JPH0475216B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a separating agent, and particularly to a separating agent containing a heteroaromatic derivative of a polysaccharide as an active ingredient. [Industrial Application Field] The separating agent of the present invention can be used for the separation of all chemical substances, especially for optical resolution. As is well known, optical isomers of the same chemical compound usually have different effects on living organisms. Therefore, in fields such as medicine, agrochemicals, and biochemistry-related industries, improvements in medicinal efficacy per unit,
The preparation of optically pure compounds has become an extremely important issue for the purpose of preventing side effects and drug damage. Conventionally, preferential crystallization methods and diastereomer methods have been used to separate optically isomeric mixtures, that is, optically resolve them, but these methods limit the types of compounds that can be optically resolved, and also require long It often takes time and a lot of effort. Therefore, there is a strong need for a technique for easily performing optical resolution using chromatography. [Prior Art] Research on optical resolution using chromatography has been conducted for some time. However, conventionally developed separation agents have problems such as poor separation efficiency and the need for special functional groups in the target compound.
There are also various problems such as poor stability of the separating agent, making it difficult to perform satisfactory optical resolution on all compounds. [Purpose of the invention] Therefore, it is possible to develop a separating agent that has a chemical structure different from existing separating agents, and thereby has different separating properties or has a higher optical isomer discrimination ability. It is an object of the present invention to provide. In particular, we aim to link the physical and chemical properties of heteroatoms (nitrogen, oxygen, sulfur, etc.) possessed by heteroaromatic rings to new separation properties. [Structure of the Invention] The present invention achieves the above object with a separation agent containing a heteroaromatic derivative of cellulose as an active ingredient. The separating agent of the present invention preferably exhibits different adsorption powers for optical isomers of some compound. (Polysaccharide) The polysaccharide in the present invention may be any optically active polysaccharide, regardless of whether it is a synthetic polysaccharide, a natural polysaccharide, or a modified natural polysaccharide, but preferably one with a highly regular bonding pattern. . Examples include β-1,4-glucan (cellulose), α-1,
4-glucan (amylose, amylopectin),
α-1,6-glucan (dextran), β-1,
6-glucan (pustulan), β-1,3-glucan (e.g. curdlan, schizophyllan, etc.), α
-1,3-glucan, β-1,2-glucan (Crown Gall polysaccharide), β-1,4-galactan,
β-1,4-mannan, α-1,6-mannan,
β-1,2-fructan (inulin), β-2,
6-fructan (levan), β-1,4-xylan, β-1,3-xylan, β-1,4-chitosan, β-1,4-N-acetyl chitosan (chitin), bullulan, agarose, alginic acid etc., and more preferably cellulose, amylose, β-1,4, from which highly purified polysaccharides can be easily obtained.
-Chitosan, chitin, β-1,4-mannan, β
-1,4-xylan, inulin, curdlan, etc. The number average degree of polymerization (average number of pyranose or furanose rings contained in one molecule) of these polysaccharides is 5 or more, preferably 10 or more, and although there is no upper limit, it is preferably 500 or less for ease of handling. . The heteroaromatic derivative of the present invention has 3 to 20 carbon atoms.
An ester of a polysaccharide with a carboxylic acid or carbamic acid having a heteroaromatic group or a substituted heteroaromatic group, preferably an acyl group, a carbamoyl group, or a heteroaromatic substituted alkyl group represented by the following formula, More preferred are an acyl group and a carbamoyl group.

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【formula】 In the above formula, X is

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[Formula] or -C _o H _2o -, where n is an integer from 0 to 5, preferably from 0 to 1
It is. Furthermore, the heteroaromatic ring of the above formula may be substituted with an alkyl group, nitro group, halogen, amino group, alkyl-substituted amino group, cyano group, hydroxyl group, or carboxyl group. In this derivative, an average of 30 to 100%, preferably 85 to 100%, of the hydroxyl groups of the corresponding polysaccharide is the above-mentioned ester. Hydroxyl groups that do not fall under this category may exist as free hydroxyl groups, but
It may be esterified, etherified, or carbamated as long as the separating ability of the separating agent is not lost. (Synthesis method) The esterification method for obtaining the polysaccharide derivative used in the present invention can be carried out in accordance with the conventionally known method used for cellulose, amylose, etc. (See page 124 of “Natural Polymer Chemistry I”). Common esterifying agents are acid halides of the corresponding carboxylic acids, the most common of which are acid chlorides. Any reaction solvent may be used as long as it does not inhibit the esterification reaction, such as pyridine or quinoline. often 4-
Catalysts such as (N,N-dimethylamino)pyridine are effective in accelerating the reaction. It can also be obtained by reacting a corresponding carboxylic acid anhydride or a carboxylic acid with a suitable dehydrating agent on a polysaccharide. The polysaccharide used as a raw material for the reaction often has poor reactivity, and in such cases it is recommended to activate it by dissolving and reprecipitating, dissolving and freeze-drying, or selecting a reaction solvent that dissolves the polysaccharide. . (How to use) In order to use the separation agent of the present invention for the purpose of separating compounds and their optical isomers, chromatography methods such as gas chromatography, liquid chromatography, and thin layer chromatography may be used. is common, but membrane separation can also be performed. In order to apply the separation agent of the present invention to liquid chromatography, there are methods such as filling a column as a powder, coating a capillary column, forming a capillary with the separation agent, and utilizing the inner wall of the separation agent. Methods include spinning the fibers and bundling them into columns, but it is common to form them into powder. In order to make the separating agent into powder, it is preferable to crush it or form it into beads. The size of the powder varies depending on the size of the column and plate used, but is 1 μm to 10 mm, preferably 1 μm to 300 μm.
The particles are preferably porous. Further, in order to improve the pressure resistance of the separating agent, prevent swelling and shrinkage due to solvent substitution, and improve the number of theoretical plates, it is preferable to hold the separating agent on a carrier. The appropriate size of the carrier varies depending on the size of the column or plate used, but is generally 1 μm to 10 mm, preferably 1 μm to 300 μm. The carrier is preferably porous, with an average pore size of 10 Å to 100 μm, preferably 50 Å to 50,000 Å. The amount of the separating agent to be retained is 1 to 100% by weight based on the carrier;
Preferably it is 5 to 50% by weight. The separating agent may be retained on the carrier by either a chemical method or a physical method. As a physical method,
A method in which the separating agent is dissolved in a soluble solvent, mixed well with the carrier, and the solvent is distilled off by air flow under reduced pressure or heating, or after the separating agent is dissolved in a soluble solvent and mixed well with the carrier. Another method is to disperse the solvent by stirring and dispersing it in a liquid that is incompatible with the solvent. When crystallizing the separation agent held on the carrier in this manner, a treatment such as heat treatment can be performed. Furthermore, by adding a small amount of solvent to once swell or dissolve the separating agent, and then distilling off the solvent again, it is possible to change the retention state and thus the separating ability. The carrier may be a porous organic carrier or a porous inorganic carrier, preferably a porous inorganic carrier. Suitable porous organic carriers include polymeric substances such as polystyrene, polyacrylamide, polyacrylate, and the like. Suitable porous inorganic carriers include synthetic or natural materials such as silica, alumina, magnesia, titanium oxide, glass, silicates, and kaolin, which may be surface-treated to improve compatibility with the separation agent. You may also do this. Examples of surface treatment methods include silanization using an organic silane compound and surface treatment using plasma polymerization. The developing solvent for liquid chromatography or thin layer chromatography is not particularly limited, except for a liquid that dissolves or reacts with the separating agent. When the separation agent is bonded to a carrier by a chemical method or made insolubilized by crosslinking, there are no restrictions except for the reactive liquid. Needless to say,
Since the separation characteristics of chemical substances or optical isomers change depending on the developing solvent, it is desirable to consider various developing solvents. On the other hand, when performing thin layer chromatography,
The separating agent consists of particles of about 0.1 μm to 0.1 mm, and if necessary, a small amount of binder, with a thickness of 0.1 to 100 mm.
layer may be formed on the support plate. When performing membrane separation, a hollow system or film is used. (Effects of the Invention) The separating agent containing the polysaccharide heteroaromatic derivative of the present invention as an active ingredient is effective in separating various compounds,
In particular, it is extremely effective in separating optical isomers, which are conventionally very difficult to separate. One of the optical isomers to be separated is more strongly adsorbed by the separating agent. EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. Synthesis example 1 Silica beads (LiChrospher manufactured by Merck)
Put 10g of SI1000) into a 200ml round-bottomed flask with branches,
After vacuum drying in an oil bath at 120°C for 3 hours, N ₂ was added. 100 ml of toluene distilled with CaH ₂ was added to the silica beads. Next, 3 ml of diphenyldimethoxysilane (Shin-Etsu Chemical KBM202) was added, stirred, and reacted at 120°C for 1 hour. 3 to 5 more
After distilling off ml of toluene, the mixture was reacted at 120°C for 2 hours.
Pass through a glass filter and add 50ml of toluene.
The mixture was washed three times with 50 ml of methanol and vacuum dried at 40° C. for 1 hour. Next, about 10 g of the silica beads were placed in a 200 ml round-bottomed flask, and after vacuum drying at 100°C for 3 hours,
After returning to normal pressure and reaching room temperature, N ₂ was added. 100ml of distilled toluene was added to the dried silica beads. Next, the trimethylsilylating agent N,O-Bis-
1 ml of (trimethylsilyl)acetamide was added, stirred, and reacted at 115°C for 3 hours. Next, after passing through a glass filter and washing with toluene,
Vacuum dried for hours. Synthesis Example 2 Cellulose triacetate (manufactured by Daicel Chemical Industries, Ltd.) with a number average degree of polymerization of 110 and a degree of substitution of 2.97 was dissolved in 1 part acetic acid (manufactured by Kanto Chemical), 5.2 ml of water and 5 ml of concentrated sulfuric acid were added, and the mixture was heated at 80°C for 30 minutes. Allowed time to react. The reaction solution was cooled, and the sulfuric acid was neutralized with an excess aqueous magnesium acetate solution. The solution was placed in water in Step 3 to precipitate cellulose triacetate having a lower molecular weight. The mixture was separated using a glass filter (G3), further dispersed in water (1), separated, and dried under vacuum. The product was purified by repeating twice an operation of dissolving the product in methylene chloride and reprecipitating it in 2-propanol, and then drying. The product is cellulose triacetate based on IR and NMR spectra, and the number average molecular weight determined by vapor pressure osmosis is 7900.
The number average degree of polymerization was 27. Vapor pressure osmometry is performed using a paper pressure osmometer.
Chloroform-1 as solvent using CORONA117
It was measured using a mixed solvent of % ethanol. Cellulose triacetate 60 thus obtained
g was dispersed in 200 ml of 2-propanol, and 60 ml of 100% hydrazine hydrade (manufactured by Hanui Chemicals) was slowly added dropwise while stirring gently. After the suspension was kept at 60°C for 3 hours, the cellulose produced was filtered out using a glass filter, washed repeatedly with acetone, and then dried under vacuum at 60°C. No absorption based on carbonyl groups near 1720 cm ^-1 was detected in the IR spectrum of the product, which matched that of cellulose. Synthesis Example 3 (Synthesis of cellulose tristhiophene-2-carboxylate) 1.5 g of cellulose obtained in Synthesis Example 2, 70 ml of dehydrated pyridine, 7.7 ml of dehydrated triethylamine,
Add 50 mg of 4-dimethylaminopyridine and add thiophene-2-carbonyl chloride while stirring.
12.2g was added, and the reaction was stirred at 100°C for 5 hours.
After cooling, the product was added to 400 ml of ethanol with stirring to precipitate it, filtered through a glass filter, and thoroughly washed with ethanol. After vacuum drying, it was dissolved in 30 ml of methylene chloride, and after removing insoluble matter, it was reprecipitated in 400 ml of ethanol. After filtering the precipitate, it was washed with ethanol, dehydrated, and dried. 3.9 g of cellulose thiophene-2-carboxylate was obtained. After dissolving it in methylene chloride, applying it to common salt and drying it, the characteristic absorption bands of the obtained infrared absorption spectrum are as follows. 3100cm ^-1 Aromatic C-H stretching vibration 1720cm ^-1 C=0 stretching vibration of carboxylic acid ester 1360, 1420, 1520cm ^-1 Thiophene ring ring stretching vibration 1260cm ^-1 C-O stretching vibration of ester 1060 to 1160cm ^-1 Cellulose C-O-C stretching vibration of 860 cm ^-1 C-H out-of-plane bending of disubstituted thiophene Almost no absorption near 3450 cm ^-1 due to OH of cellulose is observed, and it is almost a trisubstituted product. Further, the characteristic absorption of the proton NMR spectrum measured in CDCl ₃ is as follows. 6.8-7.8 ppm Thiophene ring proton 2.8-5.4 ppm Cellulose ring and methylene proton at position 6 The ratio of thiophene ring proton to cellulose proton is approximately 9:7, which is consistent with a trisubstituted product. Further, elemental analysis of sulfur showed that the sulfur content was 19.40%, indicating that it was almost trisubstituted. Example 1 Cellulose tristhiophene obtained in Synthesis Example 3
1.2 g of 2-carboxylate was dissolved in 7.5 ml of dichloromethane and filtered. Synthesis Example 1: 7.5ml of the solution
It was absorbed into the silica gel particles obtained in step 1, and the solvent was distilled off under reduced pressure to obtain a powder-like supported material. Application Example 1 The silica beads supporting cellulose tristhiophene-2-carboxylate obtained in Example 1 were packed in a stainless steel column with a length of 25 cm and an inner diameter of 0.46 cm by a slurry method. The high-performance liquid chromatograph machine is TRIROTAR-SR manufactured by JASCO Corporation, and the polarimeter detector is DIP-SR manufactured by JASCO Corporation.
181 was used. Table 1 shows the results of dividing trans-stilbene oxide. The definitions of terms when a polarimeter is used as a detector for a high performance liquid chromatograph are as follows. ′ = (Time to the top of the peak by the polarimeter detector of the enantiomer) − (dead time) / dead time β = ′ of the more strongly adsorbed enantiomer / ′ of the weaker adsorbed enantiomer

[Table] Synthesis Example 4 (Synthesis of cellulose triisonicotinate) 1.5 g of cellulose obtained in Synthesis Example 2 was mixed with pyridine 70
ml, triethylamine 19.2 ml, and 4-dimethylaminopyridine 50 mg, and after adding 14.8 g of hydrochloric acid isonicotinyl chloride,
Time reacted. After cooling, the reaction product was added to ethanol to precipitate it,
After washing with ethanol, it was vacuum dried. The dried product was dissolved in methylene chloride, filtered through a G-3 glass filter, and the solution was added to ethanol for precipitation.
It was thoroughly washed with ethanol and dried. The produced cellulose-p-cyanobenzoate was dissolved in methylene chloride and filtered through a G-3 glass filter, and then the solution was added to ethanol to precipitate, washed thoroughly with ethanol, and dried. The produced cellulose isonicotinate was dissolved in methylene chloride, applied to a rock salt cell, dried, and measured. In the infrared absorption spectrum, almost no absorption based on the OH of cellulose was observed. Example 2 1.2 g of cellulose triisonicotinate obtained in Synthesis Example 4 was dissolved in 7.5 ml of dichloromethane, and G-3
After filtration with a glass filter, the mixture was thoroughly mixed with 3.5 g of silica beads obtained in Synthesis Example 1, and dichloromethane was distilled off under reduced pressure to obtain a powdery support. Application Example 2 The support obtained in Example 2 was packed into a column using the same method as Application Example 1, and several compounds were optically resolved using the same chromatography equipment.
Of these, t-stilbene oxide is hexane-2
- using propanol (9:1) as eluent,
In the results of analysis at 20℃, the separation coefficient (α)
It showed 1.23. Note that α is defined as follows. Capacity ratio (k') = (retention time of optical isomer - dead time) / dead time Separation coefficient (α) = volume ratio of more strongly adsorbed optical isomer / volume ratio of weaker adsorbed optical isomer Synthesis example 5 (Synthesis of cellulose trinicotinate) 1.5 g of cellulose obtained in Synthesis Example 2 was mixed with 70 g of pyridine.
ml, triethylamine 19.2 ml, and 4-dimethylaminopyridine 50 mg, and after adding 14.8 g of hydrochloric acid nicotinic acid chloride, the mixture was reacted at 105°C for 5 hours. After cooling, the reaction product was added to ethanol to precipitate it, washed with ethanol, and then dried in vacuum. The dried product was dissolved in methylene chloride and filtered through a G-3 glass filter, and then the solution was added to ethanol to precipitate, washed thoroughly with ethanol, and dried. The produced cellulose nicotinate was dissolved in methylene chloride and filtered through a G-3 glass filter, and then the solution was added to ethanol to precipitate, washed well with ethanol and dried. The produced cellulose nicotinate was dissolved in methylene chloride, applied to a rock salt cell, dried, and measured.
Almost no absorption based on OH was observed. Example 3 1.2 g of cellulose trinicotinate obtained in Synthesis Example 5 was dissolved in 7.5 ml of dichloromethane, and G-3
After filtration with a glass filter, the mixture was thoroughly mixed with 3.5 g of silica beads obtained in Synthesis Example 1, and dichloromethane was distilled off under reduced pressure to obtain a powdered carrier. Application example 3 Using the support obtained in Example 3, several compounds were optically resolved using the same method and conditions as in Application example 2. Among these, benzoin had a separation coefficient of 1.25, and α-[4 -(4'-Fluorophenoxy)phenoxy]methyl propionate showed 1.21.

Claims (1)

[Claims] 1. A separation agent containing a heteroaromatic derivative of cellulose as an active ingredient.