CN118754814A - Method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using supercritical fluid chromatography - Google Patents

Abstract

The invention relates to a method for preparing cis-and trans-2, 3-dimethyl cyclopropyl carboxylic acid benzyl ester by utilizing supercritical fluid chromatography, which comprises the following steps: dissolving a2, 3-dimethyl cyclopropyl carboxylic acid benzyl ester sample by using a dissolving reagent to prepare a sample solution; subjecting the sample solution to supercritical fluid chromatographic separation to prepare cis-and trans-benzyl 2, 3-dimethylcyclopropylcarboxylate respectively; the conditions for the supercritical fluid chromatographic separation include: the mobile phase is a mixture of supercritical carbon dioxide and an alkane solvent; the stationary phase comprises a silica gel surface bonded cyano groups. The invention discovers that the supercritical fluid chromatographic system is used for realizing the separation and preparation of cis-trans-2, 3-dimethylcyclopropylcarboxylic acid benzyl ester for the first time, and can replace the existing normal phase chromatographic separation method; meanwhile, the CO ₂ is more environment-friendly, the use amount of chemical reagents can be reduced, the harm to human bodies and the environment is reduced, the solvent treatment cost is greatly reduced, the cost is reduced, and the benefit is increased.

Description

Method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using supercritical fluid chromatography

Technical Field

The invention relates to the field of pharmaceutical technology, in particular to a method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester by utilizing supercritical fluid chromatography.

Background Art

Cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester are a pair of cis-trans isomers, which are oily at room temperature, thermally stable, poorly acid-base stable and solvent stable, and easily soluble in general organic reagents such as dichloromethane, ethyl acetate, petroleum ether, etc. The structural formulas of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester are as follows: The conventional method for separating cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester is normal phase chromatography, which has the disadvantages of long separation time, low separation efficiency and large amount of solvent used.

Summary of the invention

Based on this, it is necessary to provide a method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester by using supercritical fluid chromatography, which can achieve effective separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, while greatly reducing solvent consumption and being more environmentally friendly.

The technical solution is as follows:

The present invention provides a method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester by using supercritical fluid chromatography, comprising the following steps:

Dissolve the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample using a dissolving reagent to prepare a test solution;

The test solution is subjected to supercritical fluid chromatography separation to prepare cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester respectively;

The conditions for supercritical fluid chromatography separation include: the mobile phase is a mixture of supercritical carbon dioxide and alkane solvents; the stationary phase includes cyano groups bonded to the surface of silica gel.

In one embodiment, the volume ratio of the supercritical carbon dioxide to the alkane solvent is (97-100): (3-0).

In one embodiment, the alkane solvent includes n-hexane and/or n-heptane.

In one embodiment, the supercritical fluid chromatography separation uses isocratic elution.

In one embodiment, the supercritical fluid chromatography separation conditions include: column temperature is 20°C-45°C.

In one embodiment, the supercritical fluid chromatography separation conditions include: the back pressure of the supercritical fluid chromatography system is set to 8Mpa-15Mpa.

In one embodiment, the supercritical fluid chromatography separation conditions include: a flow rate of 5 mL/min-10 mL/min.

In one embodiment, the conditions for supercritical fluid chromatography separation include: an injection volume of 10 μL-100 μL; and/or a detection wavelength of 200 nm-220 nm.

In one embodiment, the dissolving agent includes one or more of n-hexane, n-heptane and dichloromethane.

In one embodiment, the concentration of the test solution is 50 mg/mL-250 mg/mL.

Compared with the prior art, this application has the following beneficial effects:

1. The present application has discovered a method for separating cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system, which can replace the existing high performance liquid chromatography method;

2. The use of _CO2 in this application can reduce the use of organic reagents, and the critical temperature and pressure of _CO2 are compatible with chromatographs, and it is non-destructive to the compounds to be analyzed and purified, has low reactivity, low toxicity, and is non-flammable. _CO2 itself is abundant and cheap, which is more environmentally friendly, reduces harm to the human body and the environment, and also greatly reduces the cost of solvent treatment in subsequent drug production;

3. The method provided in the present application can reduce the use of chemical reagents while quickly processing a large number of samples, thereby achieving less cost investment and more benefit output; at the same time, the method provided in the present application has a short separation time and a good separation effect, and the purity of the separated cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester can reach more than 98%, and has broad application prospects in the field of separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a separation spectrum obtained after supercritical fluid chromatography separation of cis-trans 2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 1.

FIG. 2 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 1.

FIG3 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 1.

FIG4 is a separation spectrum obtained after supercritical fluid chromatography separation of cis-trans 2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 2.

FIG5 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 2.

FIG6 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 2.

FIG. 7 is a separation spectrum obtained after supercritical fluid chromatography separation of cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 3.

FIG8 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 3.

FIG. 9 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 3.

FIG. 10 is a separation spectrum obtained after supercritical fluid chromatography separation of cis-trans isomers of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Example 4.

FIG. 11 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 4.

FIG. 12 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 4.

FIG. 13 is a separation spectrum obtained after supercritical fluid chromatography separation of cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 5.

FIG. 14 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 5.

FIG. 15 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 5.

FIG. 16 is a separation spectrum obtained after supercritical fluid chromatography separation of cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 6.

FIG. 17 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 6.

FIG. 18 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 6.

FIG. 19 is a separation spectrum obtained after supercritical fluid chromatography separation of cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester isomers in Example 7.

FIG. 20 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 7.

FIG. 21 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Example 7.

Figure 22 is the separation spectrum obtained after the cis-trans isomers of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Comparative Example 1 were separated by supercritical fluid chromatography.

FIG. 23 is a detection spectrum of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Comparative Example 1.

FIG. 24 is a detection spectrum of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester obtained by supercritical fluid chromatography separation in Comparative Example 1.

DETAILED DESCRIPTION

The present application is further described in detail below in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

Herein, “further”, “furthermore”, “particularly”, etc. are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present invention.

In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

The percentage content involved in the present invention, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.

The percentage concentrations involved in the present invention, unless otherwise specified, refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

The temperature parameters in the present invention, if not specifically limited, allow both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±2°C, ±1°C, ±0.5°C, ±0.4°C, ±0.3°C, ±0.2°C, ±0.1°C are allowed. Normal temperature or room temperature in the present invention refers to no temperature control operation, generally 4°C to 35°C, preferably 20±5°C.

Supercritical fluid chromatography (SFC) is a chromatographic method that uses a supercritical fluid as a mobile phase and a solid adsorbent (such as silica gel) or an organic high molecular polymer bonded to a carrier as a stationary phase. At present, supercritical fluid chromatography (SFC) uses carbon dioxide in a supercritical state instead of an organic reagent. With the unique physicochemical properties of supercritical carbon dioxide, it is used in stereoisomerization, analysis of petroleum products, separation of lipids and natural products, and pharmaceutical and food analysis. However, there is currently no method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using SFC.

The technicians of the present application unexpectedly discovered during the research process that, based on the differences in the chemical properties of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and benzyl chloroacetate, they have different distribution coefficients in a system consisting of a stationary phase and a mobile phase. When the two phases interact with each other, these substances move together with the mobile phase and are repeatedly distributed between the two phases, thereby achieving separation of the substances. Based on this, the present application uses a mixture of supercritical carbon dioxide and an alkane solvent as a mobile phase, utilizes the unique mobile phase properties of supercritical _CO2 mixed with an alkane solvent, and selects a suitable stationary phase to achieve complete separation and preparation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and has broad application prospects in the separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and other impurities present in 2,3-dimethylcyclopropylcarboxylic acid benzyl ester samples, such as benzyl chloroacetate.

The present invention provides a method for preparing cis- and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester by using supercritical fluid chromatography, comprising the following steps:

Dissolve the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample using a dissolving reagent to prepare a test solution;

The test solution is subjected to supercritical fluid chromatography separation to prepare cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester respectively;

The conditions for supercritical fluid chromatography separation include: the mobile phase is a mixture of supercritical carbon dioxide and alkane solvents; the stationary phase includes cyano groups bonded to the surface of silica gel.

In some of the examples, the composition of the benzyl 2,3-dimethylcyclopropylcarboxylate sample includes cis-benzyl 2,3-dimethylcyclopropylcarboxylate, trans-benzyl 2,3-dimethylcyclopropylcarboxylate and benzyl chloroacetate, as well as other related impurities.

In some of the examples, the volume ratio of the supercritical carbon dioxide to the alkane solvent is (97-100):(3-0). Further, the volume ratio of the supercritical carbon dioxide to the alkane solvent is (98-100):(2-0). It can be understood that the volume ratio of the supercritical carbon dioxide to the alkane solvent is 99.1:0.9, 98.5:1.5, 98.1:1.9, 97:3.

In some examples, the alkane solvent includes n-hexane and/or n-heptane.

In some examples, the supercritical fluid chromatography separation uses isocratic elution.

In some of the examples, the specifications of the chromatographic column for supercritical fluid chromatography separation are 5um, 10*250mm.

In some examples, the conditions for supercritical fluid chromatography separation include: a column temperature of 20° C.-45° C. Further, the conditions for supercritical fluid chromatography separation include: a column temperature of 25° C.-45° C. It can be understood that the column temperature for supercritical fluid chromatography separation includes but is not limited to 25° C., 30° C., 35° C., 40° C., 45° C.

In some examples, the conditions for supercritical fluid chromatography separation include: a back pressure of 8 MPa-15 MPa. Further, the conditions for supercritical fluid chromatography separation include: a back pressure set by the supercritical fluid chromatography system is 8 MPa-10 MPa. It is understandable that the back pressure set by the supercritical fluid chromatography system includes but is not limited to 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, and 10 MPa.

In some of the examples, the conditions for the supercritical fluid chromatographic separation include: a flow rate of 5 mL/min-10 mL/min. It is understandable that the flow rate for the supercritical fluid chromatographic separation includes but is not limited to 5 mL/min, 6 mL/min, 7 mL/min, 8 mL/min, 9 mL/min, and 10 mL/min.

In some examples, the conditions for supercritical fluid chromatography separation include: an injection volume of 10 μL-100 μL. It is understandable that the injection volume for supercritical fluid chromatography separation includes but is not limited to 10 μL, 20 μL, 30 μL, 40 μL, 50 μL, 60 μL, 70 μL, 80 μL, 90 μL, 100 μL.

In some examples, the conditions for supercritical fluid chromatography separation include: a detection wavelength of 200nm-220nm. It can be understood that the detection wavelength of supercritical fluid chromatography separation includes but is not limited to 200nm, 210nm, 215nm, and 220nm.

In some examples, the dissolving agent includes one or more of n-hexane, n-heptane and dichloromethane.

In some examples, the concentration of the test solution is 50 mg/mL-250 mg/mL. It is understandable that the concentration of the test solution includes but is not limited to 50 mg/mL, 80 mg/mL, 110 mg/mL, 140 mg/mL, 170 mg/mL, 200 mg/mL, 230 mg/mL, 250 mg/mL.

In some examples, the supercritical fluid chromatography separation conditions include: the temperature of the carbon dioxide when passing through the pump is 5° C.-10° C. It can be understood that the temperature of the carbon dioxide when passing through the pump includes but is not limited to 5° C., 6° C., 7° C., 8° C., 9° C., and 10° C.

The following is further described in conjunction with specific embodiments. The raw materials involved in the following specific embodiments, unless otherwise specified, can all be commercially available; the instruments used, unless otherwise specified, can all be commercially available; the processes involved, unless otherwise specified, are all routinely selected by those skilled in the art.

The present invention is further described in detail below in conjunction with specific examples. For experimental parameters not specified in the following specific examples, reference is made to the instructions given in the present application document, and reference may also be made to the experimental manuals in the art or other experimental methods known in the art, or to the experimental conditions recommended by the manufacturer. It is understood that the instruments and raw materials used in the following examples are relatively specific, and may not be limited thereto in other specific examples.

The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample used in the examples and comparative examples is derived from chemical synthesis and can be prepared by referring to the existing literature method. The purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in the sample is 27%, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester is 60%, and the purity of benzyl chloroacetate is 13%.

The following are specific embodiments.

Example 1

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 10Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 1-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 1.

Table 1-1 SFC separation conditions in Example 1

The specific steps corresponding to Example 1 are as follows: dissolving the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample in n-hexane, ultrasonic dissolution, configuring into a 205 mg/mL solution, and filtering with a nylon membrane with a pore size of 0.45 microns, using Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) as a chromatographic column on a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., controlling the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column according to Table 1-1, and ensuring that the temperature of carbon dioxide entering the pump is 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in FIG1 , and baseline separation can be achieved.

Table 1-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 1

As shown in Table 1-2, the peak with a retention time of 4.18 min in Figure 1 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 5.31 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, indicating that the method can achieve complete separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in Figure 2 and Table 1-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in Figure 3 and Table 1-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.689%.

Table 1-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 2

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.227 4814.394 684.331 100

Table 1-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 3

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 11.273 12.370 0.036 0.311 14.627 3965.151 575.176 99.689

Example 2

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 10Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 2-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 2.

Table 2-1 SFC separation conditions in Example 2

The specific steps corresponding to Example 2 are: dissolving the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample in n-hexane, ultrasonic dissolution, configuring into a 205mg/mL solution, and filtering with a nylon membrane with a pore size of 0.45 microns, using Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) as a chromatographic column on a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., controlling the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column according to Table 2-1, and ensuring that the temperature of carbon dioxide entering the pump is 6°C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in Figure 4, which can achieve baseline separation.

Table 2-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 4

As shown in Table 2-2, the peak with a retention time of 4.79 min in FIG. 4 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 6.20 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, indicating that the method can achieve complete separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in FIG. 5 and Table 2-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.284%, and as shown in FIG. 6 and Table 2-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 98.901%.

Table 2-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 5

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 14.467 33.194 5.114 0.419 15.073 7863.254 1092.784 99.284 15.940 23.503 3.008 0.297

Table 2-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 6

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 11.240 61.452 11.159 0.416 12.893 27.005 4.238 0.183 14.480 14607.777 1445.775 98.901 15.080 73.859 11.509 0.500

Example 3

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 10Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 3-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 3.

Table 3-1 SFC separation conditions in Example 3

The specific steps corresponding to Example 3 are: dissolving the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample in n-hexane, ultrasonic dissolution, configuring a 205 mg/mL solution, and filtering with a nylon membrane with a pore size of 0.45 microns, using Nucifera CN (5um, 10*250mm) (cyano bonded on the silica gel surface) as a chromatographic column on a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., controlling the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column according to Table 3-1, and ensuring that the temperature of carbon dioxide entering the pump is 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in Figure 7, which can achieve baseline separation.

Table 3-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 7

As shown in Table 3-2, the peak with a retention time of 3.79 min in FIG. 7 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 4.74 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, indicating that the method can achieve complete separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in FIG. 8 and Table 3-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in FIG. 9 and Table 3-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.488%.

Table 3-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 8

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.087 865.822 131.253 100

Table 3-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 9

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 9.847 14.941 0.122 0.512 14.513 2904.760 444.086 99.488

Example 4

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 8Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 4-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 4.

Table 4-1 SFC separation conditions in Example 4

The specific steps corresponding to Example 4 are as follows: the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is dissolved in n-hexane, ultrasonic dissolution is performed, a 205 mg/mL solution is prepared, and a nylon membrane with a pore size of 0.45 microns is used for filtration. On the supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) is selected as the chromatographic column, and the volume ratio, total flow rate, back pressure and chromatographic column temperature of the supercritical carbon dioxide and n-hexane in the mobile phase are controlled according to Table 4-1, and the temperature of the carbon dioxide entering the pump is ensured to be 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in Figure 10, and baseline separation can be achieved.

Table 4-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 10

As shown in Table 4-2, the peak with a retention time of 4.76 min in FIG. 10 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 6.12 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, indicating that the method can achieve complete separation of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in FIG. 11 and Table 4-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in FIG. 12 and Table 4-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%.

Table 4-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 11

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.107 10944.949 1422.916 100

Table 4-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 12

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 14.493 3538.708 541.287 100

Example 5

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 15Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 5-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 5.

Table 5-1 SFC separation conditions in Example 5

The specific steps corresponding to Example 5 are as follows: the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is dissolved in n-hexane, ultrasonic dissolution is performed, a 205 mg/mL solution is prepared, and a nylon membrane with a pore size of 0.45 microns is used for filtration. On the supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) is selected as the chromatographic column, and the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column are controlled according to Table 5-1, and the temperature of carbon dioxide entering the pump is ensured to be 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in FIG13, and baseline separation can be achieved.

Table 5-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 13

As shown in Table 5-2, the peak with a retention time of 3.71 min in Figure 13 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 4.56 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in Figure 14 and Table 5-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in Figure 15 and Table 5-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%.

Table 5-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 14

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.133 11309.445 1420.407 100

Table 5-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 15

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 14.447 5995.771 902.309 100

Example 6

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 10Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 6-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 6.

Table 6-1 SFC separation conditions in Example 6

The specific steps corresponding to Example 6 are: dissolving the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample in n-hexane, ultrasonic dissolution, configuring a 205 mg/mL solution, and filtering with a nylon membrane with a pore size of 0.45 microns, using Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) as a chromatographic column on a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., controlling the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column according to Table 6-1, and ensuring that the temperature of carbon dioxide entering the pump is 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in Figure 16, which can achieve baseline separation.

Table 6-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 16

As shown in Table 6-2, the peak with a retention time of 3.72 min in Figure 16 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 4.66 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in Figure 17 and Table 6-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in Figure 18 and Table 6-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.531%.

Table 6-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 17

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.153 4078.407 630.287 100

Table 6-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 18

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 9.967 22.283 3.499 0.469 14.547 4725.588 729.119 99.531

Example 7

The chromatograph used in this embodiment is a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 7mL/min, the back pressure is set to 10Mpa, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 205mg/mL, the injection volume is 30μL, and the detection wavelength is 210nm.

Table 7-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a supercritical fluid chromatography system in Example 7.

Table 7-1 SFC separation conditions in Example 7

The specific steps corresponding to Example 7 are as follows: the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is dissolved in n-hexane, ultrasonic dissolution is performed, a 205 mg/mL solution is prepared, and a nylon membrane with a pore size of 0.45 microns is used for filtration. On the supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., Nucifera CN (5um, 10*250mm) (cyano group bonded to the silica gel surface) is selected as the chromatographic column, and the volume ratio of supercritical carbon dioxide and n-hexane in the mobile phase, the total flow rate, the back pressure and the column temperature of the chromatographic column are controlled according to Table 7-1, and the temperature of carbon dioxide entering the pump is ensured to be 6° C. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in FIG. 19, and baseline separation can be achieved.

Table 7-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 19

As shown in Table 7-2, the peak with a retention time of 4.18 min in Figure 19 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 5.27 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in Figure 20 and Table 7-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%. As shown in Figure 21 and Table 7-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.523%.

Table 7-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 20

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.133 7256.078 1088.250 100

Table 7-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 21

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 9.973 18.584 2.936 0.477 14.547 3879.880 601.600 99.523

Comparative Example 1

The chromatograph used in this comparative example is a high pressure liquid chromatograph of Jiangsu Hanbang Technology Co., Ltd. The chromatographic column specification is 10*250mm, the mobile phase flow rate is 3mL/min, the concentration of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is 33mg/mL, the injection volume is 1.5mL, and the detection wavelength is 210nm.

Table 8-1 shows other relevant conditions selected in the method for separating and preparing cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester and trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester using a high pressure liquid chromatography system in Comparative Example 1.

Table 8-1 HPLC separation conditions in Comparative Example 1

The specific steps corresponding to Comparative Example 1 are as follows: dissolve the 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample in a solution of n-heptane: dichloromethane = 7:3, dissolve with ultrasonic aid, prepare a 33 mg/mL solution, and filter with a nylon membrane with a pore size of 0.45 microns, select Nucifera SI (30um, 10*250mm) (silica gel) as a chromatographic column on a supercritical fluid chromatograph of Jiangsu Hanbang Technology Co., Ltd., and control the volume ratio of dichloromethane and n-hexane in the mobile phase, the total flow rate and the column temperature of the chromatographic column according to Table 8-1. The 2,3-dimethylcyclopropylcarboxylic acid benzyl ester sample is separated, and the separation effect is shown in Figure 22. The target component can be separated, but there is a serious tailing phenomenon.

Table 8-2 Retention time and peak area of 2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 22

As shown in Table 8-2, the peak with a retention time of 19.183 min in Figure 22 is cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester, and the peak with a retention time of 31.824 min is trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester. As shown in Figure 23 and Table 8-3, the purity of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 100%, and as shown in Figure 24 and Table 8-4, the purity of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester detected by HPLC is 99.703%.

Table 8-3 Retention time and peak area of cis-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 23

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 15.127 8765.230 1257.164 100

Table 8-4 Retention time and peak area of trans-2,3-dimethylcyclopropylcarboxylic acid benzyl ester in Figure 24

Retention time (min) Peak area (mAu*s) Peak height (mAu) area(%) 9.960 19.726 3.889 0.297 14.540 6622.536 999.481 99.703

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims (10)

1. A process for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography, comprising the steps of:

dissolving a2, 3-dimethyl cyclopropyl carboxylic acid benzyl ester sample by using a dissolving reagent to prepare a sample solution;

Carrying out supercritical fluid chromatographic separation on the sample solution to prepare cis-2, 3-dimethyl cyclopropyl carboxylic acid benzyl ester and trans-2, 3-dimethyl cyclopropyl carboxylic acid benzyl ester respectively;

the conditions for the supercritical fluid chromatographic separation include: the mobile phase is a mixture of supercritical carbon dioxide and an alkane solvent; the stationary phase comprises a silica gel surface bonded cyano groups.

2. The method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to claim 1, characterized in that the volume ratio of supercritical carbon dioxide to alkane solvent is (97-100): (3-0).

3. The method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to claim 1, wherein the alkane solvent comprises n-hexane and/or n-heptane.

4. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1 to 3, characterized in that the supercritical fluid chromatography separation uses isocratic elution.

5. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1 to 3, characterized in that the conditions of supercritical fluid chromatographic separation include: the column temperature is 20-45 ℃.

6.A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1 to 3, characterized in that the conditions of supercritical fluid chromatographic separation include: the back pressure of the supercritical fluid chromatographic system is set to be 8-15 Mpa.

7. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1 to 3, characterized in that the conditions of supercritical fluid chromatographic separation include: the flow rate is 5mL/min-10mL/min.

8. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1 to 3, characterized in that the conditions of supercritical fluid chromatographic separation include: the sample injection volume is 10 mu L-100 mu L; and/or the detection wavelength is 200nm-220nm.

9. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate using supercritical fluid chromatography according to any one of claims 1-3, wherein the dissolving reagent comprises one or more of n-hexane, n-heptane and dichloromethane.

10. A method for preparing benzyl cis-and trans-2, 3-dimethylcyclopropylcarboxylate according to any one of claims 1 to 3, characterized in that the concentration of the sample solution is 50mg/mL to 250mg/mL.