An octyl and pomalidomide derivative double-modified silica gel, a preparation method and an application as a reverse phase chromatography packing

Abstract

The application discloses octyl and pomalidomide derivative double-modified silica gel, a preparation method and an application as a reversed-phase chromatography filler, and belongs to the material field. The application claims a kind of octyl and pomalidomide derivative double-modified silica gel, the double-modified silica gel takes porous spherical silica gel as a matrix, and the surface of the silica gel is simultaneously bonded with octyl groups and pomalidomide derivative groups through siloxane bonds. Under the same mobile phase composition, elution mode, flow rate and column temperature conditions, the double-modified silica gel is used as a reversed-phase high performance liquid chromatography filler, and the separation performance of polycyclic aromatic hydrocarbons, phenyl esters and aniline compounds is significantly better than that of a commercially available octyl bonded silica gel (SiO2-C8) filler. In addition, the preparation process of the octyl and pomalidomide derivative double-modified silica gel is simple and controllable, the reaction conditions are mild, the raw materials are easy to obtain, and the silica gel has the potential for large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of materials and relates to the synthesis and application of novel chromatographic packing materials, specifically to an octyl and pomalidomide derivative dual-modified silica gel, its preparation method, and its use as a reversed-phase chromatographic packing material. Background Technology

[0002] High performance liquid chromatography (HPLC) is a core technology for modern substance separation, component detection, and sample analysis. As the core medium of the chromatographic column, the surface structure, functional group types, and physicochemical properties of the chromatographic packing material directly determine the sample separation effect, selectivity, and analytical accuracy. It is widely used in many fields such as pharmaceuticals, chemicals, biological detection, environmental monitoring, and food quality inspection.

[0003] Silica gel matrix is ​​the most widely used commercial chromatographic packing material due to its advantages such as high mechanical strength, regular pore structure, large specific surface area, and good chemical stability. Conventional unmodified silica gel relies solely on polar interactions to achieve substance separation, which limits its applicability to various separation systems. Most mainstream monofunctional modified silica gel packing materials on the market suffer from a single functional mode, capable of separating components only through a single interaction force, making it difficult to accommodate multiple separation mechanisms such as hydrophobic interactions, specific recognition, and molecular coordination.

[0004] With the continuous development of modification technology, researchers have gradually carried out research on the modification of functional groups on the surface of silica gel. By grafting different groups such as alkyl, heterocyclic, and aromatic groups, they have successively developed a variety of modified chromatographic packings, which has effectively expanded the types of packings and improved the separation adaptability of complex samples to a certain extent.

[0005] However, existing modified packing materials still have significant shortcomings. When faced with complex systems such as structurally similar isomers, polar-nonpolar mixed components, and trace drug derivatives, a single modified structure cannot provide multi-component interactions, resulting in insufficient separation selectivity, peak tailing, and difficulty in completely separating components. Existing packing material categories can no longer meet the current practical needs of refined and complex chemical separation analysis.

[0006] To address the shortcomings of existing chromatographic packing materials, such as limited functionality, poor separation selectivity, and difficulty in effectively separating complex samples, this invention provides a silica gel material dual-modified with octyl and pomalidomide derivatives. This material simultaneously grafts two functional groups onto the surface of a silica matrix, constructing a novel packing system that synergistically exerts hydrophobic interactions and specific molecular recognition capabilities. This effectively improves the inherent performance defects of traditional packing materials and provides a new technical approach for the efficient chromatographic separation of complex components. This invention is therefore proposed. Summary of the Invention

[0007] In order to overcome the technical drawbacks of existing chromatographic packing materials, such as single function, poor separation selectivity, and difficulty in effectively separating complex samples, the first objective of this invention is to provide a silica gel with dual modification of octyl and pomalidomide derivatives; the second objective is to provide a method for preparing the dual-modified silica gel; and the third objective is to provide the application of the dual-modified silica gel as a reversed-phase chromatographic packing material.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution: An octyl and pomalidomide derivative dual-modified silica gel, wherein the octyl and pomalidomide derivative dual-modified silica gel uses porous spherical silica gel as a matrix, and the silica gel surface is simultaneously bonded with two groups as shown in Formula I and Formula II through silicon-oxygen bonds:

[0009] Ι

[0010] II In Equations I and II, the wavy lines represent sites connected to the surface of the silicone matrix.

[0011] Preferably, the porous spherical silica gel has a particle size of 1-50 μm. Considering the varying particle size requirements of chromatographic packing materials for different applications: porous spherical silica gel for UHPLC (ultra-high performance liquid chromatography) typically has a particle size of 1.7-3 μm, for conventional HPLC analytical chromatography it typically has a particle size of 3-5 μm, and for preparative / semi-preparative chromatography it typically has a particle size of 10-50 μm. Therefore, this invention preferably uses dual modification on porous spherical silica gel with a particle size in the range of 1-50 μm to adapt to various chromatographic applications.

[0012] More preferably, the porous spherical silica gel has a particle size of 1.7-5 μm. The present invention preferably employs dual modification on porous spherical silica gel with a particle size in the range of 1.7-5 μm to adapt to UHPLC (ultra-high performance liquid chromatography) and conventional HPLC analytical chromatography applications.

[0013] A method for preparing any of the octyl and pomalidomide derivative dual-modified silica gels includes the following steps: Step S1, acidifying porous spherical silica gel with an acidic aqueous solution to obtain acidified silica gel; Step S2, reacting the acidified silica gel with dichloromethyloctylsilane in an organic solvent under nitrogen protection to obtain an octyl-bonded silica gel precursor; Step S3, reacting the octyl-bonded silica gel precursor with mercaptopropyltrimethoxysilane in an organic solvent under nitrogen protection to obtain a thiolated intermediate; Step S4, reacting the thiolated intermediate with a pomalidomide derivative and azobisisobutyronitrile in an organic solvent under nitrogen protection to obtain the final product. The chemical structural formula of the pomalidomide derivative is shown in Formula III:

[0014] III.

[0015] Preferably, the acid solution used in step S1 is a hydrochloric acid aqueous solution. The hydrochloric acid aqueous solution is only one specific embodiment; those skilled in the art should know that other acid solutions can also be used to acidify the porous spherical silica gel, all for the purpose of activating it.

[0016] Preferably, the organic solvent used in steps S2 and S3 is toluene. Toluene is only an organic solvent used in one specific embodiment, and those skilled in the art should know that other suitable organic solvents can also be used.

[0017] Preferably, the organic solvent used in step S4 is methanol. Methanol is only an organic solvent used in one specific embodiment, and those skilled in the art should know that other suitable organic solvents can also be used.

[0018] The octyl and pomalidomide derivative-modified silica gel is used as a reversed-phase chromatography packing material for separating polycyclic aromatic hydrocarbons.

[0019] The octyl and pomalidomide derivative-modified silica gel is used as a reversed-phase chromatography packing material for separating phenyl ester compounds.

[0020] The octyl and pomalidomide derivative-modified silica gel is used as a reversed-phase chromatography packing material for separating aniline compounds.

[0021] Beneficial effects: This invention provides a silica gel double-modified with octyl and pomalidomide derivatives. Under the same mobile phase composition, elution method, flow rate, and column temperature, this double-modified silica gel, when used as a reversed-phase high-performance liquid chromatography (RP-HPLC) packing material, exhibits significantly better separation performance for polycyclic aromatic hydrocarbons, phenyl esters, and aniline compounds than commercially available octyl-bonded silica gel (SiO2-C8) packing material. Specifically, firstly, the resolution of adjacent chromatographic peaks of the target analytes is significantly improved, achieving baseline separation with good peak shape; secondly, the improved resolution does not depend on sacrificing elution time. Furthermore, the preparation process of this octyl and pomalidomide derivative double-modified silica gel is simple and controllable, with mild reaction conditions and readily available raw materials, possessing the potential for large-scale production. Attached Figure Description

[0022] Figure 1 The above is a route diagram for the preparation of SiO2-Po-Oc in Example 1; where A is a route diagram for the preparation of thiolized intermediate (3), B is a route diagram for the preparation of compound 5, and C is a route diagram for the preparation of SiO2-Po-Oc (TM) from thiolized intermediate (3) and compound 5. Figure 2The infrared spectra of SiO2 (acidified silica gel) and SiO2-Po-Oc in Example 1 are shown below. Figure 3 SEM images of SiO2 (acidified silica gel, A) and SiO2-Po-Oc (B) in Example 1; Figure 4 Chromatograms showing the separation of polycyclic aromatic hydrocarbons using SiO2-Po-Oc prepared in Example 1 and commercial SiO2-C8 as reversed-phase high-performance liquid chromatography packing materials, respectively. Figure 5 The chromatograms show the separation of phenyl ester compounds using SiO2-Po-Oc prepared in Example 1 and commercial SiO2-C8 as reversed-phase high-performance liquid chromatography packing materials, respectively. Figure 6 The images show the separation chromatograms of aniline compounds using SiO2-Po-Oc prepared in Example 1 and commercial SiO2-C8 as reversed-phase high-performance liquid chromatography packing materials, respectively. Detailed Implementation

[0023] The substantive content of the present invention is described in detail below with reference to specific embodiments. However, those skilled in the art should understand that the scope of protection of the present invention should not be limited to these specific embodiments. Unless otherwise stated, the experimental materials and methods used in the embodiments are all common techniques in the art. In the following embodiments, the octyl and pomalidomide derivative dual-modified silica gel provided by the present invention is represented as SiO2-Po-Oc.

[0024] Example 1: Preparation and characterization of SiO2-Po-Oc.

[0025] Preparation route as follows Figure 1 As shown, A is the route for preparing thiolated intermediate (3), B is the route for preparing compound 5, and C is the route for preparing SiO2-Po-Oc(TM) from thiolated intermediate (3) and compound 5.

[0026] Specifically, the preparation steps are as follows.

[0027] Take 20 g of silica gel (porous spherical silica gel, particle size 1.8 μm) and place it in a 500 mL reaction flask. Add 200 mL of 20% hydrochloric acid solution and sonicate for 2 h. Filter and collect the silica gel. Wash with deionized water until the pH of the washing solution stabilizes at 7. Place it in a vacuum drying oven at 80 ℃ for 10 h to obtain acidified silica gel.

[0028] Under nitrogen protection, acidified silica gel (1), 12 mL of dichlorodimethyloctylsilane, and 120 mL of toluene were added to a 250 mL reaction flask and reacted at 100 °C for 24 hours. After the reaction was completed, the solid was collected by filtration and washed successively with methanol, tetrahydrofuran, and methanol. The solid was then dried in a vacuum drying oven at 80 °C for 10 h to obtain octyl-bonded silica gel precursor (2).

[0029] Under nitrogen protection, 20 g of octyl-bonded silica precursor (2), 12 mL of mercaptopropyltrimethoxysilane, and 120 mL of toluene were added to a 250 mL reaction flask and reacted at 100 °C for 24 hours. After the reaction was completed, the solid was collected by filtration and washed successively with methanol, tetrahydrofuran, and methanol. The solid was then dried in a vacuum drying oven at 80 °C for 10 h to obtain the thiolized intermediate (3).

[0030] Under nitrogen protection, 50 g of compound 4 (181.01 mmol), 15.45 g of 3-buten-1-amine (217.22 mmol), and 15 ml of triethylamine (TEA) were dissolved in 200 mL of N,N-dimethylformamide (DMF) and reacted at 80 °C for 24 h. After the reaction, the sample was extracted with dichloromethane. The dichloromethane extract was dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to give compound 5 (pomalidomide derivative, 43 g). The 1H NMR spectrum (400 MHz, d-DMSO, δ / ppm) was as follows: δ = 11.08 (s, 1H), 7.58 (dd, 1H), 7.10 (d, 1H), 7.02 (d, 1H), 6.55 (t, 1H), 5.79 (m, 1H), 5.13–4.99 (m, 2H), 5.05 (dd, 1H), 3.26 (q, 2H), 2.88 (m, 1H), 2.64–2.51 (m, 2H), 2.08–2.00 (m, 1H), 1.59 (m, 2H). MS (m / z): [M] + calcd. for:C 17 H 17 N3O4, 328.129; found, 328.126.

[0031] Under nitrogen protection, 20 g of the thiolized intermediate (3) was dissolved in 200 mL of methanol along with compound 5 (pomalidomide derivative, 54 mmol) and 9.8 g of AIBN (azobisisobutyronitrile), and reacted at 60 °C for 24 h. After the reaction was complete, the solid was collected by filtration and washed alternately with dichloromethane and methanol, and then dried in a vacuum drying oven at 80 °C for 6 h to obtain SiO2-Po-Oc(TM).

[0032] Infrared spectra of SiO2 (acidified silica gel) and SiO2-Po-Oc, for example Figure 2 As shown. By Figure 2 It can be seen that, compared to SiO2, the infrared spectrum of SiO2-Po-Oc is at 2916.89 cm⁻¹. -1 An asymmetric contraction vibration peak of -CH2- appears at 2851.16 cm⁻¹. -1 The appearance of a symmetric contraction vibration peak of -CH2- at this point indicates the presence of an alkyl group. Furthermore, a peak at 1600 cm⁻¹... -1 and 1450 cm -1 A new absorption peak appeared, which is attributed to the skeletal vibration of the benzene ring in the SiO2-Po-Oc structure. In summary, most of the hydroxyl groups on the silica gel surface have been successfully bonded to functional groups.

[0033] SEM comparison of SiO2 (acidified silica gel) and SiO2-Po-Oc, for example Figure 3 As shown. By Figure 3 It can be seen that the silicone particles were not damaged before and after bonding, and their shape was intact with uniform particle size.

[0034] Example 2: SiO2-Po-Oc was used as a reversed-phase chromatography packing column for the separation of polycyclic aromatic hydrocarbons.

[0035] The SiO2-Po-Oc obtained in Example 1 and commercial SiO2-C8 (octyl-bonded silica gel packing material) were packed into two 4.6 × 50 mm columns respectively using conventional packing methods in the art. Polycyclic aromatic hydrocarbons (including naphthalene, biphenyl, fluorene, phenanthrene, anthracene, o-terphenyl, fluoranthene, pyrene, m-terphenyl, p-terphenyl, 9,10-benzophenanthrene, and 1,2-benzophenanthrene) were separated in reversed-phase chromatography mode, and the separation performance was evaluated using high-performance liquid chromatography-ultraviolet detection.

[0036] The chromatographic conditions were as follows: mobile phase was acetonitrile / water (55 / 45, v / v), isocratic elution; flow rate was 1.5 mL / min; column temperature was 30℃; detection wavelength was 210 nm; and injection volume was 5 μL.

[0037] Figure 4This is a chromatogram of the separation of polycyclic aromatic hydrocarbons using two different silica gel packing materials as the stationary phase of reversed-phase high-performance liquid chromatography. Peak 4-1 is naphthalene, peak 4-2 is biphenyl, peak 4-3 is fluorene, peak 4-4 is phenanthrene, peak 4-5 is anthracene, peak 4-6 is o-terphenyl, peak 4-7 is fluoranthene, peak 4-8 ​​is pyrene, peak 4-9 is m-terphenyl, peak 4-10 is p-terphenyl, peak 4-11 is 9,10-benzophenanthrene, and peak 4-12 is 1,2-benzophenanthrene.

[0038] Figure 4 Experimental results show that, under the same mobile phase, elution method, flow rate and column temperature conditions, the SiO2-Po-Oc reversed-phase chromatography packing prepared in Example 1 has a significantly better separation effect on polycyclic aromatic hydrocarbons. Adjacent chromatographic peaks can achieve baseline separation and the peak shapes are all good. In contrast, the commercial SiO2-C8 reversed-phase chromatography packing has a poorer separation effect on polycyclic aromatic hydrocarbons (some components have longer retention times and diffuse chromatographic peak shapes).

[0039] Example 3: SiO2-Po-Oc was used as a reversed-phase chromatography packing column for the separation of phenyl ester compounds.

[0040] The SiO2-Po-Oc obtained in Example 1 and commercial SiO2-C8 (octyl-bonded silica gel packing material) were packed into two 4.6 × 50 mm columns respectively using conventional packing methods in the art. Phenyl esters (including dimethyl phthalate, diethyl phthalate, ethyl acetate, 3,5-dichlorophenyl isocyanate, diisobutyl phthalate, dibutyl phthalate, and dibenzyl phthalate) were separated in reversed-phase chromatography mode, and the separation performance was evaluated using high-performance liquid chromatography-ultraviolet detection.

[0041] The chromatographic conditions were as follows: mobile phase was acetonitrile / water (55 / 45, v / v), isocratic elution; flow rate was 1.5 mL / min; column temperature was 30℃; detection wavelength was 210 nm; and injection volume was 5 μL.

[0042] Figure 5 This is a chromatogram of the separation of phenyl esters using two different silica gel packing materials as the stationary phase of reversed-phase high-performance liquid chromatography. Peak 5-1 is dimethyl phthalate, peak 5-2 is diethyl phthalate, peak 5-3 is ethyl acetate, peak 5-4 is 3,5-dichlorophenyl isocyanate, peak 5-5 is diisobutyl phthalate, peak 5-6 is dibutyl phthalate, and peak 5-7 is dibenzyl phthalate.

[0043] Figure 5Experimental results show that, under the same mobile phase, elution method, flow rate and column temperature conditions, the SiO2-Po-Oc reversed-phase chromatography packing prepared in Example 1 achieved good separation of seven phenyl esters, and the separation speed was faster, which was significantly better than that of commercial SiO2-C8 reversed-phase chromatography packing for the separation of phenyl esters.

[0044] Example 4: SiO2-Po-Oc was used as a reversed-phase chromatography packing column for the separation of aniline compounds.

[0045] The SiO2-Po-Oc obtained in Example 1 and commercial SiO2-C8 (octyl-bonded silica gel packing material) were packed into two 4.6 × 50 mm columns respectively using conventional packing methods in the art. Aniline compounds were separated in reversed-phase chromatography mode, and the separation performance was evaluated using high-performance liquid chromatography-ultraviolet detection.

[0046] Acetonitrile / 0.1% sodium dihydrogen phosphate aqueous solution (55 / 45, v / v) was used as the mobile phase, with isocratic elution, flow rate of 1.0 mL / min, column temperature of 30℃, detection wavelength of 210 nm, and injection volume of 5 μL.

[0047] Figure 6 This is a chromatogram of the separation of aniline compounds using two different silica gel packing materials as reversed-phase high-performance liquid chromatography stationary phases; peak 6-1 is benzidine, peak 6-2 is 2-naphthylamine, peak 6-3 is 1-naphthylamine, peak 6-4 is 4-nitroaniline, peak 6-5 is o-chloroaniline, peak 6-6 is p-chloroaniline, and peak 6-7 is 2,4-dinitroaniline.

[0048] Figure 6 Experimental results show that, under the same mobile phase, elution method, flow rate and column temperature conditions, the SiO2-Po-Oc reversed-phase chromatography packing material prepared in Example 1 can achieve baseline separation of aniline compounds, and its separation speed for aniline compounds is faster than that of commercial SiO2-C8.

[0049] The purpose of the above embodiments is to specifically illustrate the substantive content of the present invention, but those skilled in the art should know that the scope of protection of the present invention should not be limited to the specific embodiments.

Claims

1. The use of a silica gel modified with octyl and pomalidomide derivatives as a reversed-phase chromatography packing material for separating amine compounds, wherein the silica gel is based on porous spherical silica gel, and the silica gel surface is simultaneously bonded with two groups as shown in Formula I and Formula II through silicon-oxygen bonds: ； Ι; ； Ⅱ； In Equations I and II, the wavy lines represent sites connected to the surface of the silicone matrix; The amine compounds are benzidine, 2-naphthylamine, 1-naphthylamine, 4-nitroaniline, o-chloroaniline, p-chloroaniline and 2,4-dinitroaniline.

2. The use according to claim 1, characterized in that: The porous spherical silica gel has a particle size of 1-50 μm.

3. The use according to claim 2, characterized in that: The porous spherical silica gel has a particle size of 1.7-5 μm.

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