Method for synthesizing multifunctional pyrrole compound through imine 1, 2-rearrangement
By reacting γ-hydroxy-α,β-unsaturated olefinic aldehydes and imines with α-hydrogen to undergo rearrangement and cyclization reactions under the catalysis of Lewis acids and bases, the problems of poor regioselectivity and harsh reaction conditions in the synthesis of pyrrole derivatives were solved, and efficient and economical preparation of multifunctionalized pyrrole compounds was achieved.
Patent Information
- Application Number
- CN202510929782.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-07
- Publication Date
- 2025-10-17
AI Technical Summary
The existing pyrrole derivatives have poor regioselectivity, require multi-step precursor synthesis, rely on precious metal catalysts, and have harsh reaction conditions, resulting in uneconomical and inefficient synthesis methods.
Multifunctional pyrrole compounds are prepared by rearrangement and cyclization reactions of γ-hydroxy-α,β-unsaturated olefinic aldehyde, imine with α-hydrogen, Lewis acid catalyst and base at room temperature and pressure.
The high-yield and high-purity preparation of multifunctional pyrrole compounds is achieved, the reaction conditions are mild, and industrial production is easy.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of organic synthesis, and particularly relates to a multifunctional pyrrole compound and a preparation method thereof. BACKGROUND
[0002] Pyrrole derivatives, as an important class of nitrogen-containing heterocyclic compounds, have an irreplaceable position in the field of drug research and development due to their complex structural diversity and significant biological activity. However, the existing methods have problems such as poor regioselectivity, need for multi-step synthesis of precursors, dependence on noble metal catalysts, and harsh reaction conditions. Therefore, it is of great significance to develop an economical and efficient synthesis method of multifunctional pyrrole compounds for organic chemistry and medicinal chemistry. SUMMARY
[0003] Therefore, the application provides a multifunctional pyrrole compound and a preparation method thereof. The preparation method of the multifunctional pyrrole compound is simple and easy to operate, and the multifunctional pyrrole compound prepared has a high yield.
[0004] The application provides a preparation method of a multifunctional pyrrole compound, which comprises the following steps:
[0005] The gamma-hydroxy-alpha, beta-unsaturated aldehyde, the imine having alpha-hydrogen, the Lewis acid catalyst, the base and the organic solvent are mixed to perform rearrangement and ring formation reaction, so that the multifunctional pyrrole compound is obtained.
[0006] The gamma-hydroxy-alpha, beta-unsaturated aldehyde has a structure shown in formula 1, and the imine having alpha-hydrogen has a structure shown in any one of formulae 2-3.
[0007]
[0008] When the gamma-hydroxy-alpha, beta-unsaturated aldehyde is , the imine having alpha-hydrogen has a structure shown in any one of formulae 2-3; when the imine having alpha-hydrogen is , the multifunctional pyrrole compound has a structure shown in formula I, and when the imine having alpha-hydrogen is , the multifunctional pyrrole compound has a structure shown in formula II.
[0009]
[0010] wherein R 1 and R 2 are independently phenyl;
[0011] R 3 and R 4 are independently alkyl;
[0012] R 5 is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, or alkoxy-substituted phenyl.
[0013] Preferably, the Lewis acid catalyst comprises aluminum triflate (Al(OTf)3), indium triflate (In(OTf)3), or gallium triflate (Ga(OTf)3). including (E)-N-(2-methylpropylidene)-4-methylbenzenesulfonamide;
[0014] Preferably, the base comprises sodium acetate, sodium trifluoroacetate, sodium benzoate, or sodium pivalate.
[0015] The molar ratio of the γ-hydroxy-α,β-unsaturated aldehyde and the Lewis acid catalyst is 1:0.15-0.25.
[0016] Preferably, the base comprises sodium acetate, sodium trifluoroacetate, sodium benzoate, or sodium pivalate.
[0017] The molar ratio of the γ-hydroxy-α,β-unsaturated aldehyde and the base is 1:0.10-0.25.
[0018] Preferably, the Lewis acid catalyst comprises aluminum triflate (Al(OTf)3), indium triflate (In(OTf)3), or gallium triflate (Ga(OTf)3). including (E)-N-(2-methylpropylidene)-4-methylbenzenesulfonamide;
[0019] The molar ratio of the γ-hydroxy-α,β-unsaturated aldehyde and the Lewis acid catalyst is 1:0.15-0.25. including (E)-N-(cyclopentylmethylidene)-4-methylbenzenesulfonamide, (E)-4-tert-butyl-N-(cyclopentylmethylidene)benzenesulfonamide, (E)-N-(cyclopentylmethylidene)-4-methoxybenzenesulfonamide, (E)-4-bromo-N-(cyclopentylmethylidene)benzenesulfonamide, and (E)-N-(cyclopentylmethylidene)benzenesulfonamide.
[0020] Preferably, the molar ratio of the γ-hydroxy-α,β-unsaturated aldehyde and the imine having α-hydrogen is 1:2.8-3.2.
[0021] Preferably, the temperature of the ring-forming reaction is 20-30°C, and the time is 16-20 h.
[0022] The present application also provides a multifunctional pyrrole compound prepared by the preparation method described in the above technical solution, having a structure shown in Formula I-II:
[0023]
[0024] wherein, R 1 and R 2 are independently phenyl;
[0025] R 3 and R 4 are independently alkyl;
[0026] R 5 is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, or alkoxy-substituted phenyl.
[0027] Preferably, the compound has a structure represented by any one of Formula I-1, II-1 to II-5:
[0028] 、
[0029] The present application provides a preparation method of a multifunctional pyrrole compound, which comprises the following steps: DETAILED DESCRIPTION
[0030] The present application provides a preparation method of a multifunctional pyrrole compound, which comprises the following steps:
[0031] The multifunctional pyrrole compound is obtained by mixing γ-hydroxy-α,β-unsaturated aldehyde, imine having α-hydrogen, Lewis acid catalyst, base and organic solvent, and then performing rearrangement and ring formation reaction.
[0032] The γ-hydroxy-α,β-unsaturated aldehyde has a structure represented by Formula 1, and the imine having α-hydrogen has a structure represented by any one of Formula 2 to 3.
[0033]
[0034] When the γ-hydroxy-α,β-unsaturated aldehyde has a structure represented by Formula 1, the imine having α-hydrogen has a structure represented by any one of Formula 2 to 3. When the imine having α-hydrogen has a structure represented by Formula 2, the multifunctional pyrrole compound has a structure represented by Formula I.
[0035]
[0036] In the present application, R 1 is phenyl; and R 2 is phenyl.
[0037] As a specific embodiment of the present application, R 1 and R 2 may be phenyl simultaneously.
[0038] As a specific embodiment of the present invention, the Gamma-hydroxy-gamma-diphenyl-alpha, beta-unsaturated alkenal may be included.
[0039] In the present invention, R 3 is an alkyl group, the R 3 The alkyl group includes methyl; R 4 is an alkyl group, the R 4 The alkyl group includes methyl; R 5 is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, alkoxy-substituted phenyl, and the R 5 The halogen-substituted phenyl group includes 4-bromophenyl, wherein R 5 The alkyl substituted phenyl group includes 4-methylphenyl and 4-tert-butylphenyl. 5 The alkoxy-substituted phenyl group includes 4-methoxyphenyl.
[0040] As a specific embodiment of the present invention, R 3 and R 4 It can also be a methyl group.
[0041] As a specific embodiment of the present invention, the including (E)-N-(2-methylpropylene)-4-methylbenzenesulfonamide;
[0042] described Including (E)-N-(cyclopentylmethylene)-4-methylbenzenesulfonamide, (E)-4-tert-butyl-N-(cyclopentylmethylene)benzenesulfonamide, (E)-N-(cyclopentylmethylene)-4-methoxybenzenesulfonamide, (E)-4-bromo-N-(cyclopentylmethylene)benzenesulfonamide, and (E)-N-(cyclopentylmethylene)benzenesulfonamide.
[0043] As a specific embodiment of the present invention, the Lewis acid catalyst may include aluminum trifluoromethanesulfonate (Al(OTf)3), indium trifluoromethanesulfonate (In(OTf)3), or gallium trifluoromethanesulfonate (Ga(OTf)3). In the present invention, the Lewis acid catalyst has multiple activation functions, which can promote the efficient and highly selective synthesis of products, and realize the synthesis of multifunctionalized pyrrole compounds at room temperature and pressure. During the reaction process, there is no need to activate the reactants in advance.
[0044] As a specific embodiment of the present invention, the molar ratio of the γ-hydroxy-α,β-unsaturated olefinic aldehyde to the Lewis acid catalyst may be 1:0.15 to 0.25.
[0045] As a specific embodiment of the present application, the base can include sodium acetate, sodium trifluoroacetate, sodium benzoate or sodium pivalate.
[0046] As a specific embodiment of the present application, the substance amount ratio of the γ-hydroxy-α, β-unsaturated alkenal and the base can be 1:0.10-0.25.
[0047] As a specific embodiment of the present application, the organic solvent can be acetonitrile; the molar concentration of the γ-hydroxy-α, β-unsaturated alkenal in the solution system to be reacted in the rearrangement and ring formation reaction can be 0.08-0.12 mol / L, and can be specifically 0.1 mol / L. When the addition amount of the organic solvent is too high or too low, the molar concentration of the γ-hydroxy-α, β-unsaturated alkenal in the solution system to be reacted in the ring formation reaction will be reduced or increased accordingly, and then the yield of the multi-functionalized pyrrole compound will be reduced.
[0048] As a specific embodiment of the present application, the substance amount ratio of the γ-hydroxy-α, β-unsaturated alkenal and the imine having α-hydrogen can be 1:2.8-3.2, and can be specifically 1:3.
[0049] As a specific embodiment of the present application, the temperature of the ring formation reaction can be 20-30°C; and the time of the ring formation reaction can be 16-20 h.
[0050] As a specific embodiment of the present application, the preparation of the multi-functionalized pyrrole compound of formula I is shown in the following reaction equation:
[0051] The reaction equation for preparing the multi-functionalized pyrrole compound of formula II is shown as follows:
[0052] In the present application, after the rearrangement and ring formation reaction, the system after the ring formation reaction is concentrated and then separated and purified by silica gel column chromatography to obtain the multi-functionalized pyrrole compound. The present application does not have special requirements for the concentration and silica gel column chromatography, and the conventional methods in the art can be used.
[0053] The multi-functionalized pyrrole compound prepared by the preparation method according to the above technical solution has the structure shown in formula I-II:
[0054]
[0055] wherein, R 1 and R 2 are independently phenyl;
[0056] R 3 and R 4 are independently alkyl;
[0057] R 5 is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, or alkoxy-substituted phenyl.
[0058] As a specific embodiment of the present application, the multifunctional pyrrole compound can have any of the structures shown in Formulae I-1, II-1 to II-5:
[0059]
[0060] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.
[0061] After the preparation of each example is completed, in order to further verify that the purified compound is indeed the target product prepared in the present example, the obtained solid product is analyzed, and the analysis means adopts nuclear magnetic resonance and high resolution mass spectrometry, and the detection results are listed in each example.
[0062] Example 1
[0063] R 1 = R 2 (E)-N-(cyclopentylmethylidene)-4-methylbenzenesulfonamide as the reaction raw material, using aluminum trifluoromethanesulfonate catalyst and base for reaction, the specific implementation process is as follows:
[0064] Dissolve γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde (95.8 mg, 0.4 mmol), (E)-N-(cyclopentylmethylidene)-4-methylbenzenesulfonamide (303.2 mg, 1.2 mmol), aluminum trifluoromethanesulfonate (39.0 mg, 0.08 mmol) and sodium acetate (6.9 mg, 0.08 mmol) in acetonitrile (4 mL), and react at room temperature for 18 h. The reaction equation is as follows:
[0065]
[0066] After the reaction solution is concentrated, silica gel column chromatography is used to obtain 107.3 mg of solid product, and the calculated yield is 59%.
[0067] The analysis of the test is as follows:
[0068] 1. Hydrogen spectrum and carbon spectrum of nuclear magnetic resonance analysis:
[0069] 1H NMR (300 MHz, CDC13) δ 7.51 - 7.41 (m, 5H), 7.35 - 7.19 (m, 9H), 6.69 (s, 1H), 6.07 (s, 1H), 2.64 - 2.60 (m, 2H), 2.40 (s, 3H), 2.38 - 2.31 (m, 2H), 1.75 - 1.57 (m, 4H) ppm.
[0070] 13 C NMR (75 MHz, CDC13) δ 144.4, 142.2, 141.3, 141.1, 136.2, 129.8, 129.6, 129.0, 128.6, 128.2, 127.6, 127.1, 126.79, 126.77, 123.7, 122.7, 118.6, 117.8, 23.0, 22.8, 22.3, 21.6, 21.5 ppm.
[0071] 2. High resolution mass spectrum: HRMS (ESI) C 29 H 28 NO2S + [M+H] + : 454.1835, Found: 454.1828.
[0072] From the results, it can be seen that the theoretical mass is 454.1835, while the observed value of the peak found in the actual mass spectrum is 454.1828; combined with nuclear magnetic resonance, the product structure can be determined as follows:
[0073] Product of this example.
[0074] Example 2
[0075] R 1 = R 2 is a γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde, (E)-4-tert-butyl-N- (cyclopentylmethylidene) benzenesulfonamide as the reaction raw material, using aluminum triflate catalyst and base for reaction, the specific implementation process is as follows:
[0076] γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde (96.5 mg, 0.4 mmol), (E)-4-tert-butyl-N-(cyclopentylmethylidene) benzenesulfonamide (353.2 mg, 1.2 mmol), aluminum triflate (38.5 mg, 0.08 mmol) and sodium acetate (6.8 mg, 0.08 mmol) were dissolved in acetonitrile (4 mL) and reacted at room temperature for 18 h. The reaction equation is as follows:
[0077]
[0078] The reaction solution was concentrated and then subjected to silica gel column chromatography to obtain 98.1 mg of solid product, with a calculated yield of 49%.
[0079] The analysis of the test is as follows:
[0080] 1. Hydrogen spectrum and carbon spectrum of nuclear magnetic resonance analysis:
[0081] 1 H NMR (300 MHz, CDC13) δ 7.53-7.40 (m, 7H), 7.33-7.18 (m, 7H), 6.70 (s, 1H), 6.08 (s, 1H), 2.65 (t, J = 5.9 Hz, 2H), 2.38 (t, J = 5.7 Hz, 2H), 1.73-1.58 (m, 4H), 1.31 (s, 9H) ppm.
[0082] 13 C NMR (75 MHz, CDC13) δ 157.2, 142.2, 141.3, 141.1, 136.2, 129.6, 129.0, 128.7, 128.2, 127.6, 127.1, 126.8, 126.6, 126.2, 123.5, 122.6, 118.6, 117.8, 35.2, 31.0, 23.0, 22.8, 22.3, 21.5 ppm.
[0083] 2. High resolution mass spectrum: HRMS (ESI) C 32 H 34 NO2S + [M+H] + : 496.2305, Found: 496.2306.
[0084] As can be seen from the results, the theoretical mass is 496.2305, and the observed value of the peak found in the actual mass spectrum is 496.2306; in combination with nuclear magnetic resonance, the product structure can be determined as follows:
[0085] is the product of this example.
[0086] Example 3
[0087] R 1 = R 2 is a γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde, (E)-N-(cyclopentylmethylidene)-4-methoxybenzenesulfonamide, as a reaction raw material, reacts with aluminum triflate catalyst and base, and the specific implementation process is as follows:
[0088] Y-hydroxy-Y-diphenyl-a, b-unsaturated aldehyde (96.9 mg, 0.4 mmol), (E)-N- (cyclopentylmethylidene)-4-methoxybenzenesulfonamide (322.9 mg, 1.2 mmol), aluminum trifluoromethanesulfonate (38.5 mg, 0.08 mmol) and sodium acetate (7.0 mg, 0.08 mmol) were dissolved in acetonitrile (4 mL) and reacted at room temperature for 18 h. The reaction equation is as follows:
[0089]
[0090] After the reaction solution was concentrated, silica gel column chromatography was used to obtain solid product 101.4 mg, and the calculated yield was 54%.
[0091] The analysis of the test is as follows:
[0092] 1. Hydrogen spectrum of nuclear magnetic resonance analysis, carbon spectrum:
[0093] 1 H NMR (300 MHz, CDC13) δ 7.53-7.42 (m, 5H), 7.33-7.21 (m, 7H), 6.92-6.89 (m, 2H), 6.69 (s, 1H), 6.07 (s, 1H), 3.83 (s, 3H), 2.62 (t, J = 5.8 Hz, 2H), 2.37 (t, J = 5.6 Hz, 2H), 1.74-1.58 (m, 4H) ppm.
[0094] 13 C NMR (75 MHz, CDC13) δ 163.4, 142.2, 141.2, 141.1, 130.7, 129.6, 129.0, 128.6, 128.2, 127.5, 127.1, 126.8, 123.6, 122.6, 118.6, 117.8, 114.3, 55.6, 23.0, 22.8, 22.3, 21.5 ppm.
[0095] 2. High resolution mass spectrum: HRMS (ESI) C 29 H 28 NO3S + [M+H] + : 470.1784, Found: 470.1778.
[0096] From the results, it can be seen that the theoretical mass is 470.1784, and the observed value of the peak found in the actual mass spectrum is 470.1778; combined with nuclear magnetic resonance, the product structure can be determined as follows:
[0097] is the product of the present example.
[0098] Example 4
[0099] R 1 = R 2 As a reaction raw material, γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde, (E)-4-bromo-N-(cyclopentylmethylidene)benzenesulfonamide, in which the phenyl group is substituted with a bromine atom, was reacted with an aluminum trifluoromethanesulfonate catalyst and a base, and the specific implementation process was as follows:
[0100] γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde (96.7 mg, 0.4 mmol), (E)-4-bromo-N-(cyclopentylmethylidene)benzenesulfonamide (380.5 mg, 1.2 mmol), aluminum trifluoromethanesulfonate (38.0 mg, 0.08 mmol), and sodium acetate (6.9 mg, 0.08 mmol) were dissolved in acetonitrile (4 mL) and reacted at room temperature for 18 h. The reaction equation is as follows:
[0101]
[0102] After the reaction solution was concentrated, silica gel column chromatography was performed to obtain 108.1 mg of solid product, and the calculated yield was 52%.
[0103] The analysis of the test is as follows:
[0104] 1. Hydrogen spectrum and carbon spectrum of nuclear magnetic resonance analysis:
[0105] 1 H NMR (300 MHz, CDCl3) δ 7.61-7.57 (m, 2H), 7.47-7.39 (m, 5H), 7.32-7.20 (m, 7H), 6.68 (s, 1H), 6.03 (s, 1H), 2.61 (t, J = 5.8 Hz, 2H), 2.37 (t, J = 4.9 Hz, 2H), 1.74-1.60 (m, 4H) ppm.
[0106] 13 C NMR (75 MHz, CDCl3) δ 142.1, 141.9, 141.0, 138.1, 132.5, 129.6, 129.0, 128.8, 128.5, 128.23, 128.21, 127.6, 127.3, 126.8, 124.3, 123.4, 118.6, 117.5, 23.0, 22.8, 22.2, 21.5 ppm.
[0107] 2. High-resolution mass spectrometry: HRMS (ESI) C 28 H 25 BrNO2S + [M+H] +:518.0784, Found: 518.0780.
[0108] From the results, it can be seen that the theoretical mass is 518.0784, while the observed value of the peak found in the actual mass spectrum is 518.0780; combined with nuclear magnetic resonance, the product structure can be determined as follows:
[0109] The product of the present example.
[0110] Example 5
[0111] R 1 = R 2 The γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde with phenyl as the reaction raw material, (E)-N-(cyclopentylmethylidene) benzenesulfonamide as the reaction raw material, aluminum triflate catalyst and base were used for the reaction, and the specific implementation process was as follows:
[0112] γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde (96.7 mg, 0.4 mmol), (E)-N-(cyclopentylmethylidene) benzenesulfonamide (289.3 mg, 1.2 mmol), aluminum triflate (37.7 mg, 0.08 mmol) and sodium acetate (6.6 mg, 0.08 mmol) were dissolved in acetonitrile (4 mL) and reacted at room temperature for 18 h. The reaction equation is as follows:
[0113]
[0114] After the reaction solution was concentrated, silica gel column chromatography was used to obtain 94.8 mg of solid product, and the calculated yield was 54%.
[0115] The analysis of the test is as follows:
[0116] 1. Hydrogen spectrum and carbon spectrum of nuclear magnetic resonance analysis:
[0117] 1 H NMR (300 MHz, CDCl3) δ 7.59-7.54 (m, 3H), 7.49-7.42 (m, 5H), 7.31-7.21 (m, 7H), 6.69 (s, 1H), 6.08 (s, 1H), 2.63 (t, J = 5.9 Hz, 2H), 2.37 (t, J = 5.5 Hz, 2H), 1.72-1.60 (m, 4H) ppm.
[0118] 13C NMR (75 MHz, CDC13) δ 142.2, 141.6, 141.0, 139.2, 133.4, 129.6, 129.2, 129.0, 128.8, 128.2, 127.6, 127.2, 126.8, 126.7, 123.9, 122.9, 118.7, 117.7, 23.0, 22.8, 22.3, 21.5 ppm.
[0119] 2. High resolution mass spectrum: HRMS (ESI) C 28 H 26 NO2S + [M+H] + : 440.1679, Found: 440.1679.
[0120] From the results, it can be seen that the theoretical mass is 440.1679, and the observed value of the peak found in the actual mass spectrum is 440.1679; combined with nuclear magnetic resonance, the product structure can be determined as follows:
[0121] The product of this example.
[0122] Example 6
[0123] R 1 = R 2 is phenyl, γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde, R 3 = R 4 is methyl, (E)-N-(2-methylpropylidene)-4-methylbenzenesulfonamide as a reaction raw material, using aluminum triflate catalyst and base to react, the specific implementation process is as follows:
[0124] γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehyde (96.2 mg, 0.4 mmol), (E)-N-(2-methylpropylidene)-4-methylbenzenesulfonamide (272.9 mg, 1.2 mmol), aluminum triflate (37.9 mg, 0.08 mmol) and sodium acetate (6.8 mg, 0.08 mmol) were dissolved in acetonitrile (4 mL) and reacted at room temperature for 18 h. The reaction equation is as follows:
[0125]
[0126] After the reaction solution was concentrated, silica gel column chromatography was used to obtain 91.2 mg of solid product, with a calculated yield of 53%.
[0127] The analysis of the test is as follows:
[0128] 1. Hydrogen spectrum and carbon spectrum of nuclear magnetic resonance analysis:
[0129] 1 H NMR (300 MHz, CDC13) δ 7.47 - 7.39 (m, 5H), 7.34 - 7.20 (m, 9H), 6.73 (s, 1H), 6.23 (s, 1H), 2.38 (s, 3H), 2.16 (s, 3H), 1.89 (s, 3H) ppm.
[0130] 13 C NMR (75 MHz, CDC13) δ 144.4, 142.3, 141.6, 141.0, 136.2, 129.74, 129.72, 128.9, 128.2, 127.5, 127.2, 126.9, 126.8, 125.5, 123.4, 121.2, 119.3, 118.4, 21.5, 10.9, 9.5 ppm.
[0131] 2. High resolution mass spectrum: HRMS (ESI) C 27 H 26 NO2S + [M+H] + : 428.1679, Found: 428.1668.
[0132] From the results, it can be seen that the theoretical mass is 428.1679, while the observed value of the peak found in the actual mass spectrum is 428.1668; combined with nuclear magnetic resonance, the product structure can be determined as follows:
[0133] Product of the present example.
[0134] Although the above examples make a detailed description of the present application, it is only a part of the embodiments of the present application, but not all the embodiments, and people can also obtain other embodiments according to the present example without creativity, which all belong to the protection scope of the present application.
Claims
1. A method for preparing a multifunctional pyrrole compound, characterized in that: The following steps are involved: Mixing γ-hydroxy-α,β-unsaturated olefinic aldehyde, an imine having α-hydrogen, a Lewis acid catalyst, a base and an organic solvent, and performing rearrangement and cyclization reactions to obtain the multifunctionalized pyrrole compound; The γ-hydroxy-α,β-unsaturated olefinic aldehyde has a structure shown in Formula 1, and the imine having α-hydrogen has a structure shown in any one of Formulas 2 to 3: When the γ-hydroxy-α,β-unsaturated olefinic aldehyde is When the imine having α-hydrogen is any one of the structures shown in Formulas 2 to 3; when the imine having α-hydrogen is When the multifunctional pyrrole compound has the structure shown in formula I, when the imine having α-hydrogen is When the multifunctional pyrrole compound has the structure shown in Formula II: Among them, R 1 and R 2 Independently, phenyl; R 3 and R 4 is independently an alkyl group; R 5 It is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, or alkoxy-substituted phenyl.
2. The preparation method according to claim 1, characterized in that described Including γ-hydroxy-γ-diphenyl-α,β-unsaturated aldehydes.
3. The preparation method according to claim 1 or 2, characterized in that The Lewis acid catalyst includes aluminum trifluoromethanesulfonate (Al(OTf)3), indium trifluoromethanesulfonate (In(OTf)3) or gallium trifluoromethanesulfonate (Ga(OTf)3); The molar ratio of the gamma-hydroxy-alpha, beta-unsaturated olefinic aldehyde to the Lewis acid catalyst is 1:0.15 to 0.
25.
4. The preparation method according to claim 1 or 2, characterized in that The base includes sodium acetate, sodium trifluoroacetate, sodium benzoate or sodium pivalate; The molar ratio of the gamma-hydroxy-alpha, beta-unsaturated olefinic aldehyde to the base is 1:0.10-0.
25.
5. The preparation method according to claim 1, characterized in that: described including (E)-N-(2-methylpropylene)-4-methylbenzenesulfonamide; described Including (E)-N-(cyclopentylmethylene)-4-methylbenzenesulfonamide, (E)-4-tert-butyl-N-(cyclopentylmethylene)benzenesulfonamide, (E)-N-(cyclopentylmethylene)-4-methoxybenzenesulfonamide, (E)-4-bromo-N-(cyclopentylmethylene)benzenesulfonamide, and (E)-N-(cyclopentylmethylene)benzenesulfonamide.
6. The preparation method according to claim 1 or 5, characterized in that: The molar ratio of the γ-hydroxy-α,β-unsaturated aldehyde to the imine having α-hydrogen is 1:2.8-3.
2.
7. The preparation method according to claim 1, characterized in that: The temperature of the cyclization reaction is 20-30° C., and the time is 16-20 h.
8. The multifunctional pyrrole compound prepared by the preparation method according to any one of claims 1 to 7, characterized in that: Having the structure shown in any one of formulas Ⅰ to Ⅱ: Among them, R 1 and R 2 Independently, phenyl; R 3 and R 4 is independently an alkyl group; R 5 It is phenyl, halogen-substituted phenyl, alkyl-substituted phenyl, or alkoxy-substituted phenyl.
9. The multifunctional pyrrole compound according to claim 8, characterized in that: It has the structure shown in any one of formulas Ⅰ-1, Ⅱ-1 to Ⅱ-5: