JPH0430928B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel separating agent, particularly a packing material for liquid chromatography for optically resolving racemic compounds. The separation agent proposed by the present invention uses silica gel as a carrier, reacts a so-called silanizing agent to the carrier, introduces a spacer portion, and then adds D or L optically active proline or a copper salt of its thiocarboxylic acid. It is made by chemically bonding. Conventionally, as a filler for optical resolution made by chemically bonding optically active proline or hydroxyproline to silica gel, J.High by GG¨ubitz et al.
Resolut.Chromatogr.and.Chromatogr.Comm，
2, 145 (1979) or K. Sugden et al., J.
Chromatogr.192, 228 (1980) or VA
Angew.Chem.Int.Ed. by Davankov et al.
As described in Engl. 21, 930 (1982), all of them have a carboxyl group that is coordinately or ionically bonded to a copper ion, and each antipode of a racemic amino acid 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 to further improve the performance of these known separation 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 resolving power, so it is difficult to design the separation packing. In doing so, there were major constraints on the synthesis method. Also,
Chromatographia 13 by VADavankov et al.
677 (1980), carbon number 7 to 16
In the method of optical resolution by adsorbing L-hydroxyproline into which a straight-chain alkyl group has been introduced into a reversed-phase silica gel column, when introducing a straight-chain alkyl group into an amino group, it is important to consider the reactivity and selection of an appropriate solvent. There's a problem. In the present invention, since any group can be introduced into the amino group, the active center for optical resolution can be freely designed, and the silane treatment agent that acts as a spacer and the hydroxy group, thiol group, which has almost no effect on the active center,
It was discovered that by reacting and bonding amino groups, etc., it was possible to avoid the effects of the silane treatment agent, and as a result, the resolving power was significantly improved compared to conventional separation packing materials. That is, the present invention provides a separating agent comprising a substance represented by the following general formula (I). [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, an alkyl group having 1 to 20 carbon atoms, and 6 to 20 carbon atoms, respectively. represents an aryl group having 7 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, a halogen, 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 or It is an optically active group represented by However, B represents a copper salt of carboxylic acid or thiocarboxylic acid, and Z represents an oxygen atom, a sulfur atom, or an amino group. A is hydrogen, an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, and 7 carbon atoms.
~47 arylalkyl group, or carbon number 1~
Contains 40 heteroatoms. That is, it is a group containing any bonding mode such as an ether bond, an amino bond, a thioether bond, an amide bond, or an ester bond. A' indicates methylene having 2 to 6 carbon atoms. Moreover, the * mark indicates an asymmetric carbon atom. ]. The separating agent 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 chromatogram device. Since the separation agent of the present invention made of the substance represented by the above general formula (I) 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, and a pore size of 10 Å to 10000 Å can be used. Preferably, the particle size is 1 μm to 100 μm and the pore size is 50 Å to 5000 Å. (B) Silanizing agent Any known silanizing agent can be used as the silanizing agent for forming the spacer portion of the filler of the present invention, but these are expressed by the following general formula ()
It is expressed as 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, and 7 carbon atoms.
-20 arylalkyl group, halogen, hydroxy group, or alkoxy group having 1 to 20 carbon atoms, or any combination thereof. Note that after this silane treatment agent reacts with silica gel, Y, Y', and Y'', which did not react with silica gel, are the remainder of Y ¹ , Y ² , and Y ³ in the above general formula (I) that 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, ether bond, ester bond, amino bond,
Any mode of attachment of an amide bond can be included. Therefore, X in general formula (I) is represented by general formula ()
X' is the residue bonded to R. Specifically, the silanizing agent represented by the above general formula () has a functional group capable of reacting with a hydroxyl group, an amino group, or a thiol group to form a covalent bond, and examples thereof include the following. 1 X'=- _CH2Cl or X'=- _CH2Br Chloromethyldimethylchlorosilane Chloromethylethoxysilane Bromomethyldimethylchlorosilane Chloromethylmethyldichlorosilane 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-bromopropyldimethylchlorosilane 3-bromopropyltrichlorosilane 3-bromopropyltrimethoxysilane 3 -Chloropropyldimethylchlorosilane 3-chloropropylmethyldimethoxysilane 3-chloropropyltriethoxysilane 3-chloropropylphenyldichlorosilane n-propyl(3-chloropropyl)dichlorosilane 3 X'=-CH ₂ CH ₂ Cl or

【formula】 things of 1-chloroethylmethyldichlorosilane 2-chloroethylmethyldichlorosilane 1-chloroethyltrichlorosilane 2-chloroethyltrichlorosilane 4

[Formula] p-chlorophenyltrimethoxysilane p-chlorophenyltriethoxysilane 5

[Formula] 2-(3,4-epoxycyclohexylethyl)trimethoxysilane 6 3-Glycidoxypropyltrimethoxysilane Diethoxy-3-glycidoxypropylmethylsilane 3-glycidoxypropyldimethylethoxysilane 7 Where X'=alkylhalogen 8-bromooctyltrichlorosilane 4-(methyldichlorosilyl)butylene Lyruchloride 8 Optical active group The optically active group R forming the characteristic part of the filler of the present invention has the following general formula: or It is an optically active group represented by However, B represents a copper salt of carboxylic acid or thiocarboxylic acid, and Z represents an oxygen atom, a sulfur atom, or an amino group. A includes 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, it is a group containing any bonding mode such as an ether bond, an amino bond, a thioether bond, an amide bond, or an ester bond. A' indicates methylene having 2 to 6 carbon atoms. In addition, the mark 〓 indicates an asymmetric carbon atom. Specifically, it is obtained by tertiating an optically active form of either the D-form or the L-form of proline as a raw material by introducing a substituent containing the above A into its secondary amino group. More specifically, it can be obtained by ring-opening addition reaction to α-olefin epoxide, cyclic epoxide, or the like. Specific examples of A include straight chain or branched hydrocarbons such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, eicosyl, cyclopentyl, cyclohexyl, etc. Cyclic hydrocarbons, aromatics such as phenyl, benzyl, or hydrocarbons containing them;
Heterocycles such as pyridyl, imidazolyl, or
Examples thereof include hydrocarbon groups containing cyclic or non-cyclic hydrocarbon groups containing heteroatoms such as methoxyethyl, methylthioethyl, N-morpholylethyl, and N,N-dimethylaminoethyl. The method for producing the separating agent of the present invention from the starting materials (A), (B), and (C) above includes treating silica gel with silane and then bonding an optically active group, or combining the silanizing agent with an optically active group. Any method is possible in which the groups are reacted with pre-bonded silica gel. Further, the reaction of converting the carboxyl group or its ester into a metal salt of thiocarboxylic acid may be carried out before bonding with silica gel, or may be carried out after bonding. This metal salt can be converted into a copper salt by an exchange reaction with a strong acid copper salt. As described above, the separating agent 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 suitable for use as a packing material for liquid chromatography, particularly for the optical resolution of amino acids. It is suitable. Synthesis examples and examples of the separation 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 dry nitrogen stream for 3.5 hours at 120°C.
Heat to 150℃ and dry. dry silica gel
50 g was suspended in 300 ml of anhydrous benzene, 20 ml of glycidoxypropyltrimethoxysilane was added thereto, and the mixture was heated to reflux under a stream of dry nitrogen. The methanol produced at this time is removed from the system and the reaction is allowed to proceed for 16 hours. 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.
3.0 g of an adduct obtained by reacting the sodium salt of L-proline with cyclohexene epoxide was dissolved in 50 ml of anhydrous dimethylformamide, and a glycidoxypropylsilyl group was introduced into the silica gel.
Add 3.5 g to suspend and shake at 90°C for 15 hours. The modified silica gel was filtered and washed with methanol, and then transferred to an aqueous solution in which 2 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 N-substituted-L-proline 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, the packing material obtained in Synthesis Example 1 above was added to a fully porous silica gel with an average particle size of 10 μm and an average pore size of 60 Å, and was placed in a stainless steel column for high performance liquid chromatography (25 μm).
cm x 0.46 cm) and optically resolved the amino acid racemate using a 5 x 10 ^-4 M copper nitrate aqueous solution as the solvent at a flow rate of 2 ml/min and a temperature of 50°C.
Good division results were obtained.

[Table] Opposite palm that is more weakly adsorbed
Body volume ratio synthesis example 2 Silica gel was heated at 120-150 for 2 hours in a dry nitrogen stream.
℃ and further heat-dried in vacuum for 4 hours.
50 g of dried silica gel is suspended in 300 ml of anhydrous benzene, 25 ml of glycidoxypropyltrimethoxysilane is added thereto, and the suspension is heated to reflux under a stream of dry nitrogen. The methanol produced at this time is removed from the system and the reaction is allowed to proceed for 8 hours. After the reaction is completed, it is cooled to room temperature and filtered through a glass filter. The obtained modified silica gel was washed with anhydrous benzene and then stored in vacuum.
Dry at 40℃. Sodium salt of L-proline
1.5 g of the adduct was reacted with 5.0 g of linear α-olefin epoxide having 15 to 18 carbon atoms, and the adduct was dissolved in 10 ml of anhydrous dimethylformamide, and 6 g of the above silica gel was prepared by introducing a glycidoxypropylsilyl group into this.
Add to the suspension and shake at 90°C for 15 hours. The modified silica gel was filtered and washed with methanol, and then transferred to an aqueous solution in which 1 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 N-substituted-L-proline 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. R'' indicates a straight-chain alkyl group having 13 to 16 carbon atoms. Example 2 The filler obtained in Synthesis Example 2 was used to optically resolve various amino acid racemates. That is, the average The packing material obtained in Synthesis Example 1 above was added to a fully porous silica gel with a particle size of 10 μm and an average pore size of 60 Å, and then placed in a stainless steel column for high performance fluid chromatography (25 μm).
cm x 0.46 cm), and optical resolution of the amino acid racemate was performed using a 5 x 10 ^-4 M copper nitrate aqueous solution as the solvent at a flow rate of 2 ml/min and a temperature of 50°C, the results were as good as in Example 1. A good segmentation result was obtained.

Claims (1)

[Claims] 1. A separating agent comprising a substance represented by the following general formula (I) [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 or It is an optically active group represented by However, B represents a copper salt of carboxylic acid or thiocarboxylic acid, and Z represents an oxygen atom, a sulfur atom, or an amino group. A is hydrogen, an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, and 7 carbon atoms.
~47 arylalkyl group, or carbon number 1~
It is a group containing 40 heteroatoms, ie, any bonding mode of ether bond, amino bond, thioether bond, amide bond, or ester bond. A' indicates methylene having 2 to 6 carbon atoms. Moreover, the * mark indicates an asymmetric carbon atom. ]