Pyrazole-pyrrole atropisomer and synthesis method thereof

Abstract

The invention belongs to the technical field of organic chemical synthesis, and particularly discloses a pyrazole-pyrrole atropisomer and a synthesis method thereof.The structure of the pyrazole-pyrrole atropisomer is as shown in the formula I. The method comprises the steps that 1, 4-diketone derivatives, aminopyrazole and a chiral protonic acid catalyst are sequentially added into a dry reaction container, stirring is performed for 1-3 h, and a reaction solution is obtained; and then adding an organic solvent as a reaction medium, and stirring at a certain temperature until the reaction is finished to obtain the axially chiral pyrazole-pyrrole atropisomer. The synthesis method disclosed by the invention has the advantages of high target compound yield, easiness in purification, excellent enantioselectivity, wide substrate application range, simplicity and convenience in post-treatment and the like.

Description

Technical Field

[0001] This invention relates to the field of organic chemical synthesis technology, specifically to a pyrazole-pyrrole-based transisomer and its synthesis method. Background Technology

[0002] Trans-restricted isomers are widely found in natural products, bioactive molecules, chiral ligands, organocatalysts, and functional materials. In recent years, the enantioselective synthesis of various trans-restricted isomers, especially biaryl trans-restricted isomers, has attracted considerable attention. Although synthetic chemists have developed strategies, including transition metal-catalyzed and organocatalytic strategies, for the asymmetric construction of six-membered biaryl trans-restricted isomers and have made significant progress, research on five-membered-five-membered heterobiaryl trans-restricted isomers remains in its early stages due to their low rotational energy barriers and poor conformational stability. Currently, only a few examples exist of transition metal-catalyzed kinetic resolution and organocatalytic recyclization strategies for the asymmetric synthesis of indole derivative trans-restricted isomers; reliable methods are still lacking for the synthesis of pyrazole-pyrrole trans-restricted isomers containing polynitrogen heteroatoms, which have even lower axial stability.

[0003] Furthermore, pyrazoles and pyrroles, as two important five-membered nitrogen-containing heterocycles, possess significant insecticidal, antibacterial, antitumor, and antifungal bioactivities. However, in medicinal chemistry, only one enantiomer typically functions. Therefore, the asymmetric synthesis of pyrazole-pyrrole transisomers holds promise not only for obtaining molecular entities with both structural novelty and biological functionality but also for developing novel chiral catalysts or functional materials. However, due to the aforementioned conformational instability and synthetic difficulty, there is currently no efficient and universal asymmetric catalytic method for constructing such axially chiral five-membered heterocyclic aromatic systems. Therefore, finding a method for synthesizing axially chiral pyrazole-pyrrole transisomers with high yield, excellent enantioselectivity, and broad substrate applicability is particularly important. Summary of the Invention

[0004] The present invention addresses the various problems mentioned in the background section by providing a method for synthesizing pyrazole-pyrrole-based transisomers with high yield, excellent enantioselectivity, and broad substrate applicability.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a pyrazole-pyrrole-based transisomer, wherein the structure of the pyrazole-pyrrole-based transisomer is as follows:

[0006]

[0007] Among them, R, R 1 R 2 R 4 All are selected from any one of aryl, heterocyclic aryl, substituted aryl, alkyl, and substituted alkyl; the R 3It is selected from any one of alkyl esters, aryl esters and benzyl esters; the aryl, substituted aryl and heterocyclic aryl are phenyl, naphthyl, thiophene or furanyl; the substituent of the ester group is any one of saturated alkyl, aryl or substituted aryl; the substituent of the substituted alkyl and substituted aryl are any one or more of halogen atom, saturated alkyl, alkoxy, phenyl, substituted phenyl, naphthyl, thiophene, furanyl, alkenyl and alkynyl.

[0008] As an improvement, the synthesis method specifically includes sequentially adding a 1,4-diketone derivative, an aminopyrazole, a chiral protic acid, and a reaction solvent to a dry reaction flask, stirring at a certain temperature until the reaction is complete, and separating by column chromatography to obtain the axially chiral pyrazole-pyrrole-based transisomer. The reaction formula is as follows:

[0009]

[0010] As an improvement, the chiral protic acid has at least one of the following structural formulas:

[0011]

[0012] Wherein, Ar is selected from substituted phenyl, naphthyl, anthraceneyl, phenanthryl and pyrene; the substituent of the substituted phenyl is one of monosubstituted or polysubstituted halogen atoms, saturated alkyl, trifluoromethyl, aryl or alkoxy.

[0013] As an improvement, the aminopyrrole is any one of the following VII structural formulas:

[0014]

[0015] As an improvement, the aminopyrrole is any one of the following VIII structural formulas:

[0016]

[0017] As an improvement, the molar ratio of the 1,4-dione derivative, aminopyrazole, and chiral protic acid is 1.0:(1.0-3.0):(0.02-0.20).

[0018] As an improvement, the solvent is selected from any one or more of dichloromethane, trichloromethane, carbon tetrachloride, 1,2-dichloroethane, diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, and acetonitrile.

[0019] As an improvement, the reaction time is 24-72 h.

[0020] As an improvement, the reaction temperature is -30 to 30°C.

[0021] As an improvement, column chromatography purification was performed using a mixed solvent of petroleum ether / ethyl acetate or petroleum ether / dichloromethane.

[0022] The advantages of this invention compared to the prior art are:

[0023] This invention provides a method for the efficient and highly enantioselective synthesis of pyrazole-pyrrole-based transisomers. This technique utilizes a chiral protic acid as a small organic molecule catalyst to catalyze the cyclization condensation reaction between a 1,4-diketone derivative and an aminopyrazole, successfully constructing axially chiral pyrazole-pyrrole-based transisomers. The method employs mild reaction conditions (temperature range -30 to 30°C), moderate reaction time (24–72 hours), and is applicable to substrates with various substituents (such as aryl, heterocyclic aryl, alkyl, and various ester groups), exhibiting good substrate versatility and functional group compatibility. Common organic solvents are used (such as dichloromethane, toluene, acetonitrile, etc.), and high-purity target products can be obtained through conventional column chromatography (petroleum ether / ethyl acetate or petroleum ether / dichloromethane system). This synthetic strategy not only avoids the use of metal catalysts, aligns with the trend of green chemistry, and possesses broad substrate universality, but also achieves efficient and diverse construction of axial chiral elements, providing an important structural platform and technical support for the development of novel chiral functional molecules, drug intermediates, and chiral catalysts. Attached Figure Description

[0024] Figure 1 The compound (3aa) prepared in Example 1 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography;

[0025] Figure 2 The compound (3ab) prepared in Example 2 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography;

[0026] Figure 3 The compound (3ac) prepared in Example 3 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography;

[0027] Figure 4 The compound (3ad) prepared in Example 4 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography;

[0028] Figure 5 The compound (3ae) prepared in Example 5 of this invention 1 H NMR,13 C NMR data and high performance liquid chromatography.

[0029] Figure 6 The compound (3ba) prepared in Example 6 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography.

[0030] Figure 7 The compound (3ca) prepared in Example 7 of this invention 1 H NMR, 13 Data from C NMR and high-performance liquid chromatography.

[0031] Figure 8 The compound (3da) prepared in Example 8 of this invention 1 H NMR, 13 C NMR data and high performance liquid chromatography; Detailed Implementation

[0032] This invention provides a pyrazole-pyrrole-based transisomer, the structure of which is as follows:

[0033]

[0034] Among them, R, R 1 R 2 R 4 All are selected from any one of aryl, heterocyclic aryl, substituted aryl, alkyl and substituted alkyl;

[0035] R 3 Selected from any one of alkyl esters, aryl esters, and benzyl esters;

[0036] The aryl, substituted aryl, and heterocyclic aryl groups are phenyl, naphthyl, thiophene, or furanyl.

[0037] The substituent of the ester group is any one of saturated alkyl, aryl, or substituted aryl;

[0038] The substituents of the substituted alkyl and substituted aryl groups are any one or more selected from halogen atoms, saturated alkyl groups, alkoxy groups, phenyl groups, substituted phenyl groups, naphthyl groups, thiophenyl groups, furanyl groups, alkenyl groups, and alkynyl groups.

[0039] A 1,4-diketone derivative, aminopyrazole, a chiral protic acid, and a reaction solvent were added sequentially to a dry reaction flask. The mixture was stirred at a certain temperature until the reaction was complete. Separation by column chromatography yielded the axially chiral pyrazole-pyrrole-based transisomers. The reaction process is as follows:

[0040]

[0041] The structural formula of the chiral protic acid is as follows:

[0042]

[0043] Ar is selected from substituted phenyl, naphthyl, anthraceneyl, phenanthryl and pyrene;

[0044] The substituent of the substituted phenyl group is any one of mono- or poly-substituted halogen atoms, saturated alkyl groups, trifluoromethyl groups, aryl groups, or alkoxy groups.

[0045] The aminopyrrole is any one of the following VII and VIII structural formulas:

[0046]

[0047] The molar ratio of the 1,4-dione derivative, aminopyrazole, and chiral protic acid is 1.0:(1.0-3.0):(0.02-0.20).

[0048] The solvent is selected from any one or more of dichloromethane, trichloromethane, carbon tetrachloride, 1,2-dichloroethane, diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, and acetonitrile.

[0049] The reaction time is 24-48 h, and the reaction temperature is -30 to 30 °C. After the reaction is completed, the solution is purified by column chromatography using a mixture of petroleum ether / ethyl acetate or petroleum ether / dichloromethane.

[0050] The following is in conjunction with the appendix Figure 1 —Appendix Figure 8 The invention will be described in detail with reference to the embodiments of the present invention. It should be noted that each accompanying drawing contains three figures, which are respectively of the compounds prepared in the embodiments. 1 HNMR, 13 C NMR data and high performance liquid chromatography.

[0051] Example 1:

[0052] The reaction equation is as follows:

[0053]

[0054] Compounds 1a (5 mmol), 2a (6 mmol), and a chiral protic acid (0.5 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of toluene. The reaction was carried out at 30 °C for 48 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain pure 3aa. The yield of 3aa was 92%, and the ER value was 95:5.

[0055]

[0056] In the above reaction, when the R of compound 1a 1 When tert-butyl (tBu) was selected, the yield was 92% and the er value was 95:5, compared to R 1 The following were selected: isopropyl (iPr) yield 89%, er value 78:22; cyclohexyl (Cy) yield 90%, er value 83:17; and phenyl (Ph) yield 85%, er value 81:19. 1 The higher enantioselectivity of the compound when it is tert-butyl indicates that the sterically hindered N-tert-butyl group on the aminopyrazole can generate stronger rotational steric hindrance when constructing axially chiral compounds, which is the key to obtaining excellent enantioselectivity.

[0057] The NMR data for 3aa are as follows:

[0058] 1 H NMR(400MHz, CDCl3)δ7.90(d,J=7.5Hz,2H),7.46(t,J=7.3Hz,2H),7.40–7.18 (m,6H),6.89(s,1H),6.72(s,1H),3.89(s,3H),2.44(s,3H),1.22(s,9H)ppm.

[0059] 13 C NMR (101MHz, CDCl3) δ165.6,148.4,139.8,135.3,134.9,133.2,131.8,128.7,128 .6,127.9,127.2,127.2,125.4,113.5,110.1,104.4,61.8,51.1,29.29,12.3ppm.

[0060] HPLC conditions: DAIICEL CHIRALCELAD-H, n-hexane / isopropanol = 98 / 2, 1.0 mL / min, λ = 254 nm; Figure 1 The high-performance liquid chromatography (HPLC) data for 3aa are shown below:

[0061] t R (major) = 15.9 min, t R (minor)=14.5min, er=95:5.

[0062] Example 2:

[0063] The reaction equation is as follows:

[0064]

[0065] Compounds 1a (5 mmol), 2b (7 mmol), and a chiral protic acid (0.4 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of acetonitrile / dichloromethane (1:1). The reaction was carried out at 30 °C for 48 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain pure 3ab. The yield of 3ab was 87%, and the ER value was 95:5.

[0066] The NMR data for 3ab are as follows:

[0067] 1 H NMR (400MHz, CDCl3) δ7.95–7.79(m,2H),7.44(t,J=7.5Hz,2H),7.34(m,1H),7.28(m,2H),7.24–7.14(m,1H),6.86(s ,1H),6.75(s,1H),3.87(s,3H),3.15(dq,J=14.8,7.4Hz,1H),2.40(dq,J=14.6,7.3Hz,1H),1.22–1.16(m,12H)ppm.

[0068] 13 C NMR (101MHz, CDCl3) δ165.4,148.4,145.9,135.4,134.9,133.4,132.0,128.8,128.7 ,128.1,127.4,127.4,125.5,113.0,110.5,104.8,62.1,51.2,29.3,19.9,14.7ppm.

[0069] HPLC conditions: DAIICEL CHIRALCELAD-H, n-hexane / isopropanol = 98 / 2, 1.0 mL / min, λ = 254 nm; Figure 2 As shown, the high-performance liquid chromatography (HPLC) data for 3ab are as follows:

[0070] t R (major) = 6.2 min, t R (minor)=9.7min, er=95:5.

[0071] Example 3:

[0072] The reaction equation is as follows:

[0073]

[0074] Compounds 1a (5 mmol), 2c (5 mmol), and a chiral protic acid (0.4 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of toluene. The reaction was carried out at 0 °C for 24 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and dichloromethane in a volume ratio of 5:1 to obtain pure 3ac. The yield of 3ac was 95%, and the ER value was 91:9.

[0075] The NMR data for 3ac are as follows:

[0076] 1 H NMR(400MHz, CDCl3)δ7.85(m,2H),7.46–7.41(m,3H),7.38–7.32(m,1H),7.26(d,J=8.5Hz,1H),7 .04(dd,J=8.5,2.2Hz,1H),6.92(s,1H),6.66(s,1H),3.87(s,3H),2.41(s,3H),1.25(s,9H)ppm.

[0077] 13 C NMR (101MHz, CDCl3) δ165.3,149.0,140.8,135.0,133.1,132.9,132.4,131.9,13 1.3,130.7,128.8,128.2,125.6,114.0,111.4,104.5,62.2,51.3,29.6,12.5ppm.

[0078] HPLC conditions: DAICL CHIRALCEL IC, n-hexane / isopropanol = 95 / 5, 1.0 mL / min, λ = 254 nm; Figure 3 As shown, the high-performance liquid chromatography (HPLC) data for 3ac are as follows:

[0079] t R (major) = 6.3 min, t R (minor)=8.2min, er=91:9.

[0080] Example 4:

[0081] The reaction equation is as follows:

[0082]

[0083] Compounds 1a (5 mmol), 2d (5 mmol), and a chiral protic acid (0.5 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of dioxane. The reaction was carried out at 0 °C for 24 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 15:1 to obtain pure 3ad. The yield of 3ad was 96%, and the ER value was 96:4.

[0084] The NMR data of 3ad are as follows

[0085] 1 H NMR (400MHz, CDCl3) δ7.92–7.84(m,2H),7.43(t,J=7.5Hz,2H),7.34(t,J=7.4Hz,1H),7.08(dd,J=5.1,0.8H z,1H),6.89(s,1H),6.85(m,1H),6.73–6.67(m,1H),6.65(s,1H),3.86(s,3H),2.42(s,3H),1.31(s,9H)ppm.

[0086] 13 C NMR (101MHz, CDCl3) δ165.5,148.9,139.7,134.8,133.9,133.3,129.5,128.8,12 8.1,127.5,125.5,124.5,123.9,113.8,109.7,104.7,62.2,51.3,29.6,12.5ppm.

[0087] HPLC conditions: DAICL CHIRALCEL IC, n-hexane / isopropanol = 95 / 5, 1.0 mL / min, λ = 254 nm; Figure 4 As shown, the high-performance liquid chromatography (HPLC) data for 3ad are as follows:

[0088] t R (major) = 6.7 min, t R (minor)=8.2min, er=96:4.

[0089] Example 5:

[0090] The reaction equation is as follows:

[0091]

[0092] Compounds 1a (5 mmol), 2d (6 mmol), and a chiral protic acid (0.3 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of toluene. The reaction was carried out at 10 °C for 24 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 15:1 to obtain pure 3ae. The yield of 3ae was 94%, and the ER value was 92:8.

[0093] The NMR data for 3ae are as follows:

[0094] 1 H NMR(400MHz, CDCl3)δ7.93–7.79(m,2H),7.49–7.38(m,6H),7.37–7.27(m,4H),7.24–7 .14(m,3H),6.90(s,1H),6.69(s,1H),5.51–5.20(m,2H),2.42(s,3H),1.20(s,9H)ppm.

[0095] 13 C NMR (101MHz, CDCl3) δ165.0,148.6,140.2,136.8,135.4,135.1,133.4,131.9,128.8,128.7,12 8.7,128.2,128.2,128.1,127.4,127.3,125.5,113.6,110.4,104.6,65.8,62.0,29.5,12.6ppm.

[0096] HPLC conditions: DAIICEL CHIRALCELAD-H, n-hexane / isopropanol = 98 / 2, 1.0 mL / min, λ = 254 nm; Figure 5 The high-performance liquid chromatography (HPLC) data for 3ae are shown below:

[0097] t R (major) = 13.0 min, t R (minor)=20.3min, er=92:8.

[0098] Example 6:

[0099] The reaction equation is as follows:

[0100]

[0101] Compounds 1b (5 mmol), 2a (5 mmol), and a chiral protic acid (0.5 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of n-hexane. The reaction was carried out at 25 °C for 24 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain pure 3ba. The yield of 3ba was 91%, and the ER value was 93:7.

[0102] The MRI data for 3ba are as follows:

[0103] 1 H NMR(400MHz, CDCl3)δ7.85–7.74(m,2H),7.34–7.27(m,2H),7.24–7.13(m,3H),6.99–6.94 (m,2H),6.87(s,1H),6.61(s,1H),3.87(s,3H),3.85(s,3H),2.41(s,3H),1.19(s,9H)ppm.

[0104] 13 C NMR (101MHz, CDCl3) δ165.7,159.7,148.5,140.0,135.3,135.0,132.0,128.7,127.3 ,127.3,126.8,126.3,114.2,113.6,110.2,104.0,61.8,55.5,51.2,29.4,12.5ppm.

[0105] HPLC conditions: DAICL CHIRALCEL IC, n-hexane / isopropanol = 95 / 5, 1.0 mL / min, λ = 254 nm; Figure 6 The high-performance liquid chromatography (HPLC) data for 3ba are shown below:

[0106] t R (major) = 11.1 min, t R (minor)=16.4min, er=93:7.

[0107] Example 7:

[0108] The reaction equation is as follows:

[0109]

[0110] Compounds 1c (5 mmol), 2a (8 mmol), and a chiral protic acid (0.5 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of tetrahydrofuran / acetonitrile (3:2). The reaction was carried out at -30 °C for 48 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and dichloromethane in a volume ratio of 5:1 to obtain pure 3ca. The yield of 3ca was 91%, and the ER value was 93:7.

[0111] The NMR data for 3ca are as follows:

[0112] 1 H NMR (400MHz, CDCl3) δ8.12 (s, 1H), 8.03 (d, J = 7.5Hz, 1H), 7.56 (m, 2H), 7.28 (m, 2H) ,7.20(m,3H),6.87(s,1H),6.75(s,1H),3.87(s,3H),2.41(s,3H),1.21(s,9H)ppm.

[0113] 13 C NMR (101MHz, CDCl3) δ165.5,147.1,139.7,135.8,135.0,134.0,131.8,131.3,130.9,129.1,12 8.6,128.5,127.3,127.2,124.4,122.1,122.1,113.7,110.2,104.6,62.2,51.1,29.3,12.3ppm.

[0114] HPLC conditions: DAICL CHIRALCEL OD-H, n-hexane / isopropanol = 95 / 5, 1.0 mL / min, λ = 254 nm; Figure 7 As shown, the high-performance liquid chromatography (HPLC) data for 3ca are as follows:

[0115] t R (major) = 6.4 min, t R (minor)=5.7min, er=93:7.

[0116] Example 8:

[0117] The reaction equation is as follows:

[0118]

[0119] Compounds 1b (5 mmol), 2d (8 mmol), and a chiral protic acid (0.3 mmol) were sequentially added to a reactor, followed by the addition of 50 mL of dioxane. The reaction was carried out at 25 °C for 24 hours. After the reaction was completed by TLC monitoring, the reaction solvent was removed by evaporation under reduced pressure. The crude product was subjected to column chromatography with a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 10:1 to obtain pure 3da. The yield of 3da was 91%, and the ER value was 94:6.

[0120] The 3da NMR data are as follows:

[0121] 1 H NMR(400MHz, CDCl3)δ7.49(d,J=1.1Hz,1H),7.27(m,2H),7.25–7.15(m,3H),6.85(s,1H),6.71(d, J=3.3Hz,1H),6.62(s,1H),6.49(dd,J=3.3,1.8Hz,1H),3.86(s,3H),2.39(s,3H),1.18(s,9H)ppm.

[0122] 13 C NMR (101MHz, CDCl3) δ165.7,148.8,142.1,141.7,139.9,135.4,135.1,131.9,12 8.8,127.4,127.4,113.8,111.5,110.3,106.1,104.7,62.2,51.2,29.4,12.4ppm.

[0123] HPLC conditions: DAICL CHIRALCEL IC, n-hexane / isopropanol = 95 / 5, 1.0 mL / min, λ = 254 nm; Figure 8 As shown, the high-performance liquid chromatography (HPLC) data for 3da are as follows:

[0124] t R (major) = 6.6 min, t R (minor)=7.5min, er=94:6.

[0125] As can be seen from the above examples, the method for synthesizing axially chiral pyrazole-pyrrole isomers according to the present invention can obtain a variety of products with high yield and excellent enantioselectivity.

[0126] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structural methods to the embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A pyrazole-pyrrole-based transisomer, characterized in that: The structure of the pyrazole-pyrrole-type transisomer is as follows: Among them, R, R 1 R 2 R 4 All are selected from one of aryl, heterocyclic aryl, substituted aryl, alkyl, and substituted alkyl; the R 3 It is selected from any one of alkyl esters, aryl esters and benzyl esters; the aryl, substituted aryl and heterocyclic aryl are phenyl, naphthyl, thiophene or furanyl; the substituent of the ester group is one of saturated alkyl, aryl or substituted aryl; the substituent of the substituted alkyl or substituted aryl is one or more of halogen atom, saturated alkyl, alkoxy, phenyl, substituted phenyl, naphthyl, thiophene, furanyl, alkenyl and alkynyl.

2. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 1, characterized in that: The synthesis method specifically includes sequentially adding a 1,4-diketone derivative, an aminopyrazole, a chiral protic acid, and a reaction solvent to a dry reaction flask, stirring at a certain temperature until the reaction is complete, and separating by column chromatography to obtain the axially chiral pyrazole-pyrrole-based transisomer, as shown in the following reaction formula:

3. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The chiral protic acid has at least one of the following structural formulas: Wherein, Ar is selected from substituted phenyl, naphthyl, anthraceneyl, phenanthryl and pyrene; the substituent of the substituted phenyl is any one of monosubstituted or polysubstituted halogen atoms, saturated alkyl, trifluoromethyl, aryl or alkoxy.

4. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The aminopyrrole is any one of the following VII structural formulas:

5. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The aminopyrrole is any one of the following VIII structural formulas:

6. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The molar ratio of the 1,4-dione derivative, aminopyrazole, and chiral protic acid is 1.0:(1.0-3.0):(0.02-0.20).

7. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The solvent is selected from any one or more of dichloromethane, trichloromethane, carbon tetrachloride, 1,2-dichloroethane, diethyl ether, tetrahydrofuran, 1,4-dioxane, toluene, and acetonitrile.

8. The method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: The reaction time is 24-72 hours.

9. A method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that, The reaction temperature is -30 to 30°C.

10. A method for synthesizing a pyrazole-pyrrole-based transisomer according to claim 2, characterized in that: Purification was performed by column chromatography using a mixed solvent of petroleum ether / ethyl acetate or petroleum ether / dichloromethane.

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