JP2023001795A - Purification method of cyclic compound - Google Patents

Abstract

To provide a purification method of a cyclic compound, which enables a high purity cyclic compound to be taken out efficiently even when the concentration of raw material is low.SOLUTION: Provided is a purification method of a cyclic compound, comprising: a preparation step of preparing a raw material liquid containing a cyclic compound before purification and water; an extraction step of adding an extraction agent to the raw material liquid to obtain an extract containing the cyclic compound and the extraction agent; and a distillation step of subjecting the extract to distillation treatment to take out the cyclic compound after purification, where the melting point of the cyclic compound is 60°C or less, the boiling point of the cyclic compound is 200°C or more, the boiling point of the extraction agent is 150°C or less, the log P of the extraction agent is 0 or more, and the Hansen solubility parameter distance, dHSP, between the extraction agent and the cyclic compound is 11 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for purifying cyclic compounds.

Cyclic compounds having specific structures are used as raw materials for various applications such as fragrances, cosmetics, pharmaceuticals, and agricultural chemicals. In these applications, the cyclic compounds must be sufficiently purified, since impurities in the raw materials affect the applications.

For example, Patent Document 1 discloses a method for purifying β-phenylethyl alcohol having an alkali washing step and an extractive distillation step.

Among these, the alkali washing step is a step of washing the crude β-phenylethyl alcohol with an alkali aqueous solution.

In the extractive distillation step, crude β-phenylethyl alcohol after alkali washing is supplied to the extractive distillation column, and a mixture of water and 1,2-propanediol is supplied to the extractive distillation column as the extraction solvent (A). , the highly volatile extraction solvent (A) and impurities are distilled from the top of the extractive distillation column, and β-phenylethyl alcohol is taken out from the bottom of the column.

Japanese Patent Application Laid-Open No. 2000-290205

The purification method described in Patent Document 1 is a method of further purifying β-phenylethyl alcohol crudely produced by various production methods such as a method of hydrogen reduction of styrene oxide.

Therefore, in the purification method described in Patent Document 1, it is assumed that crude β-phenylethyl alcohol is supplied to an extractive distillation column in a state of being concentrated to some extent. Therefore, when the concentration of β-phenylethyl alcohol in the supplied raw material is low, the purification efficiency may be low.

An object of the present invention is to provide a method for purifying a cyclic compound that can efficiently extract a highly pure cyclic compound even when the concentration of the starting material is low.

Such objects are achieved by the present invention described in (1) to (6) below.
(1) a preparation step of preparing a raw material liquid containing a cyclic compound before purification and water;
an extraction step of adding an extractant to the raw material solution to obtain an extract containing the cyclic compound and the extractant;
A distillation step of subjecting the extract to a distillation process to extract the purified cyclic compound;
has
The melting point of the cyclic compound is 60° C. or lower,
The boiling point of the cyclic compound is 200° C. or higher,
The boiling point of the extractant is 150° C. or lower,
logP of the extracting agent is 0 or more,
A method for purifying a cyclic compound, wherein the Hansen solubility parameter distance dHSP between the extractant and the cyclic compound is 11 or less.

(2) The method for purifying a cyclic compound according to (1) above, wherein the extractant has a logP of 0.20 or more.

(3) The method for purifying a cyclic compound according to (1) or (2) above, wherein the concentration of the cyclic compound in the raw material liquid is more than 0% by mass and not more than 10.0% by mass.

(4) The method for purifying a cyclic compound according to any one of (1) to (3) above, wherein the cyclic compound is an aromatic alcohol or an aromatic ester.

(5) the extraction step includes a first separation operation of separating the extractant from the raffinate;
The method for purifying a cyclic compound according to any one of (1) to (4) above, wherein the extraction step includes a first reuse operation of reusing the extractant separated in the first separation operation.

(6) the distillation step includes a second separation operation for separating the extractant from the extract;
The method for purifying a cyclic compound according to any one of (1) to (5) above, wherein the extraction step includes a second reuse operation of reusing the extractant separated in the second separation operation.

ADVANTAGE OF THE INVENTION According to this invention, even when the density|concentration of a raw material is low, a highly pure cyclic compound can be taken out efficiently.

It is a process diagram for explaining the purification method of the cyclic compound according to the embodiment. 1. It is a schematic diagram which shows an example of the refiner|purifier used for the refinement|purification method of FIG.

BEST MODE FOR CARRYING OUT THE INVENTION The method for purifying a cyclic compound of the present invention will now be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a process chart for explaining a method for purifying a cyclic compound according to an embodiment. FIG. 2 is a schematic diagram showing an example of a refining apparatus used in the refining method of FIG.

In the method for purifying a cyclic compound according to the present embodiment, a cyclic compound before purification is purified to obtain a highly pure cyclic compound. Cyclic compounds are used, for example, as raw materials for various applications such as chemical products, fragrances, cosmetics, pharmaceuticals, and agricultural chemicals. In order to realize its use, it is essential to highly purify the cyclic compound used as the raw material.

The method for purifying a cyclic compound shown in FIG. 1 includes a preparation step S102, an extraction step S106, and a distillation step S110.

Such a purification method is performed using, for example, a purification apparatus 1 shown in FIG. The refiner 1 will be described below.

1. Refining Apparatus The refining apparatus 1 shown in FIG. Note that the refining apparatus 1 shown in FIG. 2 is a continuous apparatus that performs refining treatment continuously. The method for purifying a cyclic compound according to this embodiment can also be performed using a batch-type apparatus.

The raw material liquid preparation tank 2 is a container that stores a raw material liquid 22 containing a cyclic compound before purification.
The extraction tank 4 is a container for performing liquid-liquid extraction processing in which the raw material liquid 22 is brought into contact with the extraction agent 42 to obtain the extraction liquid 44 . By this liquid-liquid extraction process, a raffinate 46 is obtained in addition to the extract 44 .

The distillation column 6 is a vessel for distilling the liquid extract 44 . This distillation process removes the regenerated extractant 42 b from the top of the distillation column 6 and removes the high boiling point impurities 64 from the bottom of the distillation column 6 . Then, the purified cyclic compound can be extracted from the middle of the distillation column 6 . In FIG. 2, the cyclic compound after purification is referred to as "purified cyclic compound 66". Although not shown, the distillation column 6 includes a reboiler provided at the bottom and a condenser provided at the top. Further, the distillation column 6 may be a single distillation column shown in FIG. 2, or may be a multi-stage distillation column (not shown).

Although the purification apparatus 1 has been described above, this purification apparatus 1 is an example of an apparatus used in the method for purifying a cyclic compound described later, and is not limited to the described configuration.

2. Purification Method Next, a purification method for the cyclic compound shown in FIG. 1 will be described.

2.1. Preparing Step In the preparing step S102 , first, the raw material liquid 22 is supplied to the raw material liquid preparation tank 2 . In the raw material liquid preparation tank 2, the supplied raw material liquid 22 is stored and the pH thereof is adjusted as necessary.

The raw material liquid 22 contains a cyclic compound before purification and water. Hereinafter, a cyclic compound before purification is referred to as an "unpurified cyclic compound".

The crude cyclic compound may be a compound derived from fossil resources, but may also be a compound derived from biomass. Biomass refers to organic resources derived from plants. Specific examples include those that have been converted into forms such as starch and cellulose and stored, the bodies of animals that grow by eating plants, and the products that are produced by processing plants and animals. By using a biomass-derived compound as the unpurified cyclic compound, the purified cyclic compound contributes to suppressing an increase in carbon dioxide. Therefore, the preparation step S102 may be a step of obtaining the raw material liquid 22 from any source, but may be a step of crudely purifying an unpurified cyclic compound from these biomass.

The cyclic compound purified in this embodiment preferably has a solubility in water at 20° C. of 100,000 mg/L or less, more preferably 50,000 mg/L or less. Since such a cyclic compound has sufficiently high hydrophobicity, it becomes difficult for the cyclic compound to mix with water in the extraction step S106 described later. As a result, the final purified cyclic compound 66 can be more reliably improved in yield and purity.

Although the concentration of the cyclic compound in the raw material liquid 22 is not particularly limited, it is preferably more than 0% by mass and 10.0% by mass or less, and more preferably 0.05% by mass or more and 5.0% by mass or less. , more preferably 0.10% by mass or more and 3.0% by mass or less. The method for purifying a cyclic compound according to the present embodiment can purify a cyclic compound with an excellent yield even when such a relatively low-concentration raw material liquid 22 is used.

Moreover, although the content of water in the raw material liquid 22 is not particularly limited, it is preferably 50% by mass or more, and more preferably 80% by mass or more. When the raw material liquid 22 contains water in such a ratio, the raw material liquid 22 containing a large amount of water can be used without being concentrated, which is useful from the viewpoint of reducing man-hours.

The cyclic compound contained in the raw material liquid 22 satisfies the following two elements (a) and (b). By targeting a cyclic compound that satisfies the elements (a) and (b), the yield and purity of the purified cyclic compound 66 can be improved even when the concentration of the cyclic compound in the raw material liquid 22 is low. As it increases, the recovery operation becomes easier.

(a) The melting point of the cyclic compound is 60°C or lower (b) The boiling point of the cyclic compound is 200°C or higher

When the cyclic compound satisfies the element (a), it becomes easier to recover the purified cyclic compound 66 recovered in the distillation step S110 as a liquid. This facilitates the recovery operation of the purified cyclic compound 66 compared to the recovery as a solid. The melting point of the cyclic compound is preferably −40° C. or higher and 50° C. or lower, more preferably −30° C. or higher and 40° C. or lower. When the melting point of the cyclic compound exceeds the upper limit, the purified cyclic compound 66 is recovered as a solid, which may complicate the recovery operation.

When the cyclic compound satisfies the element (b), the difference between the boiling point of the cyclic compound and the boiling point of the extractant 42 becomes sufficiently large. Separability is improved. This facilitates increasing the yield and purity of the recovered purified cyclic compound 66 . The boiling point of the cyclic compound is preferably 210° C. or higher and 400° C. or lower, more preferably 215° C. or higher and 300° C. or lower. If the boiling point of the cyclic compound exceeds the above upper limit, there is a risk that the ability to separate the purified cyclic compound 66 and the high-boiling impurities 64 in the distillation step S110 may deteriorate.

Examples of cyclic compounds contained in the raw material liquid 22 include aromatic alcohols, aromatic esters, aromatic aldehydes, aromatic ethers, and the like. Among these, the cyclic compounds contained in the raw material liquid 22 are preferably aromatic alcohols or aromatic esters. These are compounds that are particularly useful as raw materials for various applications.

Aromatic alcohols include, for example, benzyl alcohol, cinnamic alcohol, β-phenylethyl alcohol (phenethyl alcohol), p-anisyl alcohol, p-methylbenzyl alcohol, phenoxyethanol, 2-benzyloxyethanol, dimethylbenzyl carbinol. , phenylethyldimethylcarbinol, phenylhexanol, and the like.

Examples of aromatic esters include methyl anthranilate (methyl anthranilate), ethyl anthranilate, and dimethyl anthranilate (methyl N-methyl anthranilate).
Table 1 shows the melting points and boiling points of main cyclic compounds.

The raw material liquid 22 may be subjected to adsorption treatment as necessary. The adsorption process is a process of causing impurities in the raw material liquid 22 to be adsorbed by an adsorbent to lower the impurity concentration.

Examples of adsorbents include activated carbon, zeolite, silica gel, alumina gel, silica-alumina gel, activated clay, molecular sieves, molecular sieving carbon, and the like, and one or more of these may be used in combination. .

2.2. Extraction Step In the extraction step S106, the raw material liquid 22 is brought into contact with the extraction agent 42 in the extraction tank 4 to perform a liquid-liquid extraction process to obtain the extraction liquid 44. FIG. The liquid-liquid extraction process is a process of selectively extracting the cyclic compounds contained in the raw material liquid 22 by utilizing the difference in solubility with respect to the extractant 42 . By this liquid-liquid extraction process, the cyclic compound can be selectively transferred to the extractant 42 and the impurities can be selectively transferred to water. An extract 44 containing the cyclic compound and the extractant 42 and a raffinate 46 containing impurities and water are then obtained.

The extraction agent 42 used in the extraction step S106 satisfies the following three elements (c), (d), and (e). By using the extractant 42 that satisfies the elements (c), (d), and (e), the yield of the purified cyclic compound 66 is increased even when the concentration of the cyclic compound in the raw material liquid 22 is low. At the same time, the recovery operation becomes easier. In addition, the separation of the cyclic compound can be enhanced in the distillation step S110, and the yield and purity of the purified cyclic compound 66 can be enhanced.

(c) The boiling point of the extractant 42 is 150° C. or less (d) The logP of the extractant 42 is 0 or more (e) The Hansen solubility parameter distance dHSP between the extractant 42 and the cyclic compound is 11 or less

When the extracting agent 42 satisfies the element (c), the difference between the boiling point of the extracting agent 42 and the boiling point of the cyclic compound becomes sufficiently large. Separability is improved. This facilitates increasing the yield and purity of the recovered purified cyclic compound 66 . The boiling point of the extractant 42 is preferably 40° C. or higher and 120° C. or lower, more preferably 50° C. or higher and 100° C. or lower. If the boiling point of the extractant 42 is below the lower limit, the extractant 42 becomes difficult to handle as a liquid. When the boiling point of the extractant 42 exceeds the upper limit, the difference between the boiling point of the extractant 42 and the boiling point of the cyclic compound becomes small.

The difference (boiling point difference) between the boiling point of the extractant 42 and the boiling point of the cyclic compound is preferably 60° C. or higher and 300° C. or lower, more preferably 70° C. or higher and 200° C. or lower. If the boiling point difference exceeds the above upper limit, the boiling point of the cyclic compound becomes too high, and there is a risk that the separation of the purified cyclic compound 66 and the high boiling point impurities 64 in the distillation step S110 may be reduced.

The miscibility of the extracting agent 42 with water is lowered by satisfying the element (d). Therefore, the separation of the extracting agent 42 and water in the extraction step S106 is enhanced, and the extraction efficiency of the cyclic compound can be enhanced in the extraction step S106. As a result, the yield of purified cyclic compound 66 can be increased.

The logP of the extractant 42 refers to the octanol/water partition coefficient of the extractant 42, for example, Crippen's fragmentation method ("Ghose A.K. and Crippen G.M., Atomic physicochemical parameters for three-dimensional-structure-directed quantitative structure 2. Modeling dispersive and hydrophobic interactions., J. Chem. Inf. Comput. Sci., 27, 21-35, 1987.”).

Specific methods for measuring logP include, for example, the shaking flask method described in JIS Z 7260-107:2000. Also, logP can be estimated by a computational chemical method or an empirical method instead of the actual measurement method as described above.

Computational chemistry estimates can be made with computer software based on the structural formula of the compound. This software includes, for example, ChemDraw Ultra ver. 10.0.

The solubility of the cyclic compound in the extractant 42 can be enhanced by satisfying the element (e) in the extractant 42 . Thereby, even when the concentration of the cyclic compound in the raw material liquid 22 is low, the extraction efficiency of the cyclic compound can be increased in the extraction step S106. As a result, the yield of purified cyclic compound 66 can be increased. The Hansen solubility parameter distance dHSP between the extractant 42 and the cyclic compound is preferably 10 or less, more preferably 9 or less, and even more preferably 8 or less.

The Hansen solubility parameter distance dHSP is one index for determining the solubility of a plurality of compounds, that is, the strength of affinity between a plurality of compounds. For example, when the distance dHSP of the Hansen solubility parameter HSP between two compounds is small, the solubility between these compounds tends to be high. The HSP of a mixture of a plurality of compounds can be obtained by adding the product of the HSP of each compound contained in the mixture and the composition ratio.

For the definition and method of calculation of the Hansen Solubility Parameter HSP, see Charles M. et al. Hansen, "Hansen Solubility Parameters: A User's Handbook" (CRC Press, 2007).

The Hansen solubility parameter HSP consists of a dispersion force term (δD) corresponding to van der Waals interactions, a polar term (δP) caused by the attractive force generated by the dipole moment, and hydrogen generated by active hydrogen and lone electron pairs. and a hydrogen bonding term (δH) due to bonding. Then, the Hansen solubility parameter distance (dHSP) of the two types of compounds a and b can be calculated by the following formula (1) based on the respective solubility parameter components. In formula (1), the units of δD, δP, and δH are all (J/cm ³ ) ^1/2 .
(dHSP) ² = 4 × (δDa-δDb) ² + (δPa-δPb) ² + (δHa-δHb) ² (1)

This calculation can be performed using computer software based on the structural formula of the compound. This software includes, for example, HSPiP (Hansen Solubility Parameters in Practice) 4th Edition (4.1.07).

Examples of the extraction agent 42 used in the extraction step S106 include ethyl acetate, chloroform, methyl ethyl ketone, and organic solvents containing at least one of these.

The amount of the extractant 42 to be added is not particularly limited, but is preferably 10% by mass or more, more preferably 10 to 100% by mass, more preferably 20 to 90% by mass, relative to the raw material liquid 22. is more preferable. By setting the addition amount of the extraction agent 42 within the above range, sufficient opportunities for contact between the extraction agent 42 and the cyclic compound and between water and impurities can be obtained. As a result, it is possible to particularly increase the extraction rate of the cyclic compound, and finally, it is possible to achieve high yield and high purity of the purified cyclic compound 66 more reliably.

It should be noted that the extraction liquid 44 obtained in the extraction step S106 may be subjected to a concentration process, if necessary. The concentration process is a process of removing the extractant 42 contained in the liquid extract 44 and concentrating the cyclic compounds, for example, a process of evaporating the extractant 42 contained in the liquid extract 44 . Specific operations of the concentration treatment include, for example, heating, depressurization, gas blowing, etc., and an operation combining one or more of these is used.

Among these, the heating operation is preferably used. The heating temperature is not particularly limited as long as it is a temperature that can volatilize the extractant 42 and is lower than the boiling point of the cyclic compound, but is appropriately set according to the atmospheric pressure. For example, when the atmospheric pressure is atmospheric pressure (50 to 110 kPa), the heating temperature is preferably 70 to 100.degree. C., more preferably 80 to 100.degree. When the atmospheric pressure is less than atmospheric pressure (less than 50 kPa), the heating temperature is preferably 30 to 70.degree. C., more preferably 40 to 60.degree. It should be noted that the pressure below atmospheric pressure is preferably 20 to 50 kPa in consideration of decompression cost and the like.

The heating time is not particularly limited, but is preferably 1 to 120 minutes, more preferably 5 to 90 minutes.

Also, the extractant 42 evaporated in the concentration process may be reused in the extraction step S106. Thereby, the reduction of refining cost can be aimed at.

Note that the extraction step S106 may include a first separation operation for separating the extraction agent 42 from the raffinate 46 . The first separation operation is an operation of separating water and an extractant 42 in the extractant recovery section 8 shown in FIG. In FIG. 2, the separated extractant 42 is returned to the extraction tank 4 as a regenerated extractant 42a. That is, the extraction step S106 may include a first reuse operation of reusing the extractant 42 separated in the first separation operation.

By including such a first separation operation and a first reuse operation, in the extraction step S106, the waste amount of the extraction agent 42 can be reduced, and the running cost can be reduced.

The refining apparatus 1 shown in FIG. 2 is also configured to return the water separated in the extractant recovery unit 8 to the raw material liquid preparation tank 2 as reclaimed water 82 . With such a configuration, not only the extractant 42 but also water can be reused. Thereby, the running cost of the purification method can be further reduced.

Examples of the extraction agent recovery unit 8 include an oil-water separator using porous fibers. Moreover, the extracting agent recovery unit 8 may be provided as required, and may be omitted.

2.3. Distillation Step In the distillation step S110, the liquid extract 44 is subjected to a distillation treatment in the distillation column 6. FIG. This distillation process removes the extractant 42 from the top of the distillation column 6 and removes the high-boiling impurities 64 from the bottom of the distillation column 6 . Then, the purified cyclic compound 66 can be extracted from the middle of the distillation column 6 .

The distillation process is a process of separating the purified cyclic compound 66 by utilizing the difference in boiling points of substances. The distillation column 6 shown in FIG. 2 is configured so that the purified cyclic compounds 66 can be separated from the extractant 42 and high boiling impurities 64 so that the purified cyclic compounds 66 can be removed as a sidecut. It's becoming

The side cut position is not particularly limited as long as it is other than the top and bottom of the distillation column 6, and is appropriately set according to the boiling point of the cyclic compound and the like.

Further, the bottom temperature and the degree of pressure reduction of the distillation column 6 are appropriately set in consideration of the types and concentrations of the cyclic compound and the extractant 42 contained in the raw material liquid 22 . As an example, the column bottom temperature is preferably 100 to 250°C. The degree of pressure reduction in the column is preferably 110 kPa or less, more preferably 5 to 50 kPa in terms of absolute pressure.

Various impurities such as high-boiling impurities 64 include, for example, lactic acid, propionic acid, formic acid, acetic acid, butyric acid, benzoic acid, amino acids, fumaric acid, etc., or derivatives thereof, one or two of which are More than one species can be included.

The content ratio of impurities in the purified cyclic compound 66 is not particularly limited, but is preferably 1.0% by mass or less, more preferably 0.5% by mass or less. This makes the purified cyclic compound 66 sufficiently purified.

As described above, the method for purifying a cyclic compound according to this embodiment includes the preparation step S102, the extraction step S106, and the distillation step S110. In the preparation step S102, a raw material liquid 22 containing an unpurified cyclic compound (cyclic compound before purification) and water is prepared. In the extraction step S106, the extraction agent 42 is added to the raw material liquid 22 to obtain an extraction liquid 44 containing the cyclic compound and the extraction agent 42 . In the distillation step S110, the liquid extract 44 is subjected to a distillation process to extract the purified cyclic compound 66 (the cyclic compound after purification).

A cyclic compound to be purified by such a purification method has a melting point of 60° C. or lower and a boiling point of 200° C. or higher. The extractant 42 used in this purification method is an organic solvent having a boiling point of 150° C. or lower, a logP of 0 or higher, and a Hansen solubility parameter distance dHSP of 11 or lower with respect to the cyclic compound.

With such a configuration, the yield and purity of the purified cyclic compound 66 can be increased even when the concentration of the cyclic compound in the raw material liquid 22 is low. Moreover, since the recovery operation is facilitated, the purified cyclic compound 66 can be efficiently recovered.

The logP of the extraction agent 42 is 0 or more, preferably 0.20 or more and 8.0 or less, more preferably 0.30 or more and 3.0 or less.

This further reduces the miscibility of the extractant 42 with water. Therefore, in the extraction step S106, the separation between the extractant 42 and water is particularly enhanced, and the extraction efficiency of the cyclic compound can be particularly enhanced in the extraction step S106. The logP of the extracting agent 42 may exceed the upper limit, but in that case, the affinity between the extracting agent 42 and the cyclic compound may slightly decrease.

Note that the distillation step S110 may include a second separation operation for separating the extractant 42 from the liquid extract 44 . The second separation operation is an operation for selectively separating the extracting agent 42 from the distillation column 6 . In FIG. 2, the separated extractant 42 is returned to the extraction tank 4 as a regenerated extractant 42b. That is, the extraction step S106 may include a second reuse operation of reusing the extractant 42 separated in the second separation operation.

By including the second separation operation and the second reuse operation, the amount of waste of the extractant 42 can be reduced in the distillation step S110, and the running cost can be reduced.

The purified cyclic compound 66 taken out is, as described above, particularly useful as raw materials for chemical products, fragrances, cosmetics, pharmaceuticals, agricultural chemicals, and the like. The raw materials include intermediates.

Although the method for purifying a cyclic compound of the present invention has been described above based on the embodiments, the present invention is not limited to these.

For example, the method for purifying a cyclic compound of the present invention may be obtained by adding an optional step to the above embodiment.

Next, specific examples of the present invention will be described.
3. Production of Cyclic Compounds 3.1. Example 1
In Example 1, β-phenylethyl alcohol before purification (unpurified cyclic compound) was purified using the purification apparatus shown in FIG.

Specifically, first, a raw material liquid containing β-phenylethyl alcohol before purification and water was prepared.

Next, a liquid-liquid extraction process was carried out by contacting the raw material liquid with an extractant. An extract was thus obtained. Ethyl acetate was used as an extractant in an amount of 50% by mass based on the raw material solution.

Next, the obtained extract was subjected to a distillation treatment. As a result, impurities were removed to obtain purified β-phenylethyl alcohol. The bottom temperature of the distillation column was 195° C., and the degree of pressure reduction in the column was 30 kPa.

3.2. Examples 2-5 and Comparative Examples 1-4
A crude cyclic compound was purified in the same manner as in Example 1, except that the purification conditions were changed as shown in Table 2.

3.3. Example 6
An unpurified cyclic compound was purified in the same manner as in Example 1, except that the cyclic compound to be purified was changed to methyl anthranilate (methyl anthranilate). The purification conditions are as shown in Table 3.

3.4. Examples 7-9 and Comparative Examples 5-9
A crude cyclic compound was purified in the same manner as in Example 1, except that the purification conditions were changed as shown in Table 3.

3.5. Example 10
An unpurified cyclic compound was purified in the same manner as in Example 1, except that the cyclic compound to be purified was changed to cinnamic alcohol. The purification conditions are as shown in Table 4.

3.6. Examples 11-13 and Comparative Examples 10-14
A crude cyclic compound was purified in the same manner as in Example 1, except that the purification conditions were changed as shown in Table 4.

4. Evaluation of Cyclic Compounds 4.1. Purity of β-phenylethyl alcohol after purification Purity of β-phenylethyl alcohol after purification obtained in each example and each comparative example was measured by high performance liquid chromatography (HPLC). . The purity was defined as the ratio of the mass of β-phenylethyl alcohol to the total mass of the recovered substance. Table 2 shows the measurement results.

The measurement conditions are as follows.
<HPLC analysis conditions for β-phenylethyl alcohol>
Column: COSMOSIL 5C18-AR-II (φ4.6 mm × 250 mm) manufactured by Nacalai Tesque Mobile phase: water/methanol/perchloric acid = 4/1/0.0075 (vol/vol/vol) isocratic elution Flow rate: 1 mL/mm
Column temperature: 40°C
Detection method: photodiode array (PDA) detector

4.2. Yield of β-phenylethyl alcohol after purification Regarding β-phenylethyl alcohol after purification obtained in each example and each comparative example, 4.1. The yield of β-phenylethyl alcohol was calculated based on the purity calculated in . The yield was defined as the ratio of the mass of recovered β-phenylethyl alcohol to the mass of β-phenylethyl alcohol contained in the raw material solution. Table 2 shows the calculation results.

As is clear from Table 2, in each example, high-purity β-phenylethyl alcohol could be obtained in a higher yield than in each comparative example.

4.3. Purity of Methyl Anthranilate After Purification Purity of methyl anthranilate of the purified methyl anthranilate obtained in each example and each comparative example was measured by high performance liquid chromatography (HPLC). The measurement conditions are the same as in the case of β-phenylethyl alcohol. Table 3 shows the measurement results.

4.4. Yield of methyl anthranilate after purification Regarding methyl anthranilate after purification obtained in each example and each comparative example, 4.3. The yield of methyl anthranilate was calculated based on the purity calculated in . Table 3 shows the calculation results.

As is clear from Table 3, in each example, high-purity methyl anthranilate could be obtained in a higher yield than in each comparative example.

4.5. Purity of cinnamic alcohol after purification The purity of cinnamic alcohol after purification obtained in each example and each comparative example was measured by high performance liquid chromatography (HPLC). The measurement conditions are the same as in the case of β-phenylethyl alcohol. Table 4 shows the measurement results.

4.6. Yield of cinnamic alcohol after purification Regarding the cinnamic alcohol after purification obtained in each example and each comparative example, 4.5. The yield of cinnamic alcohol was calculated based on the purity calculated in . Table 4 shows the calculation results.

As is clear from Table 4, in each example, high-purity cinnamic alcohol could be obtained in a higher yield than in each comparative example.

From the above, it has been clarified that the present invention can efficiently purify a high-purity cyclic compound even when the concentration of the raw material, that is, the cyclic compound, in the supplied raw material liquid is low.

1 purification device 2 raw material liquid preparation tank 4 extraction tank 6 distillation column 8 extractant recovery unit 22 raw material liquid 42 extractant 42a regenerated extractant 42b regenerated extractant 44 extract 46 raffinate 64 high boiling point impurity 66 purified cyclic compound 82 Reclaimed water S102 Preparation step S106 Extraction step S110 Distillation step

Claims (6)

A preparation step of preparing a raw material liquid containing a cyclic compound before purification and water;
an extraction step of adding an extractant to the raw material solution to obtain an extract containing the cyclic compound and the extractant;
A distillation step of subjecting the extract to a distillation process to extract the purified cyclic compound;
has
The melting point of the cyclic compound is 60° C. or lower,
The boiling point of the cyclic compound is 200° C. or higher,
The boiling point of the extractant is 150° C. or lower,
logP of the extracting agent is 0 or more,
A method for purifying a cyclic compound, wherein the Hansen solubility parameter distance dHSP between the extractant and the cyclic compound is 11 or less. 2. The method for purifying a cyclic compound according to claim 1, wherein the extractant has a logP of 0.20 or more. 3. The method for purifying a cyclic compound according to claim 1, wherein the concentration of the cyclic compound in the raw material liquid is more than 0% by mass and 10.0% by mass or less. 4. The method for purifying a cyclic compound according to any one of claims 1 to 3, wherein the cyclic compound is an aromatic alcohol or an aromatic ester. The extraction step includes a first separation operation for separating the extractant from the raffinate,
5. The method for purifying a cyclic compound according to any one of claims 1 to 4, wherein the extraction step includes a first reuse operation of reusing the extractant separated in the first separation operation. The distillation step includes a second separation operation for separating the extractant from the extract,
6. The method for purifying a cyclic compound according to any one of claims 1 to 5, wherein the extraction step includes a second reuse operation of reusing the extractant separated in the second separation operation.

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