Quaternary phosphonium benzisothiazolinone derivative as well as preparation method and application thereof
By synthesizing quaternized benzisothiazolinone derivatives, the problems of insufficient antibacterial spectrum and cumbersome reaction steps of benzisothiazolinone compounds in the prior art have been solved, achieving broad-spectrum antibacterial effect and high yield.
Patent Information
- Application Number
- CN202511876136.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-02-10
AI Technical Summary
Existing benzisothiazolinone compounds have weak antifungal and antiviral effects, and suffer from problems such as multiple reaction steps, low yield, and harsh reaction conditions.
By synthesizing quaternized benzisothiazolinone derivatives, and utilizing the synergistic effect of triphenylquaternary phosphonate salt and benzisothiazolinone, a compound with broad-spectrum antibacterial properties was prepared by reacting with a specific solvent and condensing agent at a certain temperature.
The compound's antibacterial spectrum was improved, enhancing its inhibitory ability against fungi and viruses. Furthermore, the reaction steps were simplified, the yield was increased, and it exhibited low toxicity, high temperature resistance, and high stability.
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Figure CN121494891A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, and specifically to a quaternized benzisothiazolinone derivative, its preparation method, and its application. Background Technology
[0002] Since Collier and Ramsey synthesized 1,2-benzisothiazolin-3-one (BIT) in 1990, and its successful market development by Imperial Chemical Industries (ICI), benzisothiazolinone (BIT) has become a broad-spectrum and highly effective industrial bactericide. Its low toxicity, high stability, and strong bactericidal activity have led to its widespread application in industrial circulating water, coatings, and adhesives. The bioactivity of isothiazolinone compounds is based on their strong penetrating ability to receptor cell membranes and cell walls. They then interact with sulfur-containing proteins, enzymes, or simple molecules within the cell, breaking their SN bonds and forming SS bonds with the receptor, thereby disrupting normal cell function. Upon contact with microorganisms, it rapidly and irreversibly inhibits their growth, leading to microbial cell death. Benzisothiazolinone (BIT) is the second most widely used in-can preservative in the coatings industry, after Kathon. It is rapidly degraded in soil and does not accumulate in aquatic organisms, making it an environmentally friendly bactericide.
[0003] However, BIT's antibacterial spectrum also has certain blind spots: its inhibitory ability against fungi and viruses is relatively weak. Although BIT is called a "broad-spectrum bactericide," its antibacterial advantage is mainly concentrated on bacteria (especially Gram-negative and Gram-positive bacteria), and its inhibitory effect on fungi (such as molds and yeasts) and viruses is significantly insufficient. In humid environments (such as bathroom walls and basement paint), paints containing BIT can inhibit bacterial growth, but it is difficult to prevent the germination of mold spores and the growth of hyphae, and mold growth may still occur in the paint film. In the daily chemical industry, BIT has a weak inhibitory ability against fungi that cause skin problems (such as Candida albicans and Malassezia furfur). Therefore, in antifungal skin care products (such as anti-dandruff shampoos and athlete's foot care products), it needs to be used in combination with dedicated antifungal ingredients such as ketoconazole and bifonazole. Using BIT alone cannot achieve the expected antifungal effect. In addition, BIT has almost no inhibitory effect on viruses (such as influenza viruses and coronaviruses) and cannot be used as an effective ingredient in antiviral products, further limiting its application in the public health field.
[0004] Triphenyl quaternary phosphonium salts can increase the cell membrane permeability of molecules, enhance their penetrating power and mitochondrial accumulation capacity. They exhibit synergistic effects with benzisothiazolinone, filling gaps in the antibacterial spectrum of benzisothiazolinone, reducing the occurrence of drug resistance, and giving the product a broad antibacterial spectrum. Triphenyl quaternary phosphonium is a type of cationic bactericide. Quaternary phosphonium salts are a novel type of cationic antibacterial agent. Because phosphorus is a third-period element with a large ionic radius, strong polarization, and strong positive charge, quaternary phosphonium salts possess excellent antibacterial properties, broad spectrum, low toxicity, high temperature resistance, and high stability. They also exhibit low foaming, strong slime-removing ability, and a wide pH range, making them a suitable replacement and upgrade for traditional bactericides in industrial circulating water and oilfield water injection systems. Summary of the Invention
[0005] In view of the problems existing in the prior art, the present invention develops a quaternized benzisothiazolinone derivative. Its preparation method solves the problems of multiple steps, low yield and harsh reaction conditions in the production of benzisothiazolinone compounds in the current technology. The target compound obtained by this method has the characteristics of good antibacterial properties, broad antibacterial spectrum, low toxicity, high temperature resistance and high stability.
[0006] This invention discloses a quaternized benzo[a]isothiazolinone derivative, the general structural formula of which is shown in Formula P. In the formula, R is selected from C1-C8 straight-chain or branched alkyl groups with substituents, aryl groups with substituents, wherein at least one substituent in the C1-C8 straight-chain or branched alkyl groups with substituents is hydrogen, halogen, trifluoromethyl, or C1-C6 alkyl; X is selected from chlorine or bromine; n = 0-10.
[0007] In a preferred embodiment of the present invention, the general structural formula is shown in formula P-02. In the formula, X is selected from chlorine or bromine; n = 1-6.
[0008] In a preferred embodiment of the present invention, the representative compound structure is as follows: .
[0009] This invention also discloses a method for preparing quaternized benzisothiazolinone derivatives, comprising the following steps: The chemical reaction equation is as follows:
[0010] (1) Compound SO1 and compound SO2 were added sequentially to a reaction vessel in ethyl acetate or toluene as the first reaction solvent. The reaction temperature was 0℃-120℃, and the reaction time was 8h-24h. After the reaction was complete, the mixture was cooled, concentrated, and recrystallized to obtain compound M. (2) In the reaction vessel, compound M and compound SO3 undergo a condensation reaction in the second reaction solvent under the action of a condensing agent. The reaction temperature is 0-50℃ and the reaction time is 8h-24h. After the reaction is complete, the mixture is cooled, concentrated, and recrystallized to obtain the quaternary phosphonated benzisothiazolinone derivative. The second reaction solvent is selected from one or more of dichloromethane, tetrahydrofuran, DMF, DMSO and 1,2-dichloroethane; the condensing agent is selected from one or more of DCC, DIC, EDC, EDCI, HATU, HBTU, TBTU, CDI and EEDQ. In the formula, R is selected from C1-C8 straight-chain or branched alkyl groups with substituents, aryl groups with substituents, wherein the substituents in the C1-C8 straight-chain or branched alkyl groups with substituents are at least one hydrogen, halogen, trifluoromethyl, C1-C6 alkyl; X is selected from chlorine or bromine; n=0-10.
[0011] In a preferred embodiment of the present invention, in step (2), the molar ratio of compound M to compound SO3 is 1:0.3-3.
[0012] In a preferred embodiment of the present invention, in step (1), the compound SO1 is triphenylphosphine, and in step (2), the compound obtained is a triphenylquaternary phosphonate benzisothiazolinone derivative, wherein X is selected from chlorine or bromine; n=1-6.
[0013] This invention also discloses the application of quaternized benzisothiazolinone derivatives as antibacterial agents or antibacterial drugs.
[0014] In a preferred embodiment of the present invention, the application as an antibacterial agent or antimicrobial drug includes its application against Escherichia coli, Candida albicans, Staphylococcus aureus, Salmonella, Pseudomonas aeruginosa, or Aspergillus niger.
[0015] This invention comprises two functional groups, benzisothiazolinone and quaternary phosphine salt, which work synergistically to kill bacteria, thereby improving the antibacterial properties and antibacterial spectrum. It has the advantages of being both a rapid bactericide and a long-lasting bactericide, and has broad application prospects and development potential. In particular, it has a highly efficient and broad-spectrum bactericidal effect in the biomedical, healthcare and food packaging industries. At the same time, this invention improves the problem of easy precipitation in resins due to small molecular weight and weak interaction, thereby improving the long-lasting antibacterial ability. Attached Figure Description
[0016] Figure 1 This is the hydrogen NMR spectrum of compound P1.
[0017] Figure 2 The images show high-performance liquid chromatograms of compound P1 at different wavelengths. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] All raw materials used in this invention are purchased from the market.
[0020] I. Synthesis of compounds P1-P12 Example 1
[0021]
[0022] (1) Synthesis of compound M-1: Under magnetic stirring, ω-bromocarboxylic acid (64 g, 383 mmol, 1.0 eq) and triphenylphosphine (100 g, 381 mmol, 1.0 eq) were dissolved in 500 mL of ethyl acetate in a 1 L four-necked flask, and the mixture was refluxed under argon protection for 24 hours. After the mixture cooled to room temperature, it was concentrated under vacuum. The residue was crystallized from ethyl acetate, slurried, washed, and dried to give 150 g of the corresponding 3-(carboxypropyl)triphenylphosphine bromide as a white solid, with a yield of 92% and a purity of 98%.
[0023] 1H NMR (400 MHz, DMSO- d 6 ) δ 12.36 (s, 1H), 8.04-7.55 (m, 15H), 3.61 (m, 2H), 2.58-2.36 (m, 2H), 1.72 (m, 2H) ppm. ESI-HRMS (m / z): 349.2 [M-Br] + ; (2) Synthesis of compound P1: Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 3-(carboxypropyl)triphenylphosphine bromide (28.4 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 30 g of white solid. Yield: 81%, Purity: 98%.
[0024] 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.04 – 7.75 (m, 18H), 7.49 (t, 1H), 3.77–3.64 (m, 2H), 3.38 (t, 2H), 1.99-1.85 (m, 2H) ppm. ESI-HRMS (m / z): 482.1 [M-Br] + The calculated value is 562.46. Example 2
[0025] Synthesis of compound P2
[0026] Following the synthesis of compound M-1, 55 g of 3-(carboxyethyl)triphenylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 3-(carboxyethyl)triphenylphosphine bromide (27.5 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 28 g of white solid. Yield: 77%, Purity: 97%.
[0027] 1H NMR (400 MHz, DMSO-d6) δ 8.12 – 7.82 (m, 18H), 7.55 (t, 1H), 3.92–3.80 (t, 2H), 3.58 (t, 2H) ppm. ESI-HRMS (m / z): 468.1 [M-Br] + The calculated value is 548.43. Example 3
[0028] Synthesis of compound P3
[0029] Following the synthesis of compound M-1, 50 g of 4-(carboxybutyl)triphenylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 4-(carboxybutyl)triphenylphosphine bromide (29.3 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 30 g of white solid. Yield: 79%, Purity: 96%.
[0030] 1 H NMR (400 MHz, DMSO- d 6 ) δ 8.12 – 7.73 (m, 18H), 7.40 (t, 1H), 3.65–3.52 (m, 2H), 3.22 (t, 2H), 1.82-1.70 (m, 2H) , 1.38-1.25 (m, 2H)ppm. ESI-HRMS (m / z): 496.2 [M-Br] + The calculated value is 576.49. Example 4
[0031] Synthesis of compound P4
[0032] Following the synthesis of compound M-1, 49 g of 5-(carboxypentyl)triphenylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 5-(carboxypentyl)triphenylphosphine bromide (30.3 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 33 g of white solid. Yield: 84%, Purity: 97%.
[0033] ESI-HRMS (m / z): 510.2 [M-Br] + The calculated value is 590.52. Example 5
[0034] Synthesis of compound P5
[0035] Following the synthesis of compound M-1, 54 g of 6-(carboxyhexyl)triphenylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 6-(carboxyhexyl)triphenylphosphine bromide (31.2 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 32 g of white solid. Yield: 80%, Purity: 96%.
[0036] ESI-HRMS (m / z): 524.2 [M-Br] + The calculated value is 604.54. Example 6
[0037] Synthesis of compound P6
[0038] Following the synthesis of compound M-1, 56 g of 7-(carboxyheptyl)triphenylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 7-(carboxyheptyl)triphenylphosphine bromide (32.1 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 32 g of white solid. Yield: 78%, Purity: 94%.
[0039] ESI-HRMS (m / z): 538.2 [M-Br] + The calculated value is 618.57. Example 7
[0040] Synthesis of compound P7
[0041]
[0042] Following the synthesis of compound M-1, 50 g of 3-(carboxypropyl)triphenylphosphine chloride was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 3-(carboxypropyl)triphenylphosphine chloride (25.5 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 30 g of white solid. Yield: 88%, Purity: 95%.
[0043] ESI-HRMS (m / z): 482.1 [M-Br] + The calculated value is 518.01. Example 8
[0044] Synthesis of compound P8
[0045] Following the synthesis of compound M-1, 48 g of 3-(carboxypropyl)tri-n-butylphosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) 3-(carboxypropyl)tri-n-butylphosphine bromide (24.4 g, 66.2 mmol, 1.0 eq) was dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 25 g of white solid. Yield: 75%, Purity: 96%.
[0046] ESI-HRMS (m / z): 422.2 [M-Br] + The calculated value is 502.49. Example 9
[0047] Synthesis of compound P9
[0048] Following the synthesis of compound M-1, 47 g of 3-(carboxypropyl)diphenyl-tert-butylphosphine chloride was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) and 3-(carboxypropyl)diphenyl tert-butylphosphine chloride (24.4 g, 66.2 mmol, 1.0 eq) were dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) were slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 25 g of white solid. Yield: 75%, Purity: 96%.
[0049] ESI-HRMS (m / z): 462.2 [M-Br] + The calculated value is 542.47. Example 10
[0050] Synthesis of compound P10
[0051] Following the synthesis of compound M-1, 55 g of 3-(carboxypropyl)tris(4-fluoro-phenyl)phosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) 3-(carboxypropyl)tris(4-fluoro-phenyl)phosphine bromide (32 g, 66.2 mmol, 1.0 eq) was dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 32 g of white solid. Yield: 78%, Purity: 97%.
[0052] ESI-HRMS (m / z): 536.1 [M-Br] + The calculated value is 616.43. Example 11
[0053] Synthesis of compound P11
[0054] Following the synthesis of compound M-1, 60 g of 3-(carboxypropyl)tris(4-trifluoromethyl-phenyl)phosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) 3-(carboxypropyl)tris(4-trifluoromethyl-phenyl)phosphine bromide (41.9 g, 66.2 mmol, 1.0 eq) was dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 36 g of white solid. Yield: 71%, Purity: 96%.
[0055] ESI-HRMS (m / z): 686.1 [M-Br] + The calculated value is 766.46. Example 12
[0056] Synthesis of compound P12
[0057] Following the synthesis of compound M-1, 50 g of 3-(carboxypropyl)tris(4-methyl-phenyl)phosphine bromide was synthesized; Under magnetic stirring, 1,2-benzisothiazol-3-one (10 g, 66.2 mmol, 1.0 eq) 3-(carboxypropyl)tris(4-methyl-phenyl)phosphine bromide (31.2 g, 66.2 mmol, 1.0 eq) was dissolved in CH2Cl2 (500 mL) in a 1 L four-necked flask. N,N'-diisopropylcarbodiimide (DIC, 10 g, 79.4 mmol, 1.2 eq) was slowly added at room temperature. After reacting for 24 h at room temperature, the reaction was monitored by TLC and HPLC. The solvent was directly evaporated by rotary evaporation and concentrated to obtain a light yellow viscous semi-solid. Isopropanol (300 mL) was added, and the mixture was mechanically stirred, cooled in an ice bath, and slurried for 1 h. The mixture was then filtered, and the filter cake was washed with isopropanol (50 mL). The filter cake was dried to obtain 30 g of white solid. Yield: 75%, Purity: 95%.
[0058] ESI-HRMS (m / z): 524. [M-Br] + The calculated value is 604.54.
[0059] II. Microbial sterilization rate test: Referencing GB15979-2024 E.5.1, the bactericidal performance test of antibacterial agents. Preparation of bacterial suspension Pick typical colonies from the target strain (purchased second or third generation strain slant) using an inoculation loop and inoculate them onto a nutrient agar slant. Incubate at 37°C for 18-24 hours to obtain the next generation culture (usually the third generation). Use a 5ml pipette to add 3-5ml of diluent to the slant tube, repeatedly pipetting and aspirating to wash away the bacterial growth. Then, use a 5ml pipette to transfer all the washings to another sterile test tube (empty tube), shake for 20 seconds, first roughly determine the bacterial concentration using a bacterial concentration turbidimetric method, and then dilute to the desired concentration with 9ml of diluent at a 1:10 ratio.
[0060] Microbial killing effect test (1) Prepare the bacterial suspension for the experiment and roughly measure the concentration of the bacterial suspension using a bacterial turbidimeter; dilution solution: 0.03 mol / L PBS, pH 7.2 or 0.85-0.9% physiological saline; (2) Use a pipette to draw 4.5 ml of the disinfectant sample solution to be tested and inject it into a sterile test tube for later use. Perform 3 replicates for each sample. (3) Take 0.5 ml of the test bacterial suspension into a test tube containing 4.5 ml of the disinfectant sample solution to be tested, and shake to mix well; (4) After the disinfectant and bacterial suspension have reacted for 2 minutes, take 1.0 ml of sample solution and determine the number of viable bacteria according to the viable bacteria culture counting method. Each sample solution can be inoculated into 2 petri dishes. If there are many colonies growing on the plates, serial 10-fold dilutions can be performed before viable bacteria culture counting. (5) At the same time, a diluent was used instead of a disinfectant to conduct parallel tests as a positive control; (6) All test samples were cultured in an incubator at 37℃. The bacterial vegetative cells were cultured for 48 hours and the final results were observed. The Candida albicans samples were cultured for 72 hours and the final results were observed. (7) Candida albicans was cultured on Sabouraud agar, while other strains were cultured on nutrient agar; (8) Calculation of sterilization rate.
[0061] In the formula: K – Sterilization rate; Nc – Average colony count of positive control samples, expressed in colony forming units per milliliter (CFU / mL). Ns – Average colony count of the test sample, expressed as colony forming units per milliliter (CFU / mL).
[0062] The results of the antibacterial activity tests of the compounds are as follows (Table 1):
[0063] illustrate: 1. Sample concentration: Prepare a 0.4% concentration using a 20% solution of P1-P12; 2. No colonies grew in the negative control group.
[0064] In conclusion, the quaternary phosphonium salt derivatives P1-P12 of benzisothiazolinone exhibit excellent bactericidal effects against Escherichia coli, Candida albicans, Staphylococcus aureus, Salmonella, Pseudomonas aeruginosa, and Aspergillus niger. In particular, they also show good bactericidal activity against Candida albicans and Aspergillus niger, which have relatively weak inhibitory effects on benzisothiazolinone, thus expanding the antibacterial spectrum and application range of benzisothiazolinone.
[0065] The above examples are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A quaternized benzo[a]isothiazolinone derivative, characterized in that, Its general structural formula is shown in equation P. In the formula, R is selected from C1-C8 straight-chain or branched alkyl groups with substituents, aryl groups with substituents, wherein the substituents in the C1-C8 straight-chain or branched alkyl groups with substituents are at least one hydrogen, halogen, trifluoromethyl, C1-C6 alkyl; X is selected from chlorine or bromine; n=0-10.
2. The quaternized benzo[a]isothiazolinone derivative according to claim 1, characterized in that, Its general structural formula is shown in formula P-02. In the formula, X is selected from chlorine or bromine; n = 1-6.
3. The quaternized benzo[a]isothiazolinone derivative according to claim 1 or 2, characterized in that, The structures of its representative compounds are as follows: .
4. A method for preparing a quaternized benzo[a]isothiazolinone derivative, characterized in that, The steps are as follows, and the chemical reaction equation is as follows: , (1) Compound SO1 and compound SO2 were added sequentially to a reaction vessel in ethyl acetate or toluene as the first reaction solvent. The reaction temperature was 0℃-120℃, and the reaction time was 8h-24h. After the reaction was complete, the mixture was cooled, concentrated, and recrystallized to obtain compound M. (2) In the reaction vessel, compound M and compound SO3 undergo a condensation reaction in the second reaction solvent under the action of a condensing agent. The reaction temperature is 0-50℃ and the reaction time is 8h-24h. After the reaction is complete, the mixture is cooled, concentrated, and recrystallized to obtain the quaternary phosphonated benzisothiazolinone derivative. The second reaction solvent is selected from one or more of dichloromethane, tetrahydrofuran, DMF, DMSO and 1,2-dichloroethane; the condensing agent is selected from one or more of DCC, DIC, EDC, EDCI, HATU, HBTU, TBTU, CDI and EEDQ. In the formula, R is selected from C1-C8 straight-chain or branched alkyl groups with substituents, aryl groups with substituents, wherein the substituents in the C1-C8 straight-chain or branched alkyl groups with substituents are at least one hydrogen, halogen, trifluoromethyl, C1-C6 alkyl; X is selected from chlorine or bromine; n=0-10.
5. The method for preparing the quaternized benzo[a]isothiazolinone derivative according to claim 4, characterized in that, In step (2), the molar ratio of compound M to compound SO3 is 1:0.3-3.
6. The method for preparing the quaternized benzo[a]isothiazolinone derivative according to claim 5, characterized in that, In step (1), the compound SO1 is triphenylphosphine, and in step (2), the compound obtained is a triphenylquaternary phosphonated benzisothiazolinone derivative, wherein X is selected from chlorine or bromine; n=1-6.
7. The use of the quaternized benzisothiazolinone derivative according to claim 1 or 2 as an antibacterial agent or antimicrobial drug.
8. The application of the quaternized benzisothiazolinone derivative according to claim 6 as an antibacterial agent, characterized in that, The applications as antibacterial agents or antimicrobial drugs include those against Escherichia coli, Candida albicans, Staphylococcus aureus, Salmonella, Pseudomonas aeruginosa, or Aspergillus niger.