3-Oxopropyl-2,3-dihydrobenzofuran derivatives with antibacterial activity, their preparation methods and applications

Abstract

This invention discloses a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, its preparation method, and its application. The method includes: Step 1, adding compound I, compound II, and a catalyst to an organic solvent, stirring thoroughly at room temperature, and performing an alkylation-Mike addition tandem reaction, followed by vacuum rotary evaporation to remove the organic solvent from the crude product, yielding the crude product; wherein compound I is o-hydroxybenzyl acetone or an o-hydroxybenzyl acetone derivative, and compound II is a 1-bromobenzyl acetone derivative; Step 2, removing the catalyst, unreacted raw materials, and other impurities using column chromatography to obtain the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity. This invention not only has the advantages of simple preparation method, low cost, and high yield, but also the prepared compound has good antibacterial activity.

Description

Technical Field

[0001] This invention relates to dihydrobenzofuran compounds, specifically 3-oxopropyl-2,3-dihydrobenzofuran derivatives with antibacterial activity, their preparation methods, and applications. Background Technology

[0002] 2,3-Dihydrobenzofurans are a class of low-molecular-weight heterocyclic compounds with good biological activity, widely used in agriculture, medicine, and chemical industries, and have great application value. Studies have reported that dihydrobenzofurans (DHBs) are essential structural units for the biological activity of various non-natural products such as polyether ion-carrier antibiotics and macrolide drugs, and are also basic structural units of many important natural products such as plant lignin and sandalwood. Furthermore, it is noteworthy that compounds with the dihydrobenzofuran structure also have applications in treating cancer [Tistechok S, Stierhof M, Myronovskyi M, et al. Furaquinocins K and L:. Antibiotics, 2022, 11(11):1587.], insomnia [Takagi S, Sugihara G, Takahashi H, et al.. Frontiers in Neurology, 2023, 14:1280131], and antibacterial [Mehdi SH, Hashim R, Ghalib RM, et al. Journal] of Molecular Structure, 2011, 1006(1-3):318-323.], anti-inflammatory [Closse A, Haefliger W, Hauser D, et al. Journal of Medicinal Chemistry, 1981, 24(12):1465-1471.], insecticidal [Wangjin X, Dianjing S, Xiaojun C, et al. Environmental Science and Pollution Research, 2023, 30:106047-106058.] and antioxidant [Shaw CY, Chen CC, Tsai Y C.. Journal of Natural Products, 2002, 65(5):740-741.], therefore, the synthesis of benzodihydrofuran compounds has always been a hot topic in medicinal chemistry research, for example:

[0003] In 2011, Kan et al. [Wakimoto T, Miyata K, Ohuchi H, et al. Organic Letters 2011, 13(10), 2789-2791.] reported a rhodium-catalyzed enantioselective synthesis of cis-2-amide-3-aryl-2,3-dihydrobenzofuran, the reaction process of which is as follows;

[0004]

[0005] In 2017, Li and Xu's research group [Li Y, Tang Y, He X, et al. Chemistry (Weinheim an der Bergstrasse, Germany), 2017, 23(31): 7453-7457.] synthesized a series of novel 2,3-dihydrobenzofuran compounds by cyclizing 1,1-disubstituted alkenes with anisole compounds using a rhodium(III)-catalyzed CH bond activation strategy. The reaction process is as follows:

[0006]

[0007] In 2021, Professor Xu Minghua's research group [Zhu DX, Liu JG, Xu MH. Journal of the American Chemical Society, 2021, 143(23): 8583-8589.] used a one-pot method with quinine-derived thiourea catalyst and rhodium (I) metal catalyst as synergistic catalysts to synthesize a series of chiral benzodihydrofuran compounds in a stereodispersive manner. They cleverly utilized the OH in the reaction substrate and the α,β-unsaturated ester structure generated during the reaction to carry out an intramolecular oxa-Michael tandem reaction, constructing a chiral benzodihydrofuran skeleton and obtaining compounds corsifuran A and corsifuran B. The reaction process is as follows:

[0008]

[0009] In 2024, Feng Miao et al. [Feng Miao, Lü Lanlan, Guo Yijia, et al. Organic Chemistry, 2024, 1-12.] reported a silver-catalyzed 5-exo-dig cyclization reaction of o-hydroxyphenylpropynyl alcohol with isonitrile as ligand, constructing a series of 2-methylene-2,3-dihydrobenzofuran-3-ol compounds in moderate to excellent yields. The reaction process is as follows:

[0010]

[0011] However, the synthesis of 2,3-dihydrobenzofuran derivatives is usually complicated by complex substrates, long steps, high cost, and environmental unfriendliness. Therefore, there is an urgent need to explore a new method to synthesize novel 2,3-dihydrobenzofuran derivatives. Summary of the Invention

[0012] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, its preparation method and application, which not only has the advantages of simple preparation method, low price and high yield, but also the prepared compound has good antibacterial effect.

[0013] To achieve the above objectives, the present invention employs the following technical solution:

[0014] A 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity has the following structural formula:

[0015]

[0016] In the formula, R 1 and R 2 It can be hydrogen, chlorine, bromine, or methoxy.

[0017] A method for preparing a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity includes the following steps:

[0018] Step 1: Compound I, Compound II, and the catalyst are added to an organic solvent and stirred thoroughly at room temperature. The mixture undergoes an alkylation-Mike addition tandem reaction. The organic solvent is then removed from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0019]

[0020] Compound I is o-hydroxybenzyl acetone or an o-hydroxybenzyl acetone derivative, and compound II is a 1-bromobenzyl acetone derivative;

[0021] Step 2: Remove the catalyst, unreacted raw materials and other impurities by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity.

[0022] Furthermore, the ratio of compound I, compound II, catalyst, and organic solvent is 1 mmol: 2 mmol: 1.2 mmol: 2 mL.

[0023] Furthermore, the o-hydroxybenzyl acetone derivative is 5-bromo-o-hydroxybenzyl acetone, 5-chloro-o-hydroxybenzyl acetone, or 4-methoxy-o-hydroxybenzyl acetone.

[0024] Further, the 1-bromobenzylacetone derivative is 1-bromo-4-phenyl-3-buten-2-one, 1-bromo-4(4-bromophenyl)-3-buten-2-one, 1-bromo-4(4-chlorophenyl)-3-buten-2-one or 1-bromo-4(4-methoxyphenyl)-3-buten-2-one.

[0025] Furthermore, the organic solvent is tetrahydrofuran or dioxane.

[0026] Furthermore, the catalyst is potassium carbonate, potassium acetate, or sodium carbonate.

[0027] Furthermore, the eluent used in the column chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of (20-40):1.

[0028] Application of a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity as an antibacterial agent.

[0029] Compared with the prior art, the present invention has the following technical effects:

[0030] This invention uses readily available and inexpensive o-hydroxybenzyl acetone or its derivatives, and 1-bromobenzyl acetone derivatives as raw materials. Under the action of a catalyst, and in an organic solvent, a simple and rapid alkylation-Mike addition tandem reaction is performed to prepare 3-oxopropyl-2,3-dihydrobenzofuran derivatives. After conventional purification by rotary evaporation under reduced pressure and column chromatography, the product purity reaches over 99%, and the yield reaches 60%–84%. Furthermore, the prepared 3-oxopropyl-2,3-dihydrobenzofuran derivatives exhibit certain inhibitory effects against apple rot fungus, potato wilt fungus, rapeseed black shank fungus, and tomato gray mold fungus. In short, this invention not only has the advantages of simple operation steps, low cost, green and mild reaction conditions, simple post-processing, and high yield, making it suitable for industrial production, but also the prepared compounds have good antibacterial activity, thus possessing potential socio-economic benefits. Attached Figure Description

[0031] Figures 1(a) to 1(b) The nuclear magnetic resonance spectrum of compound 3aa prepared in Example 1 of this invention;

[0032] Figures 2(a) to 2(b) The nuclear magnetic resonance spectrum of compound 3bb prepared in Example 2 of this invention. Detailed Implementation

[0033] The specific content of the present invention will be further explained in detail below with reference to the embodiments.

[0034] Example 1

[0035] Step 1: Add 1 mmol of o-hydroxybenzyl acetone, 2 mmol of 1-bromo-4-phenyl-3-buten-2-one, and 1.2 mmol of potassium carbonate to 2 mL of tetrahydrofuran. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the tetrahydrofuran from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0036]

[0037] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 40:1 as the eluent. Potassium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3aa, with a yield of 72%.

[0038] The structure of compound 3aa was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer manufactured by Bruker, Germany, via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: Figures 1(a) to 1(b) As shown: 1 H NMR (600MHz, CDCl3) δ7.78(d,J=16.0Hz,1H),7.60(dd,J=7.0,1.8Hz,2H),7.39(d,J=6.4Hz,3H),7.28(s,1H),7.25(s,1H),7.19(d,J= 7.6Hz,1H),7.14(d,J=7.4Hz,1H),6.97-6.87(m,2H),4.92(d,J=5.8Hz,1H),4.09(d,J=6.4Hz,1H),2.97(d,J=6.9Hz,2H),2.23(s,3H); 13 C NMR (151MHz, CDCl3) δ206.3,196.9,158.9,145.2,134.5,130.9,129.0,128.9,1 28.8,128.6,124.8,121.5,120.6,110.0,89.9,49.1,40.9,30.3; HRMS(ESI)m / z Calcd for C 20 H 18 O3[M+Na] + 329.1148, found 329.1154. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran synthesized in Example 1 has the structure shown in structural formula 3aa.

[0039] Example 2

[0040] Step 1: Add 1 mmol of 5-bromo-o-hydroxybenzylacetone, 2 mmol of 1-bromo-4-(4-bromophenyl)-3-buten-2-one, and 1.2 mmol of potassium carbonate to 2 mL of tetrahydrofuran. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the tetrahydrofuran from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0041]

[0042] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 30:1 as the eluent. Potassium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3bb, with a yield of 70%.

[0043] The structure of compound 3bb was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: Figures 2(a) to 2(b) As shown: 1 H NMR (400MHz, CDCl3) δ7.70(d,J=16.0Hz,1H),7.53(d,J=8.5Hz,2H),7.46(d,J=8.5Hz,2H),7.29(dd,J=8.5,2.0Hz,1H),7.26 -7.19(m,2H),6.81(d,J=8.5Hz,1H),4.93(d,J=5.7Hz,1H),4.05(dd,J=12.8,6.6Hz,1H),2.96(d,J=6.9Hz,2H),2.23(s,3H); 13 C NMR (101MHz, CDCl3) δ206.1,196.0,158.0,144.0,133.2,132.2,131.8,131.0,1 30.1,127.9,125.4,120.9,113.4,111.5,90.1,48.8,40.6,30.2; HRMS(ESI)m / z Calcd for C 20 H 16 Br2O3[M+Na] + 484.9358, found 484.9359. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 2 has the structure shown in structural formula 3bb.

[0044] Example 3

[0045] Step 1: Add 1 mmol of 5-chloro-o-hydroxybenzyl acetone, 2 mmol of 1-bromo-4-phenyl-3-buten-2-one, and 1.2 mmol of potassium carbonate to 2 mL of tetrahydrofuran. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the tetrahydrofuran from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0046]

[0047] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 25:1 as the eluent. Potassium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3ca, with a yield of 84%.

[0048] The structure of compound 3ca was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: 1 H NMR (600MHz, CDCl3) δ7.77(d,J=16.0Hz,1H),7.58(dd,J=7.4,1.7Hz,2H),7.38(d,J=6.8Hz,3H),7.22(d,J=16.0Hz,1H),7. 12(dd,J=10.6,2.1Hz,2H),6.83(d,J=8.4Hz,1H),4.94(d,J=5.8Hz,1H),4.13-4.01(m,1H),2.99-2.89(m,2H),2.20(s,3H); 13 C NMR (151MHz, CDCl3) δ206.0,196.1,157.5,145.4,134.3,131.0,128.9,128 .8,128.8,126.2,125.0,120.4,110.8,90.2,48.7,40.6,30.; HRMS(ESI)m / z Calcd for C 20 H 17 ClO3[M+Na] + 363.0758, found 363.0759. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 3 has the structure shown in structural formula 3ca.

[0049] Example 4

[0050] Step 1: Add 1 mmol of 4-methoxy-o-hydroxybenzyl acetone, 2 mmol of 1-bromo-4-phenyl-3-buten-2-one, and 1.2 mmol of potassium carbonate to 2 mL of tetrahydrofuran. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the tetrahydrofuran from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0051]

[0052] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 20:1 as the eluent. Potassium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3da, with a yield of 73%.

[0053] The structure of compound 3da was identified using a Bruker AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured in Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: 1 H NMR (600MHz, CDCl3) δ7.78(d,J=15.9Hz,1H),7.63-7.56(m,2H),7.39(d,J=5.9Hz,3H),7.23(s,1H),7.02(d,J=8.3Hz,1H),6.53(d,J=2.2 Hz,1H),6.44(dd,J=8.3,2.1Hz,1H),4.93(d,J=5.5Hz,1H),4.00(dd,J=12.6,6.6Hz,1H),3.78(s,3H),2.93(d,J=6.9Hz,2H),2.21(s,3H); 13 CNMR (151MHz, CDCl3) δ206.6,196.9,161.0,160.2,145.1,134.5,130.9,128.9 ,128.8,124.9,120.5,107.2,96.5,90.7,55.6,49.4,40.4,30.3; HRMS(ESI)m / z Calcd for C 21 H 20 O4[M+Na] + 359.1254, found 359.1255. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 4 has the structure shown in structural formula 3da.

[0054] Example 5

[0055] Step 1: Add 1 mmol of o-hydroxybenzylacetone, 2 mmol of 1-bromo-4-(4-bromophenyl)-3-buten-2-one, and 1.2 mmol of potassium carbonate to 2 mL of tetrahydrofuran. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the tetrahydrofuran from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0056]

[0057] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 30:1 as the eluent. Potassium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3ab, with a yield of 80%.

[0058] The structure of compound 3ac was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: 1 H NMR (400MHz, CDCl3) δ7.69(d,J=15.9Hz,1H),7.51(d,J=8.5Hz,2H),7.44(d,J=8.5Hz,2H),7.25-7.07(m,3H), 6.91(dd,J=18.7,7.8Hz,2H),4.91(d,J=5.7Hz,1H),4.07(q,J=6.5Hz,1H),2.96(d,J=6.9Hz,2H),2.22(s,2H); 13 C NMR (101MHz, CDCl3) δ206.5,196.6,158.8,143.6,133.3,132.2,131.3,130.0,1 29.0,128.4,124.7,121.6,121.1,109.9,89.8,49.0,40.7,30.2; HRMS(ESI)m / z CalcdforC 20 H 17 BrO3[M+Na] + 384.0361, found 384.0363. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 5 has the structure shown in structural formula 3ab.

[0059] Example 6

[0060] Step 1: Add 1 mmol of o-hydroxybenzylacetone, 2 mmol of 1-bromo-4-(4-chlorophenyl)-3-buten-2-one, and 1.2 mmol of potassium acetate to 2 mL of dioxane. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the dioxane from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0061]

[0062] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 40:1 as the eluent. Potassium acetate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3ac, with a yield of 72%.

[0063] The structure of compound 3ac was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: 1 H NMR (400MHz, CDCl3) δ7.72(d,J=16.0Hz,1H),7.52(d,J=8.5Hz,2H),7.36(d,J=8.5Hz,2H),7.23-7.11(m,3H) ,6.96-6.87(m,2H),4.91(d,J=5.7Hz,1H),4.07(dd,J=12.8,6.5Hz,1H),2.96(d,J=6.9Hz,2H),2.22(s,3H); 13 CNMR(151MHz,CDCl3)δ205.9,197.4,158.7,143.3,137.1,132.8,131.9,129.9,129 .3,129.0,128.4,124.7,121.9,121.6,110.0,87.6,44.5,40.0,30.5; HRMS(ESI)m / z Calcdfor C 20 H 17 ClO3[M+Na] + 363.0758, found 363.0758. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 6 has the structure shown in structural formula 3ac.

[0064] Example 7

[0065] Step 1: Add 1 mmol of o-hydroxybenzylacetone, 2 mmol of 1-bromo-4-(4-methoxyphenyl)-3-buten-2-one, and 1.2 mmol of sodium carbonate to 2 mL of dioxane. Stir at room temperature for 3 h. Monitor the reaction by TLC until the reactants are completely reacted. Then remove the dioxane from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows:

[0066]

[0067] Step 2: Petroleum ether and ethyl acetate were mixed at a volume ratio of 30:1 as the eluent. Sodium carbonate, unreacted raw materials and other impurities were removed by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, denoted as 3ad, with a yield of 60%.

[0068] The structure of compound 3bb was identified using an AVANCE NEO 600M nuclear magnetic resonance spectrometer (manufactured by Bruker, Germany) via nuclear magnetic resonance and high-resolution mass spectrometry. The results are as follows: 1 H NMR (600MHz, CDCl3) δ7.72(d,J=15.9Hz,1H),7.53(d,J=8.5Hz,2H),7.20(t,J=7.7Hz,1H),7.13(t,J=6.9Hz,1H),6.97-6.87(m,5H),5. 35(d,J=9.6Hz,1H),4.35(dd,J=15.9,7.8Hz,1H),3.85(s,3H),2.78(dd,J=18.0,6.4Hz,1H),2.66(dd,J=18.0,7.9Hz,1H),2.09(s,3H); 13 C NMR (151MHz, CDCl3) δ205.1,197.5,160.8,160.6,144.2,135.1,131.2,127.6, 127.9,123.8,121.2,106.9,97.6,91.6,57.8,50.3,41.1,31.5.HRMS(ESI)m / z Calcd for C 21 H 20 O4[M+Na]+359.1254,found359.1255.HRMS(ESI)m / z Calcd for C 20 H 18 O3[M+Na] + 329.1148, found 329.1154. This indicates that the 3-oxopropyl-2,3-dihydrobenzofuran derivative synthesized in Example 7 has the structure shown in structural formula 3ad.

[0069] The mycelial growth rate method was used to test the inhibitory effects of the 3-oxopropyl-2,3-dihydrobenzofuran derivatives synthesized in Examples 1 to 7 on four plant-derived fungi. The specific procedure was as follows: the concentrations of the 3-oxopropyl-2,3-dihydrobenzofuran derivatives and the existing antibacterial drug pyraclostrobin were both set at 50 μg / mL, and antibacterial tests were performed on the four plant-derived fungi. The results are shown in Table 1.

[0070] Table 1. Antibacterial results of 3-oxopropyl-2,3-dihydrobenzofuran derivatives and pyraclostrobin.

[0071]

[0072] As shown in Table 1, although all compounds exhibited some inhibitory effects against *Valsa mali* (VM), *Fusarium solani* (FS), *Leptosphaeria biglobosa* (LB), and *Botrytis cinerea* (BC), the inhibitory effects of the same concentration of the same compound on the mycelial growth of different plant-derived pathogenic fungi varied. Furthermore, different compounds showed varying inhibitory effects on the mycelial growth of the same plant-derived pathogenic fungi. Most of the 3-oxopropyl-2,3-dihydrobenzofuran derivatives synthesized in Examples 1–7 showed relatively significant inhibitory effects against *Valsa mali* (VM) and *Leptosphaeria biglobosa* (LB). In particular, compound 3aa synthesized in Example 1, compound 3da synthesized in Example 4, and compound 3ab synthesized in Example 5 showed significant inhibitory effects against *Valsa mali* (VM). The growth inhibition rate of *Malus malaria* (VM) exceeded 70%, and its antibacterial effect was significantly higher than that of the control group positive drug pyraclostrobin.

Claims

1. A 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity, characterized in that, The structural formula is as follows: In the formula, R 1 and R 2 It can be hydrogen, chlorine, bromine, or methoxy.

2. The method for preparing the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity according to claim 1, characterized in that, Includes the following steps: Step 1: Compound I, Compound II, and the catalyst are added to an organic solvent and stirred thoroughly at room temperature. The mixture undergoes an alkylation-Mike addition tandem reaction. The organic solvent is then removed from the crude product by rotary evaporation under reduced pressure to obtain the crude product. The reaction formula is as follows: Compound I is o-hydroxybenzyl acetone or an o-hydroxybenzyl acetone derivative, and compound II is a 1-bromobenzyl acetone derivative; The organic solvent is tetrahydrofuran or dioxane; The catalyst is potassium carbonate, potassium acetate, or sodium carbonate. Step 2: Remove the catalyst, unreacted raw materials and other impurities by column chromatography to obtain a 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity.

3. The method for preparing the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity according to claim 2, characterized in that, The ratio of compound I, compound II, catalyst, and organic solvent is 1 mmol: 2 mmol: 1.2 mmol: 2 mL.

4. The method for preparing the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity according to claim 2, characterized in that, The o-hydroxybenzyl acetone derivative is 5-bromo-o-hydroxybenzyl acetone, 5-chloro-o-hydroxybenzyl acetone, or 4-methoxy-o-hydroxybenzyl acetone.

5. The method for preparing the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity according to claim 2, characterized in that, The 1-bromobenzylacetone derivative is 1-bromo-4-phenyl-3-buten-2-one, 1-bromo-4(4-bromophenyl)-3-buten-2-one, 1-bromo-4(4-chlorophenyl)-3-buten-2-one or 1-bromo-4(4-methoxyphenyl)-3-buten-2-one.

6. The method for preparing the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity according to claim 2, characterized in that, The eluent used in the column chromatography was a mixture of petroleum ether and ethyl acetate in a volume ratio of (20-40):

1.

7. The application of the 3-oxopropyl-2,3-dihydrobenzofuran derivative with antibacterial activity as described in claim 1 as an antibacterial agent for plant-derived fungi.

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