CN109956983B - Method for extracting sucralose-6-ethyl ester - Google Patents
Method for extracting sucralose-6-ethyl ester Download PDFInfo
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- CN109956983B CN109956983B CN201711417933.0A CN201711417933A CN109956983B CN 109956983 B CN109956983 B CN 109956983B CN 201711417933 A CN201711417933 A CN 201711417933A CN 109956983 B CN109956983 B CN 109956983B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H1/00—Processes for the preparation of sugar derivatives
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H1/00—Processes for the preparation of sugar derivatives
- C07H1/06—Separation; Purification
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H13/00—Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids
- C07H13/02—Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids by carboxylic acids
- C07H13/04—Compounds containing saccharide radicals esterified by carbonic acid or derivatives thereof, or by organic acids, e.g. phosphonic acids by carboxylic acids having the esterifying carboxyl radicals attached to acyclic carbon atoms
- C07H13/06—Fatty acids
Abstract
The invention provides a method for extracting sucralose-6-ethyl ester, which comprises the steps of neutralizing an obtained acidic material with alkali after a chlorination working section for preparing sucralose-6-ethyl ester by chlorination of sucrose-6-ethyl ester in the production process of preparing sucralose by a monoester method, then adding a non-polar or low-polar solvent, stirring, standing to enable sucralose-6-ethyl ester to form a solid and settle, then carrying out solid-liquid separation to obtain a crude sucralose-6-ethyl ester solid product, optionally, rectifying and separating a liquid part, then recycling the liquid part, and recrystallizing the crude sucralose-6-ethyl ester solid product.
Description
Technical Field
The invention relates to the field of sweetener production, in particular to a method for extracting a key intermediate sucralose-6-ethyl ester in a process of preparing a food sweetener sucralose.
Background
Sucralose is one of the most excellent high-sweetness food sweeteners in the world at present, and has the characteristics of high sweetness, good sweetness characteristic, no absorption by human bodies and the like. Sucralose has a high solubility in water and does not generate bubbles when dissolved, so it is widely used in carbonated beverages. Sucralose is a natural semisynthetic sweetener which is chemically treated and takes sucrose as a main raw material.
Most of the production enterprises adopt the monoester method to produce sucralose at present, namely: firstly, esterifying sucrose to obtain sucrose-6-ethyl ester, then chlorinating to generate sucralose-6-ethyl ester, purifying the generated sucralose-6-ethyl ester, and then hydrolyzing and deacetylating to generate sucralose.
In the process of preparing sucralose by the monoester method, the preparation and extraction of the intermediate sucralose-6-ethyl ester are very critical steps. In the chlorination step, most domestic enterprises select thionyl chloride as a chlorinating agent, trichloroethane and N, N-Dimethylformamide (DMF) as solvents, and sucrose-6-ethyl ester is used for preparing the sucralose-6-ethyl ester. After the chlorination reaction is finished, neutralizing the reaction material with an alkaline substance, distilling the material to remove solvents of trichloroethane and DMF, adding a certain amount of water into the residual material to prepare sucralose-6-ethyl ester aqueous solution, crystallizing, and filtering to extract sucralose-6-ethyl ester solid.
CN1271077C discloses a preparation method of sucralose-6-ethyl ester, which comprises the following steps: adding sucrose-6-ethyl ester into a solvent containing DMF, using thionyl chloride as a chlorinating agent, chlorinating in three temperature stages to obtain sucralose-6-ethyl ester, cooling a reaction mixture to room temperature, adjusting the pH value to be neutral by using an alkali solution, then extracting the sucralose-6-ethyl ester by using ethyl acetate, distilling an organic phase obtained by extraction to remove the ethyl acetate to obtain a concentrated solution of the sucralose-6-ethyl ester, and adding a small amount of ether solvent or water into the solution to obtain a sucralose-6-ethyl ester crystal.
In the method of the prior art, a great difficulty is troubled manufacturers, namely in the process of removing the solvent from the solution of sucralose-6-ethyl ester, because the boiling point of the solvent is relatively high, such as 114 ℃ of the boiling point of trichloroethane, 153 ℃ of the boiling point of DMF, 77 ℃ of the boiling point of ethyl acetate, and the amount of the solvent to be removed is large, the solvent is usually heated and distilled for a long time, such as more than 10 hours; and the sucralose-6-ethyl ester is heated for a long time at the temperature of more than 70 ℃ and is easy to coke or decompose, so the process of removing the solvent must adopt high vacuum and low temperature distillation, which results in high process operation cost. Even so, over 10% decomposition of sucralose-6-ethyl ester and over 20% decomposition of DMF are caused during the distillation process to remove the solvent.
Disclosure of Invention
The invention provides a method for extracting sucralose-6-ethyl ester, which comprises the steps of neutralizing an obtained acidic material with alkali after a chlorination working section for preparing the sucralose-6-ethyl ester by chlorinating sucrose-6-ethyl ester in the production process of the sucralose, then adding a non-polar or low-polar solvent, stirring, standing, forming solid and settling the sucralose-6-ethyl ester, then carrying out solid-liquid separation to obtain a solid crude product of the sucralose-6-ethyl ester, and optionally, rectifying and separating a liquid part for recycling.
The extraction method of the sucralose-6-ethyl ester avoids the decomposition of the sucralose-6-ethyl ester caused by long-time heating and solvent removal after the neutralization step, reduces the decomposition of DMF, and simultaneously reduces the production cost by recycling the liquid part.
Optionally, recrystallizing the crude solid sucralose-6-ethyl ester obtained by the above method with water to obtain sucralose-6-ethyl ester crystals.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.
All percentages, parts, ratios, etc., are by weight unless otherwise indicated.
The extraction method of the sucralose-6-ethyl ester is suitable for all processes for producing the sucralose by adopting a monoester method, no matter what chlorinating agent and solvent are adopted in the chlorination step of the sucralose-6-ethyl ester.
The invention provides a method for extracting sucralose-6-ethyl ester, which comprises the steps of in the production process of sucralose, after sucralose-6-ethyl ester is prepared by chlorination of sucrose-6-ethyl ester, neutralizing a sucralose-6-ethyl ester product solution by using alkali, adding a non-polar or low-polar solvent into the neutralized material without distilling to remove the solvent, stirring and standing to enable sucralose-6-ethyl ester to form a solid and settle, then carrying out solid-liquid separation to obtain a crude sucralose-6-ethyl ester solid product, and optionally, carrying out rectification separation on a liquid part and recycling the liquid.
In the present application, the "non-polar or low-polar solvent" is selected from all solvents having a solvent polarity lower than that of cyclopentane, more preferably a solvent having a polarity of 0 to 0.2, particularly preferably petroleum ether, cyclohexane, white oil, and the like.
In a preferred embodiment of the invention, wherein the addition of the non-polar or low-polar solvent to the neutralized sucralose-6-ethyl ester reaction mass is carried out at a temperature of from 10 ℃ to 40 ℃, preferably from 15 ℃ to 35 ℃, more preferably at room temperature.
In a preferred embodiment of the present invention, wherein the amount of said non-polar or low-polar solvent added thereto is in the range of from 30 to 150%, preferably from 40 to 90%, by weight based on the total weight of the neutralized sucralose-6-ethyl ester reaction mass.
In the present application, the term "solid-liquid separation" includes any known means of separating solids from liquids, such as filtration, pouring of liquids, centrifugation, and the like.
In a preferred embodiment of the present invention, the method further comprises adding water to the crude solid sucralose-6-ethyl ester obtained by the above method to prepare an aqueous solution of sucralose-6-ethyl ester, the concentration of the aqueous solution is 5 to 20 wt%, preferably 8 to 12 wt%, heating to 100 ℃, sampling and analyzing the aqueous solution of sucralose-6-ethyl ester until the aqueous solution does not contain trichloroethane and other organic solvents, then cooling to 3 to 10 ℃, preferably 5 to 8 ℃, stirring for 3 to 15 hours, preferably 8 to 12 hours, and recrystallizing and separating out sucralose-6-ethyl ester. Filtering to obtain sucralose-6-ethyl ester crystals.
According to a preferred embodiment of the invention, the acidic chlorinated liquid feed from the chlorination section is fed to a neutralization reactor and a basic feed, preferably aqueous ammonia, is added to carry out the neutralization reaction so that the feed has a pH of 7 to 9, preferably 7 to 8, more preferably 7. Transferring the neutralized reaction material into a settling kettle, adding one or more nonpolar solvents selected from petroleum ether, cyclohexane, white oil and the like, stirring and mixing uniformly, settling for enough time, performing solid-liquid separation until the content of sucralose-6-ethyl ester in the liquid-phase mixed solvent is lower than 0.2%, sending the liquid to a rectification system to separately recycle various solvents, dissolving the solid material in water, performing recrystallization, and further purifying to obtain sucralose-6-ethyl ester solid.
The invention omits the step of directly distilling and removing the solvent in the process of extracting the sucralose-6-ethyl ester in the prior art, and adds a non-polar or low-polar solvent instead, so that sucrose derivatives such as the sucralose-6-ethyl ester and the like are solidified and settled under the mild temperature condition, then solid-liquid separation is carried out to obtain the sucralose-6-ethyl ester solid, and the fine product is obtained by recrystallization. The product decomposition and the solvent decomposition caused in the process of distilling and removing a large amount of solvent are avoided, the yield of the sucralose-6-ethyl ester is obviously improved, for example, the yield is improved by more than 5%, the loss of the solvent such as DMF is reduced, for example, the loss of DMF is reduced by more than 20%, and the production consumption and the production cost are greatly reduced.
Examples
Example 1
Sending the acidic sucralose-6-ethyl ester product mixture from the chlorination section of the sucralose preparation process into a neutralization reactor, and adding ammonia water for neutralization reaction to ensure that the pH value of the material is 7. 1000 g of the solution after chlorination neutralization (containing 4 wt% of sucralose-6-ethyl ester, 80 wt% of trichloroethane, 5 wt% of DMF and 11 wt% of impurities) is taken and added into a 2000 ml three-neck flask with stirring and electric heating, 400 g of cyclohexane is added at normal temperature, namely the weight ratio of cyclohexane to trichloroethane is 0.5, the mixture is fully stirred for 15 minutes and is kept still for 30 minutes, a solid of sucralose-6-ethyl ester is settled to the bottom of the flask, 1 ml of an upper liquid phase mixed solvent is taken for chromatographic analysis, the content of sucralose-6-ethyl ester in the mixed solvent is measured to be 0.18%, at this time, 1200 g of the upper liquid is poured into another 2000 ml of beaker, and 200 g of a total solid crude product of sucralose-6-ethyl ester and the residual mixed solvent are left in the three-neck flask.
Adding 350 g of water into the obtained crude solid sucralose-6-ethyl ester mixture, heating to 80 ℃, vacuumizing to 0.05 MPa, keeping for 0.5 hour, distilling out part of water and residual small amount of trichloroethane, cyclohexane, DMF and the like to obtain 150 g in total, and remaining 400 g of concentrated sucralose-6-ethyl ester aqueous solution, and sampling and detecting the result: the aqueous solution contained 9.46% of sucralose-6-ethyl ester, that is, the total amount of sucralose-6-ethyl ester contained in the aqueous solution was 37.84 g, and the yield of sucralose-6-ethyl ester was 94.6% relative to 1000 g of sucralose-6-ethyl ester contained in the stock solution.
The obtained concentrated sucralose-6-ethyl ester aqueous solution is cooled to 5-8 ℃, stirred for 8 hours to obtain recrystallized sucralose-6-ethyl ester, and then filtered and dried to obtain a refined product 33.8 g, and the yield is 84.5%.
The 1200 g of mixed solvent which is poured out is sampled and analyzed, the mixed solvent contains 64 percent of trichloroethane, 32 percent of cyclohexane and 4 percent of DMF, and the mixed solvent is separated by a rectifying tower to obtain 768 percent of trichloroethane, 384 percent of cyclohexane and 48 percent of DMF, and the recovery rate of DMF is 96 percent.
Comparative example 1
1000 g of a solution obtained after chlorination neutralization of sucrose-6-ethyl ester (containing 4 wt% of sucralose-6-ethyl ester, 80 wt% of trichloroethane, 5 wt% of DMF and 11 wt% of impurities) is put into a 2000 ml three-neck flask with a stirrer and an electric heater, the flask is heated to 80 ℃ under stirring, the vacuum is opened to 0.09 MPa, the flask is kept for 10 hours, 810 g of a mixed solution of the trichloroethane and the DMF is distilled out, wherein 1.25% of DMF and 98.75% of trichloroethane are added into the residual 190 g of concentrated solution, 200 g of mixed solution is distilled out under high vacuum and 0.09 MPa and at the temperature of 80 ℃, 11% of DMF and 89% of water are added into the residual liquid, 400 g of water is added into 590 g of the residual liquid, the content of sucralose-6-ethyl ester is detected, namely the total amount of the sucralose-6-ethyl ester is 35 g, the yield is 87.5%, and 12.5% of sucralose-6-ethyl ester is decomposed in the evaporation process.
Transferring 590 g of the liquid into a 1000 ml three-neck flask, cooling to 0-5 ℃ under stirring, stirring for 20 hours to obtain sucralose-6-ethyl ester crystals, filtering and drying to obtain 31 g of sucralose-6-ethyl ester refined product, wherein the yield is 77.5 percent and is 7 percent lower than that of the new method.
The DMF content in the mixture of trichloroethane and DMF, which was distilled out for the first time, was 1.25%, extracted with water and then distilled, and 9.5 g of DMF was recovered. In 200 g of the mixture distilled out by the second water distillation, the total amount of DMF is 22 g, 31.5 g of DMF is recovered, 50 g of DMF is contained in the original 1000 ml of chlorination neutralizing liquid, the actual yield is 63%, and 18.5 g of DMF is decomposed in the two distillations.
Claims (14)
1. A process for extracting trichlorosucrose-6-ethyl ester includes such steps as neutralizing the acidic material with alkali, adding non-polar or low-polar solvent, stirring, laying aside to make trichlorosucrose-6-ethyl ester become solid, settling, solid-liquid separation to obtain crude trichlorosucrose-6-ethyl ester, rectifying and separating liquid, and recovering the liquid from it, and features that the non-polar or low-polar solvent is chosen from petroleum ether, cyclohexane and white oil, and the weight of said non-polar or low-polar solvent added to it is 40-90% based on the total weight of the solution of trichlorosucrose-6-ethyl ester.
2. The method for extracting sucralose-6-ethyl ester according to claim 1, wherein the non-polar or low-polar solvent is added at a temperature of 10 to 40 ℃.
3. The method of extracting sucralose-6-ethyl ester according to claim 1, wherein the non-polar or low-polar solvent is added at a temperature of 15-35 ℃.
4. The method of extracting sucralose-6-ethyl ester according to claim 1, wherein the non-polar or low-polar solvent is added at room temperature.
5. The method for extracting sucralose-6-ethyl ester according to any one of claims 1 to 4, further comprising adding water to the obtained crude solid sucralose-6-ethyl ester to prepare an aqueous solution of sucralose-6-ethyl ester, then cooling and stirring to recrystallize and separate out sucralose-6-ethyl ester, and filtering to obtain sucralose-6-ethyl ester crystals.
6. The method of claim 5, wherein the aqueous solution of sucralose-6-ethyl ester is 5-20 wt%.
7. The method of claim 5, wherein the aqueous solution of sucralose-6-ethyl ester has a concentration of 8 to 12 wt%.
8. The method of extracting sucralose-6-ethyl ester according to claim 5, wherein the recrystallization is performed at 3-10 ℃ with stirring for 3-15 hours.
9. The method of extracting sucralose-6-ethyl ester according to claim 5, wherein the recrystallization is performed at 5-8 ℃ with stirring for 3-15 hours.
10. The method for extracting sucralose-6-ethyl ester according to claim 8 or 9, wherein the recrystallization is performed with stirring for 8 to 12 hours.
11. The process for the extraction of sucralose-6-ethyl ester according to claim 1, wherein the acidic chlorination product solution from the chlorination stage is fed into a neutralization reactor, and an alkaline material is added to perform a neutralization reaction so that the pH value of the material is 7 to 9.
12. The process for the extraction of sucralose-6-ethyl ester according to claim 1, wherein the acidic chlorination product solution from the chlorination stage is fed into a neutralization reactor, and an alkaline material is added to perform a neutralization reaction so that the pH value of the material is 7 to 8.
13. The process for the extraction of sucralose-6-ethyl ester according to claim 1, wherein the acidic chlorination product solution from the chlorination stage is fed into a neutralization reactor, and an alkaline material is added to perform a neutralization reaction so as to make the material pH 7.
14. The method of extracting sucralose-6-ethyl ester according to any one of claims 11 to 13, wherein the alkaline material is selected from ammonia.
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110563777B (en) * | 2019-08-30 | 2020-07-24 | 山东新和成精化科技有限公司 | Method for post-treating sucralose chlorination liquid |
| WO2022056840A1 (en) * | 2020-09-18 | 2022-03-24 | 安徽金禾实业股份有限公司 | Post-treatment method of sucrose-6-carboxylic ester chlorination reaction liquid |
| CN112125938A (en) * | 2020-09-26 | 2020-12-25 | 安徽金禾实业股份有限公司 | Method for extracting sucralose-6-ethyl ester from sugar residues |
| EP4215539A4 (en) * | 2020-11-27 | 2024-01-17 | Anhui Jinhe Industrial Co., Ltd. | Method for purifying sucralose-6-ethyl ester |
| CN112457356A (en) * | 2020-11-30 | 2021-03-09 | 安徽金禾实业股份有限公司 | Method for removing ethyl ester from secondary esterified crude product in sucralose production |
| WO2023010323A1 (en) * | 2021-08-04 | 2023-02-09 | 安徽金禾实业股份有限公司 | Method for preparing sucralose |
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