阅读说明：本技术 一种吡啶离子液体功能化β-环糊精硅胶色谱固定相的制备及应用 (Preparation and application of pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase ) 是由 邱洪灯 周行 陈佳 于 2020-08-13 设计创作，主要内容包括：本发明公开了一种吡啶离子液体功能化β-环糊精硅胶,是先将硅胶微球与异氰酸酯硅烷超声分散于无水吡啶中,在氮气或氩气氛围保护下升温至50~80℃搅拌反应24~48 h；再将β-环糊精加入上述反应体系中在60~80℃下搅拌反应24~72 h,然后将卤代异氰酸酯逐滴反应体系中,并在60~100℃下机械搅拌反应24~72 h,离心洗涤,真空干燥,得到吡啶离子液体功能化β-环糊精硅胶。色谱分离选择性能结果表明,本发明制备的吡啶离子液体功能化β-环糊精硅胶作为固定相对于双萘酚类手性物质、安息香类手性物质、醇类手性物质具有较好的手性分离选择性。(The invention discloses pyridine ionic liquid functionalized beta-cyclodextrin silica gel, which is prepared by ultrasonically dispersing silica gel microspheres and isocyanate silane in anhydrous pyridine, heating to 50-80 ℃ under the protection of nitrogen or argon atmosphere, and stirring for reaction for 24-48 h; and adding beta-cyclodextrin into the reaction system, stirring and reacting for 24-72 h at 60-80 ℃, then dropwise adding halogenated isocyanate into the reaction system, mechanically stirring and reacting for 24-72 h at 60-100 ℃, centrifugally washing, and drying in vacuum to obtain the pyridine ionic liquid functionalized beta-cyclodextrin silica gel. Chromatographic separation and selection performance results show that the pyridine ionic liquid functionalized beta-cyclodextrin silica gel prepared by the invention has better chiral separation selectivity for dinaphthol chiral substances, benzoin chiral substances and alcohol chiral substances as a stationary phase.)

1. A pyridine ionic liquid functionalized beta-cyclodextrin silica gel has a structural formula as follows:

in the formula, R₁Is methoxy or ethoxy; x is Cl or Br; m =2 or 3.

2. The preparation method of pyridine ionic liquid functionalized beta-cyclodextrin silica gel as claimed in claim 1, comprising the steps of ultrasonically dispersing silica gel microspheres and isocyanate silane in anhydrous pyridine, heating to 50-80 ℃ under the protection of nitrogen or argon atmosphere, stirring and reacting for 24-48 h; and adding beta-cyclodextrin into the reaction system, stirring and reacting for 24-72 h at 60-80 ℃, then dropwise adding halogenated isocyanate into the reaction system, mechanically stirring and reacting for 24-72 h at 60-100 ℃, centrifugally washing, and drying in vacuum to obtain the pyridine ionic liquid functionalized beta-cyclodextrin silica gel.

3. The method for preparing pyridine ionic liquid functionalized beta-cyclodextrin silica gel according to claim 2, wherein the method comprises the following steps: the structural formula of the isocyanate silane coupling agent is as follows:

in the formula, R₁Is methoxy or ethoxy.

4. The method for preparing pyridine ionic liquid functionalized beta-cyclodextrin silica gel according to claim 2, wherein the method comprises the following steps: the mass ratio of the silica gel microspheres to the isocyanate silane is 1: 0.8-1: 1.2.

5. The method for preparing pyridine ionic liquid functionalized beta-cyclodextrin silica gel according to claim 2, wherein the method comprises the following steps: the mass ratio of the isocyanate silane to the beta-cyclodextrin is 1: 0.7-1: 1.1.

6. The method of claim 2, wherein the halogenated isocyanate has a formula of:

in the formula, X is Cl or Br; m =2 or 3.

7. The method for preparing pyridine ionic liquid functionalized beta-cyclodextrin silica gel according to claim 2, wherein the mass ratio of isocyanate silane to halogenated isocyanate is 1: 0.6-1: 1.0.

8. The pyridine ionic liquid functionalized beta-cyclodextrin silica gel as claimed in claim 1, which is used as a chromatographic stationary phase for separating the chiral substances of the bis-naphthols.

9. The pyridine ionic liquid functionalized beta-cyclodextrin silica gel as claimed in claim 1, which is used as a chromatographic stationary phase for separation of benzoin chiral substances.

10. The pyridine ionic liquid functionalized beta-cyclodextrin silica gel as claimed in claim 1, which is used as a chromatographic stationary phase for separating alcohol chiral substances.

Technical Field

The invention relates to preparation and application of a liquid chromatography stationary phase, in particular to preparation and application of a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatography stationary phase serving as a bonding phase, and belongs to the technical field of novel chromatography stationary phases.

Background

Since the emergence of the "seal baby" event in europe over the 50 s of the last century, the demands of people on the separation and analysis of chiral drugs have been increasing, and the separation and analysis of enantiomers of active ingredients required in drugs plays an important role in drug development. High Performance Liquid Chromatography (HPLC) is one of the important methods for separating and analyzing enantiomers of synthetic drugs and natural products, and mainly depends on the innovation of chiral chromatographic stationary phases, so the development of novel chiral chromatographic packing is the core for promoting the application of chromatographic separation and analysis technology in new drug development.

Beta-cyclodextrin (beta-cyclodextrin, beta-CD) is a cyclic compound formed by combining 7 glucose residues with beta-1, 4-glycosidic bonds, also called cyclomaltoheptaose, and is a molecule with a special structure of a hydrophobic inner surface and a hydrophilic outer surface, wherein an inner cavity of the molecule can be matched with a molecular weight of 200-400 g mol^-1The object molecules form inclusion compounds, hydroxyl functional groups at the edges of the object molecules are easily modified by various types of substituent groups to form cyclodextrin derivatives with enhanced chirality, and the characteristics enable the cyclodextrin and the derivatives thereof to be used as chiral selection agents in the chiral separation fields of liquid chromatography, gas chromatography, capillary electrophoresis and the like.

Ionic Liquids (ILs) are non-molecular substances composed of organic cations and anions, are generally liquid at normal temperature and normal pressure, and have replaceability and modifiability of anions and cations, so that the Ionic liquids are successfully applied to various fields. The ionic liquid can generate hydrophobic (hydrophilic), electrostatic, ion exchange, pi-pi stacking, hydrogen bond interaction and other effects with different types of compounds, and a large amount of functionalized ionic liquid is used as an additive or modified molecules on the surface of a stationary phase in the field of chromatographic separation analysis at present and shows excellent chromatographic separation performance.

However, the preparation method of the ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase is complex, and each step of experiment needs separation and purification, and the process is complicated. Therefore, the invention provides a simple preparation method, and the novel pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase is prepared by adopting a one-pot method.

Disclosure of Invention

The invention aims to provide a preparation method of pyridine ionic liquid functionalized beta-cyclodextrin silica gel.

The invention also aims to research the chiral chromatographic separation performance of the pyridine ionic liquid functionalized beta-cyclodextrin silica gel as a chromatographic stationary phase.

Preparation of pyridine ionic liquid functionalized beta-cyclodextrin silica gel

The preparation method of pyridine ionic liquid functionalized beta-cyclodextrin silica gel comprises the steps of ultrasonically dispersing silica gel microspheres and isocyanate silane in anhydrous pyridine, heating to 50-80 ℃ under the protection of nitrogen or argon atmosphere, and stirring for reaction for 24-48 hours; and adding beta-cyclodextrin into the reaction system, stirring and reacting for 24-72 h at 60-80 ℃, then dropwise adding halogenated isocyanate into the reaction system, mechanically stirring and reacting for 24-72 h at 60-100 ℃, centrifugally washing, and drying in vacuum to obtain the pyridine ionic liquid functionalized beta-cyclodextrin silica gel.

The structural formula of the isocyanate silane coupling agent is as follows:

in the formula, R₁Is methoxy or ethoxy.

The mass ratio of the silica gel microspheres to the isocyanate silane is 1: 0.8-1: 1.2.

The mass ratio of the isocyanate silane to the beta-cyclodextrin is 1: 0.7-1: 1.1.

The halogenated isocyanate has a structural formula as follows:

in the formula, X is Cl or Br; m =2 or 3;

the mass ratio of the isocyanate silane to the halogenated isocyanate is 1: 0.6-1: 1.0.

The structural formula of the obtained pyridine ionic liquid functionalized beta-cyclodextrin silica gel is as follows:

in the formula, R₁Is methoxy or ethoxy; x is Cl or Br; m =2 or 3.

The structural formula shows that one end of the pyridine ionic liquid functionalized beta-cyclodextrin silica gel modifies the pyridine ionic liquid functionalized beta-cyclodextrin silica gel on the surface of the beta-cyclodextrin modified silica gel through reaction with hydroxyl, and the other end of the pyridine ionic liquid functionalized beta-cyclodextrin silica gel modifies the pyridine ionic liquid functionalized beta-cyclodextrin silica gel through nucleophilic substitution reaction.

Structural representation of pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase

Table 1 shows the results of elemental analysis of the products of each step in the chromatographic stationary phase of pyridine ionic liquid functionalized beta-cyclodextrin silica gel. Comprises three materials of silica gel microspheres, beta-cyclodextrin modified silica gel and pyridine ionic liquid functionalized beta-cyclodextrin silica gel. The element analysis result shows that the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase is successfully prepared.

Chiral chromatographic separation performance of pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase

1. Separation of bis-naphthols chiral substances

FIG. 1 and FIG. 2 are chromatograms of pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase for chiral mixture I (R/S) -bisnaphthol and chiral mixture II (R/S) -dibromobisnaphthol, respectively, in a reversed phase mode. Wherein the chromatographic conditions of figure 1 are: mobile phase: methanol-water (30/70, v/v); wavelength: 218 nm; column temperature: 30 ℃; flow rate: 0.8 mL/min. The chromatographic conditions of FIG. 2 were: mobile phase: methanol-water (40/60, v/v); wavelength: 218 nm; column temperature: 30 ℃; flow rate: 0.8 mL/min). As can be seen from the figure, the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic immobilization prepared by the invention has good chiral separation selectivity relative to the bis-naphthol isomer.

2. Separation of benzoin chiral substances

Fig. 3 and fig. 4 are chromatograms of two pairs of chiral benzoin substances separated by a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase in a reversed phase mode, respectively. FIG. 3 shows benzoin methyl ether, the chromatographic conditions are mobile phase: methanol-water (30/70, v/v); wavelength: 218 nm; column temperature: 30 ℃; flow rate: 0.8 mL/min. FIG. 4 shows benzoin ethyl ether, the chromatographic conditions are mobile phase: methanol-water (40/60, v/v), other conditions were the same as in FIG. 3. The result shows that the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic immobilization prepared by the invention also has better separation selectivity compared with benzoin chiral compounds.

3. Separation of chiral substances from alcohols

Fig. 5 to 7 are chromatograms of four pairs of alcohol chiral substances separated by a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase in a reversed phase mode. Fig. 5 shows salbutamol, chromatographic conditions are mobile phase: methanol-water (40/60, v/v); wavelength: 218 nm; column temperature: 30 ℃; flow rate: 0.8 mL/min. FIG. 6 shows hexaconazole under the same chromatographic conditions as in FIG. 5. Fig. 7 shows the naphthyl ethanol, and the chromatographic conditions are that the detection wavelength is: 218nm, the rest conditions are the same as in FIG. 6. The result shows that the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase prepared by the invention can successfully realize the baseline separation of three alcohol chiral substances.

In summary, the present invention has the following advantages over the prior art:

1. the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase has high bonding amount of each element, has higher chiral resolution capability on chiral compounds of different types in a reversed phase mode, and has good market application prospect;

2. the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase is prepared by adopting a one-pot method, the raw materials are cheap and easy to obtain, the preparation process is simple and convenient, the operation is easy, and the commercial batch production is favorably realized.

Drawings

FIG. 1 is a chromatogram separation diagram of (R/S) -binaphthol on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 2 is a chromatogram separation diagram of (R/S) -dibromo-binaphthol on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 3 is a chromatogram separation chart of (R/S) -benzoin methyl ether on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 4 is a chromatogram separation chart of (R/S) -benzoin ethyl ether on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 5 is a chromatogram separation chart of (R/S) -salbutamol on pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 6 is a chromatogram separation chart of (R/S) -hexaconazole on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

FIG. 7 is a chromatogram separation chart of (R/S) -naphthyl alcohol on a pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatogram stationary phase.

Detailed Description

The preparation method of the pyridine ionic liquid functionalized beta-cyclodextrin silica gel chromatographic stationary phase is further explained by the following specific examples.