3-methyl-1-styrylbenzofuran [2, 3-c] pyridine derivative as well as synthesis method and application thereof

Abstract

The invention discloses a 3-methyl-1-styryl benzofuran [2, 3-c] pyridine derivative with antibacterial activity and a synthetic method and application thereof.The synthetic method comprises the steps that a 3-oxopropyl-2, 3-dihydrobenzofuran derivative (1) and ammonium acetate serve as raw materials, potassium carbonate serves as a catalyst, a reflux reaction is conducted for 8 hours in an organic solvent, and the 3-methyl-1-styryl benzofuran [2, 3-c] pyridine derivative with antibacterial activity is obtained. The 3-methyl-1-styryl benzofuran [2, 3-c] pyridine derivative with antibacterial activity is obtained through a cyclization / oxidative aromatization cascade reaction. The synthesis method has the advantages of simple and easily available raw materials, low price, simple operation, high yield and convenient post-treatment, and is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the fields of synthetic medicine and chemical engineering, and mainly relates to a heterocyclic compound with antibacterial activity—3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative, and a synthetic method for synthesizing it through a cascade reaction of cyclization / oxidative aromatization. Background Technology

[0002] The benzofuranopyridine skeleton is widely found in many natural products and drugs and has excellent biological activity; the benzofuranopyridine skeleton is also a key core structure of many bioactive molecules. Molecules containing these structural units have been shown to exhibit prolyl hydroxylase inhibitory activity [Ma Guanglei, Guo Qingjun. China: CN110305143, 2019-10-08.], topoisomerase inhibitory activity [Jung KY, Wang H, Teriete P, et al. Journal of Medicinal Chemistry, 2015, 58(7):3002-3024.], antitumor activity [Lai Z, Ni H, Hu X, et al. Journal of Medicinal Chemistry, 2023, 66(15):10791-10807.], analgesic activity [Khan IA, Kulkarni MV, Gopal M, et al. Bioorganic & Medicinal Chemistry Letters, 2005, 15(15):3584-3587.], and antibacterial activity [B. Février, Dupas G, Bourguignon]. J, et al. Journal of Heterocyclic Chemistry, 2009, 30(4): 1085-1088.], Eg5 kinesin inhibitor activity [Khan IA, Kulkarni MV, Gopal M, et al. Bioorganic & Medicinal Chemistry Letters, 2005, 15(15): 3584-3587.], central α2-adrenergic receptor antagonist activity (Figure 1-47, 8) [L.E.J. Kenneth, C.J. Lowe, F.P. Bischoff. China: CN1237179, 1999-12-01.], anti-inflammatory activity [Klioze S S.:US4544745A,2024-03-20.], Phosphodiesterase inhibitor activity [LAGharat,JMG,NJKhairatkar,et.al..US8524905B2,2013-09-03.].

[0003] Because compounds with benzofuranopyridine structures possess rich biological activities and wide applications, their synthetic methods are attracting increasing attention from scientists.

[0004] In 1990, Haidera et al. [N Haider, VDHC Plas.Tetrahedron, 1990, 46(10):3641-3650.] reported a method for constructing benzofuranopyridine compounds by heating 2-(2-ethynylphenoxy)pyrazines. First, 2-(2-ethynylphenoxy)pyrazines undergo an intramolecular Diels-Alder reaction under heating to generate a bridged ring intermediate. Subsequently, this intermediate loses one molecule of HCN to obtain benzofurano[2,3-c]pyridine compounds (Formula 1).

[0005]

[0006] Synthetic methods of benzofurano[2,3-c]pyridine compounds of Formula 1

[0007] In 2005, Voigt et al. [Voigt B, Meijer L, Lozach O, et al. Bioorganic & medicinal chemistry letters. 2005, 15, 823-825.] reacted N-phenoxycarbonyl-4-phenyl-1,4-dihydropyridine with p-benzoquinone under perchloric acid catalysis to prepare a series of compounds with different cyclin-dependent kinase inhibitor activities. Since this structure possesses various cyclin-dependent kinase inhibitor activities, subsequent bioactivity tests on the synthesized novel 3-substituted benzofuranopyridine compounds revealed that changes in the 3-position substituent had a certain influence on both the inhibitory activity and selectivity of the compounds (Equation 2). In the same year, Parmentier's research group, using acetonitrile as the reaction medium and potassium carbonate as the catalyst, under reflux conditions, induced an intramolecular substitution cyclization reaction of 2-(2-chloropyridin-3-yl)phenol, similarly obtaining benzofuranopyridine compounds (Equation 3).

[0008]

[0009] In 2009, Yoon et al. [Woo Sub Yoon, Su Jung Lee, Seung Kyu Kang, et al. Tetrahedron Letters, 2009, 50(31): 4492-4494.] employed a CH bond activation strategy to catalyze the intramolecular cyclization reaction of 2-(2-bromophenoxy)pyridine using a palladium acetate-sodium carbonate catalytic system, constructing benzofuranopyridine compounds. This method is simple to operate, but the starting materials are difficult to obtain, and the yield is low, making it unsuitable for industrial production (Equation 4).

[0010]

[0011] Wang's research group [Wang YF, Toh KK, Lee JY, et al. Angewandte Chemie International Edition, 2011, 50(26): 5927-5931.] used 2-azidovinylbenzofuran compounds and 1,2-diphenylacetylene as reaction substrates, employed a catalytic system of rhodium and copper acetate as co-catalysts, and used acetic acid as an additive, and carried out the reaction in DMF solvent to synthesize benzofuran[2,3-c]pyridine compounds with good yields (Equation 5).

[0012]

[0013] This invention synthesizes a novel 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative and studies its antibacterial activity. Summary of the Invention

[0014] The first objective of this invention is to provide a novel compound with antibacterial activity.

[0015] A 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity has the following structural formula:

[0016]

[0017] Among them, R 1 Yes: hydrogen, halogen, trifluoromethyl, C1-C4 alkyl or C1-C4 alkoxy; R 2 It is: hydrogen, halogen, trifluoromethyl, C1-C4 alkyl or C1-C4 alkoxy, preferably, R 1 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy; R 2 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy.

[0018] Another object of the present invention is to provide a method for synthesizing the above-mentioned 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity. This method uses readily available and inexpensive raw materials, is easy to operate, and has convenient post-processing, making it suitable for industrial production.

[0019] A method for synthesizing a 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity, wherein the method uses 3-oxopropyl-2,3-dihydrobenzofuran derivative (1) and ammonium acetate as raw materials, and refluxes in tetrahydrofuran (THF) for 2-8 hours to obtain the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity through a cascade cyclization / oxidative aromatization reaction, as shown in the following reaction formula:

[0020]

[0021] Among them, R 1 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy; R 2 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy.

[0022] Furthermore, the feed ratio of the raw materials in the synthesis method is calculated by molar ratio as follows: 3-oxopropyl-2,3-dihydrobenzofuran derivative (1): ammonium acetate: potassium carbonate = 1:3~5:3~5.

[0023] The synthesis method includes the following steps: dissolving 3-oxopropyl-2,3-dihydrobenzofuran derivative, ammonium acetate, and potassium carbonate in tetrahydrofuran (THF) and refluxing to obtain the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative.

[0024] The synthesis method further includes the step of separating and purifying the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative obtained by the reaction: the reaction product is subjected to column chromatography with a solution of petroleum ether:ethyl acetate = 10:1 to 6:1 (v / v).

[0025] The organic solvent is tetrahydrofuran (THF).

[0026] The advantages of the synthesis method of this invention are mainly reflected in the following: starting from readily available ammonium acetate, potassium carbonate, and 3-oxopropyl-2,3-dihydrobenzofuran derivative (1), tetrahydrofuran (THF) is selected as the reaction solvent, and 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivatives are prepared simply and quickly through a cyclization / oxidative aromatization tandem reaction, with a product purity of over 99%. The operation steps of this invention are simple, namely, preparation by one-pot method, with inexpensive and readily available raw materials, green and mild reaction conditions, simple post-processing, and high yield. The reaction conditions of this invention can also be applied to large-scale preparation, suitable for the industrial production of 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivatives, thus having high implementation value and potential socio-economic benefits.

[0027] The final objective of this invention is to provide the application of the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative in the preparation of antibacterial agents, wherein the antibacterial agent uses the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative as the active ingredient. Extensive antibacterial experiments have demonstrated that the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative of this invention can be used as an antibacterial agent, especially exhibiting inhibitory effects against fruit rot fungi, potato wilt fungi, rapeseed blackleg fungi, and tomato gray mold fungi.

[0028] Preferably, the antibacterial agent is used to inhibit at least one of the following: fruit rot fungus, potato wilt fungus, rapeseed black shank fungus, and tomato gray mold fungus, wherein the 3-methyl-1-styrene-benzofuran[2,3-c]pyridine derivative is one of compounds 2b, 2c, 2e, 2f, and 2g.

[0029] The antibacterial agent is used to inhibit at least one of potato wilt pathogen and tomato gray mold pathogen, and the 3-methyl-1-styrene-benzofuran[2,3-c]pyridine derivative is compound 2a. Attached Figure Description

[0030] Figure 1 The image shows the nuclear magnetic resonance spectrum of compound 2a.

[0031] Figure 2 This is the NMR spectrum of compound 2b. Detailed Implementation

[0032] The technical solution of the present invention will be further illustrated by specific embodiments below, but the present invention is not limited to the following embodiments.

[0033] The present invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. The scope of protection of the present invention is not limited to the following embodiments. All variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in the present invention and are protected by the appended claims. The processes, conditions, reagents, and test methods for implementing the present invention, except as specifically mentioned below, are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations.

[0034] The testing instruments used in this invention are as follows:

[0035]

[0036] Example 1:

[0037] 3-Oxopropyl-2,3-dihydrobenzofuran derivative 1a (1.0 mmol), ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL), refluxed and stirred for 8 hours, and monitored by TLC until the reaction of the starting material was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown in Formula 2a.

[0038]

[0039] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 10:1) to obtain pure product 2a in 70% yield. The product structure was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR (600MHz, CDCl3) δ8.06(d,J=16.3Hz,1H),7.96(d,J=7.7Hz,1H),7.72(d,J=7.3Hz,2H),7.68–7.6 4(m,2H),7.61–7.53(m,3H),7.40(ddd,J=14.9,11.6,4.1Hz,3H),7.31(t,J=7.4Hz,1H),2.72(s,3H). 13 C NMR (151MHz, CDCl3) δ157.0,151.5,149.0,140.0,137.0,134.7,132.1,129.5,12 8.8,128.4,127.4,123.2,123.1,122.4,122.1,112.8,112.3,24.4.HRMS(ESI)m / z Calcd for C 20 H 16 NO[M+H] +286.1226, found 286.1225. indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2a.

[0040] Example 2:

[0041] 5-Chloro-3-oxopropyl-2,3-dihydrobenzofuran derivative 1b (1.0 mmol), ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL), refluxed and stirred for 8 hours, and monitored by TLC until the reaction of the starting material was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown in Formula 2b.

[0042]

[0043] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 9:1) to obtain pure product 2b in 75% yield. The structure of the product was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR (600MHz, CDCl3) δ8.04(d,J=16.3Hz,1H),7.95(d,J=2.0Hz,1H),7.72(d,J=7.4Hz,2H),7.62(dd ,J=12.6,3.7Hz,2H),7.56–7.52(m,2H),7.43(t,J=7.6Hz,2H),7.35(t,J=7.4Hz,1H),2.75(s,3H). 13 C NMR (151MHz, CDCl3) δ155.2,151.9,149.5,140.5,137.0,135.3,131.1,129.7,12 8.9,128.9,128.5,127.2,123.8,122.8,121.6,113.4,112.7,24.4.HRMS(ESI)m / z Calcd for C 20 H 15 ClNO[M+H] + 320.0837, found 320.0839.

[0044] This indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2b.

[0045] Example 3:

[0046] 5-Bromo-3-oxopropyl-2,3-dihydrobenzofuran derivative 1c (1.0 mmol), ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL). The mixture was refluxed and stirred for 8 hours. TLC was monitored until the reaction was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown below.

[0047] As shown in Equation 2c.

[0048]

[0049] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 10:1) to obtain pure product 2c in 55% yield. The structure of the product was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR (400MHz, CDCl3) δ8.01(d,J=6.4Hz,1H),7.96(s,1H),7.67(d,J=8.3Hz,1H),7.64–7.51(m,7H),7.41(t,J=7.4Hz,1H),2.73(s,3H); 13 C NMR (151MHz, CDCl3) δ156.8,151.4,149.1,139.5,136.0,134.1,133.4,131.8,13 0.9,129.8,128.7,124.3,123.8,123.2,122.1,113.2,112.4,24.6.HRMS(ESI)m / z Calcdfor C 20 H 15 BrNO[M+H] + 364.0332, found 364.0334.

[0050] This indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2c.

[0051] Example 4:

[0052] 1.0 mmol of 4-methoxy-3-oxopropyl-2,3-dihydrobenzofuran derivative 1d, ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in 5.0 mL of tetrahydrofuran (THF). The mixture was refluxed and stirred for 8 hours. TLC was monitored until the reaction was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown below.

[0053] As shown in Equation 2d.

[0054]

[0055] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 6:1) to obtain a pure product 2d in 73% yield. The product structure was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR (600 MHz, CDCl3) δ8.02(d,J=16.3 Hz,1H),7.84(d,J=8.6 Hz,1H),7.73(d,J=7.5 Hz,2H),7.62(d,J=16.3 Hz,1H),7.50(s,1H),7.42(t,J=7.6 Hz, 2H), 7.33 (t, J = 7.3 Hz, 1H), 7.16 (d, J = 2.2 Hz, 1H), 7.00 (dd, J = 8.6, 2.2 Hz, 1H), 3.95 (s, 3H), 2.72 (s, 3H). 13 C NMR(151 MHz, CDCl3)δ161.8,158.4,151.5,149.4,139.4,137.1,134.5,132.3,128.7,128. 4,127.3,123.4,122.3,115.4,112.3,112.1,96.5,55.8,24.5.HRMS(ESI)m / zCalcd for C 21 H 18 NO2[M+H]+316.1332,found316.1333. indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2d.

[0056] Example 5:

[0057] 1.0 mmol of 3-oxopropyl-2,3-dihydrobenzofuran derivative 1e, ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL), refluxed and stirred for 8 hours, and monitored by TLC until the reaction of the starting material was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown in Formula 2e.

[0058]

[0059] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 10:1) to obtain pure product 2e in 66% yield. The structure of the product was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1H NMR (400 MHz, CDCl3) δ8.06 (dd, J = 14.2, 1.8 Hz, 1H), 7.96 (d, J = 16.3 Hz, 1H), 7.68 (dd, J = 8.8, 1.9 Hz, 1H), 7.62–7.49 (m, 7H), 2.73 (s, 3H). 13 C NMR(151 MHz, CDCl3)δ155.6,151.8,149.5,140.1,135.79,134.3,133.7,132.6,131.9,13 0.8,130.8,128.6,124.8,123.4,116.2,114.0,113.6,24.5.HRMS(ESI)m / zCalcd for C 20 H 14 Br2NO[M+H] + 441.9437, found 441.9439. This indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2e.

[0060] Example 6:

[0061] 3-Oxopropyl-2,3-dihydrobenzofuran derivative 1f, ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL), refluxed and stirred for 8 hours, and monitored by TLC until the reaction of the starting material was complete. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown in Formula 2f.

[0062]

[0063] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 6:1) to obtain pure product 2f in 70% yield. The structure of the product was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR (400MHz, CDCl3) δ7.91(s,1H),7.52(d,J=3.5Hz,3H),7.39(d,J=8.3Hz,2H),7.16( d, J=8.3Hz, 2H), 3.40 (dd, J=9.6, 6.7Hz, 2H), 3.14 (dd, J=9.6, 6.7Hz, 2H), 2.69 (s, 3H). 13CNMR (101MHz, CDCl3) δ155.1,151.3,150.0,145.1,140.5,131.3,130.2,129. 6,128.6,124.1,121.8,119.7,113.4,112.6,34.6,34.1,24.4.HRMS(ESI)m / z Calcd forC 20 H 15 BrClNO[M+Na] + 421.9918, found 421.9932. This indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2f.

[0064] Example 7:

[0065] 1 g (1.0 mmol) of 3-oxopropyl-2,3-dihydrobenzofuran derivative, ammonium acetate (4.0 mmol), and potassium carbonate (3.0 mmol) were dissolved in tetrahydrofuran (THF) (5.0 mL). The mixture was refluxed and stirred for 8 hours. The reaction was monitored by TLC until the starting material was completely reacted. After cooling, the solvent was removed by rotary evaporation under reduced pressure to obtain the crude product, the structure of which is shown in Formula 2g.

[0066]

[0067] The crude product was subjected to column chromatography (petroleum ether: ethyl acetate = 7:1) to obtain 2 g of pure product, with a yield of 65%. The product structure was identified by nuclear magnetic resonance and high-resolution mass spectrometry. 1 H NMR(400MHz, CDCl3) δ7.86(d,J=8.6Hz,1H),7.45(s,1H),7.24(s,4H),7.07(d,J=2.1Hz,1H),6.96(dd, J=8.6,2.2Hz,1H),3.93(s,3H),3.37(dd,J=9.7,6.7Hz,2H),3.16(dd,J=9.7,6.7Hz,2H),2.68(s,3H). 13 C NMR (101MHz, CDCl3) δ161.9,158.5,151.2,149.7,145.3,143.8,140.1,131.6,131.5,129.8, 129.2,128.5,122.3,115.5,112.0,111.8,96.4,55.7,34.5,34.3,24.4.HRMS(ESI)m / zCalcd for C 21 H 19 ClNO2[M+H] +352.1099, found 352.1101. indicates that the obtained 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative has the structure shown in structural formula 2g.

[0068] Example 8: Antibacterial Test

[0069] The mycelial growth rate method was used to test the inhibitory activity of the compounds against four plant-derived fungi.

[0070] The concentration of the compounds was set at 50 μg / ml for initial screening of all test compounds. The concentrations of the test compounds and azoxystrobin were both 50 μg / ml. The antimicrobial test results for four plant-derived fungi are shown in Table 1. The results of the antimicrobial experiments revealed that, at the same concentration, the inhibitory activity of the same compound on the mycelial growth of different tested plant-derived pathogenic fungi varied, and different compounds also showed different inhibitory effects on the mycelial growth of the same plant-derived pathogenic fungi. The compounds all showed certain inhibitory effects against *Valsa mali* (VM), *Fusarium solani* (FS), *Leptosphaeria biglobosa* (LB), and *Botrytis cinerea* (BC). Table 1 shows that compounds 2b, 2c, 2e, 2f, and 2g had good inhibitory effects on the above four fungi, with better antimicrobial effects than the positive control agent; compound 2a showed better antimicrobial effects against *Fusarium solani* and *Botrytis cinerea* than the positive control agent.

[0071] Table 1. Preliminary antifungal activity of compound 2 at a concentration of 50 μg / ml.

[0072]

[0073]

Claims

1. A 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity, the structural formula of which is: in, R 1 Yes: hydrogen, halogen, trifluoromethyl, C1-C4 alkyl or C1-C4 alkoxy; R 2 It is: hydrogen, halogen, trifluoromethyl, C1-C4 alkyl or C1-C4 alkoxy.

2. The 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity according to claim 1, characterized in that, The R 1 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy; R 2 Yes: hydrogen, fluorine, chlorine, bromine, trifluoromethyl, methyl or methoxy.

3. A method for synthesizing a 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity as described in claim 1 or 2, characterized in that, The method uses 3-oxopropyl-2,3-dihydrobenzofuran derivative (1) and ammonium acetate as raw materials, potassium carbonate as catalyst, and reflux reaction in an organic solvent to obtain 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative with antibacterial activity through a cascade reaction of cyclization / oxidative aromatization. The reaction formula is shown below: Among them, R 1 and R 2 The definition is as described in claim 1 or 2.

4. The synthesis method according to claim 3, characterized in that, The feed ratio of the raw materials in the synthesis method is calculated by molar ratio as follows: 3-oxopropyl-2,3-dihydrobenzofuran derivative (1): ammonium acetate: potassium carbonate = 1:3~5:3~5.

5. The synthesis method according to claim 3, characterized in that, The synthesis method includes the following steps: dissolving 3-oxopropyl-2,3-dihydrobenzofuran derivative (1) and ammonium acetate in an organic solvent and refluxing to obtain the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative.

6. The synthesis method according to claim 3, characterized in that, The synthesis method further includes the step of separating and purifying the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative obtained by the reaction: the reaction product is subjected to column chromatography with a solution of petroleum ether:ethyl acetate = 10:1 to 6:1 (v / v).

7. The synthesis method according to claim 3, characterized in that, The organic solvent is tetrahydrofuran (THF).

8. The use of a 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative as described in claim 1 or 2 in the preparation of an antibacterial agent, characterized in that, The antibacterial agent uses the 3-methyl-1-styrene-benzofuran[2,3-c]pyridine derivative as its active ingredient.

9. The use of the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative according to claim 8 in the preparation of antibacterial agents, characterized in that, The antibacterial agent is used to inhibit at least one of the following: fruit rot fungus, potato wilt fungus, rapeseed black shank fungus, and tomato gray mold fungus.

10. The use of the 3-methyl-1-styrylbenzofuran[2,3-c]pyridine derivative according to claim 9 in the preparation of antibacterial agents, characterized in that, The antibacterial agent is used to inhibit at least one of the following: fruit rot fungus, potato wilt fungus, rapeseed black shank fungus, and tomato gray mold fungus; the 3-methyl-1-styrene-benzofuran[2,3-c]pyridine derivative is one of compounds 2b, 2c, 2e, 2f, and 2g. The antibacterial agent is used to inhibit at least one of potato wilt pathogen and tomato gray mold pathogen, and the 3-methyl-1-styrene-benzofuran[2,3-c]pyridine derivative is compound 2a.

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