catalytic action of phosphate; (2) the cracked product is rearranged under the action of organic amine; (3) and separating the rearrangement reaction product to obtain the citral. The preparation process greatly reduces the cracking separation cost, simplifies the process flow, reduces the equipment cost and has high citral yield.
Description
Technical Field
The invention relates to the field of spice synthesis, and in particular relates to a preparation method of citral.
Background
Citral, namely 2, 6-dimethyl-3, 7-octadiene-1-aldehyde, is a terpene spice with wide application, can be used for preparing fruit type edible essences such as strawberry, apple, apricot, sweet orange, lemon and the like, and can also be used as a daily chemical essence raw material to be widely used as a detergent of tableware, a flavoring agent of soap and floral water.
The synthesis technology of citral has high difficulty, belongs to an oligopolistic product in the industry, and Germany BASF company in EP0021074A1 and WO 2008037693A 1 describes that 3-methyl-2-butenal diisopentenyl acetal is cracked in a decompression rectifying tower under high-temperature and acidic conditions, generated isopentenol and intermediate products are timely evaporated out to be separated from a high-temperature acidic system, and then thermal rearrangement is carried out to obtain a citral product, but the method has more by-products and seriously influences the reaction yield. EP0344043 of RHONE POULENC SANTE describes that in a vacuum distillation column, 3-methyl-2-butenal diisopentenyl acetal is cracked under the condition of halide salt, hydroquinone is used as an auxiliary agent to inhibit side reaction, generated isopentenol and an intermediate product are timely distilled out and separated from a high-temperature acidic system, and then thermal rearrangement is carried out to obtain a citral product. The method has the advantages of long process flow, more required equipment and high production energy consumption cost.
Disclosure of Invention
In order to solve the technical problem, the invention provides a preparation method of citral.
In order to achieve the purpose, the invention is realized by the following technical scheme:
a preparation method of citral specifically comprises the following steps:
(1) 3-methyl-2-butenal diisopentenyl acetal is subjected to cracking reaction under the catalytic action of phosphate;
(2) the cracked product is rearranged under the action of organic amine;
(3) and separating the rearrangement reaction product to obtain the citral.
In some preferred embodiments of the invention, the 3-methyl-2-butenal diisopentenyl acetal has the formula:
it can be obtained by condensation reaction of isoamylene alcohol and isoamylene aldehyde by using known conventional process and separation process.
The molecular structure of citral is shown below:
in step (1) of the present invention, the phosphate includes, but is not limited to, one or more of sodium hydrogen phosphate, potassium hydrogen phosphate, magnesium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and magnesium dihydrogen phosphate, preferably magnesium hydrogen phosphate or magnesium dihydrogen phosphate, and particularly preferably magnesium hydrogen phosphate.
Preferably, the cleavage reaction product of step (1) is directly fed to step (2) without separation for rearrangement reaction.
In the step (1), because the intermediate generated by the acetal cleavage reaction has high activity, the intermediate is easy to undergo a polymerization reaction in a cleavage reaction high-temperature acidic system to generate a heavy component, and the yield is reduced, so as to carry out the acetal cleavage reaction under a reduced pressure condition, so that the intermediate generated by the reaction is rectified and removed from the high-temperature reaction system in time, as described in the above documents; however, the inventors have surprisingly found that if magnesium hydrogen phosphate is used as the catalyst, the mixture of acetal and magnesium hydrogen phosphate is fed into the tubular reactor as a plug flow and the intermediate product is obtained in high yield without rectification, which is associated with the particularly weak activity of magnesium hydrogen phosphate, which greatly reduces the cost of the cracking separation and simplifies the process.
In the step (1), the molar concentration of the phosphate is 50-500 ppm (calculated by taking acetal as a standard), preferably 100-300 ppm, and the cracking reaction temperature is 150-240 ℃, preferably 180-220 ℃, based on the molar amount of the 3-methyl-2-butenal diisopentenyl acetal.
In step (2) of the present invention, the organic amine is one or more of C5 to C10 organic amines, preferably octylamine or nonylamine, and particularly preferably nonylamine.
In the step (2), because the rearrangement reaction temperature is higher than the cracking reaction temperature, if the cracking reaction product directly enters the rearrangement reactor without being separated, the side reaction of the heavy components such as the polymer generated in the step (2) will be increased due to the phosphate, and the yield of the citral product is reduced; therefore, before the cracking product enters the rearrangement reactor, the organic amine is added, so that the yield of the citral can be improved, and the advantages of adding the organic amine are mainly as follows:
(1) through the acid-base synergistic effect, the total amount of byproduct poly-heavy components is reduced while the high yield of the rearrangement reaction is realized;
(2) the organic amine can form an imine complex with an aldehyde functional group in the rearrangement product citral, so that multiple polymerization of the citral is prevented, and the polymerization degree of the polymerized heavy component is reduced;
(3) the process of forming the imine complex is reversible, the citral product can be released again in the subsequent separation process, and the use of the C1-C4 organic amine with strong alkalinity can cause the citral to form corresponding imine substances with stable properties, so that the process is irreversible.
Therefore, the reduction of the total amount of the polymeric heavy component and the reduction of the polymerization degree bring about viscosity reduction, thereby bringing convenience to the model selection of the flow pump in industrial production and reducing the equipment cost. ,
in the step (2), the molar concentration of the organic amine in the rearrangement reaction is 500-5000 ppm (calculated by taking acetal as a standard), preferably 1000-3000 ppm, and the rearrangement reaction temperature is 180-260 ℃, preferably 200-240 ℃.
In the step (2), the molar weight of the organic amine added in the rearrangement reaction is 8-18 times of that of the phosphate in the step (1).
In the step (3), the rearrangement reaction solution is rectified according to a known conventional method, and the citral product can be obtained by rectifying for removing light components and rectifying for removing heavy components, which is not described herein again.
In the step (3), the viscosity of the concentrated heavy component of the citral is less than 3000cp (25 ℃).
The invention has the following beneficial effects:
the invention adopts a tubular reactor, simplifies the form of the reactor, adopts the mutual cooperation of the cracking reaction catalyst and the rearrangement reaction auxiliary agent, reduces the total amount and the polymerization degree of heavy components, reduces the viscosity, greatly reduces the cracking separation cost because a negative pressure rectifying device is not needed in the cracking step, simplifies the process flow, reduces the equipment cost and has high yield of the product citral.
Detailed Description
The present invention will be further described with reference to specific examples, but the scope of the present invention includes, but is not limited to, these.
In the materials described in the examples, wherein: prenol, magnesium dihydrogen phosphate, sodium dihydrogen phosphate and magnesium hydrogen phosphate trihydrate were obtained from carbofuran reagent, and isopropenal and nonanamine were obtained from merck reagent; the preparation method of the acetal comprises the following steps: mixing isopentenol, isopentenyl aldehyde and hydrochloric acid (the molar ratio of alcohol to aldehyde in the mixed solution is 3/1, the concentration of the hydrochloric acid is 1000mg/kg), reacting for 3 hours at the temperature of 75 ℃ under the condition of 6KPaA, continuously removing water generated in the reaction, and then rectifying and purifying the reaction solution at the temperature of 85 ℃ under the condition of 1KPaA to obtain 3-methyl-2-butenal diisopentenyl acetal.
An analytical instrument:
gas chromatograph: agilent 7890, chromatographic column DB-5, injection port temperature: 250 ℃; the split ratio is 40: 1; carrier gas flow: 30 ml/min; temperature rising procedure: 80-230 ℃,3 ℃/min, detector temperature: 280 ℃.
Viscosity measuring instrument: pointer viscometer, model: NDJ-1
Example 1
1.74g magnesium hydrogen phosphate trihydrate and 23.8kg 3-methyl-2-butenal diisopentenyl acetal (hereinafter referred to as acetal) are mixed uniformly to prepare an acetal solution with the molar concentration of magnesium hydrogen phosphate of 100ppm, and then the acetal solution enters a tubular reactor (a) (b) at the speed of 508.8g/h
84.8mL), controlling the temperature of 180 ℃ by an oil bath jacket, uniformly mixing the cracking reaction liquid at the outlet of the reactor and nonanamine (the feeding speed is 0.3g/h), and then feeding the mixture into a subsequent rearrangement tubular reactor (a)
V is 56.5mL), the temperature of an oil bath jacket is controlled at 200 ℃, the first-stage light component removal is carried out on the outlet rearrangement reaction liquid under the conditions of 5KPaA and 100 ℃, then the second-stage light component removal and heavy component removal are carried out under the conditions of 1KPaA and 110 ℃, and distillation separation is carried out, so that a citral product (with the GC purity of 97.8 percent) is obtained, the extraction speed of 320.6g/h, the product yield of 96.5 percent and the heavy component viscosity of 2300cp (25 ℃) are obtained.
Example 2
5.22g of magnesium hydrogen phosphate trihydrate and 23.8kg of 3-methyl-2-buteneMixing aldehyde diisopentenyl acetal (hereinafter referred to as acetal) to prepare an acetal solution with the molar concentration of magnesium hydrogen phosphate of 300ppm, and then feeding the acetal solution into a tubular reactor (at a speed of 508.8 g/h)
84.8mL), controlling the temperature of 220 ℃ by an oil bath jacket, uniformly mixing the cracking reaction liquid at the outlet of the reactor and nonanamine (the feeding speed is 0.9g/h), and then feeding the mixture into a subsequent rearrangement tubular reactor (a)
And V is 56.5mL), the temperature of an oil bath jacket is controlled to be 240 ℃, the first-stage light component removal is carried out on the outlet rearrangement reaction liquid under the conditions of 5KPaA and 100 ℃, then the second-stage light component removal and heavy component removal are carried out under the conditions of 1KPaA and 110 ℃, and distillation separation is carried out, so that a citral product (with the GC purity of 97.4%) is obtained, the extraction speed is 318.3g/h, the product yield is 95.4%, and the heavy component viscosity is 280cp (25 ℃).
Example 3
4.36g of magnesium dihydrogen phosphate and 23.8kg of 3-methyl-2-butenal diisopentenyl acetal (hereinafter referred to as acetal) were mixed uniformly to prepare an acetal solution, which was fed into a tubular reactor at a rate of 508.8g/h (
84.8mL), controlling the temperature of 220 ℃ by an oil bath jacket, uniformly mixing the cracking reaction liquid at the outlet of the reactor and octylamine (the feeding speed is 1.0g/h), and then feeding the mixture into a subsequent rearrangement tubular reactor(s) (
And V is 56.5mL), the temperature of an oil bath jacket is controlled to be 240 ℃, the first-stage light component removal is carried out on the outlet rearrangement reaction liquid under the conditions of 5KPaA and 100 ℃, then the second-stage light component removal and the heavy component removal are carried out under the conditions of 1KPaA and 110 ℃, and distillation separation is carried out, so that a citral product (with the GC purity of 97.2%) is obtained, the extraction speed of 306.9g/h, the product yield of 91.8% and the viscosity of the heavy component of 324cp (25 ℃).
Example 4
2.4g of sodium dihydrogen phosphateAnd 23.8kg of 3-methyl-2-butenal diisopentenyl acetal (hereinafter referred to as acetal) were mixed to prepare a solution, which was fed into a tubular reactor at a rate of 508.8g/h (
84.8mL), controlling the temperature of 220 ℃ by an oil bath jacket, uniformly mixing the cracking reaction liquid at the outlet of the reactor and octylamine (the feeding speed is 0.9g/h), and then feeding the mixture into a subsequent rearrangement tubular reactor (C)
And V is 56.5mL), the temperature of an oil bath jacket is controlled to be 240 ℃, the first-stage light component removal is carried out on the outlet rearrangement reaction liquid under the conditions of 5KPaA and 100 ℃, then the second-stage light component removal and heavy component removal are carried out under the conditions of 1KPaA and 110 ℃, and distillation separation is carried out, so that a citral product (with the GC purity of 97.3 percent) is obtained, the extraction speed is 299.3g/h, the product yield is 89.6 percent, and the heavy component viscosity is 332cp (25 ℃).
Comparative example 1
5.22g of magnesium hydrogen phosphate trihydrate and 23.8kg of 3-methyl-2-butenal diisopentenyl acetal (hereinafter referred to as acetal) are mixed uniformly to prepare an acetal solution with the molar concentration of magnesium hydrogen phosphate of 300ppm, and then the acetal solution enters a tubular reactor (a) (b) at the speed of 508.8g/h
84.8mL), controlling the temperature by an oil bath jacket at 220 ℃, and directly feeding the cracking reaction liquid at the outlet of the reactor into a subsequent rearrangement tubular reactor(s) without adding auxiliary agent nonane
And V is 56.5mL), the temperature of an oil bath jacket is controlled to be 240 ℃, the first-stage light component removal is carried out on the outlet rearrangement reaction liquid under the conditions of 5KPaA and 100 ℃, then the second-stage light component removal and heavy component removal are carried out under the conditions of 1KPaA and 110 ℃, and distillation separation is carried out, so that a citral product (with the GC purity of 96.3%) is obtained, the extraction speed is 200.4g/h, the product yield is 59.4%, and the heavy component viscosity is 5500cp (25 ℃).
Comparative example 2
Raw material 3-AThe 2-butenal diisopentenyl acetal (hereinafter referred to as acetal) is added with magnesium hydrogen phosphate trihydrate without catalyst and enters a tubular reactor (at a speed of 508.8 g/h)
84.8mL), controlling the temperature by an oil bath jacket at 220 ℃, and directly feeding the cracking reaction liquid at the outlet of the reactor into a subsequent rearrangement tubular reactor(s) without adding auxiliary agent nonane
V56.5 mL), the outlet rearrangement reaction was distilled off by controlling the temperature of 240 ℃ through an oil bath jacket according to a conventional method (including but not limited to: the first-stage lightness removal is carried out under the conditions of 5KPaA and 100 ℃, and then the second-stage lightness removal and weight removal are carried out under the conditions of 1KPaA and 110 ℃ to obtain a citral product (the GC purity is 95.7 percent), the extraction rate is 192.9g/h, the product yield is 56.8 percent, and the viscosity of heavy components is 3700cp (25 ℃).
Claims (9)
1. A preparation method of citral is characterized by comprising the following steps:
(1) 3-methyl-2-butenal diisopentenyl acetal is subjected to cracking reaction under the catalytic action of phosphate;
(2) the cracked product is rearranged under the action of organic amine;
(3) and separating the rearrangement reaction product to obtain the citral.
2. The method for preparing citral according to claim 1, wherein the cleavage reaction product of step (1) is subjected to the rearrangement reaction in step (2) without separation.
3. The method of claim 1, wherein the phosphate comprises one or more of, but is not limited to, sodium hydrogen phosphate, potassium hydrogen phosphate, magnesium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and magnesium dihydrogen phosphate, preferably magnesium hydrogen phosphate or magnesium dihydrogen phosphate, and particularly preferably magnesium hydrogen phosphate.
4. The method for preparing citral according to claim 1, wherein in step (1), the molar concentration of phosphate is 50 to 500ppm, preferably 100 to 300ppm, based on the molar amount of 3-methyl-2-butenal diisopentenyl acetal.
5. The method for preparing citral according to claim 1, wherein in step (1), the temperature of the cleavage reaction is 150 to 240 ℃, preferably 180 to 220 ℃.
6. The method for producing citral according to claim 1, wherein in step (2), the organic amine is one or more organic amines having carbon atoms of C5 to C10, preferably octylamine or nonylamine, and particularly preferably nonylamine.
7. The method for preparing citral according to claim 1, wherein in step (2), the molar concentration of the organic amine in the rearrangement reaction is 500 to 5000ppm, preferably 1000 to 3000ppm, based on the molar amount of the 3-methyl-2-butenal diisopentenyl acetal.
8. The process for producing citral according to claim 1, wherein the rearrangement reaction temperature is 180 to 260 ℃, preferably 200 to 240 ℃.
9. The method for preparing citral according to claim 1, wherein in step (2), the organic amine is added in a molar amount 8 to 18 times the molar amount of the phosphate in step (1) during the rearrangement reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110885534.7A CN113563173B (en) | 2021-08-03 | 2021-08-03 | Preparation method of citral |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110885534.7A CN113563173B (en) | 2021-08-03 | 2021-08-03 | Preparation method of citral |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113563173A true CN113563173A (en) | 2021-10-29 |
| CN113563173B CN113563173B (en) | 2022-07-12 |
Family
ID=78170167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110885534.7A Active CN113563173B (en) | 2021-08-03 | 2021-08-03 | Preparation method of citral |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113563173B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114105744A (en) * | 2021-11-25 | 2022-03-01 | 国药集团威奇达药业有限公司 | Method for catalyzing Claisen rearrangement at lower temperature |
| CN115677469A (en) * | 2022-11-17 | 2023-02-03 | 万华化学集团股份有限公司 | Citral with excellent fragrance and preparation method thereof |
| CN116462577A (en) * | 2022-01-11 | 2023-07-21 | 万华化学集团股份有限公司 | Method for preparing citral intermediate |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0462252A1 (en) * | 1990-01-03 | 1991-12-27 | Rhone Poulenc Sante | Method for preparing citral. |
| EP0992477A1 (en) * | 1998-10-07 | 2000-04-12 | Basf Aktiengesellschaft | Process for the preparation of citral |
-
2021
- 2021-08-03 CN CN202110885534.7A patent/CN113563173B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0462252A1 (en) * | 1990-01-03 | 1991-12-27 | Rhone Poulenc Sante | Method for preparing citral. |
| EP0992477A1 (en) * | 1998-10-07 | 2000-04-12 | Basf Aktiengesellschaft | Process for the preparation of citral |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114105744A (en) * | 2021-11-25 | 2022-03-01 | 国药集团威奇达药业有限公司 | Method for catalyzing Claisen rearrangement at lower temperature |
| CN116462577A (en) * | 2022-01-11 | 2023-07-21 | 万华化学集团股份有限公司 | Method for preparing citral intermediate |
| CN116462577B (en) * | 2022-01-11 | 2024-02-27 | 万华化学集团股份有限公司 | Method for preparing citral intermediate |
| CN115677469A (en) * | 2022-11-17 | 2023-02-03 | 万华化学集团股份有限公司 | Citral with excellent fragrance and preparation method thereof |
| CN115677469B (en) * | 2022-11-17 | 2024-04-09 | 万华化学集团股份有限公司 | Citral with excellent fragrance and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113563173B (en) | 2022-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113563173B (en) | Preparation method of citral | |
| TWI324991B (en) | Process for producing alcohol | |
| CN112574018B (en) | Low-color-number citral and preparation method thereof | |
| CN104649878A (en) | Continuous synthesis technology of beta-isophorone | |
| CN106278854B (en) | A kind of preparation method by α-isophorone isomery β-isophorone | |
| CN113429275A (en) | Method for reducing production cost of pseudo ionone | |
| CN110028392B (en) | Method for isomerizing and synthesizing isopropenal by using methylbutynol | |
| CN110882722A (en) | Acid-base composite catalyst and method for preparing methacrolein by using same | |
| CN113603571B (en) | 3-methyl-2-butene-1-aldehyde diisopentenylacetal | |
| CN112142571B (en) | Method for preparing citral precursor by continuous catalytic cracking of acetal | |
| CN112225655B (en) | Preparation method of citral | |
| JPH08208544A (en) | Reducing method for phenol tar waste | |
| CN109810118B (en) | Method for synthesizing 1,8-cineole from alpha-terpineol | |
| CN113443975B (en) | Method for producing methyl isopropyl ketone under pressure and application thereof | |
| CN101215219A (en) | Preparation method for p-isoproplyl toluene | |
| CN114773264B (en) | Preparation device and preparation method of rubber antioxidant TMQ | |
| CN1288882A (en) | Method for continuously preparing 3,5,5-trimethylcyclohexan-3-ene-one-(beta-isophorone) | |
| CN1915984A (en) | Method for preparing whisky lactone | |
| CN209906679U (en) | Device for preparing methyl formate by catalytic distillation | |
| CN113636951B (en) | Treatment method of waste DMF in sucralose production | |
| CN112723992B (en) | Process for preparing high-purity decanediol by side-line vacuum rectification | |
| CN113443956B (en) | Method for utilizing linalyl acetate kettle residue waste liquid | |
| KR20010049591A (en) | CONTINUOUS PROCESS FOR THE MANUFACTURE OF 3,5,5-TRIMETHYLCYCLOHEXA-3-EN-1-ONE (β-ISOPHORONE) | |
| CN112574015B (en) | Method for preparing cyclocitral from C10 unsaturated aldehyde rectifying tower bottoms | |
| CN111960922B (en) | Method for separating natural terpineol from heavy turpentine |
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 |