JPH11147843A - Adsorption separation method for optical isomers - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To adsorb and separate optical isomers. SOLUTION: A specific optical isomer is separated from a mixture (B) containing an optical isomer by contacting a mobile phase containing an optically active compound (A), a mixture (B) containing an adsorbent and an optical isomer. At this time, any of the optical isomers (B ′) in the mixture (B) containing the optically active compound (A) and the optical isomer
The optical isomer is adsorbed and separated using an adsorbent having an adsorption selectivity coefficient αB ′ / A of 2.0 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for adsorptive separation of optical isomers.

[0002] Optical isomers are widely used as various chemical products such as agricultural chemicals, pharmaceuticals, food additives and intermediates thereof.

Specifically, optically active amino acids, amino acid derivatives, carboxylic acids, carboxylic acid derivatives, amine-containing compounds, alcohol compounds, hydroxycarboxylic acids,
And hydroxycarboxylic acid derivatives.

[0004]

2. Description of the Related Art In the adsorption separation of optical isomers, adsorption separation using an adsorbent having an optically active source immobilized thereon is widely known. For example, as an adsorbent for adsorption and separation of optical isomers, a polysaccharide derivative (ester or carbamate, such as cellulose or amylose) or a polysaccharide derivative supported on silica gel, a cyclodextrin derivative, a cyclodextrin derivative supported on silica gel, or the like And polyacrylate derivatives, and those in which polyacrylate derivatives are supported on silica gel or the like are known. Adsorption separation of optical isomers using polysaccharide derivatives was reported by Yashima and Okamoto (Bull. Chem. Soc. Jp.
n. , 68, 3289-3307 (1995).

On the other hand, a method is also known in which an optically active compound is added to a mobile phase to adsorb and separate optical isomers. For example, a method of adsorbing and separating optical isomers using an optically active compound having a similar structure as a mobile phase is disclosed in French Patent No. 2,593,409.

[0006]

When one kind of compound is to be taken out of a mixed compound, there are various methods by the above-mentioned adsorption separation. However, to meet the need to separate mixed compounds, a method known so far is not always perfect, and a new separation method is desired.

[0007] For example, as a method for adsorptive separation of optical isomers, separation using an adsorptive separating agent in which a polysaccharide derivative or the like is supported on silica gel is generally well known. But,
These adsorptive separation agents have low mechanical strength and are difficult to use in industrial separation processes. Furthermore, these adsorbents are very expensive due to the long manufacturing process,
In addition, since only the polysaccharide derivative is supported, there is a problem that the polysaccharide derivative is eluted in long-term use. In addition, since there is no adsorptive separating agent capable of separating all of a large number of optical isomers, various new adsorptive separating agents and separation systems are being studied.

[0008] The adsorption separation method disclosed in French Patent No. 2593409 is a novel separation concept. According to this patent, it is described that good separation performance can be obtained by improving only the adsorbent without selecting an adsorbent, but this is not always the case, and there is still room for improving the adsorbent. ing.

[0009] In order to cope with such various problems, a different separation method using a novel adsorption separation system has been desired.

[0010]

Means for Solving the Problems The present inventors have made intensive studies on a method for adsorptive separation of optical isomers. As a result, a mobile phase containing an optically active compound (A), a mixture containing an adsorbent and an optical isomer (B) ) Is contacted to separate a specific optical isomer from the mixture (B) containing the optical isomer, and any one of the optical isomers in the mixture (B) containing the optically active compound (A) and the optical isomer is separated. Adsorption selection coefficient αB '/ A between body (B')
It has been found that the use of an adsorbent having a value of 2.0 or more allows efficient adsorption and separation of optical isomers.

That is, the present invention provides an optically active compound (A)
When a specific optical isomer is separated from the mixture (B) containing the optical isomer by contacting the mixture (B) containing the mobile phase containing the adsorbent and the optical isomer with the optically active compound (A), Adsorption of optical isomers, characterized by using an adsorbent having an adsorption selectivity αB ′ / A of 2.0 or more between any of the optical isomers (B ′) in the mixture (B) containing the optical isomers It relates to a separation method.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the text, the term “optical isomer” refers to a mixture of a plurality of optically active compounds, and the term “optically active compound” refers to one optically active compound.

The optically active compound (A) in the mobile phase in the present invention is preferably an amino acid, an optically active amine, an optically active carboxylic acid, an optically active hydroxycarboxylic acid, an optically active hydrocarbon, an optically active alcohol or a derivative thereof. Optically active alcohols, optically active amines, optically active carboxylic acids or derivatives thereof are more preferred. In particular, natural optically active compounds such as l-menthol, polysaccharides and cyclodextrins and derivatives thereof are preferred. These optically active compounds interact with the optical isomer to be separated in the mobile phase. The higher the optical purity of these optically active compounds, the better. However, even if the optical purity is low, the effect of the present invention is exhibited, so there is no problem. Preferably 30% ee
(Enatiomer excess) or more, more preferably 50% e
e or more and 90% ee or more is particularly preferable. The solvent is not particularly limited but is preferably a solvent capable of sufficiently dissolving the optically active compound, such as water, alcohols such as methanol and ethanol, aromatic compounds such as benzene and toluene, and n.
-Various substances such as aliphatic hydrocarbons such as hexane and petroleum ether can be used. The higher the concentration of the optically active compound contained in the mobile phase, the better the discrimination ability for the separation target is. Preferred concentration is 1% by weight
As described above, the content is more preferably 5% by weight or more, further preferably 10% by weight or more, and particularly preferably 40% by weight or more.

In the present invention, the characteristics of the adsorbent are represented by the following adsorption selectivity coefficient αB '/ A.

ΑB ′ / A = (adsorption phase B ′ / adsorption phase A) /
(Liquid phase B ′ / Liquid phase A) Here, A and B ′ are each an optical isomer (B ′) in a mixture containing an optically active compound (A) and an optical isomer.
Is shown. The adsorption selection coefficient αB ′ / A can be easily calculated by analyzing the concentration of each component in the liquid phase by liquid chromatography or gas chromatography. The density change is preferably determined by the internal standard method. Preferred examples of the internal standard include n-nonane.When the mobile phase is water-soluble or a polar solvent does not dissolve n-nonane, a non-adsorbed component is appropriately selected and the internal standard is used. There is a need to.

When αB ′ / A is larger than 1, the component (B ′) is adsorbed, and when αB ′ / A is smaller than 1, the component (A) is adsorbed. Further, as this value is larger than 1 (or smaller than 1 and closer to 0), the concentration difference between (A) and (B ′) between the inside of the adsorbent and the outside of the adsorbent becomes large.

In the present invention, as a result of intensive studies focusing on the adsorption characteristics between the optically active compound (A) in the mobile phase and the optical isomer to be separated, the optically active compound (A) was found to be an optical isomer ( B ′) is hardly adsorbed inside the adsorbent, and the optically active compound (A) strongly interacts only with a specific optical isomer among the optical isomers (B) outside the adsorbent. It has been found that the adsorption selection coefficient αB ′ / A increases. In the present invention, the adsorption selection coefficient αB '/ A is
It is preferably 2.0 or more, more preferably 5.0 or more, and particularly preferably 10.0 or more.

The degree of adsorption in the present invention is an index of the amount of the optically active compound adsorbed on the adsorbent, and can be determined by the following measuring method. The adsorbent and the mobile phase solvent are placed in a closed bottle, and an optically active compound (a substance having a low solubility up to a saturated amount) and a substance to be separated are added and stirred. After allowing to stand at room temperature for 4 hours, the supernatant is removed and the concentration is analyzed. The concentration of the optically active compound before and after adsorption can be easily analyzed by using an analytical method such as gas chromatography or liquid chromatography.

Here, the degree of adsorption is

(Equation 1) Is defined by The adsorption degree is preferably 0.03 or less, more preferably 0.00 or less, that is, a negative value. As can be seen from the above equation, the degree of adsorption is an index of whether the concentration of the optically active compound has increased or decreased with respect to the initial stage.
When the optically active compound is adsorbed by the adsorbent, the concentration of the optically active compound after the adsorption becomes lower than the concentration of the optically active compound before the adsorption, so that the degree of adsorption takes a positive value. If the optically active compound is not easily adsorbed by the adsorbent, the concentration of the optically active compound after the adsorption becomes relatively higher than the concentration of the optically active compound before the adsorption. Become. In the present invention, since it is preferable that the optically active compound is not adsorbed, the adsorption degree is 0.03 or less,
Further, it is preferable that the value be a negative value.

By using an optically active compound which satisfies such an adsorption degree as an additive component, the optically active compound for identifying an optical isomer is present in a mobile phase sufficiently unevenly, and the separation ability is improved. become.

The porous adsorbent in the present invention may be an organic or inorganic substance as long as it is a porous composition.

Examples of the organic substance include polymer compositions such as polystyrene, polyacrylamide, and polyacrylate.

As the inorganic substance, silica, alumina,
Examples include magnesia, titanium oxide, silicate, diatomaceous earth, aluminosilicate, layered compound, zeolite, activated carbon, graphite, and the like. As the porous adsorbent in the present invention, a porous adsorbent composed of an inorganic substance is preferable, and a composition such as silica, alumina, and silica alumina having uniform mesopores and micropores, and zeolite are particularly preferable.

The porous adsorbent of the present invention preferably has a pore diameter peak or an average pore diameter of 500 ° or less by analyzing adsorption isotherm data obtained by measurement by a nitrogen adsorption method. If the above condition is satisfied, the adsorption / separation performance will be improved, and thus the adsorbent will be a preferable adsorbent. In particular, those having a uniform pore diameter peak are more preferable. In addition, the pore diameter peak and the average pore diameter in the present invention can be calculated by obtaining the pore distribution by using the Dollimore & Heal method. Regarding the method of obtaining the pore distribution using the Dollimore & Heal method based on the nitrogen adsorption method, see "Adsorption Chemistry" (Seiichi Kondo,
Tatsuo Ishikawa and Ikuo Abe, Maruzen Co., Ltd. (1991)).

The preferred particle size of these porous adsorbents is 5
~ 500 mesh, more preferably 10 ~ 250
The mesh is preferably 10 to 100 mesh.

The zeolite in the present invention is what is called a molecular sieve, and is a crystalline inorganic porous material having a three-dimensionally regular space. Generally, zeolite refers to crystalline aluminosilicates such as faujasite-type zeolite, β-type zeolite, mordenite-type zeolite, pentasil-type zeolite, crystalline aluminophosphate, silica aluminophosphate, and the like. For these zeolites in the present invention,
ALTAS OF ZEOLITE Structur
E TYPES (WM Meier, DH Ols)
on, Butterworths, 1987).

In the zeolite of the present invention, the number of open ring oxygen atoms in the pores is preferably at least 10 atoms, particularly preferably at least 12 atoms so that the space formed three-dimensionally is used efficiently. preferable. The open ring oxygen number of zeolite refers to the number of oxygen atoms in the skeleton portion that forms pores through which molecules can pass in the zeolite skeleton. In addition, regarding the number of open ring oxygen, ALTAS OF ZEOLI
TE STRUCTURE TYPES (WM Me
ier, D.E. H. Olson, Butterworth
hs, 1987). When the zeolite is a crystalline aluminosilicate, the silica / alumina ratio is preferably 2 or more. This is because ordinary aluminosilicates have difficulty in forming sufficiently large pores when the silica / alumina ratio is small. Particularly, the zeolite used in the present invention is preferably faujasite-type zeolite, β-type zeolite and pentasil-type zeolite, more preferably faujasite-type zeolite and β-type zeolite, and faujasite-type zeolite Y and faujasite-type zeolite X. Is particularly preferred. In industrial use, zeolite is usually preferably used after being molded using a binder such as silica, alumina or benton. In the present invention, a molded zeolite or a powdered zeolite may be used, but a molded zeolite is particularly preferable. The preferred particle size of the molded product is 5 to 500 mesh, more preferably 10 to 250 mesh, and particularly preferably 10 to 100 mesh.

The optical isomer to be separated is preferably an amino acid, an optically active amine, an optically active carboxylic acid, an optically active hydroxycarboxylic acid, an optically active hydrocarbon, an optically active alcohol or a derivative thereof. Active carboxylic acids or derivatives thereof are more preferred, and optically active carboxylic acids or derivatives thereof are particularly preferred. Further, the method of the present invention has two or more optically active sites and can be used for separating a specific isomer from a mixture containing not only optical isomers but also geometric isomers.

The technique for adsorption separation using the method of the present invention is preferably a batch method by a so-called chromatography method, or an adsorption separation method by a moving bed or a simulated moving bed which is a continuous method. In particular, a continuous adsorption separation technique using a simulated moving bed is preferable as an industrial process. As the basic operation of the adsorption separation by the simulated moving bed system, the following adsorption operation, concentration operation and desorption operation are continuously circulated and performed.

(1) Adsorption operation: The optical isomer to be separated comes into contact with the adsorption / separation agent, and the strongly adsorbed component is adsorbed while selectively leaving the weakly adsorbed component. The strongly adsorbed component is recovered together with a mobile phase containing an optically active substance as an extract component.

(2) Concentration operation: The raffinate containing a large amount of weakly adsorbed components is further brought into contact with an adsorbent, and the strongly adsorbed components are selectively adsorbed, so that the weakly adsorbed components in the raffinate are highly purified.

(3) Desorption operation: The highly purified weakly adsorbed component is recovered as a raffinate, while the strongly adsorbed component is expelled from the adsorbent by the mobile phase containing the optically active compound, and becomes an extract component with the desorbent. Collected.

In this method, the components obtained from the extract can be highly purified. Further, the undesired isomer can be recovered, then isomerized and returned as an adsorbed separated product (mixture to be separated).

[0035]

Next, the effects of the present invention will be described with reference to examples.

In the present invention, the characteristics of the adsorbent are represented by the following adsorption selection coefficient αB / A.

ΑB / A = (adsorption phase B / adsorption phase A) / (liquid phase B / liquid phase A) where A and B indicate the concentration of each component. The adsorption selectivity can be easily calculated by analyzing the concentration of each component in the liquid phase by liquid chromatography or gas chromatography.

When αB / A is larger than 1, the component B is adsorbed, and when αB / A is smaller than 1, the component A is adsorbed. Also, as this value is larger than 1 (or smaller than 1 and closer to 0), the concentration difference between A and B inside the adsorbent and outside the adsorbent becomes larger.

The evaluation results of the batch system in this example were measured under static conditions, but it is considered that the adsorptive separation ability obtained by another evaluation method such as the flow system is substantially evaluated. be able to. In other words, a product obtained by adsorption selectivity under static conditions can find a large difference depending on the flow system. For this reason, what obtained the difference under static conditions can be separated by the chromatography method by a substantially batch system or a moving bed system.

(Preparation of Optically Active Compound) l-menthol-2-chloropropionate 30.0 g of l-menthol (manufactured by Aldrich) was placed in a 300 ml three-necked flask equipped with a thermometer and a dropping funnel.
16.0 g of pyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) and 80 ml of dichloromethane were added, and the mixture was stirred while cooling with ice water.
Chloropropionic acid chloride (Tokyo Kasei) 25.0
g was added dropwise over 40 minutes. After the dropwise addition, the product was poured into ice water and extracted with dichloromethane. Further, the extract was washed with diluted hydrochloric acid, water, an aqueous solution of sodium hydrogen carbonate and water in that order, and dried over anhydrous sodium sulfate. After evaporating the solvent under reduced pressure, the residue was purified by distillation under reduced pressure (74 ° C./1 mmHg) to obtain 1-menthol-2-chloropropionate.

2. l-Menthol methyl ether A 300 ml three-necked flask equipped with a dropping funnel and a Dimroth condenser was heated and dried, then replaced with nitrogen, 9.20 g of oily 60% sodium hydride (Tokyo Kasei Co., Ltd.) and dried n-hexane About 10 ml was added, and the oil was removed.
After drying, THF (dry overnight with molecular sieve 3A) 5
0 ml was added, the mixture was stirred, and kept at 45 to 50 ° C., and 38.31 g of methyl iodide (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. A solution of 28.13 g of l-menthol (manufactured by Aldrich) in 100 ml of THF was added dropwise over 90 minutes, and the mixture was further stirred for 40 minutes. After cooling, a small amount of ethanol was added to crush the remaining sodium hydride, and water was added. After liquid separation of the organic phase, the aqueous phase was extracted with ether. These organic phases were washed with saturated saline, dried over anhydrous sodium sulfate, the solvent was distilled off, and the residue was purified by distillation under reduced pressure (102 ° C / 35 mmHg) to obtain 1-menthol methyl ether.

3. (S) -N, N-dimethyl-α-phenylethylamine 500 equipped with a dropping funnel, a thermometer and a Dimroth condenser
Formic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 116.2
g, and 60.6 g of (S) -α-phenylethylamine (98% ee, manufactured by Yamakawa Chemical Co., Ltd.) was added dropwise with stirring over 20 minutes. To this, 128.6 g of a 35% formaldehyde solution was added over 10 minutes and heated for 4 hours. After the reaction, 57.4 g of concentrated HCl was added to form a hydrochloride, and water and formic acid were distilled off under reduced pressure. After adding 50 ml of water, 160 g of a 25% aqueous NaOH solution was added, and the organic phase was separated by a separating funnel. After KOH was added to dry the organic phase, distillation under reduced pressure (67 ° C./10 mmHg) was performed to obtain the desired product.

(Preparation of Adsorbent) K ion exchange type Y zeolite (KY) KY is NaY (manufactured by Tosoh Corporation, silica / alumina = 4.8 (mo
l / mol)) by ion exchange. The preparation method used was one that was ion-exchanged five times with a saturated aqueous solution of potassium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) in an amount 10 times the weight of NaY, and then washed with water.

2. K ion exchange type X zeolite (KX) KX is NaX (manufactured by Tosoh Corporation, silica / alumina = 2.5
(Mol / mol)) by ion exchange. The preparation method used was one that was ion-exchanged five times with a saturated aqueous solution of potassium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) in an amount 10 times the weight of NaY, and then washed with water.

3. Ba ion exchange type X zeolite (Ba
X) BaX was prepared in the same manner as above, except that potassium nitrate was changed to barium nitrate.

4. Ca ion exchange type X zeolite (Ca
X) CaX was prepared in the same manner as described above, except that potassium nitrate was changed to calcium nitrate.

5. Cu ion exchange type Y zeolite (Cu
Y) CuY was prepared in the same manner as in the preparation of KY, except that potassium nitrate was changed to copper nitrate.

6 Ba ion exchange type Y zeolite (Ba
Y) BaY was prepared in the same manner as in the preparation of KY, except that potassium nitrate was changed to barium nitrate.

7. Naβ β-type zeolite Naβ was prepared as follows. P
After sintering CP-806β25 (silica / alumina = 25 (mol / mol)) manufactured by Q Corporation at 500 ° C. for 2 hours, 10 g was weighed and added to 100 ml of an aqueous saturated sodium chloride solution. After keeping it at 80 ° C for 1 hour,
The aqueous sodium chloride solution was removed by filtration. After performing ion exchange five times by this operation, washing was performed three times and dried at 120 ° C. to obtain Naβ.

8. Na pentasil type zeolite Na pentasil type zeolite was prepared as follows. After calcining the pentasil-type zeolite for 2 hours at 500 ° C., 10 g was weighed and added to 100 ml of a saturated aqueous sodium chloride solution. After keeping the temperature at 80 ° C. for 1 hour, the aqueous sodium chloride solution was removed by filtration. After performing ion exchange five times by this operation, washing was performed three times and drying was performed at 120 ° C.

9. ALPO ₄ -5 ALPO ₄ -5 is, Handbook of Mole
Culcular Sieves (R. Szostak, V
AN NOSTRAND REINHOLD, 198
It was prepared by the synthesis method described in 4).

10. Na mordenite zeolite Na mordenite zeolite was prepared as follows. Mordenite-type zeolites are available in Handbook
of Molecular Sieves (R. Sz
ostak, VAN NOSTRAND REINH
OLD, 1984). After calcining the mordenite-type zeolite at 500 ° C. for 2 hours, 10 g was weighed and added to 100 ml of an aqueous saturated sodium chloride solution. After keeping the temperature at 80 ° C. for 1 hour, the aqueous sodium chloride solution was removed by filtration. After performing ion exchange by this operation 5 times, washing with water 3 times is performed.
It was dried at 0 ° C. to obtain a Na mordenite zeolite.

(Evaluation of Adsorption Separation Performance) Example 1 l-menthol-2-chloropropionate: n
-Nonane (manufactured by Nacalai Tesque): RS-methyl chloropropionate (manufactured by Tokyo Kasei) = 75.78: 10.2
A solution having a composition of 9: 16.06 (weight ratio) was prepared.
0 g was weighed and placed in a conical flask with a file. 1.0 g of NaY (silica / alumina = 4.8 (mol / mol), manufactured by Tosoh Corporation) calcined at 500 ° C. for 2 hours was weighed and added thereto. After leaving for 1 hour at room temperature, the mixture was stirred well and left for another 3 hours. Thereafter, the supernatant was collected and subjected to component analysis by gas chromatography using a Chiraldex B-TA capillary column (manufactured by ASTEC). The adsorption selection coefficient was calculated by regarding n-nonane as an internal standard component. From the analysis results, the adsorption selectivity coefficients αR / S, αR / CH (R and S
Represents methyl R-chloropropionate and methyl S-chloropropionate, and CH represents an optically active compound l-menthol-2-chloropropionate), and the degree of adsorption was calculated. Table 1 shows the obtained results.

This example shows that when αR / CH is 2 or more and the degree of adsorption is 0.03 or less, adsorption selectivity (αR / S) is developed.

Example 2 In the same manner as in Example 1, NaY was changed to KY, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained.
Table 1 shows the obtained results.

Example 3 In the same manner as in Example 1, NaY was converted to NaX (manufactured by Tosoh Corporation;
(Silica / alumina = 2.5 (mol / mol)) and the adsorptive separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 4 In the same manner as in Example 1, NaY was changed to KX, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained.
Table 1 shows the obtained results.

Example 5 In the same manner as in Example 1, NaY was changed to BaX, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 6 In the same manner as in Example 1, NaY was changed to CaX, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 7 In the same manner as in Example 1, NaY was changed to Naβ, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 8 In the same manner as in Example 1, NaY was changed to Na pentasil type zeolite, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 9 In the same manner as in Example 1, NaY was changed to Na mordenite-type zeolite, and the adsorptive separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 10 In the same manner as in Example 1, NaY was changed to BaY, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 11 In the same manner as in Example 1, NaY was changed to CuY, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Example 12 1-menthol methyl ether: n-nonane (manufactured by Nacalai Tesque): methyl RS-chloropropionate (manufactured by Tokyo Kasei) = 71.79: 12.01: 18.76 (weight ratio) Was prepared, 1.7 g was weighed and placed in a conical flask with a file. There, NaY calcined at 500 ° C. for 2 hours (manufactured by Tosoh Corporation, silica / alumina = 4.8)
(mol / mol)) and weighed 1.0 g. After leaving for 1 hour at room temperature, the mixture was stirred well and left for another 3 hours. Thereafter, the supernatant was collected and subjected to component analysis by gas chromatography using a Chiraldex B-TA capillary column (manufactured by ASTEC). The adsorption selection coefficient is n
-Calculated by considering nonane as an internal standard component. From the analysis results, the adsorption selectivity coefficients αR / S and αR / CH (R and S are methyl R-chloropropionate and methyl S-chloropropionate respectively, and CH is the optically active compound l-menthol-2-chloropropionic acid) And the degree of adsorption was calculated. Table 1 shows the obtained results.

This example shows that when αR / CH is 2 or more and the degree of adsorption takes a negative value, the adsorption selectivity (αR / S) is developed.

Example 13 In the same manner as in Example 12, NaY was changed to KY, and the adsorption separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Example 14 In the same manner as in Example 12, NaY was changed to BaX, and the adsorption separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Example 15 In the same manner as in Example 12, NaY was changed to CaX, and the adsorption separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Example 16 In the same manner as in Example 12, except that NaY was changed to ALPO ₄ -5, the adsorption separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Example 17 In the same manner as in Example 12, NaY was changed to BaY, and the adsorption separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Example 18 In the same manner as in Example 12, NaY was changed to CuY, and the adsorptive separation ability was evaluated. The same results as in Example 12 were obtained. Table 1 shows the obtained results.

Comparative Example 1 (S) -N, N-dimethyl-α-phenylethylamine: n-nonane (manufactured by Nacalai Tesque): methyl RS-chloropropionate (manufactured by Tokyo Chemical Industry) = 56.98: 2
A solution having a composition of 4.20: 28.52 (weight ratio) was prepared, 1.7 g was weighed and placed in a conical flask with a file. 1.0 g of NaY (silica / alumina = 4.8 (mol / mol), manufactured by Tosoh Corporation) calcined at 500 ° C. for 2 hours was weighed and added thereto. After leaving for 1 hour at room temperature, the mixture was stirred well and left for another 3 hours. Thereafter, the supernatant was collected and subjected to component analysis by gas chromatography using a Chiraldex B-TA capillary column (manufactured by ASTEC). The adsorption selection coefficient was calculated by regarding n-nonane as an internal standard component. From the analysis results, the adsorption selectivity coefficient αR / S, αR / CH
(R and S are each methyl R-chloropropionate,
CH represents methyl S-chloropropionate and CH represents an optically active compound l-menthol-2-chloropropionate. ) And the degree of adsorption was calculated. Table 1 shows the obtained results.

From this comparative example, it can be seen that when αR / CH is 2 or less and the degree of adsorption is 0.03 or more, the adsorption selectivity (αR / S) does not appear.

Comparative Example 2 In the same manner as in Comparative Example 1, NaY was changed to NaX, and the adsorption separation ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

Comparative Example 3 In the same manner as in Comparative Example 1, NaY was changed to KX, and the adsorptive separation ability was evaluated. The same results as in Example 1 were obtained.
Table 1 shows the obtained results.

Comparative Example 4 In the same manner as in Comparative Example 1, NaY was changed to BaX, and the adsorbing and separating ability was evaluated. The same results as in Example 1 were obtained. Table 1 shows the obtained results.

[0078]

[Table 1]

[0079]

The mobile phase containing the optically active compound (A), the adsorbent and the mixture (B) containing the optical isomer are brought into contact with each other to separate the specific optical isomer from the mixture (B) containing the optical isomer. In this case, any of the optical isomers (B ′) in the mixture (B) containing the optically active compound (A) and the optical isomer
By using an adsorbent having an adsorption selectivity αB '/ A of 2.0 or more, the optical isomers could be efficiently adsorbed and separated.

Claims (7)

[Claims] 1. A specific optical isomer is separated from a mixture (B) containing an optical isomer by contacting a mixture (B) containing a mobile phase containing an optically active compound (A), an adsorbent and an optical isomer. In this case, any of the optical isomers (B ′) in the mixture (B) containing the optically active compound (A) and the optical isomer
A method for adsorbing and separating optical isomers, wherein an adsorbent having an adsorption selection coefficient αB ′ / A of 2.0 or more is used. 2. A specific optical isomer is separated from a mixture (B) containing an optical isomer by contacting a mixture (B) containing a mobile phase containing an optically active compound (A), an adsorbent and an optical isomer. A method for adsorbing and separating optical isomers, wherein an adsorbent having an adsorption degree of the optically active compound (A) to the adsorbent of 0.03 or less is used. 3. A specific optical isomer is separated from the mixture (B) containing the optical isomer by contacting the mobile phase containing the optically active compound (A), the adsorbent and the mixture (B) containing the optical isomer. In this case, any of the optical isomers (B ′) in the mixture (B) containing the optically active compound (A) and the optical isomer
Using an adsorbent having an adsorption selectivity αB ′ / A of at least 2.0 and an adsorbent of the optically active compound (A) to the adsorbent of at most 0.03. . 4. The method for adsorbing and separating optical isomers according to claim 1, wherein the adsorbent is a porous adsorbent. 5. The method of claim 1, wherein the optical isomer to be separated is a nitrogen-containing compound, a carboxylic acid or a derivative thereof. 6. An optically active compound (A) contained in a mobile phase.
6. The method for adsorptive separation of optical isomers according to claim 1, wherein the concentration of the isomer is 5% by weight or more. 7. The adsorption / separation method for optical isomers according to claim 1, wherein the adsorption / separation method is a batch system, a moving bed system or a simulated moving bed system.