A benzyl cyanide derivative and its preparation method and application

Abstract

The present invention belongs to the technical field of chemical pharmaceutical preparation, specifically relating to a benzyl cyanide derivative, its preparation method, and application. The structural formula of the benzyl cyanide derivative is: #imgabs0#. This derivative exhibits significant inhibitory effects against a variety of bacteria, with the inhibition rate increasing with increasing concentration, providing strong support for the development of new antibacterial drugs. Furthermore, cell compatibility experiments have demonstrated the safety of this derivative in human fibroblasts, providing a safer option for its use in the pharmaceutical field. The preparation method utilizes green chemistry principles, avoiding the use of toxic solvents and reducing environmental pollution.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical preparation, and particularly relates to a benzyl cyanide derivative and a preparation method and application thereof. Background Art

[0002] Benzyl cyanide (C8H7N), an important organic compound, has extensive applications in various fields, including fine chemicals, pharmaceutical synthesis, and the fragrance industry. In particular, in the pharmaceutical field, phenylacetonitrile is a key intermediate in the synthesis of antibiotics, anticancer drugs, and antidepressants. Its derivatives, such as phenylacetic acid and ethyl phenylacetate, also play a vital role in the pharmaceutical, pesticide, and dye industries. In recent years, with the increasing demand for new antimicrobial agents, the antibacterial applications of phenylacetonitrile and its derivatives have gradually attracted attention.

[0003] Traditionally, the preparation of benzyl cyanide derivatives relies on complex chemical reaction conditions, such as high temperature, high pressure, or the use of toxic catalysts. This not only increases production costs but also may cause environmental pollution. In recent years, with the promotion of the concept of green chemistry, the development of environmentally friendly, energy-efficient methods for preparing benzyl cyanide derivatives has become a research hotspot. Against this backdrop, the present invention proposes a novel benzyl cyanide derivative and a method for its preparation. This preparation method adopts the concept of green chemistry, reducing environmental pollution. The prepared benzyl cyanide derivative exhibits significant inhibitory effects against Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. This discovery provides new ideas for the development of new antibacterial drugs. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a benzyl cyanide derivative and its preparation method and application. By adopting the concept of green reaction and avoiding the use of toxic solvents, a benzyl cyanide derivative that exhibits inhibitory effects on Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis is prepared, providing new ideas for the development of new antibacterial drugs.

[0005] The present invention is achieved through the following technical solutions:

[0006] A benzyl cyanide derivative, the structural formula of the benzyl cyanide derivative is as follows:

[0007]

[0008] The preparation method of the above-mentioned benzyl cyanide derivative comprises the following steps:

[0009]

[0010] (1) 2-amino-5-bromonicotinaldehyde was added to benzyl cyanide, and then a KOH solution was added, and microwave irradiation was performed. The reaction solution was separated and purified to obtain intermediate 1;

[0011] (2) Add intermediate 1 to HCl solution, then add NaNO2, stir and react, pour the reaction mixture into ice water, filter, collect the precipitate and wash, and then recrystallize the obtained crude product to obtain intermediate 2;

[0012] (3) Intermediate 2 was added to POCl3 and subjected to microwave irradiation reaction. The reaction solution was separated and purified to obtain intermediate 3;

[0013] (4) Intermediate 3, p-aminophenylboronic acid, anhydrous N-methylpyrrolidone and K2CO3 are mixed, heated for reaction, and the reaction solution is post-treated to obtain intermediate 4;

[0014] (5) The intermediate 4,3,4-dihydroxyphenylacetonitrile is added to a solvent and stirred for reaction. The reaction solution is dried, concentrated, and then purified by column chromatography to obtain a benzyl cyanide derivative.

[0015] As a preferred technical solution of the present invention, in step (1), the molar ratio of 2-amino-5-bromonicotinaldehyde to benzyl cyanide is 1:(1-1.2); the concentration of the KOH solution is 10-12 wt%; and the microwave irradiation reaction is performed by intermittent irradiation at intervals of 25-30 seconds for 3-4 minutes under 400 W microwave irradiation.

[0016] As a preferred technical solution of the present invention, the molar ratio of intermediate 1 to NaNO2 in step (2) is 1:(1-1.5); the concentration of the HCl solution is 1.5-2 mol / L.

[0017] As a preferred technical solution of the present invention, the stirring reaction time in step (2) is 0.5-1h; and the solvent for the recrystallization is ethanol.

[0018] As a preferred technical solution of the present invention, the ratio of intermediate 2 to POCl3 in step (3) is 1 mmol: (14-16) mL; the operation of the microwave irradiation reaction is: under 200 W microwave irradiation, intermittent irradiation is performed for 2.5-3 minutes at intervals of 25-30 seconds.

[0019] As a preferred technical solution of the present invention, the molar ratio of the intermediate 3, p-aminophenylboronic acid, anhydrous N-methylpyrrolidone and K2CO3 in step (4) is 1: (1-1.2): (10-11): (3.4-3.6); the temperature of the heating reaction is 70-80°C and the time is 15-25 min.

[0020] As a preferred technical solution of the present invention, the molar ratio of intermediate 4 to 3,4-dihydroxyphenylacetonitrile in step (5) is 1:(1-1.2); and the stirring reaction time is 16-20 hours.

[0021] Application of the above-mentioned benzyl cyanide derivatives in the preparation of antibacterial drugs.

[0022] The principle of preparing the benzyl cyanide derivatives of the present invention is as follows: first, under microwave irradiation conditions and in the presence of KOH, 2-amino-5-bromonicotinaldehyde and benzyl cyanide undergo a solvent-free cyclization reaction to obtain intermediate 1; then, intermediate 1 is reacted with NaNO2 to convert it into intermediate 2; intermediate 2 is reacted with POCl3 under microwave irradiation conditions to convert it into intermediate 3 in only 2-3 minutes; then, in the presence of NMP and K2CO3, intermediate 3 undergoes a substitution reaction to introduce a phenylboronic acid group to obtain intermediate 4; finally, the phenylboronic acid group of intermediate 4 forms a borate ester with 3,4-dihydroxybenzene cyanide to obtain the benzyl cyanide derivative.

[0023] The present invention has the following effects compared to the prior art:

[0024] The present invention provides a benzyl cyanide derivative that exhibits significant inhibitory effects against a variety of bacteria, with the inhibition rate increasing with increasing concentration, providing strong support for the development of new antibacterial drugs. Furthermore, cytocompatibility experiments have demonstrated the derivative's safety in human fibroblasts, providing a safer option for its use in medicine.

[0025] 2. The present invention also provides a method for preparing the above-mentioned benzyl cyanide derivatives, which adopts the concept of green chemistry, avoids the use of toxic solvents, and reduces pollution to the environment.

[0026] 3. The benzyl cyanide derivatives of the present invention can be used not only in the medical field, but also in multiple fields such as food preservation and daily chemical products, and have broad market prospects and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The antibacterial activity results of the benzyl cyanide derivatives of the present invention at different concentrations;

[0028] Figure 2 The figures show the effects of the benzyl cyanide derivatives of the present invention on the survival rate of human fibroblasts at different concentrations. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described below in conjunction with specific embodiments. However, it should be understood by those skilled in the art that the following examples are only intended to illustrate the present invention and should not be construed as limiting the present invention. Specific conditions not specified in the examples are to be followed according to conventional conditions or the conditions recommended by the manufacturer. All reagents or instruments used, unless otherwise specified, are conventional products obtained from commercial channels.

[0030] Example 1

[0031] A benzyl cyanide derivative, its structural formula is as follows:

[0032]

[0033] The preparation method of the above-mentioned benzyl cyanide derivative comprises the following steps:

[0034]

[0035] (1) 2-Amino-5-bromonicotinaldehyde (CAS: 206997-15-1, 10 mmol) was added to benzyl cyanide (11 mmol), and then 1 mL of a 10% KOH solution was added dropwise. The mixture was irradiated at 400 W for 3 min at 30-second intervals. After the reaction was completed, the reaction mixture was cooled and added to ice water. The precipitated solid was filtered, collected, and washed with water. The crude product was recrystallized from ethanol to obtain Intermediate 1. 1 HNMR:(C 14 H 10 BrN3,400MHz,DMSO-d6)δ:8.63-8.60(m,2H),8.21(s,1H),7.53-7.40(m,5H),6.41(s,2H); HRMS(ESI + ): [M+H] + The calculated value was 300.01, and the found value was 300.02; the above results confirmed that the obtained product was the target product.

[0036] (2) Intermediate 1 (10 mmol) was added to HCl solution (2 M, 100 mL), cooled to 3°C, and then 50 mL of NaNO2 (12 mmol) solution was added. The reaction mixture was stirred at room temperature for 1 h and the reaction was monitored by TLC. After the reaction was completed, the mixture was poured into ice water, filtered, and the precipitate was collected and washed with water. The crude product was recrystallized from ethanol to obtain Intermediate 2; HRMS (ESI + ): [M+H] + The calculated value was 300.99, and the found value was 300.99; the above results confirmed that the obtained product was the target product.

[0037] (3) Intermediate 2 (5 mmol) was added to 75 mL of POCl3 and irradiated under microwave radiation at 200 W for 3 min at intervals of 30 s. After the reaction was completed, the reaction mixture was cooled to room temperature and extracted and washed with ice water (2×100 mL) and saturated sodium carbonate solution in sequence. The organic phases were collected and combined, and the organic phases were evaporated to dryness to obtain a crude product, which was then recrystallized from n-pentane to obtain Intermediate 3; HRMS (ESI + ): [M+H] +The calculated value was 318.96, and the found value was 318.95; the above results confirmed that the obtained product was the target product.

[0038] (4) Intermediate 3 (5 mmol), p-aminophenylboronic acid (5.5 mmol), anhydrous N-methylpyrrolidone (52 mmol) and K2CO3 (17.5 mmol) were mixed and stirred at 75°C for 20 min. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled to room temperature and then poured into ethyl acetate. The precipitated solid was collected by filtration, washed with water, and finally recrystallized from methanol to obtain intermediate 4; 1 HNMR:(C 20 H 15 BBrN3O2,400MHz,DMSO-d6)δ:9.21(s,1H),8.63-8.60(m,2H),8.21(s,1H),7.72(d,2H),7.53-7.40(m,5H),7.19(d,2H); HRMS(ESI) + ): [M+H] + Calculated to be 420.04, found to be 420.04; the above results confirmed that the obtained product was the target product.

[0039] (5) Intermediate 4 (5 mmol) and 3,4-dihydroxybenzeneacetonitrile (5.5 mmol) were added to 25 mL of dichloromethane, and ethyl acetate was added dropwise until dissolved. The mixture was stirred at room temperature for 18 h. The reaction solution was dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography to obtain a benzeneacetonitrile derivative. 1 HNMR:(C 28 H 18 BBrN4O2,400MHz,DMSO-d6)δ:9.21(s,1H),8.63-8.60(m,2H),8.21(s,1H),7.72( d,2H),7.53-7.40(m,5H),7.19(d,2H),6.60-6.55(m,3H),4.32(s,2H); HRMS(ESI + ): [M+H] + The calculated value was 533.07, and the found value was 533.07; the above results confirmed that the obtained product was the target product.

[0040] Example 2

[0041] A benzyl cyanide derivative, whose structural formula is the same as that in Example 1.

[0042] The preparation method of the above-mentioned benzyl cyanide derivative has the same reaction process as Example 1, comprising the following steps:

[0043] (1) 2-Amino-5-bromonicotinaldehyde (10 mmol) was added to benzyl cyanide (10 mmol), and then 1 mL of 10% KOH solution was added dropwise. The mixture was irradiated at 400 W microwave power for 3 min at intervals of 25 seconds. After the reaction was completed, the reaction mixture was cooled and added to ice water. The precipitated solid was filtered, collected, and washed with water. The crude product was recrystallized from ethanol to obtain Intermediate 1. 1 HNMR, HRMS (ESI + ) are consistent with the results of Example 1.

[0044] (2) Intermediate 1 (10 mmol) was added to HCl solution (1.5 M, 100 mL), cooled to 0°C, and then 50 mL of NaNO2 (10 mmol) solution was added. The reaction mixture was stirred at room temperature for 0.5 h and the reaction was monitored by TLC. After the reaction was completed, the mixture was poured into ice water, filtered, the precipitate was collected and washed with water, and the crude product was recrystallized from ethanol to obtain Intermediate 2; HRMS (ESI + ) are consistent with the results of Example 1.

[0045] (3) Intermediate 2 (5 mmol) was added to 70 mL of POCl3 and irradiated under 200 W microwave irradiation for 2.5 min at intervals of 30 seconds. After the reaction was completed, the reaction mixture was cooled to room temperature and extracted and washed with ice water (2×100 mL) and saturated sodium carbonate solution in sequence. The organic phases were collected and combined, and the organic phases were evaporated to dryness to obtain a crude product, which was then recrystallized from n-pentane to obtain Intermediate 3; HRMS (ESI + ) are consistent with the results of Example 1.

[0046] (4) Intermediate 3 (5 mmol), p-aminophenylboronic acid (5 mmol), anhydrous N-methylpyrrolidone (50 mmol) and K2CO3 (17 mmol) were mixed and stirred at 80°C for 15 min. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled to room temperature and then poured into ethyl acetate. The precipitated solid was collected by filtration, washed with water, and finally recrystallized from methanol to obtain Intermediate 4; Intermediate 4 1 HNMR, HRMS (ESI + ) are consistent with the results of Example 1.

[0047] (5) Intermediate 4 (5 mmol) and 3,4-dihydroxybenzeneacetonitrile (5 mmol) were added to 20 mL of dichloromethane, and ethyl acetate was added dropwise until dissolved. The mixture was stirred at room temperature for 16 h. The reaction solution was dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography to obtain a benzeneacetonitrile derivative. 1 HNMR, HRMS (ESI +) are consistent with the results of Example 1.

[0048] Example 3

[0049] A benzyl cyanide derivative, whose structural formula is the same as that in Example 1.

[0050] The preparation method of the above-mentioned benzyl cyanide derivative comprises the following steps:

[0051] (1) 2-Amino-5-bromonicotinaldehyde (10 mmol) was added to benzyl cyanide (12 mmol), and then 1 mL of 12% KOH solution was added dropwise. The mixture was irradiated at 400 W microwave power for 4 min at intervals of 30 seconds. After the reaction was completed, the reaction mixture was cooled and added to ice water. The precipitated solid was filtered, collected, and washed with water. The crude product was recrystallized from ethanol to obtain Intermediate 1. 1 HNMR, HRMS (ESI + ) are consistent with the results of Example 1.

[0052] (2) Intermediate 1 (10 mmol) was added to HCl solution (2 M, 100 mL), cooled to 5°C, and then 50 mL of NaNO2 (15 mmol) solution was added. The reaction mixture was stirred at room temperature for 1 h and the reaction was monitored by TLC. After the reaction was completed, the mixture was poured into ice water, filtered, and the precipitate was collected and washed with water. The crude product was recrystallized from ethanol to obtain Intermediate 2; HRMS (ESI + ) are consistent with the results of Example 1.

[0053] (3) Intermediate 2 (5 mmol) was added to 80 mL of POCl3 and irradiated under 200 W microwave irradiation for 3.0 min at intervals of 25 seconds. After the reaction was completed, the reaction mixture was cooled to room temperature and extracted and washed with ice water (2×100 mL) and saturated sodium carbonate solution in sequence. The organic phases were collected and combined, and the organic phases were evaporated to dryness to obtain a crude product, which was then recrystallized from n-pentane to obtain Intermediate 3; HRMS (ESI + ) are consistent with the results of Example 1.

[0054] (4) Intermediate 3 (5 mmol), p-aminophenylboronic acid (6 mmol), anhydrous N-methylpyrrolidone (55 mmol) and K2CO3 (18 mmol) were mixed and stirred at 70°C for 25 min. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled to room temperature and then poured into ethyl acetate. The precipitated solid was collected by filtration, washed with water, and finally recrystallized from methanol to obtain Intermediate 4; Intermediate 4 1 HNMR, HRMS (ESI + ) are consistent with the results of Example 1.

[0055] (5) Intermediate 4 (5 mmol) and 3,4-dihydroxybenzeneacetonitrile (6 mmol) were added to 30 mL of dichloromethane, and ethyl acetate was added dropwise until dissolved. The mixture was stirred at room temperature for 20 h. The reaction solution was dried over anhydrous magnesium sulfate, concentrated, and purified by column chromatography to obtain a benzeneacetonitrile derivative. 1 HNMR, HRMS (ESI + ) are consistent with the results of Example 1.

[0056] Test Example 1 Antibacterial activity test of the benzyl cyanide derivatives prepared by the present invention

[0057] Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus aureus) were selected, and the antibacterial activity of phenylacetonitrile derivatives was evaluated by the microbroth dilution method. The specific method is: Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus were inoculated into 10mL NB culture medium and placed in a constant temperature shaker at 37°C and 220rpm for 8 hours. When the bacteria entered the logarithmic growth phase, they were diluted with NB broth to a McFarland turbidity of 0.5. At this time, the number of bacteria was 10 8 CFU / mL, then diluted 1:1000 and inoculated into 96-well plates, divided into negative control group and experimental group, the negative control group was inoculated with bacterial solution only, and the experimental group was inoculated with bacterial solution and added with 2.5μg / mL, 5μg / mL, 10μg / mL, 20μg / mL, 40μg / mL, 80μg / mL, 160μg / mL, 320μg / mL of phenylacetonitrile derivative solutions (phenylacetonitrile derivatives were dissolved in culture medium containing 0.2% DMSO to prepare 320μg / mL stock solution, and then the stock solution was diluted with culture medium to the required different concentrations of phenylacetonitrile derivative solutions). At the same time, a blank control group (no bacterial solution and phenylacetonitrile derivatives were added) was set up, and 6 replicates were set up for each group. After culturing in a 37°C constant temperature incubator for 24 hours, the OD value at a wavelength of 600nm was detected by microplate reader. The experiment was repeated 3 times and the average value was taken. The results are as follows Figure 1 shown.

[0058] from Figure 1 As can be seen, the benzyl cyanide derivatives prepared according to the present invention exhibited a moderate inhibitory effect against Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis within the 2.5-320 μg / mL range, with the inhibition rate increasing with increasing concentration. At a concentration of 160 μg / mL, the inhibition rates against Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis were 83.33%, 86.57%, and 87.69%, respectively. These results demonstrate that the benzyl cyanide derivatives prepared according to the present invention have promise as antibacterial agents.

[0059] Test Example 2 Cytocompatibility test of the benzyl cyanide derivatives prepared by the present invention

[0060] 100 μL of human fibroblast L929 cells (1×10 5 The culture medium in the 96-well plate was DMEM complete medium. The 96-well plate was placed in a cell culture incubator at 37°C and 5% CO2 for 12 hours. After that, the cell culture medium in each well was gently aspirated. 200 μL of DMEM complete medium containing 320 μg / mL of phenylacetonitrile derivative was added to the 96-well plate and the plate was cultured in the cell culture incubator for another 24 hours. DMEM serum-free medium was used as a blank control, and DMEM complete medium supplemented with 5% phenol was used as a positive control. The plates were cultured in a 37°C and 5% CO2 incubator. After 48 hours of incubation, the 96-well plate was removed and the cell morphology was observed under a microscope. The results are shown in Figure 2. Figure 2 shown.

[0061] Depend on Figure 2 The above results indicate that the benzyl cyanide compound of the present invention is safe for human fibroblasts.

[0062] In summary, the present invention utilizes green chemistry to prepare a phenylacetonitrile derivative that exhibits inhibitory activity against Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis, providing strong support for the development of new antibacterial drugs. Furthermore, cytocompatibility experiments demonstrate the safety of the derivative in human fibroblasts, providing a safer option for its use in medicine.

[0063] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A benzyl cyanide derivative, characterized in that The structural formula of the benzyl cyanide derivative is as follows:

2. The method for preparing the benzyl cyanide derivative according to claim 1, wherein The following steps are involved: (1) 2-amino-5-bromonicotinaldehyde was added to benzyl cyanide, and then a KOH solution was added, and microwave irradiation was performed. The reaction solution was separated and purified to obtain intermediate 1; (2) Add intermediate 1 to HCl solution, then add NaNO2, stir and react, pour the reaction mixture into ice water, filter, collect the precipitate and wash, and then recrystallize the obtained crude product to obtain intermediate 2; (3) Intermediate 2 was added to POCl3 and subjected to microwave irradiation reaction. The reaction solution was separated and purified to obtain intermediate 3; (4) Intermediate 3, p-aminophenylboronic acid, anhydrous N-methylpyrrolidone and K2CO3 are mixed, heated for reaction, and the reaction solution is post-treated to obtain intermediate 4; (5) The intermediate 4,3,4-dihydroxyphenylacetonitrile is added to a solvent and stirred for reaction. The reaction solution is dried, concentrated, and then purified by column chromatography to obtain a benzyl cyanide derivative.

3. The method for preparing a benzyl cyanide derivative according to claim 2, wherein In step (1), the molar ratio of 2-amino-5-bromonicotinaldehyde to benzyl cyanide is 1:(1-1.2); the concentration of the KOH solution is 10-12 wt %; and the microwave irradiation reaction is performed by intermittently irradiating for 3-4 minutes at intervals of 25-30 seconds under 400 W microwave irradiation.

4. The method for preparing a benzyl cyanide derivative according to claim 2, wherein In step (2), the molar ratio of intermediate 1 to NaNO2 is 1:(1-1.5); the concentration of the HCl solution is 1.5-2 mol / L.

5. The method for preparing a benzyl cyanide derivative according to claim 2, wherein The stirring reaction time in step (2) is 0.5-1h; the solvent for the recrystallization is ethanol.

6. The method for preparing a benzyl cyanide derivative according to claim 2, wherein In step (3), the ratio of intermediate 2 to POCl3 is 1 mmol: (14-16) mL; the microwave irradiation reaction is performed by intermittent irradiation at 200 W microwave irradiation for 2.5-3 min at intervals of 25-30 seconds.

7. The method for preparing a benzyl cyanide derivative according to claim 2, wherein: The molar ratio of the intermediate 3, p-aminophenylboronic acid, anhydrous N-methylpyrrolidone and K2CO3 in step (4) is 1: (1-1.2): (10-11): (3.4-3.6); the heating reaction temperature is 70-80 ° C, and the time is 15-25 min.

8. The method for preparing a benzyl cyanide derivative according to claim 2, wherein In step (5), the molar ratio of intermediate 4 to 3,4-dihydroxyphenylacetonitrile is 1:(1-1.2); and the stirring reaction time is 16-20 hours.

9. Use of the benzyl cyanide derivative according to claim 1 in the preparation of antibacterial drugs.

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