Preparation of indazole substituted 1,3,5-triazine-2,4-diamine compounds and their application in antibacterial activity

Abstract

The application discloses a synthesis method of 1-methyl-1H-indazolyl-substituted 1,3,5-triazine-2,4-diamine derivatives and antibacterial activity of the derivatives. The application takes 1-methyl-1H-indazole-5-amine or 1-methyl-1H-indazole-6-amine and 1,3,5-triazine compounds as raw materials, and a series of target compounds are prepared through structure modification and two-step reaction. The synthesis method is simple in operation, high in efficiency, good in selectivity and high in yield. In-vitro antibacterial experiments show that the synthesized derivatives all exhibit significant inhibitory effects on escherichia coli (EC), pseudomonas aeruginosa (PA) and vibrio parahaemolyticus (VP). Preliminary mechanism research shows that the compounds may play antibacterial functions by inhibiting bacterial proliferation, and have the potential to be developed into new antibacterial drugs. The synthesis path and antibacterial activity of the compounds provide effective basis and new ideas for research and development of new antibacterial drugs, and have wide application prospects.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to the synthesis method of 1,3,5-triazine-2,4-diamine compounds with antibacterial activity, and their application in antibacterial activity. Background Technology

[0002] With the long-term use of antibiotics in clinical and related fields, bacterial resistance has become increasingly prominent, and the efficacy of many existing antibacterial drugs is declining, significantly limiting clinical treatment options. Therefore, developing antibacterial compounds with novel structural features and their synthetic methods has become a crucial technological direction in this field. Nitrogen-containing heterocyclic compounds occupy an important position in antibacterial research due to their structural diversity and modifiability. Existing technologies have reported the applications of indazole and 1,3,5-triazine compounds in the antibacterial field. Among them, the 1-methyl-1H-indazole structure exhibits good chemical stability, while the 1,3,5-triazine structure possesses a stable heterocyclic skeleton. However, existing research largely focuses on the individual applications of these heterocyclic structures. Systematic studies are lacking on integrating different types of nitrogen-containing heterocyclic structural units into the same molecular skeleton to obtain compounds with relatively balanced physicochemical properties and application performance. The specific structural design and implementation methods still involve considerable uncertainty.

[0003] Furthermore, existing antibacterial compounds based on single heterocyclic structures may still suffer from limitations in antibacterial spectrum, insufficient structural adaptability, or incompatible physicochemical properties in practical applications, restricting their further development and application. Therefore, it is necessary to provide novel and adjustable compound structures through rational design at the molecular level, building upon existing technologies, to enrich the structural sources of antibacterial compounds. Based on the above considerations, this invention provides a class of compounds containing different nitrogen-containing heterocyclic structural units and their synthetic methods. By introducing at least one 1-methyl-1H-indazole structural unit and at least one 1,3,5-triazine structural unit into the same molecule, and achieving spatial and electronic environment matching of different heterocyclic structures through adjustable linking units, a molecular skeleton characteristic distinct from existing single-structure compounds is formed. This structural design facilitates obtaining compounds with more balanced structural composition and physicochemical properties, providing new options for subsequent structural optimization and application research. The synthetic method provided by this invention has a wide range of raw material sources, relatively mild reaction conditions, and is suitable for the construction of various substituted structures, possessing good versatility and feasibility, and can provide technical support for the preparation and further research of related compounds. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings of the existing technology and provide a new method for preparing 1,3,5-triazine-2,4-diamine compounds. This method can obtain new compounds in only two steps, which is simple and efficient, and provides a brand-new synthetic route and application scheme for solving the current technical bottleneck of antibacterial compounds.

[0005] Technical solution: The 1,3,5-triazine-2,4-diamine compound of this invention. Its structural formula is shown in Figure I:

[0006]

[0007] 1,3,5-Triazine-2,4-Diamine compounds, structural formula:

[0008]

[0009] The preparation method described in this invention has the following synthetic route:

[0010]

[0011] Compared with the prior art, the method of the present invention has the following beneficial effects:

[0012] This invention provides a novel method for synthesizing 1,3,5-triazine-2,4-diamine compounds. This method is simple to operate, safe, produces few reaction byproducts, has a high yield, and the products are easy to separate and purify.

[0013] The 1,3,5-triazine-2,4-diamine compounds of this invention have a strong inhibitory effect on the growth of Escherichia coli (EC), Pseudomonas aeruginosa (PA), and Vibrio parahaemolyticus (VP), and have broad application prospects. Attached Figure Description

[0014] Figure 1 Example 1 final product 1 H-NMR spectrum;

[0015] Figure 2 Example 1 final product 13 C-NMR spectrum;

[0016] Figure 3 Example 2 Final product 1 H-NMR spectrum;

[0017] Figure 4 Example 2 Final product 13 C-NMR spectrum;

[0018] Figure 5 Example 3 Final product 1 H-NMR spectrum;

[0019] Figure 6 Example 3 Final product 13 C-NMR spectrum;

[0020] Figure 7 Example 4: Final product 1 H-NMR spectrum;

[0021] Figure 8 Example 4: Final product 13 C-NMR spectrum; Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0023] Example 1

[0024] The 1,3,5-triazine-2,4-diamine compound A2 is described in Chinese as 6-chloro-N. 2 -Cyclohexyl-N 2 -Ethyl-N 4 -(1-Methyl-1H-indazol-5-yl)-1,3,5-triazine-2,4-diamine, its English name is 6-chloro-N 2 -cyclohexyl-N 2 -ethyl-N 4 -(1-methyl-1H-indazol-5-y1)-1,3,5-triazine-2,4-diamine.

[0025]

[0026] Specific procedure: 2 g (1.0 mmol, 1.0 equiv.) of 2,4,6-trichloro-1,3,5-triazine and 1.65 g (1.1 mmol, 1.1 equiv.) of anhydrous K₂CO₃ were dissolved in 10 mL of tetrahydrofuran (THF) and cooled at -15 °C. Then, 1.52 g (1.1 mmol, 1.1 equiv.) of N-ethylcyclohexylamine dissolved in 5 mL of THF was added dropwise. After the reaction was complete (shown by TLC), the solvent was evaporated under vacuum, and then the anhydrous K₂CO₃ and the remaining 2,4,6-trichloro-1,3,5-triazine were removed by extraction with ethyl acetate (30 mL × 3) and water. The organic layer was dried over anhydrous Na₂SO₄. The dried organic solvent was removed by rotary evaporation to obtain 2.46 g of intermediate 1. 102.9 mg of intermediate 1 (1.1 mmol) was dissolved in 2 mL of N,N-dimethylformamide, and 51.6 mg (1.1 mol) of anhydrous K₂CO₃ was added and stirred at room temperature. Then, 50 mg (1.0 mol) of 1-methyl-1H-indazole-6-amine dissolved in 1.4 mL of N,N-dimethylformamide was added, and the reaction was continued at room temperature for 4 hours. After confirming the total conversion to product by thin-layer chromatography (TLC), the reaction mixture was purified by column chromatography (petroleum ether:ethyl acetate = 3:1) to give compound A₂ 110.4 mg, a pale yellow solid, in 84.3% yield. 1 H NMR (300MHz, CDCl3) δ8.10 (d, J=10.9Hz, 1H), 7.94 (dd, J=1.8, 0.9Hz, 1H), 7.50-7.30 (m, 3H), 4.10 (d, J=2.8Hz, 3H), 3.54 (dq, J=10.9, 7.0Hz, 2H), 1.84 (s, 3H), 1.63-1.12 (m, 9H). 13 C NMR (75MHz, CDCl3) δ164.37, 137.30, 132.59, 132.52, 131.52, 124.14, 121.94, 121. 77, 112.00, 109.11, 54.88, 37.95, 35.78, 30.89, 30.78, 26.32, 25.79, 15.08, 14.55.

[0027] Example 2

[0028] The 1,3,5-triazine-2,4-diamine compound A6 is described in Chinese as N-(4-chloro-6-(2-methylpiperidin-1-yl)-1,3,5-triazine-2-yl)-1-methyl-1H-indazol-5-amine, and in English as N-(4-chloro-6-(2-methylpiperidin-1-yl)-1,3,5-triazin-2-yl)-1-methyl-1H-indazol-5-amine.

[0029]

[0030] The specific operation method is as described in Example 1, which yielded compound A 699.8 mg, a pale yellow solid, with a yield of 82.2%. 1 HNMR (300MHz, CDCl3) 67.95 (d, J=1.0Hz, 2H), 7.50-7.34 (m, 3H), 5.17-4.51 (m, 2H), 4.09 ( s, 3H), 2.99 (td, J=13.1, 2.9Hz, 1H), 1.71 (dq, J=19.6, 12.9Hz, 6H), 1.25 (d, J=7.0Hz, 3H). 13 C NMR (75MHz, CDCl3) δ164.09, 137.31, 132.54, 132.54, 131.27, 123.98, 122.16, 1 22.15, 112.31, 109.07, 77.10, 46.26, 38.87, 35.67, 30.09, 25.59, 18.81, 15.34.

[0031] Example 3

[0032] The 1,3,5-triazine-2,4-diamine compound A7 is described in Chinese as 6-chloro-N. 2 -Methyl-N 4 -(1-Methyl-1H-indazol-5-yl)-N 2 6-Phenyl-1,3,5-triazine-2,4-diamine, also known as 6-chloro-N 2 -methyl-N 4 -(1-methyl-1H-indazol-5-yl)-N 2 -phenyl-1,3,5-triazine-2,4-diamine.

[0033]

[0034] The specific operation method is as described in Example 1, which yielded compound A 763.9 mg, a white solid, with a yield of 51.5%.1 H NMR (600MHz, CDCl3) δ7.77 (t, J=83.2Hz, 2H), 7.55-7.41 (m, 3H), 7.32 (d, J=7.8Hz, 3H), 7.07 (d, J=74.6Hz, 2H), 4.01 (s, 3H), 3.55 (s, 3H). 13 C NMR (151MHz, CDCl3) δ194.90, 169.11, 165.76, 162.92, 158.81, 143.89, 132.68, 131.13, 129.36, 127.01, 124.07, 120.17, 120.16, 110.52, 108.87, 108.86, 77.03, 38.11, 35.59.

[0035] Example 4

[0036] The 1,3,5-triazine-2,4-diamine compound B3 is described in Chinese as N. 2 N 2 -diallyl-6-chloro-N 4 -(1-Methyl-1H-indazol-6-yl)-1,3,5-triazine-2,4-diamine, English name is N 2 N 2 -diallyl-6-chloro-N 4 -(1-methyl-1H-indazol-6-yl)-1,3,5-triazine-2,4-diamine.

[0037]

[0038] Specific procedure: 2 g (1.0 mmol, 1.0 equiv.) of 2,4,6-trichloro-1,3,5-triazine and 1.65 g (1.1 mmol, 1.1 equiv.) of anhydrous K₂CO₃ were dissolved in 10 mL of tetrahydrofuran (THF) and cooled at -10 °C. Then, 1.16 g (1.1 mmol, 1.1 equiv.) of diallylamine dissolved in 5 mL of tetrahydrofuran was added dropwise. After the reaction was complete (shown by TLC), the solvent was evaporated under vacuum, and then the anhydrous K₂CO₃ and the remaining 2,4,6-trichloro-1,3,5-triazine were removed by extraction with ethyl acetate (30 mL × 3) and water. The organic layer was dried over anhydrous Na₂SO₄. The dried organic solvent was removed by rotary evaporation to obtain 2.67 g of intermediate 1. 91.7 mg of intermediate 1 (1.1 mmol) was dissolved in 2 mL of N,N-dimethylformamide, and 51.6 mg (1.1 mol) of anhydrous K₂CO₃ was added and stirred at room temperature. Then, 50 mg (1.0 mol) of 1-methyl-1H-indazole-6-amine dissolved in 1.4 mL of N,N-dimethylformamide was added, and the reaction was continued at room temperature for 4 hours. After confirming the total conversion to product by thin-layer chromatography (TLC), the reaction mixture was purified by column chromatography (petroleum ether:ethyl acetate = 3:1) to give compound B377.3 mg as a white solid, in a yield of 64.1%. 1 H NMR (300MHz, CDCl3) δ8.15 (s, 1H), 7.93 (d, J = 1.0Hz, 1H), 7.64 (d, J = 8.8Hz, 1H), 7.45 (s, 1H), 6.93 (d d, J=8.6, 1.8Hz, 1H), 6.04-5.77 (m, 2H), 5.32-5.15 (m, 4H), 4.28 (dq, J=5.5, 1.8Hz, 4H), 4.03 (s, 3H). 13 C NMR (75MHz, CDCl3) δ182.62, 167.73, 165.11, 140.42, 136.48, 132.68, 132.56, 132 .14, 121.40, 120.46, 117.80, 117.69, 114.93, 99.20, 77.02, 48.95, 35.41, 29.69.

[0039] Example 5: This patent tested the antibacterial activity of 22 1,3,5-triazine-2,4-diamine compounds against three types of bacteria.

[0040] The specific testing method is as follows: EC (Escherichia coli), VP (Vibrio parahaemolyticus), and PA (Pseudomonas aeruginosa) were selected as experimental bacterial strains. Twenty-two 1,3,5-triazine-2,4-diamine compounds (A1-A14 and B1-B8) were dissolved in anhydrous DMSO, with each compound prepared as a 50 μg / ml stock solution. NB and NA culture media were prepared by placing 6.6 g NA and 3.6 g NB in ​​an Erlenmeyer flask and adding 200 ml of experimental water to dissolve them. The solution was sterilized at 108℃ for 1.5 h. After sterilization, the plates were inverted, and NA was spread to cover the entire bacterial culture dish. NB was added to centrifuge tubes, 10 ml of NB to each, followed by 10 μl of bacterial suspension. NA was allowed to solidify, while NB was incubated at 38℃ with shaking for 12 h. After the NA and NB preparations were completed, 2-3 ml of NB bacterial suspension was added to each bacterial culture dish to cover the entire dish, and excess bacterial suspension was aspirated. Filter paper discs were attached to the corresponding positions in the petri dish. Samples were pipetted onto the filter paper discs for absorption. A negative control group (with the same volume of DMSO solution added) was set up. The positive control group could be treated with common antibiotics (gentamicin). After standing for 6 hours, the inhibition zones were measured. The antibacterial activity was determined based on the diameter of the inhibition zones. The positive control drug showed inhibition diameters of 17.25 mm, 14.2 mm, and 16.33 mm against Escherichia coli, Vibrio parahaemolyticus, and Pseudomonas aeruginosa, respectively. The negative control drug showed inhibition diameters of 7.00 mm, 7.00 mm, and 7.00 mm against Escherichia coli, Vibrio parahaemolyticus, and Trichophyton mentagrophytes, respectively. Compound A14 showed antibacterial activity against EC, VP, and PA, with inhibition zone diameters of 11.50 mm, 10.90 mm, and 11.70 mm, respectively.

[0041] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. Synthesis and applications of a series of 1,3,5-triazine-2,4-diamine compounds, the structures of which are shown below:

2. The application of the 1,3,5-triazine-2,4-diamine compound of claim 1 in inhibiting the activity of Escherichia coli, Pseudomonas aeruginosa, and Vibrio parahaemolyticus.

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