CN109232184A - A method of L- isopulegol optical purity is improved by chiral resolution - Google Patents
A method of L- isopulegol optical purity is improved by chiral resolution Download PDFInfo
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- CN109232184A CN109232184A CN201811166606.7A CN201811166606A CN109232184A CN 109232184 A CN109232184 A CN 109232184A CN 201811166606 A CN201811166606 A CN 201811166606A CN 109232184 A CN109232184 A CN 109232184A
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- isopulegol
- linalool
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- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
- C07C29/88—Separation; Purification; Use of additives, e.g. for stabilisation by treatment giving rise to a chemical modification of at least one compound
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- C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
- C07B57/00—Separation of optically-active compounds
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- C07B2200/07—Optical isomers
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Abstract
The present invention provides a kind of methods for improving L- isopulegol optical purity by chiral resolution.This method reacts D, L- isopulegol and resolving agent L- linalool 3~4 hours in dispersing agent and auxiliary agent in 70~80 DEG C, after being cooled to 10~25 DEG C, then by being centrifugally separating to obtain intermediate L- isopulegol L- linalool；Alkaline hydrolysis analysis is carried out to above-mentioned intermediate, which is decomposed, then the L- isopulegol of high-purity is just made by exclusion chromatography.This method cost of material is low, energy consumption of reaction is low, is suitable for large-scale industrial production.
Description
Technical field
The invention belongs to Crystallization Separation technical fields, and in particular to one kind improves L- isopulegol by chiral resolution
The method of optical purity.
Background technique
Menthol is a kind of important aromachemicals, has strong refrigerant effect, in cosmetics, food, beverage, doctor
The fields such as medicine have a wide range of applications, and are one of industrial most important synthetic perfumes.
Menthol has 8 kinds of isomers, they are in that fragrance matter is different: wherein the peppermint fragrance of l-menthol is most strong,
Refrigerant effect is most obvious, and the refrigerant effect of racemization menthol is more faint, and other isomers are then without refrigerant effect.
In the process flow of synthesis l-menthol, L- isopulegol is a kind of important intermediate.Industrial preparation L-
The conventional method of isopulegol is to make citronellal that cyclization occur under Louis acid catalysis, but what is be a commonly-available is all
The mixture of L- isopulegol and its several isomers.Wherein, the diastereoisomer of L- isopulegol can lead to greatly
Rectifying removing is crossed, but its enantiomter D- isopulegol is difficult to separate since the two boiling point is close.Optical voidness
Spending low is a major reason for restricting L- isopulegol and l-menthol application.
Patent CN101248032A discloses a kind of method for preparing enrichment L- isopulegol by melt crystallization.But
It is that the process requirement carries out under conditions of anhydrous and oxygen-free, condition is harsh, and needs elder generation that the different Hu of L- is thin in crystallization process
Lotus alcohol crystallizes out together with its enantiomter D- isopulegol, then the fusing that heats up, and can just obtain the different Hu of L- of high-purity
Menthol, complex steps, and also the requirement to equipment is very high, applied to the with high costs of industrialized production.
Patent US5663460 disclose it is a kind of by -20 DEG C to -60 DEG C at a temperature of crystallized by petroleum ether or acetone and
The method for purifying the optical purity of L- isopulegol.But the technique is harsh to temperature requirement, huge energy consumption, and without crystal seed
Induction crystallization, leads to that Metastable zone is too wide, required crystallization time is too long, influences experiment and production efficiency, and yield is too low, insufficient
10%, be not suitable for industrialized production.
Therefore, it is necessary to develop a kind of improved method of optical purity that L- isopulegol can be improved.
Summary of the invention
It is an object of the present invention to which optical purity for L- isopulegol in existing production technology is low, existing crystallization
The process yield of separation scheme is low and condition requires the problems such as harshness, develops one kind and improves the different Hu of L- by chiral resolution
The improved method of menthol optical purity.This method cost of material is low, energy consumption of reaction is low, is suitable for large-scale industrial production.
To achieve the goals above, The technical solution adopted by the invention is as follows:
A method of L- isopulegol optical purity is improved by chiral resolution, is comprised the following steps:
(1) D, L- isopulegol and resolving agent L- linalool react in dispersing agent and auxiliary agent, pass through centrifugation after cooling
Isolated intermediate L- isopulegol L- linalool；
(2) it carries out alkaline hydrolysis analysis to above-mentioned intermediate to be decomposed, then by exclusion chromatography to obtain the different Hu of high-purity L- thin
Lotus alcohol.
In the present invention, the D of step (1), L- isopulegol is complete racemic or partial racemization.
In the present invention, the resolving agent L- linalool of step (1) and the molar ratio of D, L- isopulegol are 0.5:1~1.2:
1, preferably 0.8:1~1:1.L- linalool belongs to chain terpene alcohols, has the general character and feature of pure and mild alkenes compounds, such as
It can be dewatered reaction.Two C=C double bonds in the presence of its structure L- isopulegol and are split to being split object D
Reaction between agent L- linalool can be played the role of greatly facilitating.Contain a chiral centre in the structure of L- linalool,
For its optical isomer D- linalool, the reactivity of L- linalool is higher.
In the present invention, the auxiliary agent of step (1) is dodecyl sodium sulfate, and the mass ratio with D, L- isopulegol is
0.0001:1~0.0010:1.Dodecyl sodium sulfate is a kind of typical anionic surfactant, have excellent wetting,
Osmosis includes hydrophilic radical sulfonic group and lipophilic group dodecyl, this amphiphilic structure base in structure simultaneously
Group caused by asymmetry allow dodecyl sodium sulfate to significantly change liquid phase between interfacial tension so that being split object
Combination between D, L- isopulegol and resolving agent L- linalool is more easier, and accelerates the rate of salt-forming reaction, improves power
Learn the efficiency split.
In the present invention, the dispersing agent of step (1) is that ethyl alcohol, normal propyl alcohol, isopropanol, ethyl acetate, propyl acetate, acetic acid are different
One of propyl ester, acetonitrile and toluene are a variety of, ethyl acetate and/or toluene；Dispersing agent and D, L- isopulegol
Mass ratio is 5:1~20:1, preferably 10:1~15:1.
In the present invention, the reaction temperature of step (1) is 70~80 DEG C, the reaction time 3~4 hours, is cooled to 10~25 DEG C.
In the present invention, the parsing alkali of step (2) be sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and
One of saleratus is a variety of, preferably sodium bicarbonate and/or saleratus, and parsing alkali is added in form of an aqueous solutions.
In the present invention, it is 6.5~7.5 that the pH of step (2) alkaline hydrolysis analysis, which adjusts terminal,.
In the present invention, the exclusion chromatography of step (2) is connected using gel permeation chromatographic column, and mobile phase is tetrahydrofuran,
0.5~2.0mL/min of flow velocity, time 45min, 35~40 DEG C of chromatogram column temperature.Using exclusion chromatography come separating high-purity
L- isopulegol and resolving agent L- linalool are conducive to environmental protection, symbol so that L- linalool can be recycled with recovery
Close the requirement of green chemical industry.Chemically structure is analyzed, and contains 1 phenyl ring in the structure of L- isopulegol, therefore its molecule bone
Frame is smaller, and L- linalool is polynary enol, and molecular skeleton is more huge, and the two, can be according to when carrying out exclusion chromatography separation
The secondary inside and gap for passing through gel particle respectively causes the rate of outflow different, available good separating effect.
It is 80~90.5% with the total recovery that above-mentioned chiral separation method prepares L- isopulegol product in the present invention,
Optical purity is 99.0~99.9%e.e..
Chiral separation method of the invention prepares having the active effect that for L- isopulegol product
(1) the L- isopulegol total yield of products of above-mentioned chiral separation method preparation can achieve 80~90.5%, light
Learning purity can achieve 99.0~99.9%e.e.；
(2) resolving agent, dispersing agent, auxiliary agent, the price of parsing alkali are all cheaper, significantly reduce cost of material；
(3) resolution reaction, Crystallization Separation, the reaction condition of Basic fluxing raction are all relatively milder, reduce production energy consumption and set
Standby cost, is suitble to large-scale industrial production.
Detailed description of the invention
Fig. 1 is that embodiment 3 splits preceding D, L- isopulegol gas chromatographic detection result；
Fig. 2 is high-purity L- isopulegol gas chromatographic detection result after embodiment 3 is split；
Fig. 3 is high-purity L- isopulegol gas chromatographic detection result after comparative example 1 is split.
Specific embodiment
The following examples be technical solution provided by the present invention is further explained, but the present invention is not limited to
Listed embodiment further includes other any well known changes in interest field of the present invention.
Primary raw material information:
D, L- isopulegol, chemical purity 99%, optical purity are 50%~99%e.e., Hubei giant dragon hall medicine
Chemical Co., Ltd.；
L- linalool, chemical purity 99%, optical purity 99%e.e., Aladdin reagent Co., Ltd；
Dodecyl sodium sulfate, chemical purity 99.5%, Aladdin reagent Co., Ltd；
Ethyl alcohol, normal propyl alcohol, isopropanol, ethyl acetate, propyl acetate, isopropyl acetate, acetonitrile, toluene, chemical purity are
99%, Aladdin reagent Co., Ltd；
Sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, saleratus, chemical purity 99%, I
Fourth reagent Co., Ltd.
Exclusion chromatography: using Coupled columns, model LC-20AD/RID-10A, and chromatographic column is MZ-Gel SDplus
5 μm of 10E3A (8.0 × 300mm), 5 μm of MZ-Gel SDplus 500A (8.0 × 300mm), MZ-Gel SDplus 100A5 μ
M (8.0 × 300mm), Shimadzu；Mobile phase: tetrahydrofuran；Flow velocity: 0.5~2.0mL/min；Time: 45min；Chromatogram column temperature:
35~40 DEG C.
L- isopulegol characterizing method: gas chromatograph: GC2010-plus；Chromatographic column BETA-DEX-225；Injection port
Temperature: 220 DEG C；Split ratio 50:1；Carrier gas flux: 30ml/min；Temperature program: keeping 35min at 95 DEG C, with 20 DEG C/min's
Rate rises to 200 DEG C, keeps 5min；Detector temperature: 300 DEG C.
Embodiment 1
By 15.4g (0.1mol) D, L- isopulegol, 7.7g (0.05mol) L- linalool, 0.003g dodecyl sulphur
Sour sodium and 75g ethyl alcohol are added in 200mL jacketed crystallization kettle, are heated to 70 DEG C, are stirred to react at such a temperature 3 hours.Reaction
After, 10 DEG C are slowly cooled to, intermediate L- isopulegol L- linalool is centrifugally separating to obtain.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the hydroxide of 0.1mol/L is added
Sodium water solution adjusts pH value to 6.5, stirs 3 hours, which decomposes, then (uses gel infiltration color by exclusion chromatography
Column series connection is composed, mobile phase is tetrahydrofuran, flow velocity 0.5mL/min, time 45min, 35 DEG C of chromatogram column temperature) obtain high-purity
L- isopulegol.Through gas chromatographic detection, the optical purity of product is 99.0%e.e., total recovery 90.3%.
Embodiment 2
By 15.4g (0.1mol) D, L- isopulegol, 18.5g (0.12mol) L- linalool, 0.015g dodecyl sulphur
Sour sodium and 300g isopropyl acetate are added in 500mL jacketed crystallization kettle, are heated to 80 DEG C, it is small to be stirred to react 4 at such a temperature
When.After reaction, 25 DEG C are slowly cooled to, intermediate L- isopulegol L- linalool is centrifugally separating to obtain.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the sodium carbonate of 0.1mol/L is added
Aqueous solution adjusts pH value to 7.5, stirs 4 hours, which decomposes, then (uses gel permeation chromatography by exclusion chromatography
Column series connection, mobile phase is tetrahydrofuran, flow velocity 2.0mL/min, time 45min, 40 DEG C of chromatogram column temperature) obtain the L- of high-purity
Isopulegol.Through gas chromatographic detection, the optical purity of product is 99.4%e.e., total recovery 81.2%.
Embodiment 3
By 15.4g (0.1mol) D, L- isopulegol, 12.3g (0.08mol) L- linalool, 0.008g dodecyl sulphur
Sour sodium and 150g ethyl acetate are added in 500mL jacketed crystallization kettle, are heated to 75 DEG C, it is small to be stirred to react 3 at such a temperature
When.After reaction, 15 DEG C are slowly cooled to, intermediate L- isopulegol L- linalool is centrifugally separating to obtain.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the bicarbonate of 0.1mol/L is added
Sodium water solution adjusts pH value to 6.8, stirs 3 hours, which decomposes, then (uses gel infiltration color by exclusion chromatography
Column series connection is composed, mobile phase is tetrahydrofuran, flow velocity 1.0mL/min, time 45min, 40 DEG C of chromatogram column temperature) obtain high-purity
L- isopulegol.Through gas chromatographic detection, the optical purity of product is 99.8%e.e., total recovery 86.4%.
Embodiment 4
By 15.4g (0.1mol) D, L- isopulegol, 15.4g (0.1mol) L- linalool, 0.005g dodecyl sulphur
Sour sodium and 230g toluene are added in 500mL jacketed crystallization kettle, are heated to 75 DEG C, are stirred to react at such a temperature 3 hours.Instead
After answering, 15 DEG C are slowly cooled to, is centrifugally separating to obtain intermediate L- isopulegol L- linalool.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the bicarbonate of 0.1mol/L is added
Aqueous solutions of potassium adjusts pH value to 7.1, stirs 3 hours, which decomposes, then (uses gel infiltration color by exclusion chromatography
Column series connection is composed, mobile phase is tetrahydrofuran, flow velocity 1.0mL/min, time 45min, 35 DEG C of chromatogram column temperature) obtain high-purity
L- isopulegol.Through gas chromatographic detection, the optical purity of product is 99.9%e.e., total recovery 84.8%.
Embodiment 5
By 15.4g (0.1mol) D, L- isopulegol, 9.2g (0.06mol) L- linalool, 0.004g dodecyl sulphur
Sour sodium and 120g isopropanol are added in 200mL jacketed crystallization kettle, are heated to 70 DEG C, are stirred to react at such a temperature 3 hours.
After reaction, 10 DEG C are slowly cooled to, intermediate L- isopulegol L- linalool is centrifugally separating to obtain.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the hydroxide of 0.1mol/L is added
Aqueous solutions of potassium adjusts pH value to 7.0, stirs 3 hours, which decomposes, then (uses gel infiltration color by exclusion chromatography
Column series connection is composed, mobile phase is tetrahydrofuran, flow velocity 1.5mL/min, time 45min, 35 DEG C of chromatogram column temperature) obtain high-purity
L- isopulegol.Through gas chromatographic detection, the optical purity of product is 99.2%e.e., total recovery 88.5%.
Embodiment 6
By 15.4g (0.1mol) D, L- isopulegol, 15.4g (0.1mol) L- linalool, 0.006g dodecyl sulphur
Sour sodium and 180g acetonitrile are added in 500mL jacketed crystallization kettle, are heated to 80 DEG C, are stirred to react at such a temperature 4 hours.Instead
After answering, 15 DEG C are slowly cooled to, is centrifugally separating to obtain intermediate L- isopulegol L- linalool.
Above-mentioned intermediate L- isopulegol L- linalool is dissolved in 100mL water, the potassium carbonate of 0.1mol/L is added
Aqueous solution adjusts pH value to 6.8, stirs 3 hours, which decomposes, then (uses gel permeation chromatography by exclusion chromatography
Column series connection, mobile phase is tetrahydrofuran, flow velocity 2.0mL/min, time 45min, 35 DEG C of chromatogram column temperature) obtain the L- of high-purity
Isopulegol.Through gas chromatographic detection, the optical purity of product is 99.6%e.e., total recovery 80.2%.
Comparative example 1
By 15.4g (0.1mol) D, L- isopulegol, 15.0g (0.1mol) L-TARTARIC ACID and 150g ethyl acetate, add
Enter into 500mL jacketed crystallization kettle, be heated to 75 DEG C, is stirred to react at such a temperature 3 hours.After reaction, Slow cooling
To 15 DEG C, it is centrifugally separating to obtain intermediate L- isopulegol L-TARTARIC ACID.
Above-mentioned intermediate L- isopulegol L-TARTARIC ACID is dissolved in 100mL water, the bicarbonate of 0.1mol/L is added
Sodium water solution adjusts pH value to 6.9, stirs 3 hours, which decomposes, then (uses gel infiltration color by exclusion chromatography
Column series connection is composed, mobile phase is tetrahydrofuran, flow velocity 1.0mL/min, time 45min, 40 DEG C of chromatogram column temperature) obtain high-purity
L- isopulegol.Through gas chromatographic detection, the optical purity of product is 79.7%e.e., total recovery 75.2%.
Claims (10)
1. a kind of method for improving L- isopulegol optical purity by chiral resolution, comprises the following steps:
(1) D, L- isopulegol and resolving agent L- linalool react in dispersing agent and auxiliary agent, pass through centrifuge separation after cooling
Obtain intermediate L- isopulegol L- linalool；
(2) alkaline hydrolysis analysis is carried out to above-mentioned intermediate to be decomposed, then high-purity L- isopulegol is obtained by exclusion chromatography.
2. the method according to claim 1, wherein the D of step (1), L- isopulegol is complete racemic
Or partial racemization.
3. method according to claim 1 or 2, which is characterized in that the resolving agent L- linalool and the different Hu of D, L- of step (1)
The molar ratio of menthol is 0.5:1~1.2:1, preferably 0.8:1~1:1.
4. method according to any one of claim 1-3, which is characterized in that the auxiliary agent of step (1) is dodecyl sulphur
Sour sodium, with D, the mass ratio of L- isopulegol is 0.0001:1~0.0010:1.
5. method according to any of claims 1-4, which is characterized in that the dispersing agent of step (1) is ethyl alcohol, positive third
One of alcohol, isopropanol, ethyl acetate, propyl acetate, isopropyl acetate, acetonitrile and toluene are a variety of, ethyl acetate
And/or toluene；Dispersing agent and D, the mass ratio of L- isopulegol are 5:1~20:1, preferably 10:1~15:1.
6. method according to any one of claims 1-5, which is characterized in that the reaction temperature of step (1) is 70~80
DEG C, the reaction time 3~4 hours, it is cooled to 10~25 DEG C.
7. the method according to claim 1, wherein the parsing alkali of step (2) be sodium hydroxide, potassium hydroxide,
One of sodium carbonate, potassium carbonate, sodium bicarbonate and saleratus are a variety of, preferably sodium bicarbonate and/or saleratus, parsing
Alkali is added in form of an aqueous solutions.
8. method according to claim 1 or claim 7, which is characterized in that step (2) alkaline hydrolysis analysis pH adjust terminal be 6.5~
7.5。
9. according to claim 1, method described in any one of 7 or 8, which is characterized in that the exclusion chromatography of step (2) uses
Gel permeation chromatographic column series connection, mobile phase is tetrahydrofuran, 0.5~2.0mL/min of flow velocity, time 45min, chromatogram column temperature 35
~40 DEG C.
10. the L- isopulegol product of chiral separation method preparation according to claim 1 to 9, total recovery
It is 80~90.5%, optical purity is 99.0~99.9%e.e..
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110845305A (en) * | 2019-11-25 | 2020-02-28 | 安徽一帆香料有限公司 | Method for preparing L-menthol by adopting modified homogeneous catalyst |
| CN109232184B (en) * | 2018-10-08 | 2021-05-14 | 万华化学集团股份有限公司 | Method for improving optical purity of L-isopulegol through chiral resolution |
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| CN109232184B (en) * | 2018-10-08 | 2021-05-14 | 万华化学集团股份有限公司 | Method for improving optical purity of L-isopulegol through chiral resolution |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109232184B (en) * | 2018-10-08 | 2021-05-14 | 万华化学集团股份有限公司 | Method for improving optical purity of L-isopulegol through chiral resolution |
| CN110845305A (en) * | 2019-11-25 | 2020-02-28 | 安徽一帆香料有限公司 | Method for preparing L-menthol by adopting modified homogeneous catalyst |
| CN110845305B (en) * | 2019-11-25 | 2022-06-28 | 安徽一帆香料有限公司 | Method for preparing L-menthol by adopting modified homogeneous catalyst |
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