A cellulose-COF chiral chromatographic stationary phase, its preparation method and application

Abstract

This invention discloses a cellulose-COF chiral chromatographic stationary phase, its preparation method, and its application, belonging to the field of chiral chromatographic separation technology. The invention uses aminopropylalkylated silica gel as a matrix, with a cellulose-COF hybrid material coated on its surface. The cellulose-COF is prepared by imidization of 6-amino-6-deoxycellulose with 4,4'-biphenyldicarboxaldehyde. The 6-amino-6-deoxycellulose is prepared by sequentially brominating, azidating, and Gabriel reducing cellulose. The preparation process of this invention is simple, the conditions are mild, and the product is stable. When applied to high-performance liquid chromatography (HPLC) in a mobile phase system such as hexane-isopropanol, baseline separation of chiral drugs such as paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine hydrochloride, and ethambutol hydrochloride can be achieved with high resolution and good reproducibility, making it suitable for the efficient separation, analysis, and purification of chiral drugs.

Description

Technical Field

[0001] This invention belongs to the field of chiral chromatography separation technology, specifically relating to a cellulose-COFs chiral chromatographic stationary phase, its preparation method, and its application. Background Technology

[0002] Enantiomers exhibit significant differences in biological interactions, pharmacology, and toxicity, making chiral compounds extremely valuable in various fields such as pharmaceuticals, chemicals, and pesticides. In the pharmaceutical industry, many drugs possess chiral active ingredients, and the enantiomers of chiral drugs typically show marked differences in pharmacological properties, metabolic processes, stability, and toxicity. For example, thalidomide's R-enantiomer has sedative effects, while its S-enantiomer poses a teratogenic risk. In the chemical industry, chiral compounds serve as key intermediates or final products, and their optical purity directly determines product quality and performance. In the pesticide field, the enantiomers of chiral pesticides exhibit different degradation and transformation behaviors in the environment and different mechanisms of action in vivo. For the same efficacy, the dosage of a single chiral isomer is far lower than that of a racemic mixture, and reducing the use of undesirable isomers can also reduce the risk of teratogenicity and hormonal imbalances. Therefore, chiral resolution is a crucial technical issue in numerous scientific and commercial applications, including forensic medicine, food science, and pharmaceuticals.

[0003] Chiral selectors (CSPs) are key functional materials that achieve chiral molecule recognition and separation based on stereoselective interactions. Their type and structure directly determine the overall separation behavior of analytes in the chromatographic system. Performance-matched chiral selectors not only achieve enantiomeric baseline separation but also optimize the interaction between the analyte and the mobile phase, improve mass transfer processes in the chromatographic system, obtain sharp, symmetrical chromatographic peaks, reduce peak broadening, and enhance detection sensitivity, accuracy, and quantitative reliability. Polysaccharide chiral selectors, with natural polysaccharides such as cellulose and starch as their core framework, can significantly enhance chiral recognition capabilities through chemical modification, making them the most widely used chromatographic stationary phase materials. Among them, cellulose and starch derivatives generally exhibit superior chiral recognition performance compared to other polysaccharide derivatives, dominating chiral separation in high-performance liquid chromatography (HPLC).

[0004] Cellulose is an optically active natural polymer formed by D-glucose units linked by β-1,4-glycosidic bonds, possessing a unique helical cavity structure. The glucose units themselves are chiral, and the polymer chain exhibits a single-handed helical conformation, making cellulose easily derivatized into highly efficient chiral recognition materials. Cellulose can provide a flexible and tunable molecular recognition strategy for the separation of chiral drug enantiomers; its cavity size is suitable, and its preparation is simple, making it widely used in molecular recognition and separation. To obtain ideal chiral separation performance, researchers typically selectively functionalize the hydroxyl groups of cellulose. The introduced substituents can provide multiple interactions, including dipole interactions, dispersing forces, hydrogen bonds, π-π stacking, and electrostatic repulsion, which synergistically enhance chiral recognition and separation capabilities with the inclusion effect of the cellulose cavity. Based on this approach, various cellulose-based chiral stationary phases have been developed and used for direct enantiomer separation in HPLC.

[0005] Although existing technologies have reported some cellulose-functionalized chiral organic polymer monolithic columns, systematic studies on cellulose-based hybrid chiral materials remain scarce, especially those based on cellulose-based hybrid single-crystal capillary columns. Functionalization modification can endow cellulose derivatives with greater cavity depth, higher solubility, and the ability to form more stable inclusion complexes with analytes, significantly improving separation efficiency. However, existing cellulose-based chiral stationary phases generally suffer from insufficient structural stability, uneven distribution of chiral sites, low degree of integration with covalent organic framework materials, and limited separation selectivity and applicability, making it difficult to meet the high-throughput, high-selectivity, and high-stability separation requirements of various chiral drugs. Therefore, there is an urgent need to develop a novel cellulose-COF hybrid chiral chromatographic stationary phase with stable structure, strong chiral recognition ability, simple preparation, and wide applicability, along with its efficient preparation method, to overcome the shortcomings of existing chiral separation materials and technologies. Summary of the Invention

[0006] The first technical problem to be solved by this invention is to provide a cellulose-COF chiral chromatographic stationary phase with good thermal stability, precision and repeatability. The second technical problem to be solved by this invention is to provide a method for preparing the cellulose-COF chiral chromatographic stationary phase with high reaction selectivity and good product purity. The third technical problem to be solved by this invention is to provide the application of the cellulose-COF chiral chromatographic stationary phase in chiral separation by high performance liquid chromatography.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A cellulose-COF chiral chromatographic stationary phase is provided, with aminopropylalkylated silica gel as the matrix and a cellulose-COF hybrid material coated on the surface; the cellulose-COF is prepared by imidization reaction of 6-amino-6-deoxycellulose and 4,4'-biphenyldicarboxaldehyde; the 6-amino-6-deoxycellulose is prepared by bromination, azidation and Gabriel reduction reaction of cellulose.

[0009] Furthermore, the coating amount of the cellulose-COF hybrid material is 10% to 20%.

[0010] Furthermore, the method for preparing the cellulose-COFs chiral chromatographic stationary phase includes the following steps:

[0011] (1) Mix cellulose with DMAc, then add LiBr, and react with NBS and PPh3 to prepare 6-bromo-6-deoxycellulose;

[0012] (2) The 6-bromo-6-deoxycellulose obtained in step (1) is reacted with sodium azide in DMSO to prepare 6-azido-6-deoxycellulose;

[0013] (3) The 6-azido-6-deoxycellulose obtained in step (2) is reacted with 3,5-dimethylphenyl isocyanate in DMAc and LiBr to prepare 6-azido-3,5-dimethylphenyl isocyanate-6-deoxycellulose;

[0014] (4) The 6-azido-3,5-dimethylphenyl isocyanate-6-deoxycellulose obtained in step (3) was reduced with sodium borohydride to obtain 6-amino-6-deoxycellulose;

[0015] (5) The 6-amino-6-deoxycellulose obtained in step (4) is reacted with 4,4'-biphenyldicarboxaldehyde in a DMAc / LiBr system to produce cellulose-COFs;

[0016] (6) Add pyridine to silica gel, then add toluene and 3-aminopropyltriethoxysilane, reflux, wash, and dry to obtain aminopropylalkylated silica gel;

[0017] (7) Wet the aminopropyl alkylated silica gel with chloroform, dissolve the cellulose-COFs in chloroform and let stand overnight, take the solution and add it to the wetted aminopropyl alkylated silica gel, add methyl benzoate and glass beads, remove the chloroform by rotary evaporation, repeat the coating, wash and dry to obtain the cellulose-COFs chiral chromatographic stationary phase.

[0018] Furthermore, in step (2), the reaction temperature is 70 °C and the reaction time is 48 h.

[0019] Furthermore, in step (4), the reduction reaction temperature is 115 °C and the reaction time is 7 h.

[0020] Furthermore, in step (7), chloroform is used as the coating solvent, and the coating is repeated 2 to 3 times.

[0021] Furthermore, the application of the cellulose-COFs chiral chromatographic stationary phase in high-performance liquid chromatography (HPLC) for chiral drug separation.

[0022] Furthermore, the chiral chromatographic stationary phase is packed into a chromatographic column for the enantiomeric separation of one or more chiral drugs selected from paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine hydrochloride, and ethambutol hydrochloride.

[0023] Furthermore, when determining paroxetine, ornidazole, econazole nitrate, carteolol hydrochloride, and ethambutol hydrochloride, the mobile phase was n-hexane-isopropanol at a volume ratio of 80:20; when determining tebuconazole and atropine sulfate, the mobile phase was n-hexane-ethanol at a volume ratio of 80:20; and when determining ephedrine hydrochloride, the mobile phase was n-hexane-isopropanol-acetic acid at a volume ratio of 80:20:0.1.

[0024] Furthermore, the flow rate was 1.0 mL / min; the column temperature was 30 ℃; and the injection volume was 5 μL.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) This invention is the first to prepare a method for preparing a chiral COF chromatographic stationary phase by polymerizing derivatized cellulose with p-biphenylaldehyde, which is economical, environmentally friendly and reusable.

[0027] (2) The chiral COFs chromatographic stationary phase prepared by the present invention has good performance, especially for the separation of eight chiral drugs, namely paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine sulfate and ethambutol hydrochloride, with a maximum separation efficiency of 4.48. Attached Figure Description

[0028] Figure 1 Synthetic route for preparing the cellulose-COFs chiral chromatographic stationary phase for this application;

[0029] Figure 2 For the present application, 6-azido-3,5-dimethyl-phenylisocyanate-6-deoxycellulose 1 H NMR spectrum;

[0030] Figure 3 The following are FT-IR images of cellulose-COFs in this application; where (a) is cellulose and (b) is cellulose-COFs.

[0031] Figure 4 The SEM and EDX spectra of cellulose-COFs-CSP in this application are shown.

[0032] Figure 5 Thermogravimetric analysis diagram of cellulose-COFs-CSP in this application;

[0033] Figure 6 The images show the high performance liquid chromatograms (a) and Van't Hoff chromatogram (b) of the paroxetine enantiomers of this application on a cellulose-COFs-CSP chiral chromatographic stationary phase at 20-40 °C.

[0034] Figure 7 Chromatograms of paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine hydrochloride, and ethambutol hydrochloride are presented in this application. Detailed Implementation

[0035] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0036] In the following examples, the preparation of the cellulose-COFs chiral chromatographic stationary phase is carried out with reference to Example 1 in patent CN110330570A for step (1) and reference to Comparative Example 1 for step (2).

[0037] The following examples use paroxetine (100357-202105), ornidazole (100608-202304), tebuconazole (BWN0040-2016), econazole nitrate (100214-202005), felodipine (100717-201904), flavanone (Lot#E2025058), ephedrine hydrochloride (171241-202310), angelica extract (MUST-22120103), angelica borneol (MUST-22080202), and prazosin hydrochloride. Naprol (100783-202303), celilolol hydrochloride (100807-200501), carteolol hydrochloride (100345-202103), citalopram hydrobromide (100790-202503), atropine sulfate (100040-201613), ethambutol hydrochloride (100165-202507), ketoprofen (100337-202505), and promethazine hydrochloride (100422-202004) were all purchased from the National Institutes for Food and Drug Control, with a purity of 99.8%.

[0038] Example 1

[0039] like Figure 1 As shown, this embodiment provides a method for preparing a cellulose-COFs chiral chromatographic stationary phase, including the following steps:

[0040] (1) Preparation of 6-bromo-6-deoxycellulose: 4 g of cellulose was mixed with 500 mL of DMAc, heated to 130 °C and stirred for 2 h, cooled to 100 °C and 56.5 g of lithium bromide (LiBr) was added, and the mixture was stirred until the cellulose was completely dissolved, forming a transparent yellow homogeneous solution. In an ice bath (0~5 °C), 16.2 g of PPh3 solution (dissolved in 100 mL of DMAc) was added, and 11.0 g of NBS solution (dissolved in 100 mL of DMAc) was added dropwise over 30 min. The mixture was stirred at 70 °C for 2 h to react. After the reaction was complete, 1.2 L of water was poured in to precipitate the precipitate. The precipitate was filtered, washed with acetone, washed three times with ethanol, and dried under vacuum to obtain 5.5 g of 6-bromo-6-deoxycellulose, with a yield of 98.7%.

[0041] (2) Preparation of 6-azido-6-deoxycellulose: 4.55 g of 6-bromo-6-deoxycellulose and 13.52 g of sodium azide (NaN3) were dissolved in 230 mL of DMSO. The solution was heated to 70 °C and stirred for 48 h until the reaction was complete. The solution was then poured into 1.0 L of water to precipitate the solid. The solid was filtered, washed three times with water, and dried under vacuum to obtain 3 g of 6-azido-6-deoxycellulose (slightly red), with a yield of 79%.

[0042] (3) Preparation of 6-azido-3,5-dimethyl-phenyl isocyanate-6-deoxycellulose: 25 mL of DMAc and 60.5 g of LiBr were added to 5 g of 6-azido-6-deoxycellulose solid, followed by 10 mL of 3,5-dimethyl-phenyl isocyanate. The mixture was heated at 90 °C for 24 h under nitrogen protection. After the reaction was stopped, 60 mL of water was added for washing, and then 80 mL of methanol was added to precipitate the solid. After filtration, the solid was washed twice with methanol, dried under vacuum at 60 °C, and yielded 9.75 g of off-white solid. 1 H NMR spectrum as shown Figure 2 As shown.

[0043] (4) Preparation of 6-amino-6-deoxycellulose: 5.63 g of 6-azido-3,5-dimethyl-phenylisocyanate-6-deoxycellulose was dissolved in 350 mL of DMSO, and then 22.88 g of sodium borohydride (NaBH4) was added. The solution was stirred at 115 °C for 7 h. After cooling to room temperature, the pH of the solution was adjusted to 3-4 with diluted hydrochloric acid, and then precipitated with sodium carbonate solution to a pH of 8-9. The solution was filtered to obtain the precipitate, which was washed with water and dried under vacuum at 60 °C to obtain 1.95 g of white solid, with a yield of 83.4%.

[0044] (5) Preparation of cellulose-COFs: 0.84 g of 6-amino-6-deoxycellulose and 110 mL of DMSO were mixed, heated to 130 °C and stirred for 2 h. The mixture was cooled to 100 °C and 28.3 g of lithium bromide was added. The mixture was then stirred at 100 °C until the cellulose was completely dissolved, forming a transparent yellow solution. Subsequently, 1.87 g of 4,4'-biphenyldicarboxaldehyde and 0.92 mL of acetic acid were added. The mixture was cooled to room temperature and stirred at low speed for 2 h. After standing, the reaction solution precipitated and solidified. After 50 h, the precipitate was precipitated with methanol. The reaction solution was washed with 120 mL of methanol, filtered, washed with 120 mL of water, and the solid was dried under reduced pressure at 50 °C for 24 h to obtain 1.66 g of product.

[0045] Depend on Figure 3 The FT-IR plot of cellulose-COFs shows that 3292 cm⁻¹ -1 Absorption corresponding to the stretching vibration of amino groups (υ) N-H ); 2914 cm -1 Corresponding carbon-hydrogen stretching vibration absorption (υ) C-H ); 1637 cm -1 Corresponding to the absorption of carbon-nitrogen double bond stretching vibration ( ); 1562 cm -1 Corresponding to the in-plane bending vibration of the carbonyl group ( ); 1030 cm -1 Corresponding to the stretching vibration absorption of COC (υ) C-O-C ).

[0046] Example 2

[0047] Preparation of aminopropylalkylated silica gel (APS):

[0048] 5 g of dry silica gel was placed in a flask, and 200 mL of pyridine was added as a catalyst. 25 mL of dry toluene and 7.5 mL of 3-aminopropyltriethoxysilane were added and refluxed at 110 °C for 12 h to remove water. After the reaction was completed, the mixture was allowed to stand at room temperature. The reaction solution was colored and transparent. It was washed with 25 mL of toluene and 100 mL of methanol in sequence, and then dried under vacuum at 60 °C for 24 h to obtain 5.84 g of APS.

[0049] Example 3

[0050] Application of cellulose-COFs-CSP:

[0051] 4.3 g of APS was moistened with chloroform. 0.645 g of cellulose-COFs was dissolved in 40 mL of chloroform solution and allowed to stand overnight. 15 mL of this solution was added to the moistened APS, followed by 0.6 mL of methyl benzoate. 15 g of glass beads were added to ensure a more uniform coating. The mixture was slowly heated to 45 °C on a rotary evaporator, and the chloroform was removed by rotary evaporation. This process was repeated twice to obtain silanized silica gel coated three times. After washing with 50 mL of ethanol for three hours, the gel was vacuum dried for 12 hours to obtain 4.61 g of chiral stationary phase with a coating weight of 15%.

[0052] Depend on Figure 4 The SEM image of cellulose-COFs-CSP shows that the silica gel surface is covered and coated with COF particles with good spherical shape, confirming the successful coating of CSP. The uniform distribution of bright spots in the EDX image (ad) of CSP represents the distribution of silicon in the inorganic component and carbon, oxygen and nitrogen in the organic component, indicating that both organic and inorganic components are well dispersed on the surface of the hybrid spheres.

[0053] Depend on Figure 5 The thermogravimetric analysis of cellulose-COFs-CSP shows that CSP begins to lose weight around 155 ℃, and when the temperature reaches 252 ℃, the mass basically stops decreasing. Within this temperature range, the weight loss percentage is 57.95%. When the temperature is below 155 ℃, the weight loss rate remains basically unchanged, indicating that CSP can exist stably in the range of 20-155 ℃.

[0054] Application examples

[0055] 1. High Performance Liquid Chromatography Conditions

[0056] Mobile phase: n-hexane-isopropanol (80:20, v / v)

[0057] Flow rate: 1.0 mL / min

[0058] Column temperature: 30 ℃

[0059] Injection volume: 5 μL

[0060] 2. Solution preparation

[0061] Take appropriate amounts of each reference standard, accurately weigh them, place them in a volumetric flask, dissolve and dilute them with methanol, filter them through a 0.22 μm microporous membrane to prepare a solution with a concentration of 1 mg / mL, and store it at 4 ℃ protected from light.

[0062] 3. Sample testing methods

[0063] Inject the reference solution under the chromatographic conditions described in the method and record the chromatogram.

[0064] 4. Screening of separation conditions

[0065] (1) Effect of alcohol modifier type on separation

[0066] Using hexane as the base phase and ethanol, n-propanol, isopropanol, and n-butanol as organic modifiers, the effects of binary mobile phase systems composed of alcohols with different carbon chain lengths and stereostructures on the enantiomeric separation behavior of eight chiral compounds, including paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine hydrochloride, and ethambutol hydrochloride, on the enantiomeric separation behavior of eight chiral compounds were systematically investigated at a flow rate of 1.0 mL / min and a temperature of 30 °C.

[0067] The retention times and resolutions of each compound in different mobile phase systems are detailed in Table 1. The results show that, under a hexane to alcohol additive volume ratio of 80:20, all eight compounds achieved baseline separation when isopropanol was used as the modifier; when ethanol was used as the modifier, four pairs of compounds (paroxetine, tebuconazole, atropine sulfate, and ephedrine hydrochloride) showed a separation trend and achieved baseline separation; when n-propanol was used as the modifier, four compounds (tebuconazole, atropine sulfate, ephedrine hydrochloride, and ethambutol hydrochloride) achieved baseline separation; and when n-butanol was used as the modifier, three pairs of isomers (tebuconazole, atropine sulfate, and ethambutol hydrochloride) achieved baseline separation. Therefore, isopropanol was chosen as the solvent, mixed with n-hexane (n-hexane-isopropanol = 80:20, v / v) for subsequent experiments.

[0068] Table 1. Effects of different alcohol modifiers on the chiral separation of enantiomers of eight drugs.

[0069]

[0070]

[0071] Note: Mobile phase A: n-hexane-isopropanol (80:20, v / v); Mobile phase B: n-hexane-ethanol (80:20, v / v); Mobile phase C: n-hexane-n-propanol (80:20, v / v); Mobile phase D: n-hexane-n-butanol (80:20, v / v); ND: Not detected.

[0072] (2) Effect of acid-base additives on separation

[0073] The effects of 0.1% acetic acid, 0.1% triethylamine, and 0.1% trifluoroacetic acid + 0.1% triethylamine on enantiomeric separation were investigated. As shown in Table 2, when the mobile phase was hexane-isopropanol-acetic acid (80:20:0.1, v / v / v), four of the eight compounds, including paroxetine, ornidazole, atropine sulfate, and ephedrine hydrochloride, showed a separation trend and achieved baseline separation. When the mobile phase was hexane-isopropanol-triethylamine (80:20:0.1, v / v / v), only atropine sulfate achieved baseline separation. When the mobile phase was hexane-isopropanol-trifluoroacetic acid-triethylamine (80:20:0.1:0.1, v / v / v / v), none of the eight drugs showed any signs of separation. Therefore, based on the above separation results and peak shape, ephedrine hydrochloride was selected using hexane-isopropanol-acetic acid (80:20:0.1, v / v / v).

[0074] Table 2. Effects of different acid-base additives on the chiral separation of enantiomers of eight drugs.

[0075]

[0076]

[0077] Note: Mobile phase A: n-hexane-isopropanol (80:20, v / v); Mobile phase B: n-hexane-isopropanol-acetic acid (80:20:0.1, v / v / v); Mobile phase C: n-hexane-isopropanol-triethylamine (80:20:0.1, v / v / v); Mobile phase D: n-hexane-isopropanol-trifluoroacetic acid-triethylamine (80:20:0.1:0.1, v / v / v / v); ND: Not detected.

[0078] (3) Effect of isopropanol content in the mobile phase on separation

[0079] Taking paroxetine and ornidazole as examples, the effect of changing the mobile phase ratio of hexane:isopropanol to 70:30, 80:20, and 90:10 on the separation results was investigated. As the proportion of isopropanol in the mobile phase decreased, the analyte retention time shortened, but the resolution did not significantly improve. Furthermore, excessively low isopropanol content easily led to peak shape deterioration and increased tailing. Considering resolution, peak shape, and analytical efficiency, hexane-isopropanol (80:20, v / v) was the optimal mobile phase ratio. The results are shown in Table 3 below.

[0080] Table 3. Effects of different mobile phase ratios on the chiral separation of paroxetine and ornidazole

[0081]

[0082] (4) Effect of column temperature on separation

[0083] The separation of the drug was observed at column temperatures ranging from 20 to 40 °C. The results are shown below. Figure 6 As temperature increased, the resolution of enantiomers gradually decreased, and severe peak tailing occurred at temperatures of 20 °C and 25 °C. The thermodynamics of enantiomer separation of paroxetine was further investigated in the temperature range of 20-40 °C. Figure 6 (a) The results showed that as the column temperature increased, the retention time of the analyte decreased significantly, while the selectivity decreased only slightly; according to the Van't Hoff formula, the relationship curve of lnk versus 1 / T was plotted. Figure 6 (b) Paroxetine was investigated, and the linear correlation coefficient obtained was higher than 0.99. This result indicates that the structure of the stationary phase did not change significantly within the temperature range covered by the experiment, and the retention behavior of enantiomers and their chiral recognition mechanism with the stationary phase remained stable. Based on the resolution and peak shape, the column temperature was finally set at 30 °C.

[0084] (5) Column stability

[0085] Taking paroxetine as an example, the stability and repeatability of the chromatographic column were investigated. Intra-day (n=6) and inter-day (n=3) precision results are shown in Table 4. The intra-day RSD value for calculated peak area was 2.37%, and the inter-day RSD value was 2.48%, indicating good instrument precision. Table 5 shows that the reproducibility of the chromatographic peak area of ​​promethazine over 6 days was 2.37%, indicating good method repeatability.

[0086] Table 4 Precision results of the chromatographic column

[0087]

[0088] Table 5 Repeatability results of CSP columns

[0089]

[0090] In summary, based on Table 6 and Figure 7 It is known that the chiral COFs chromatographic stationary phase prepared in this application has good performance, especially for the separation of eight chiral drugs: paroxetine, ornidazole, tebuconazole, econazole nitrate, ephedrine hydrochloride, carteolol hydrochloride, atropine sulfate, and ethambutol hydrochloride, with the highest separation efficiency reaching 4.48.

[0091] Table 6. Separation results of 17 drugs from cellulose-COF chiral chromatographic stationary phases.

[0092]

[0093] Note: - indicates no separation results; Mobile phase A: n-hexane-isopropanol (80:20, v / v); Mobile phase B: n-hexane-ethanol (80:20, v / v); Mobile phase C: n-hexane-isopropanol-0.1% acetic acid (80:20:0.1, v / v / v).

[0094] Comparative Example 1

[0095] Using 6-amino-6-deoxycellulose (existing technology synthesis method patent CN110330570A) as the chiral chromatographic stationary phase material, a chiral stationary phase was prepared using the above-mentioned coating method and used for HPLC chiral chromatographic separation. The results are shown in Table 7. Seventeen chiral drugs were separated: paroxetine, ornidazole, tebuconazole, econazole nitrate, felodipine, flavanone, ephedrine hydrochloride, angelica sinensis extract, angelica natrol, propranolol hydrochloride, celeprol hydrochloride, carteolol hydrochloride, citalopram hydrobromide, atropine sulfate, ethambutol hydrochloride, ketoprofen, and promethazine hydrochloride.

[0096] Table 7. Separation results of 17 drugs from the chiral chromatographic stationary phase of 6-amino-6-deoxycellulose.

[0097]

[0098] Note: - indicates no separation results; Mobile phase A: n-hexane-isopropanol (80:20, v / v); Mobile phase B: n-hexane-ethanol (80:20, v / v); Mobile phase C: n-hexane-isopropanol-0.1% acetic acid (80:20:0.1, v / v / v).

[0099] As shown in Table 7, under the same chromatographic conditions, effective baseline separation could not be achieved for any of the 17 chiral drugs, with resolution Rs all below 1.5, and some drugs showing no obvious signs of separation.

[0100] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A cellulose-COF chiral chromatographic stationary phase, characterized in that, A cellulose-COF hybrid material is coated on the surface of an aminopropylalkylated silica gel matrix; the cellulose-COF is prepared by imidization reaction of 6-amino-6-deoxycellulose and 4,4'-biphenyldicarboxaldehyde; the 6-amino-6-deoxycellulose is prepared by sequential bromination, azidation and Gabriel reduction of cellulose.

2. The cellulose-COFs chiral chromatographic stationary phase according to claim 1, characterized in that: The coating amount of the cellulose-COF hybrid material is 10%~20%.

3. The method for preparing the cellulose-COFs chiral chromatographic stationary phase according to claim 1, characterized in that: Includes the following steps: (1) Mix cellulose with DMAc, then add LiBr, and react with NBS and PPh3 to prepare 6-bromo-6-deoxycellulose; (2) The 6-bromo-6-deoxycellulose obtained in step (1) is reacted with sodium azide in DMSO to prepare 6-azido-6-deoxycellulose; (3) The 6-azido-6-deoxycellulose obtained in step (2) is reacted with 3,5-dimethylphenyl isocyanate in DMAc and LiBr to prepare 6-azido-3,5-dimethylphenyl isocyanate-6-deoxycellulose; (4) The 6-azido-3,5-dimethylphenyl isocyanate-6-deoxycellulose obtained in step (3) was reduced with sodium borohydride to obtain 6-amino-6-deoxycellulose; (5) The 6-amino-6-deoxycellulose obtained in step (4) is reacted with 4,4'-biphenyldicarboxaldehyde in a DMAc / LiBr system to produce cellulose-COFs; (6) Add pyridine to silica gel, then add toluene and 3-aminopropyltriethoxysilane, reflux, wash, and dry to obtain aminopropylalkylated silica gel; (7) Wet the aminopropyl alkylated silica gel with chloroform, dissolve the cellulose-COFs in chloroform and let stand overnight, take the solution and add it to the wetted aminopropyl alkylated silica gel, add methyl benzoate and glass beads, remove the chloroform by rotary evaporation, repeat the coating, wash and dry to obtain the cellulose-COFs chiral chromatographic stationary phase.

4. The method for preparing the cellulose-COFs chiral chromatographic stationary phase according to claim 3, characterized in that: In step (2), the reaction temperature is 70 °C and the reaction time is 48 h.

5. The method for preparing the cellulose-COFs chiral chromatographic stationary phase according to claim 3, characterized in that: In step (4), the reduction reaction temperature is 115 °C and the reaction time is 7 h.

6. The method for preparing the cellulose-COFs chiral chromatographic stationary phase according to claim 3, characterized in that: In step (7), chloroform is used as the coating solvent, and the coating is repeated 2 to 3 times.

7. The application of the cellulose-COFs chiral chromatographic stationary phase according to claim 1 in the separation of chiral drugs by high performance liquid chromatography.

8. The application according to claim 7, characterized in that: The chiral chromatographic stationary phase is packed into a chromatographic column for the enantiomeric separation of one or more chiral drugs selected from paroxetine, ornidazole, tebuconazole, econazole nitrate, atropine sulfate, carteolol hydrochloride, ephedrine hydrochloride, and ethambutol hydrochloride.

9. The application according to claim 7, characterized in that: When determining paroxetine, ornidazole, econazole nitrate, carteolol hydrochloride, and ethambutol hydrochloride, the mobile phase is n-hexane-isopropanol with a volume ratio of 80:20; when determining tebuconazole and atropine sulfate, the mobile phase is n-hexane-ethanol with a volume ratio of 80:20; and when determining ephedrine hydrochloride, the mobile phase is n-hexane-isopropanol-acetic acid with a volume ratio of 80:20:0.

1.

10. The application according to claim 7, characterized in that: The flow rate was 1.0 mL / min; the column temperature was 30 ℃; and the injection volume was 5 μL.

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