A method for preparing an oxadiazole-substituted 1,2,3-triazole compound

Abstract

This invention discloses a method for preparing oxadiazole-substituted 1,2,3-triazole compounds, belonging to the field of compound synthesis technology. The method for preparing oxadiazole-substituted 1,2,3-triazole compounds includes the following steps: under alkaline conditions and in a solvent, compounds of formula I, formula II, and formula III undergo a defluorination-nucleophilic substitution-cycloaddition reaction. After the reaction, the mixture is subjected to rotary evaporation and column chromatography to obtain the 4-oxadiazole-substituted 1,2,3-triazole compound of formula IV. The method for preparing oxadiazole-substituted 1,2,3-triazole compounds described in this invention can be carried out smoothly under natural air conditions, without requiring an anhydrous or oxygen-free environment. The preparation method is simple, which helps to reduce production costs and achieve green synthesis.

Description

Technical Field

[0001] This invention relates to the field of compound synthesis technology, and in particular to a method for preparing oxadiazole-substituted 1,2,3-triazole compounds. Background Technology

[0002] 1,3,4-Oxadiazole is a class of aromatic five-membered heterocyclic compounds containing nitrogen (N) and oxygen (O). Compounds containing the 1,3,4-oxadiazole structure exhibit good biological activity and are widely used in pharmaceuticals, pesticides, and other fields. 1,3,4-Oxadiazole is an important pharmacophore, and chemists often combine 1,3,4-oxadiazole fragments with other bioactive pharmacophores to obtain novel compounds with even better biological activity. 1,2,3-Triazole is a class of five-membered nitrogen-containing heterocyclic compounds similar to 1,3,4-oxadiazole, possessing similar good biological activity. By synthetically combining 1,3,4-oxadiazole and 1,2,3-triazole pharmacophores into a single molecule, two important pharmacophores can be integrated, resulting in novel bioactive molecules with even stronger effects.

[0003] Currently, there are numerous methods for synthesizing heterocyclic compounds. For the synthesis of 1,2,3-triazole compounds, the classic method is the copper-catalyzed azido-yne cycloaddition reaction (CuAAC reaction). This reaction has the advantages of high efficiency and selectivity, but the use of copper catalysts presents potential toxicity issues, and the removal of copper ions during post-processing is cumbersome. In addition, there are some metal-free catalytic methods, such as the organic-base catalyzed azido-alkene cycloaddition reaction, but the reaction conditions are relatively harsh, and the substrate applicability is narrow.

[0004] In the synthesis of oxadiazole compounds, the most common method is the cyclization reaction of carboxylic acids or their derivatives with acylhydrazine compounds. However, these methods often require relatively harsh reaction conditions such as high temperatures and strong acids or bases, and the reaction steps are relatively complex, resulting in low atom economy.

[0005] There are relatively few methods for the direct synthesis of 4-oxadiazole-substituted 1,2,3-triazole compounds. Existing synthetic methods involve lengthy reaction steps, requiring multiple reactions to construct the target compound structure. This not only increases the synthesis cost but also reduces the yield of the final product. Some methods use expensive and difficult-to-obtain reagents or catalysts, limiting their application in practical production. In addition, some reactions have high requirements for reaction equipment and operation, which is not conducive to large-scale industrial production. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing oxadiazole-substituted 1,2,3-triazole compounds, which can be carried out smoothly under natural air conditions without the need for an anhydrous or oxygen-free environment. The preparation method is simple, which helps to reduce production costs and achieve green synthesis.

[0007] To achieve the above objectives, the present invention provides a method for preparing oxadiazole-substituted 1,2,3-triazole compounds, comprising the following steps:

[0008] Under alkaline conditions and in a solvent, the compound shown in Formula I, the compound shown in Formula II, and Formula III undergo a defluorination-nucleophilic substitution-cycloaddition reaction. After the reaction, the compound is subjected to rotary evaporation and column chromatography to obtain the 4-oxadiazole-substituted 1,2,3-triazole compound shown in Formula IV.

[0009]

[0010] In Formulas I and IV, R1 is a substituted or unsubstituted aromatic group, alkyl group, or alkoxy group;

[0011] In Formulas II and IV, R2 is a substituted or unsubstituted aromatic group, alkyl group, or alkoxy group;

[0012] In Formulas III and IV, R3 is a substituted or unsubstituted aromatic group, alkyl group, or alkoxy group.

[0013] Defluorination-nucleophilic substitution reaction

[0014] The trifluoromethyl group in Formula I exhibits a strong electron-withdrawing inductive effect under alkaline conditions (K₂CO₃ provides the alkaline environment), causing the carbon atom bonded to it to carry a partial positive charge. The amino group (-NH₂) in the aminourea compounds shown in Formula II is nucleophilic, attacking the carbon atom bonded to the trifluoromethyl group in Formula I, undergoing a nucleophilic substitution reaction, and simultaneously losing one molecule of fluoride ion (F₂). - This forms an intermediate containing an oxadiazole ring precursor structure, at which point the intermediate contains active functional groups that can further react.

[0015] Cycloaddition reaction

[0016] The azide group (-N3) in the azide compound (R3-N3) shown in Formula III exhibits high reactivity. Under alkaline conditions of K2CO3, the above intermediate undergoes a 1,3-dipolar cycloaddition reaction with the azide compound. An unsaturated bond (carbon-nitrogen double bond) in the intermediate cycloadds with the azide group, forming a 1,2,3-triazole ring structure, ultimately yielding an oxadiazole-substituted 1,2,3-triazole compound (Formula IV).

[0017] Preferably, R1 is a substituted or unsubstituted phenyl, naphthyl, thiophene, benzothiophene, or furanyl group, preferably phenyl or substituted phenyl. The number of substituents is 1 to 5, preferably monosubstituted or disubstituted, and the substituents are halogen, alkyl, alkenyl, alkoxy, aryl, fluoroalkyl, or amide groups, such as 4-bromophenyl.

[0018] Preferably, R1 is an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms, such as hexyl.

[0019] Preferably, R1 is an alkoxy group having 1 to 6 carbon atoms.

[0020] Preferably, R2 is a substituted or unsubstituted phenyl group, with phenyl being the most preferred.

[0021] Preferably, R2 is an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, such as methyl, ethyl, propyl, butyl or allyl.

[0022] Preferably, R3 is a substituted or unsubstituted phenyl group, with phenyl being the most preferred.

[0023] Preferably, R3 is an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, such as methyl, ethyl, propyl, butyl, or allyl.

[0024] Preferably, the alkaline conditions are provided by one of the alkaline agents K2CO3, Cs2CO3, Et3N, DBU, and DABCO, with K2CO3 being the most preferred.

[0025] Preferably, the temperature of the defluorination-nucleophilic substitution-cycloaddition reaction is 60℃-100℃, more preferably 100℃. The time is 6 hours to 12 hours, more preferably 6 hours.

[0026] Preferably, the molar ratio of the compound shown in Formula I, the compound shown in Formula II, K2CO3 and the compound shown in Formula III is 1:1.5~3:2~3:1.5~3, more preferably 1:3:2:2.

[0027] Preferably, the solvent is one of tetrahydrofuran, acetonitrile, 1,4-dioxane, and toluene, with acetonitrile being the most preferred.

[0028] Preferably, the 4-oxadiazole-substituted 1,2,3-triazole compound of formula IV is any one of compounds 1)-13) below:

[0029] 1) 1- N - m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-1;

[0030] 2) 1- N - p-Bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-2;

[0031] 3) 1- N - p-Fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-3;

[0032] 4) 1- N -p-Trifluoromethylphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0033] 5) 1- N -m-nitrophenyl-4-oxadiazolyl-5-phenyl-1,2,3-triazole;

[0034] 6) 1- N - m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-4;

[0035] 7) 1- N -m-nitrophenyl-4-ethyletheryloxadiazolyl-5-phenyl-1,2,3-triazole;

[0036] 8) 1- N -m-nitrophenyl-4-methoxyoxadiazolyl-5-phenyl-1,2,3-triazole;

[0037] 9) 1- N -m-nitrophenyl-4-benzylmethoxyoxadiazolyl-5-phenyl-1,2,3-triazole;

[0038] 11)1- N - p-Methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole; structural formula as shown in Formula IV-5;

[0039] 11) 1- N -m-nitro-p-cyanophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0040] 12) 1- N -3'-pyridylphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0041] 13) 1- N -Biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-6;

[0042]

[0043]

[0044] The advantages and positive effects of the method for preparing oxadiazole-substituted 1,2,3-triazole compounds described in this invention are as follows:

[0045] 1. This invention uses K2CO3, which is relatively inexpensive and readily available, as a base to carry out the reaction under alkaline conditions, thus avoiding the potential toxicity and post-processing difficulties caused by metal catalysts.

[0046] 2. The reaction conditions are relatively mild, and can be carried out at 60-100℃, with low requirements for reaction equipment; the reaction steps are simple, and a multi-step series reaction is realized through a one-pot method, which has high atom economy, can effectively reduce synthesis costs and improve production efficiency, and provides a more efficient, green and economical new route for the synthesis of 4-oxadiazole-substituted 1,2,3-triazole compounds, with broad application prospects in drug development, material synthesis and other fields.

[0047] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0048] Figure 1 As shown in Equation IV-1, 1- N The proton NMR spectrum of 1-m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0049] Figure 2 As shown in Equation IV-1, 1- N Carbon NMR spectrum of m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0050] Figure 3 As shown in Equation IV-2, 1- N - The 1H NMR spectrum of p-bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0051] Figure 4 As shown in Equation IV-2, 1- N - Carbon NMR spectrum of p-bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0052] Figure 5 As shown in Equation IV-3, 1- N -1H NMR spectrum of p-fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0053] Figure 6 As shown in Equation IV-3, 1- N -C NMR spectrum of p-fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0054] Figure 7 As shown in Equation IV-3, 1- N -NMR fluorine spectrum of p-fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0055] Figure 8 As shown in Equation IV-4, 1- NThe proton NMR spectrum of 1-m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0056] Figure 9 As shown in Equation IV-4, 1- N Carbon NMR spectrum of m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0057] Figure 10 As shown in Equation IV-5, 1- N -1H NMR spectrum of p-methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0058] Figure 11 As shown in Equation IV-5, 1- N -C NMR spectrum of p-methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0059] Figure 12 As shown in Equation IV-6, 1- N 1H NMR spectrum of 1-biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole;

[0060] Figure 13 As shown in Equation IV-6, 1- N Carbon NMR spectrum of 1,2,3-biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole. Detailed Implementation

[0061] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0062] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0063] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0064] Example 1

[0065] Synthetic formula IV-1 is shown in Figure 1- N -m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole

[0066]

[0067] Formula IV-1

[0068] Under air conditions, trifluoromethyl-substituted acetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), m-nitrophenyl azide (Formula III) (0.2 mmol), acetylhydrazine (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was allowed to proceed for 6 hours.

[0069] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0070] After weighing, 1- was separated. N - m-Nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole 33.1 mg, yield 95%.

[0071] Figure 1 and Figure 2 The 1- prepared in Example 1 of this invention N The proton and carbon NMR spectra of -m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0072] 1 H NMR (600 MHz, CDCl3) δ 8.31 (d, J = 8.4 Hz, 1H), 8.29-8.27 (m, 1H), 7.68-7.65 (m, 1H), 7.65-7.61 (m, 1H), 7.53-7.48 (m, 1H), 7.47-7.42 (m, 4H), 2.61 (s, 3H); 13 C NMR (150 MHz, CDCl3) δ 164.0, 157.8, 148.4, 138.0, 136.6,132.2, 130.8, 130.4, 130.3, 130.2, 129.0, 123.9, 120.1, 10.9; HRMS (ESI) m / z [M+Na] + Calcd for C 17 H 12 N6O3: 371.0863; Found: 371.0863.

[0073] As can be seen from the above analysis, the target compound was successfully prepared.

[0074] Example 2

[0075] Synthetic formula IV-2 is shown in Figure 1- N -p-Bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole

[0076]

[0077] Formula IV-2

[0078] Under air conditions, trifluoromethyl-substituted p-bromoacetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), m-nitrophenyl azide (Formula III) (0.2 mmol), acetylhydrazine (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was allowed to proceed for 6 hours.

[0079] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0080] After weighing, 1- was separated. N - p-Bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole 34.2 mg, yield 80%.

[0081] Figure 3 and Figure 4 The 1- prepared in Example 2 of this invention are respectively N -The 1H and 1C NMR spectra of p-bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0082] 1 H NMR (600 MHz, CDCl3) δ 8.37-8.37 (m, 1H), 8.34-8.33 (m, 1H), 7.69-7.64 (m, 1H), 7.64-7.61 (m, 1H), 7.59 (d, J = 8.5 Hz, 2H), 7.35-7.31 (d, J = 8.5Hz, 2H), 2.64 (s, 3H); 13 C NMR (150 MHz, CDCl3) δ 164.2, 157.6, 148.6, 137.0,136.4, 132.4, 131.7, 130.6, 130.4, 125.7, 124.5, 122.7, 120.3, 10.9; HRMS(ESI) m / z[M+H] + Calcd for C 17 H 11 BrN6O3: 427.0149; Found: 427.0148.

[0083] As can be seen from the above analysis, the target compound was successfully prepared.

[0084] Example 3

[0085] Synthetic formula IV-3 is shown in Figure 1- N -p-Fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole

[0086]

[0087] Formula IV-3

[0088] Under air conditions, trifluoromethyl-substituted p-fluoroacetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), m-nitrophenyl azide (Formula III) (0.2 mmol), acetylhydrazine (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was allowed to proceed for 6 hours.

[0089] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0090] After weighing, 1- was separated. N - 16.2 mg of p-fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, yield 44%.

[0091] Figure 5 , Figure 6 , Figure 7 These are the 1- prepared in Example 3 of the present invention. N -The proton, carbon, and fluorine NMR spectra of p-fluorophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0092] 1 H NMR (600 MHz, CDCl3) δ 8.35-8.32 (m, 1H), 8.32-8.29 (m, 1H), 7.68-7.64 (m, 2H), 7.48-7.44 (m, 2H), 7.15 (t, J = 8.5 Hz, 2H), 2.63 (s, 3H); 13 C NMR (150 MHz, CDCl3) δ 164.7, 164.1, 163.0, 157.7, 148.5, 137.1, 136.4, 132.5 (d, J C-F = 8.8 Hz), 130.6, 130.4, 1124.3, 120.2, 116.5 (d, J C-F = 21.9 Hz), 10.9; 19 FNMR (564 MHz, CDCl3) δ -107.7; HRMS (ESI) m / z [M+Na] + Calcd for C 17 H 11 FN6O3:389.0769; Found: 389.0762.

[0093] As can be seen from the above analysis, the target compound was successfully prepared.

[0094] Example 4

[0095] Synthetic formula IV-4 is shown in Figure 1- N -m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole

[0096]

[0097] Formula IV-4

[0098] Under air conditions, trifluoromethyl-substituted acetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), m-nitrophenyl azide (Formula III) (0.2 mmol), benzoyl hydrazine (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was carried out for 6 hours.

[0099] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0100] After weighing, 1- was separated. N - m-Nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole 38.2 mg, yield 93%.

[0101] Figure 8 and Figure 9 These are the 1- prepared in Example 4 of the present invention. NThe proton and carbon NMR spectra of -m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0102] 1 H NMR (600 MHz, CDCl3) δ 8.34–8.29 (m, 2H), 8.08 (d, J = 7.4 Hz, 2H),7.72-7.67 (m, 1H), 7.66-7.61 (m, 1H), 7.57-7.50 (m, 4H), 7.48 (d, J = 4.3 Hz, 4H); 13 C NMR (150 MHz, CDCl3) δ 164.8, 157.5, 148.5, 138.3, 136.6, 131.9, 130.9,130.5, 130.3, 130.2, 129.1, 129.0, 127.1, 124.2, 124.0, 123.3, 120.0; HRMS(ESI) m / z [M+H] + Calcd for C 22 H 15 N6O3: 411.1200; Found: 411.1200.

[0103] As can be seen from the above analysis, the target compound was successfully prepared.

[0104] Example 5

[0105] Synthetic formula IV-5 is shown in Figure 1- N -p-Methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole

[0106]

[0107] Formula IV-5

[0108] Under air conditions, trifluoromethyl-substituted acetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), p-methoxyphenyl azide (Formula III) (0.2 mmol), hydrazine acetate (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was allowed to proceed for 6 hours.

[0109] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0110] After weighing, 1- was separated. N - 26.7 mg of p-methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, yield 80%.

[0111] Figure 10 and Figure 11 These are the 1- prepared in Example 5 of the present invention. N -The 1H and 1C NMR spectra of p-methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0112] 1 H NMR (600 MHz, CDCl3) δ 7.44–7.37 (m, 5H), 7.24 (d, J = 9.0 Hz, 2H), 6.90 (d, J = 9.0 Hz 2H), 3.82 (s, 3H), 2.60 (s, 3H); 13 C NMR (150 MHz, CDCl3) δ 163.7, 160.2, 158.3, 137.9, 131.4, 130.2, 130.0, 128.6, 128.5, 126.5, 124.7,114.4, 55.5, 10.9; HRMS (ESI) m / z [M+Na] + Calcd for C 18 H 15 N5O2: 356.1118; Found:356.1116.

[0113] As can be seen from the above analysis, the target compound was successfully prepared.

[0114] Example 6

[0115] Synthetic formula IV-6 is shown in Figure 1- N -Biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole

[0116]

[0117] Formula IV-6

[0118] Under air conditions, trifluoromethyl-substituted acetophenone (Formula I) (0.1 mmol), K2CO3 (0.2 mmol), p-methoxyphenyl azide (Formula III) (0.2 mmol), hydrazine acetate (Formula II) (0.3 mmol), and acetonitrile (1.0 mL) were added sequentially to the reaction tube, and the temperature was raised to 100 °C and the reaction was carried out for 6 hours.

[0119] After the reaction was complete, the reaction solution was transferred from the reaction tube to a 50 mL pear-shaped flask, and then subjected to rotary evaporation and column chromatography.

[0120] After weighing, 1- was separated. N 35.7 mg of 4-biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, yield 94%.

[0121] Figure 12 and Figure 13 These are the 1- prepared in Example 6 of the present invention. N The proton and carbon NMR spectra of 1-biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole are characterized as follows:

[0122] 1 H NMR (600 MHz, CDCl3) δ 7.62 (d, J = 8.5 Hz, 2H), 7.57 (d, J = 7.6 Hz, 2H), 7.48-7.42 (m, 6H), 7.42-7.37 (m, 4H), 2.60 (s, 3H); 13 C NMR (150 MHz, CDCl3) δ 163.8, 158.2, 142.4, 139.2, 137.8, 134.7, 131.7, 130.3, 130.2, 128.9,128.6, 128.0, 127.9, 127.0, 125.3, 124.7, 10.9; HRMS (ESI) m / z [M+Na] + Calcd forC 23 H 17 N5O: 402.1325; Found: 402.1324.

[0123] As can be seen from the above analysis, the target compound was successfully prepared.

[0124] Therefore, the preparation method of oxadiazole-substituted 1,2,3-triazole compounds described in this invention can be carried out smoothly under natural air conditions, without the need for an anhydrous or oxygen-free environment. The preparation method is simple, which helps to reduce production costs and achieve green synthesis.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing an oxadiazole-substituted 1,2,3-triazole compound, characterized in that, Includes the following steps, Under alkaline conditions and in a solvent, the compound shown in Formula I, the compound shown in Formula II, and Formula III undergo a defluorination-nucleophilic substitution-cycloaddition reaction. After the reaction, the compound is subjected to rotary evaporation and column chromatography to obtain the 4-oxadiazole-substituted 1,2,3-triazole compound shown in Formula IV. In Formulas I and IV, R1 is phenyl or 4-bromophenyl; In formulas II and IV, R2 is phenyl or methyl; In formulas III and IV, R3 is a substituted or unsubstituted phenyl group; The alkaline conditions are provided by the alkaline agent K2CO3; The defluorination-nucleophilic substitution-cycloaddition reaction was carried out at a temperature of 100°C for 6 hours. The molar ratio of the compound shown in Formula I, the compound shown in Formula II, K2CO3, and the compound shown in Formula III is 1:3:2:2; The solvent is acetonitrile.

2. The method for preparing an oxadiazole-substituted 1,2,3-triazole compound according to claim 1, characterized in that: The 4-oxadiazole-substituted 1,2,3-triazole compound represented by Formula IV is any one of the following compounds: 1) 1- N - m-nitrophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-1; 2) 1- N - p-Bromophenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-2; 3) 1- N - m-nitrophenyl-4-phenyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-4; 4) 1- N -p-Methoxyphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole; structural formula as shown in Formula IV-5; 5) 1- N -Biphenyl-4-methyloxadiazolyl-5-phenyl-1,2,3-triazole, with the structural formula shown in Formula IV-6;

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