JPH0429651B2 - - Google Patents

Abstract

PURPOSE:To improve the separating power with a filler for liquid chromatography by using silica gel which is bound with an optically active group via a silane treating agent. CONSTITUTION:A filler for sepn. is formed of the materials expressed by the formula I . In the formula, Y<1>-Y<3> denote silica gel, the part of siloxane bound with the silica gel and the balance denote hydrogen, an alkyl group of 1-20C, an aryl group of 6-20C, an aryl alkyl group of 7-20C, halogen, hydroxy group or an alkoxy group of 1-20C or the combination thereof, X denotes the spacer of 1-30C. R is an optically active group expressed by the formula II. m, n are respectively 0 or 1-3 integer, B is copper salt of carboxylic acid or thiocarboxylic acid, Z is oxygen atom, sulfur atom or amino group, A is hydrogen, an alkyl group of 1-40C, an aryl group of 6-40C, an aryl alkyl group of 7-4C or ether bond, etc. contg. hetero atom of 1-40C. An * mark denotes asymmetrical carbon atom.

Description

[Detailed description of the invention]

The present invention relates to a novel separation packing material, particularly to a liquid chromatography packing material for optically resolving racemic compounds. The separation filler proposed by the present invention uses silica gel as a carrier, reacts it with a so-called silanizing agent to introduce a spacer portion, and adds D or L optically active 2-acetidinecarboxylic acid, It is formed by chemically bonding copper salts of any carboxylic acid or thiocarboxylic acid selected from proline, hydroxyproline, and allohydroxyproline. Conventional fillers for optical resolution made by chemically bonding optically active proline or hydroxyproline to silica gel include J.High by G. Gu¨bitz et al.
Resolu¨t.Chromatogr.and Chromatogr,
comm., 2, 145 (1979), or J. Chromatogr. 192, 228 (1980) by K. Sugden et al., or Angew.Chem.Int.Ed. by VADavankov et al.
As described in Eng 1., 21, 930 (1982), all of them have a carboxyl group that is coordinately or ionically bonded to a copper ion, and each of the antipodes of racemic amino acids that can coordinate to this carboxyl group. This method uses the difference in the free energy of interaction with the body to separate racemates. The present inventors have arrived at the present invention as a result of various studies aimed at further improving the performance of these known dividing fillers. In other words, in all of these conventional separation packings, the amino group of the optically active group is bonded to a silanizing agent that acts as a spacer, so the spacer has a large effect on the separation ability, so it is difficult to design the separation packing. In doing so, there were major constraints on the synthesis method. Also,
Chromatogkaphia13 by VADavankov et al.
677 (1980), carbon number 7 to 16
In the method of optical resolution by adsorbing L-hydroxyproline into which a linear alkyl group has been introduced into a reverse phase silica gel column, the groups introduced into the amino group are limited to hydrophobic ones. Since any group can be introduced into the material, the active center for optical decomposition can be designed freely, and the silanizing agent that acts as a spacer can be bonded by reacting with a reactive point that has little effect on the active center, such as a hydroxyl group. As a result of avoiding the influence of the silanizing agent, it has been found that the separation ability is significantly improved compared to conventional separation fillers. That is, the present invention provides a separation filler comprising a substance represented by the following general formula (). [However, at least one of Y ¹ , Y ² , Y ³ in the formula
One represents silica gel and the siloxane bonding part with silica gel, and the remaining represent hydrogen and carbon number 1, respectively.
-20 alkyl group, C6-20 aryl group,
C7-20 arylalkyl group, halogen,
It represents a hydroxy group, an alkoxy group having 1 to 20 carbon atoms, or any combination thereof. X represents a spacer having 1 to 30 carbon atoms. R is a general formula It is an optically active group represented by However, m and n are each 0 or an integer from 1 to 3, and the total is 3 or less, B represents a copper salt of carboxylic acid or thiocarboxylic acid, and Z represents an oxygen atom, a sulfur atom, or an amino acid. Indicates that it is a group. A is hydrogen, an alkyl group having 1 to 40 carbon atoms, and 6 to 40 carbon atoms.
containing an aryl group, an arylalkyl group having 7 to 47 carbon atoms, or a heteroatom having 1 to 40 carbon atoms, that is, an ether bond, an amino bond, a thioether bond, an amide bond, an ester bond, a sulfonic acid ester bond, or a urethane bond. A group that includes any bonding mode. Moreover, the * mark indicates an asymmetric carbon atom. ]. The separating packing material of the present invention can be packed into a metal or glass cylinder and used for optical resolution of racemic compounds using a conventional liquid chromatography device. Since the separation filler of the present invention made of the substance represented by the above general formula () is formed by bonding an optically active group to silica gel via a silane treatment agent, each of these will be explained below. (A) Silica gel The raw material silica gel has a particle size of 0.1 μm to 1000 μm.
Those with pore diameters of 10 Å to 10,000 Å can be used. Preferably the particle size is 1 μm to 100 μm
m and the pore diameter is 50 Å to 5000 Å. (B) Silane Treatment Agent Any known silane treatment agent may be used to form the spacer portion of the filler of the present invention, and these are represented by the following general formula (). In the formula, Y, Y′, Y″ are hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, a halogen, a hydroxy group, or a hydroxy group or a carbon number 1 to 20 represents an alkoxy group or any combination thereof.
After this silane treatment agent reacts with silica gel, Y, Y', and Y'', which did not react with silica gel, correspond to the rest of Y ¹ , Y ² , and Y ³ in the above general formula (), which do not bond with silica gel. X' is a spacer-forming group having 1 to 30 carbon atoms, and is an alkyl or aryl group having a terminal or internal halogen, amino group, or oxirane group, and may contain a heteroatom.
That is, any bonding mode such as an ether bond, an ester bond, an amino bond, or an amide bond can be included. Therefore, X in general formula () is
X'' is a bonded residue with R. Specifically, the silane treatment agent represented by the above general formula () has a functional group that can react with a secondary hydroxyl group, thiol group, or amino group to form a covalent bond. (1) Those with X'=-CH ₂ Cl or X'=-CH ₂ Br Chloromethyldimethylchlorosilane Chloromethylethoxysilane Bromomethyldimethylchlorosilane Chloromethylmethyl Dichlorosilane Chloromethylmethyldiethoxysilane Chloromethyltrichlorosilane Chloromethyltriethoxysilane Chloromethyldimethyl-n-nitrophenoxysilane Chloromethyldimethyl-p-nitrophenoxysilane Chloromethyldimethyl 2-{(2-ethoxyethoxy ) Ethoxy}silane Chloromethyldimethylphenoxysilane 1,2-bis(dimethylchlorosilin)ethane Allyloxychloromethyldimethylsilane (2) X=CH ₂ CH ₂ CH ₂ Cl or X'=-
CH ₂ CH ₂ CH ₂ Br 3-chloropropyltrimethoxysilane 3-chloropropyldimethoxymethylsilane 3-chloropropylmethyldichlorosilane 3-chloropropyltrichlorosilane 3-bromopropyldimethylichlorosilane 3-bromopropyltrichlorosilane 3 -Bromopropyltrimethoxysilane 3-chloropropyldimethylchlorosilane 3-chloropropylmethyldimethoxysilane 3-chloropropyltriethoxysilane 3-chloropropylphenyldichlorosilane n-brovyl(3-chloropropyl)dichlorosilane (3) X' =−CH ₂ CH ₂ Cl or X′=

【formula】 things of 1-chloroethylmethyldichlorosilane 2-chloroethylmethyldichlorosilane 1-chloroethyltrichlorosilane 2-chloroethyltrichlorosilane (4) X′=

[Formula] p-chlorophenyltrimethoxysilane p-chlorophenyltriethoxysilane (5) X′=

[Formula] 2-(3.4-epoxycyclohexylethyl)trimethoxysilane (6) X′=

[Formula] 3-glycidoxypropyltrimethoxysilane Diethoxy-3-glycidoxypropylmethylsilane 3-gelicidoxypropyldimethylethoxysilane (7) Where X'=alkylhalogen 8-promooctyltrichlorosilane 4-( Methyldichlorosilyl)butylluchloride (8) X'=Acid chloride 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane 3-(trichlorosilyl) Propylchloroproformate (C) Optically active group The optically active group R forming the characteristic part of the filler of the present invention has the following general formula: It is an optically active group represented by However, m,
n is each 0 or an integer from 1 to 3, the total of which is 3 or less, B indicates a copper salt of a carboxylic acid or thiocarboxylic acid, and Z is an oxygen atom, a sulfur atom, or an amino group. shows. A contains hydrogen, an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an arylalkyl group having 7 to 47 carbon atoms, or a heteroatom having 1 to 40 carbon atoms, that is, an ether bond, an amino bond, thioether bond, amide bond, ester bond,
It is a group containing any bonding mode such as a sulfonic acid ester bond or a urethane bond. Moreover, the * mark indicates an asymmetric carbon atom. Specifically, for example, using either the D-form or L-form of optically active hydroxyproline or allohydroxyproline as a raw material, the secondary amino group is converted into a tertiary amino group by introducing the substituent A above. obtained by converting However, it is necessary that the hydroxyl groups of the proline skeleton selectively react and bond with the silane treatment agent. Such substituents include methyl, ethyl,
Straight or branched hydrocarbons such as purpyl, isopyropyl, butyl, tertiarybutyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, eicosyl, cyclic hydrocarbons such as cyclopentyl, cyclohexyl, aromatics such as phenyl, benzyl or hydrocarbons containing it, heterocycles such as biridyl, imidazolyl, or hydrocarbons containing it, cyclic or non-cyclic groups containing heteroatoms such as methoxyethyl, methylthioethyl, N-morpholylethyl, N,N-dimethylaminoethyl. cyclic hydrocarbons,
Examples include carboxymethyl, paratoluenesulfonyl, carbobenzyloxy, benzoyl, and tert-butoxycarbonyl. The method for producing the separation packing material of the present invention from the above starting materials (A), (B), and (C) includes treating silica gel with silane and then bonding an optically active group, or combining it with a silanizing agent. Any method of reacting with silica gel to which an optically active group has been bonded in advance is possible. Further, the reaction of converting a carboxyl group or its ester into a metal salt of thionecarboxylic acid may be performed before bonding with silica gel,
Also, it may be converted after being combined. This metal salt can be converted into a copper salt by an exchange reaction between a strong acid and a copper salt. As described above, the separating packing material of the present invention is a substance formed by chemically bonding an optically active group to silica gel via a silane treatment agent, and is used as a packing material for liquid chromatography, particularly for the optical resolution of amino acids. It is suitable for Synthesis examples and examples of the separating filler of the present invention will be shown below together with comparative examples, but the present invention is not limited to these examples. Synthesis Example 1 Silica gel was heated in a stream of dry nitrogen for 2 to 10 hours.
Heat to ~150°C and dry. 20 g of dried silica gel is suspended in 100 ml of anhydrous benzene, 6 g of glycidoxypropyltrimethoxysilane is added thereto, and the suspension is heated to reflux under a stream of dry nitrogen. The methanol generated at this time should be removed from the system for 5 to 10 minutes.
It takes a lot of time. After the reaction is completed, it is cooled to room temperature and filtered through a glass filter. The obtained modified silica gel is washed with anhydrous benzene and then dried in vacuo at 40°C. Dissolve 1.88 g of L-N-octyl-hydroxyproline disodium in 50 ml of anhydrous dimethylformamide, add 4 g of the above-mentioned silica gel into which glycidoxypropylsilyl groups have been introduced, suspend the mixture, and shake at 90°C for 6 hours. do. The modified silica gel was filtered and washed with methanol, and then transferred to an aqueous solution in which 6 g of copper sulfate was dissolved in 50 ml of pure water to obtain a copper salt. This was filtered again and washed with pure water to obtain silica gel to which the copper salt of L-N-octyl 2-pyrrolidinecarboxylic acid was chemically bonded. The structural formula of the obtained substance is estimated to be as follows. R and R' indicate that either one or both of them is a methyl group, or both or one of them is the same silica gel. Example 1 Using the filler obtained in Synthesis Example 1, various amino acid racemates were optically resolved. That is, a fully porous silica gel with an average particle size of 10 μm and an average pore size of 100 Å was packed with the packing material obtained in Synthesis Example 1 above into a stainless steel column (25 cm x 0.46 cm) for high performance liquid chromatography, and Using 19 ^-4 M copper nitrate aqueous solution as solvent, flow rate 3 ml/min, temperature 50°C.
When optical resolution of the amino acid racemate was carried out, good resolution results were obtained as shown in Table 1 below.

【table】

[Table] In Table 1, K', α, and R _S are defined as follows. Capacity ratio (K') = [(Retention time of enantiomer) - (Det time)] / Det time separation coefficient (α) = Capacity ratio of enantiomer that is more strongly adsorbed /
Volumetric resolution of the more weakly adsorbed enantiomer (R _S = (2 x distance between the two peaks of the more strongly adsorbed enantiomer and the weaker adsorbed enantiomer)/bandwidth of both peaks Total Comparative Example 1 Using a silanizing agent having a glycidoxypropylsilyl group, the same column as in Example 1 was filled with a packing material in which copper salt of L-proline was bound to silica gel, and the same solvent was added at 2 ml/min. When the solution was poured and optical resolution was performed, leucine could not be resolved at all. Structural formula (In the formula, R and R' indicate that either one or both of them is a methyl group, or both or one of them are the same silica gel.)

Claims (1)

[Claims] 1. A separation filler made of a substance represented by the following general formula () [However, in the formula, at least one of Y ¹ , Y ² , and Y ³ represents silica gel and a siloxane bonding moiety with silica gel, and the remaining are hydrogen and carbon atoms with 1 to 1 carbon atoms, respectively.
20 alkyl groups, aryl groups with 6 to 20 carbon atoms, arylalkyl groups with 7 to 20 carbon atoms, halogen,
It represents a hydroxy group, an alkoxy group having 1 to 20 carbon atoms, or any combination thereof. X represents a spacer having 1 to 30 carbon atoms. R is a general formula It is an optically active group represented by However, m and n are each 0 or an integer from 1 to 3, and the total is 3 or less, B represents a copper salt of carboxylic acid or thiocarboxylic acid, and Z represents an oxygen atom, a sulfur atom, or an amino acid. Indicates that it is a group. A is hydrogen, an alkyl group having 1 to 40 carbon atoms, and 6 to 40 carbon atoms.
containing an aryl group, an arylalkyl group having 7 to 47 carbon atoms, or a heteroatom having 1 to 40 carbon atoms, that is, an ether bond, an amino bond, a thioether bond, an amide bond, an ester bond, a sulfonic acid ester bond, or a urethane bond. A group that includes any bonding mode. Also, * indicates an asymmetric carbon atom.