A 2-(2-benzo[d]thiazolylamino)acetamide compound and its preparation method and application

Abstract

The present invention relates to the field of medicine, and invents a class of 2-(2-benzo[d]thiazolylamino)acetamide compounds shown in formula I and their application in resisting bacterial biofilm formation. The 2-(2-benzo[d]thiazolylamino)acetamide compounds involved in the present invention have been verified for in vivo and in vitro efficacy, and most of the obtained compounds have excellent bacterial biofilm and quorum sensing inhibitory activities, can be used to prepare broad-spectrum antibiotic synergists, and can enhance the antibacterial effect of existing antibiotics.

Description

Technical Field

[0001] The present invention belongs to the field of medicine, and particularly relates to a class of 2-(2-benzo[d]thiazoleamino)acetamide compounds, a preparation method thereof, and an application thereof in the preparation of antibacterial drugs. Background Art

[0002] The discovery of antibiotics has changed the trajectory of medical development, allowing humans to greatly reduce the harm caused by microbial infections. However, in recent decades, the overuse of antibiotics and social and economic factors have accelerated the spread of drug-resistant bacteria and led to the emergence of multi-drug-resistant "superbugs", making current antimicrobial drug treatment ineffective. At present, at least 700,000 people die from antimicrobial resistance (AMR) every year worldwide. The World Health Organization predicts that if there are no new and better treatments, this number may rise to 10 million by 2050. The frequent occurrence of cellular resistance forces humans to continuously develop antibiotics with new structures and new targets. However, the development of new antibiotics requires a lot of time, manpower and material resources, which poses a major threat to human health and property.

[0003] The evolution of bacteria has derived a variety of resistance mechanisms to resist the effects of antibiotics, including reduced drug uptake, changes in drug targets, drug inactivation, and activation of drug efflux pumps, which make traditional antibiotics lose their original antibacterial efficiency and lead to treatment failure. Among them, the formation of biofilms is one of the main mechanisms for bacteria to resist the effects of antibiotics. Research in the past three decades has shown that bacteria use biofilms and quorum sensing to enhance the defense capabilities of the colony. Biofilms are composed of extracellular polymers secreted by bacteria. Using the characteristics of their structure, they form a natural barrier for bacteria, which can escape the effects of the immune system and reduce the uptake of antibiotics, which makes it difficult for bacteria in the biofilm to be killed easily. On the other hand, bacteria regulate the formation of biofilms and the growth of bacteria through quorum sensing, further enhancing the ability of bacteria to cope with harsh environments. At present, there are no effective drugs for this type of resistance mechanism in clinical practice. Compared with traditional antibiotics, biofilm and quorum sensing inhibitors can effectively weaken the resistance of bacteria, can more widely enhance the killing ability of existing antibiotics against resistant bacteria, and because they do not threaten the survival of bacteria, they are not easy to develop resistance. Therefore, the study of new anti-biofilm and quorum sensing drugs is of great significance for overcoming antibiotic resistance.

[0004] The benzothiazole skeleton has good biofilm inhibition activity. Therefore, the present invention, based on the benzothiazole structure, invents a new class of highly efficient and stable 2-(2-benzo[d]thiazoleamino)acetamide compounds. These compounds or their pharmaceutically acceptable salts can be used as potential anti-biofilm drugs and antibiotic enhancers to enhance the clinical antibacterial treatment effect. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the present invention has found a class of 2-(2-benzo[d]thiazoleamino)acetamide compounds, which have a stable chemical structure and have been shown to have anti-biofilm and quorum sensing effects through activity experiments, and have the potential to be a new antibiotic synergist.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned 2-(2-benzo[d]thiazoleamino)acetamide compounds.

[0007] Another object of the present invention is to provide the use of the above-mentioned 2-(2-benzo[d]thiazolylamino)acetamide compounds or pharmaceutically acceptable salts thereof as anti-biofilm drugs and antibiotic synergists.

[0008] The purpose of the present invention is achieved through the following solutions:

[0009] In one aspect, the present invention provides a class of 2-(2-benzo[d]thiazolylamino)acetamide compounds or pharmaceutically acceptable salts, medically acceptable variants, mesomorphs, racemates, stereoisomers, metabolites, metabolic precursors, prodrugs or solvates thereof, having a chemical structure as shown in Formula I:

[0010]

[0011] Wherein, R1 is one of -H, -Cl, -OCH3, -NO2;

[0012] When R1 is -H, R2 is a C5-C8 straight chain alkyl group:

[0013]

[0014] When R1 is one of -Cl, -OCH3, -NO2, R2 is a C4-C8 straight chain alkyl group:

[0015]

[0016] Preferably, the 2-(2-benzo[d]thiazolylamino)acetamide compounds of the present invention or their pharmaceutically acceptable salts, medically acceptable variants, mesomorphs, racemates, stereoisomers, metabolites, metabolic precursors, prodrugs or solvates have the chemical structure shown in Table 1:

[0017] Table 1. Structure and nomenclature of compounds

[0018]

[0019]

[0020]

[0021]

[0022] In another aspect, the present invention provides a method for preparing the above-mentioned 2-(2-benzo[d]thiazoleamino)acetamide compounds, which specifically comprises the following steps:

[0023] (1.1) reacting 2-aminobenzothiazole substituted with different groups, di-tert-butyl dicarbonate and triethylamine in a solvent, and purifying the reaction solution obtained after the reaction to obtain compound 2;

[0024] (1.2) Compound 2, methyl bromoacetate and sodium hydride are placed in a solvent and reacted at 0°C. The resulting reaction solution is purified to obtain compound 3;

[0025] (1.3) Compound 3 and sodium hydroxide aqueous solution were placed in a solvent for reaction at 50°C, and the obtained reaction solution was purified to obtain compounds 4a-4d;

[0026] (1.4) Compounds 4a-4d, fatty amine, HOBt and EDCI are reacted in a solvent, and the resulting reaction solution is purified to obtain compounds 5a-5q;

[0027] (1.5) Compounds 5a-5q are reacted in a methanol solution of hydrochloric acid, and the resulting reaction solution is purified to obtain compounds SN1-SN17;

[0028] The synthetic route is:

[0029]

[0030] Preferably, the reaction conditions are: (a) (Boc) 2 O, Et 3 N, DMAP, DCM, rt, 4 h; (b) ethylbromoacetate, NaH, dry DMF, rt, 3 h; (c) NaOH, H 2 O, MeOH, 40°C, 6 h; (d) Ethylamine-n-octylamine, HOBT, EDC, Et 3 N, dry DCM, 40°C, 4 h; (e) HCl, MeOH, 40°C, 6 h.

[0031] In another aspect, the present invention provides the use of the above-mentioned 2-(2-benzo[d]thiazolylamino)acetamide compounds or their pharmaceutically acceptable salts, medically acceptable variants, racemates, racemates, stereoisomers, metabolites, metabolic precursors, prodrugs or solvates in the preparation of anti-biofilm drugs and antibiotic enhancers.

[0032] Preferably, the biofilm is a bacterial biofilm. More preferably, the bacteria is Pseudomonas aeruginosa.

[0033] Preferably, the antibiotic is used to inhibit Pseudomonas aeruginosa.

[0034] In another aspect, the present invention provides the use of the above-mentioned 2-(2-benzo[d]thiazolylamino)acetamide compounds or their pharmaceutically acceptable salts, medically acceptable variants, racemates, racemates, stereoisomers, metabolites, metabolic precursors, prodrugs or solvates in the preparation of antibacterial drugs.

[0035] Preferably, the bacteria is a bacterium, more preferably Pseudomonas aeruginosa.

[0036] In another aspect, the present invention provides a pharmaceutical composition comprising at least one of a 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt, medically acceptable variant isomer, mesomer, racemate, stereoisomer, metabolite, metabolic precursor, prodrug or solvate thereof.

[0037] Preferably, the drug further comprises one or more pharmaceutically acceptable carriers or excipients.

[0038] In another aspect, the present invention provides a combination drug comprising at least one of a 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt, medically acceptable variant isomer, mesomorph, racemate, stereoisomer, metabolite, metabolic precursor, prodrug or solvate thereof, and ciprofloxacin.

[0039] Preferably, the mass ratio of the 2-(2-benzo[d]thiazolylamino)acetamide compound or its pharmaceutically acceptable salt, medically acceptable variant isomer, mesomorph, racemate, stereoisomer, metabolite, metabolic precursor, prodrug or solvate to ciprofloxacin is 50:0.5-20, preferably 50:1-10.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] (1) The present invention starts from a benzothiazole structure with certain biological activity, and after structural modification, invents a 2-(2-benzo[d]thiazolylamino)acetamide compound with stable chemical properties. The anti-biofilm inhibitory activity of the compound against Pseudomonas aeruginosa is detected by crystal violet staining, and the quorum sensing inhibitory activity of the compound is detected by fluorescent reporter strain experiment. The antibiotic synergistic effect of the optimal compound is determined by animal model, and the anti-biofilm effect and antibiotic synergistic effect of a 2-(2-benzo[d]thiazolylamino)acetamide compound described in the present invention on bacteria are determined. The results show that most of the compounds have excellent biofilm inhibitory effect on Pseudomonas aeruginosa and enhance the antibacterial effect of ciprofloxacin. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The synergistic effect of compound SN11 on ciprofloxacin. (A) Bacterial plating results of the wound infection area of ​​mice in the Control group, CIP alone group and SN11-CIP combined group. Each experiment was repeated 3 times; (B) Bacterial survival rate in the wound infection area of ​​mice. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001; (C) Photographing and monitoring of the wound infection area of ​​mice; (D) Monitoring of the wound area of ​​mice, and calculating the wound area using Image J; (E) Representative tissue immunological images of the heart, liver, spleen, lung and kidney of mice in the Control group, CIP group and SN11-CIP group. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with specific implementation modes.

[0044] Unless otherwise specified, the reagents used in the examples can be purchased from the market.

[0045] Example 1: Preparation of N-(Benzo[d]thiazol-2-yl)-N-(tert-butyloxycarbonyl)glycine (Intermediates 4a-4d)

[0046] Step 1: Preparation of tert-butyl benzo[d]thiazol-2-ylcarbamate (Intermediate 2)

[0047]

[0048] 2-Aminobenzothiazole (0.01 mol) was dissolved in dichloromethane, triethylamine and DMAP (0.0002 mol) were added, and the mixture was stirred at room temperature. Then (Boc)2O (0.012 mol) was added dropwise. After the solvent was added dropwise, the reaction was continued for about 4 hours and the reaction was terminated. The residual organic solvent in the reaction system was removed, and then recrystallized with petroleum ether / ethyl acetate (48:2), and filtered under reduced pressure to obtain a gray solid as intermediate 2 with a yield of 85%. 1 H NMR (400MHz, DMSO-d6) δ11.74(s,1H),7.92(d,J=7.9Hz,1H),7.70–7.63(m,1H),7.39(t,J=7.7Hz,1H),7.28–7.22(m,1H),1.51(d,J=2.1Hz,9H). 13 C NMR (101MHz, DMSO) δ160.05,153.41,149.53,132.56,126.46,123.61,121.89,120.61,82.28,28.31.

[0049] Step 2: Preparation of N-(Benzo[d]thiazol-2-yl)-N-(tert-butoxycarbonyl)glycine methyl ester (Intermediate 3)

[0050]

[0051] Intermediate 2 (0.01mol) is placed in a 50mL two-necked flask, dissolved with an appropriate amount of anhydrous DMF, and placed in 0 mol and added sodium hydride (0.012mol) to stir 30min, then drip methyl bromoacetate (0.011mol), continue to react for about 2h before adding a small amount of ice water to quench the reaction. After extraction with 100mL × 3 ethyl acetate, merge organic phases, then use 100mL × 3 saturated NH4Cl liquid washing and 100mL × 3 saturated NaCl liquid washing, until the outflowing water layer is neutral. Use MgSO4 Fully dry back suction filtration, remove solvent, residue flash chromatography (petroleum ether-ethyl acetate=80 / 20v / v) purifying, obtain white solid as intermediate 3, productive rate 70%. 1 H NMR (400MHz, Chloroform-d) δ7.87–7.72(m,2H),7.40(ddd,J=8.4,7.3,1.3Hz,1H),7.30–7.26(m,1H),5.01(s,2H),3.79(s,3H),1.60(s,9H). 13 C NMR (101MHz, CDCl3) δ169.12,160.52,148.80,133.67,133.41,125.78,123.51,121.20,120.82,77.24,52.31,48.10,28.08.

[0052] Step 3: Preparation of N-(Benzo[d]thiazol-2-yl)-N-(tert-butyloxycarbonyl)glycine (Intermediate 4a)

[0053]

[0054] Dissolve the intermediate 3 (0.01 mol) in methanol, add 2N sodium hydroxide aqueous solution (containing 0.02 mol of sodium hydroxide), stir at 50°C for 6 hours, and terminate the reaction. Remove the methanol, adjust the pH to 5 with 1 mol / L HCl, and the solid precipitates. After vacuum filtration and vacuum drying, a white solid is obtained as the intermediate 4a, with a yield of 90%. The preparation method of 4b-4d is the same as 4a. 1HNMR(400MHz,DMSO-d6)δ12.88(s,1H),7.95(d,J=7.9Hz,1H),7.73(d,J=8.2H z,1H),7.42(t,J=7.8Hz,1H),7.30(t,J=7.7Hz,1H),4.83(s,2H),1.52(s,9H). 13 C NMR (101MHz, DMSO) δ169.95,169.09,160.79,148.80,133.32,126.59,124.18,121.91,121.23,52.75,48.33,28.03.

[0055] Example 2: 2-(2-Benzo[d]thiazolylamino)acetamide compounds (Compound SN1)

[0056]

[0057] Intermediate 4a (0.60mmol) was dissolved in dichloromethane, 1-hydroxybenzotriazole (HOBT, 0.72mmol) and triethylamine (1.20mmol) were added, and the mixture was stirred at room temperature for 30min. EDCI (0.72mmol) and pentylamine (0.72mmol) were then added to react for 6h to terminate the reaction. The mixture was extracted with 30mL×3 ethyl acetate, and washed with 30mL×3 saturated NaHCO3, 30mL×3 saturated NH4Cl and 100mL×3 saturated NaCl respectively until the effluent water layer was neutral. The combined organic phases were fully dried with MgSO4 and then filtered to remove the solvent. The residue was purified by flash chromatography (petroleum ether-ethyl acetate = 60 / 40v / v) to obtain a white solid as intermediate 5a. 5a was placed in 6N hydrochloric acid methanol solution, stirred at room temperature for 12h, and the reaction was terminated. The pH value was adjusted to 7 with 1 mol / L NaOH, the solvent was removed, and the mixture was recrystallized with petroleum ether-ethyl acetate to obtain a white solid as compound SN1 with a yield of 53%. 1 H NMR (400MHz, DMSO-d6) δ8.23(t,J=5.6Hz,1H),7.97(t,J=5.6Hz,1H),7.67(dd,J=7.8,1.3Hz,1H),7.37(d,J=8.2Hz,1H),7.21(td,J=7.7,1.4Hz ,1H),7.02(td,J=7.6,1.3Hz,1H),3.98(d,J=5.6Hz,2H),3.08(q,J=6.6 Hz,2H),1.40(p,J=6.9Hz,2H),1.33–1.18(m,4H),0.83(t,J=6.7Hz,3H). 13C NMR (101MHz, DMSO) δ168.95,166.72,152.63,131.09,125.96,121.57,121.39,118.57,47.12,38.98,29.20,28.97,22.29,14.32.

[0058] Example 3: 2-(2-Benzo[d]thiazolylamino)-N-hexylacetamide (Compound SN2)

[0059] Using intermediate 4a (0.60 mmol) and hexylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN2 as a white solid with a yield of 47%. 1 H NMR (400MHz, DMSO-d6) δ8.23(t,J=5.6Hz,1H),7.96(t,J=5.5Hz,1H),7.67(d,J=7.8Hz,1H),7.37(d,J=7.8Hz,1H),7.21(t,J=7.6Hz,1H ),7.02(t,J=7.4Hz,1H),3.98(d,J=5.7Hz,2H),3.08(q,J=6.5Hz,2H),1.39(t,J=6.9Hz,2H),1.31–1.15(m,6H),0.83(t,J=6.2Hz,3H). 13 C NMR (101MHz, DMSO) δ168.88,166.67,152.67,131.13,125.91,121.50,121.39,118.55,47.08,39.00,31.46,29.52,26.48,22.51,14.37.

[0060] Example 4: 2-(2-Benzo[d]thiazolylamino)-N-heptylacetamide (Compound SN3)

[0061] Using intermediate 4a (0.60 mmol) and heptylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN3 as a white solid with a yield of 49%. 1H NMR (400MHz, DMSO-d6) δ8.24(t,J=5.8Hz,1H),7.96(t,J=5.7Hz,1H),7.67(dd,J=7.9,1.2Hz,1H),7.37(dd,J=8.1,1.1Hz,1H),7.22(td,J=7.7,1.3Hz ,1H),7.03(td,J=7.5,1.2Hz,1H),3.98(d,J=5.6Hz,2H),3.08(q,J=6.6Hz ,2H),1.40(t,J=6.9Hz,2H),1.23(q,J=6.5,5.3Hz,8H),0.90–0.79(m,3H). 13 C NMR (101MHz, DMSO) δ168.89,166.67,152.68,131.14,125.91,121.50,121.39,118.55,47.10,38.98,31.71,29.56,28.91,26.76,22.52,14.41.

[0062] Example 5: 2-(2-Benzo[d]thiazolylamino)-N-octylacetamide (Compound SN4)

[0063] Using intermediate 4a (0.60 mmol) and octylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN4 as a white solid with a yield of 51%. 1 H NMR (400MHz, Methanol-d4) δ7.61(d,J=8.0Hz,1H),7.46(d,J=8.2Hz,1H),7.27(t,J=7.8Hz,1H),7.09(t,J=7.6Hz,1 H),4.08(d,J=6.0Hz,2H),3.28–3.09(m,2H),1.50(q,J=7.0Hz,2H),1.26(d,J=12.7Hz,11H),0.89(t,J=6.7Hz,3H). 13 C NMR(101MHz,MeOD)δ170.19,166.61,151.66,130.38,125.48,121.62,120. 47,118.12,46.72,39.04,31.56,29.02,29.00,28.96,26.54,22.29,13.00.

[0064] Example 6: 2-[(6-Chloro-2-benzo[d]thiazolyl)amino]-N-butylacetamide (Compound SN5)

[0065] Using intermediate 4c (0.60 mmol) and butylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN5 as a white solid with a yield of 47%. 1 H NMR (400MHz, DMSO-d6) δ8.35(s,1H),7.89(d,J=73.9Hz,2H),7.28(d,J=41.1Hz,2H),3.98(s,2H),3.08(s,2H),1.33(d,J=44.1Hz,4H),0.85(s,3H). 13 C NMR (101MHz, DMSO) δ168.68,167.30,151.62,132.86,126.06,125.22,121.10,119.40,47.05,38.67,31.66,19.93,14.12.

[0066] Example 7: 2-[(6-Chloro-2-benzo[d]thiazolyl)amino]-N-pentylacetamide (Compound SN6)

[0067] Using intermediate 4c (0.60 mmol) and pentylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN6 as a white solid with a yield of 49%. 1 H NMR (400MHz, DMSO-d6) δ8.36(t,J=5.7Hz,1H),7.98(t,J=5.7Hz,1H),7.80(d,J=2.2Hz,1H),7.34(d,J=8.5Hz,1H),7.23(dd,J= 8.6, 2.3Hz, 1H), 3.98 (d, J = 5.7Hz, 2H), 3.07 (q, J = 6.6Hz, 2H), 1.40 (p, J = 7.0Hz, 2H), 1.29–1.19 (m, 4H), 0.83 (t, J = 6.8Hz, 3H). 13 C NMR (101MHz, DMSO) δ168.68,167.30,151.61,132.86,126.06,125.23,121.09,119.40,47.05,38.96,29.22,28.99,22.30,14.36.

[0068] Example 8: 2-[(6-Chloro-2-benzo[d]thiazolyl)amino]-N-hexylacetamide (Compound SN7)

[0069] Using intermediate 4c (0.60 mmol) and hexylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN7 as a white solid with a yield of 48%.1 H NMR (400MHz, DMSO-d6) δ8.36(t,J=5.7Hz,1H),7.98(t,J=5.7Hz,1H),7.80(d,J=2.2Hz,1H),7.33(d,J=8.5Hz,1H),7.23(dd, J=8.5,2.2Hz,1H),3.98(d,J=5.6Hz,2H),3.07(q,J=6.6Hz,2H),1.38(q,J=6.9Hz,2H),1.28–1.18(m,6H),0.87–0.79(m,3H). 13 C NMR (101MHz, DMSO) δ168.68,167.28,151.59,126.06,125.22,121.10,119.40,47.04,39.00,31.45,29.50,26.47,22.51,14.37.

[0070] Example 9: 2-[(6-Chloro-2-benzo[d]thiazolyl)amino]-N-heptylacetamide (Compound SN8)

[0071] Using intermediate 4c (0.60 mmol) and heptylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN8 as a white solid with a yield of 48%. 1 H NMR (400MHz, Methanol-d4) δ7.67(d,J=2.2Hz,1H),7.40(d,J=8.5Hz,1H),7.26(dd,J=8.6,2.2Hz,1H),4.08( s,2H),3.21(q,J=5.7,4.4Hz,2H),1.49(q,J=7.1Hz,2H),1.27(qd,J=7.6,3.5Hz,8H),0.88(t,J=6.9Hz,3H). 13 C NMR (101MHz, DMSO) δ169.11,166.86,149.96,131.37,125.64,125.06,119.54,118.26,45.97,38.26,30.77,28.27,27.96,25.72,21.48,12.39.

[0072] Example 10: 2-[(6-Chloro-2-benzo[d]thiazolyl)amino]-N-octylacetamide (Compound SN9)

[0073] Using intermediate 4c (0.60 mmol) and octylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN9 as a white solid with a yield of 50%.1 H NMR (400MHz, DMSO-d6) δ8.36(d,J=6.4Hz,1H),7.97(d,J=6.1Hz,1H),7.79(s,1H),7.34(dd,J=8.7,2.6Hz,1H),7.22(d,J=8 .6Hz,1H),3.98(d,J=5.7Hz,2H),3.07(t,J=7.0Hz,2H),1.38(q,J=14.1,10.5Hz,2H),1.21(s,10H),0.83(d,J=7.5Hz,3H). 13 C NMR (101MHz, DMSO) δ168.69,167.29,151.62,132.86,126.04,125.23,121. 09,119.39,47.07,38.98,31.70,29.53,29.21,29.14,26.81,22.56,14.39.

[0074] Example 11: 2-[(6-methoxy-2-benzo[d]thiazolyl)amino]-N-pentylacetamide (Compound SN10)

[0075] Using intermediate 4b (0.60 mmol) and pentylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN10 as a white solid with a yield of 52%. 1 H NMR(400MHz,DMSO-d6)δ7.97(dt,J=26.8,6.0Hz,2H),7.36–7.21(m,2H),6.87–6.78(m,1H),3.94(d,J=5.6Hz, 2H), 3.73 (s, J = 2.4Hz, 3H), 3.07 (q, J = 6.8Hz, 2H), 1.40 (p, J = 7.2Hz, 2H), 1.31–1.18 (m, 4H), 0.90–0.78 (m, 3H). 13 C NMR (101MHz, DMSO) δ169.03,165.09,154.88,146.75,132.15,118.90,113.38,106.00,55.99,47.10,38.94,29.24,28.99,22.31,14.36.

[0076] Example 12: 2-[(6-methoxy-2-benzo[d]thiazolyl)amino]-N-hexylacetamide (Compound SN11)

[0077] Using intermediate 4b (0.60 mmol) and hexylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN11 as a white solid with a yield of 51%. 1 H NMR (400MHz, DMSO-d6) δ7.98(dt,J=29.1,5.9Hz,2H),7.28(d,J=9.5Hz,2H),6.87–6.74(m,1H),3.96(d,J=5. 5Hz,2H),3.73(s,3H),3.08(q,J=6.7Hz,2H),1.39(t,J=7.1Hz,2H),1.22(d,J=8.2Hz,6H),0.88–0.76(m,3H). 13 C NMR (101MHz, DMSO) δ169.08,165.11,154.90,146.76,132.17,118.91,113.35,105.94,55.95,47.14,39.01,31.48,29.53,26.50,22.53,14.33.

[0078] Example 13: 2-[(6-methoxy-2-benzo[d]thiazolyl)amino]-N-heptylacetamide (Compound SN12)

[0079] Using intermediate 4b (0.60 mmol) and heptylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN12 as a white solid with a yield of 55%. 1 H NMR (400MHz, DMSO-d6) δ7.97(dt,J=30.9,5.6Hz,2H),7.44–7.10(m,2H),6.82(dd,J=8.7,2.9Hz,1H),3.93(d,J=5.6H z,2H),3.73(d,J=3.6Hz,3H),3.07(q,J=6.5Hz,2H),1.38(q,J=6.6Hz,2H),1.30–1.09(m,8H),0.83(t,J=6.8Hz,3H). 13 C NMR (101MHz, DMSO) δ169.03,165.08,154.88,146.75,132.16,118.90,113. 37,105.98,55.98,47.12,38.96,31.71,29.56,28.91,26.76,22.52,14.40.

[0080] Example 14: 2-[(6-methoxy-2-benzo[d]thiazolyl)amino]-N-octylacetamide (Compound SN12)

[0081] Using intermediate 4b (0.60 mmol) and octylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain compound SN12 as a white solid with a yield of 51%. 1 H NMR(400MHz,DMSO-d6)δ7.97(dd,J=34.9,6.0Hz,2H),7.35–7.21(m,2H),6.86–6.75(m,1H),3.94(s,2H),3.7 4(d,J=1.9Hz,3H),3.07(q,J=6.7Hz,2H),1.38(q,J=7.1Hz,2H),1.23(d,J=12.2Hz,10H),0.90–0.78(m,3H). 13 C NMR(101MHz,DMSO)δ169.01,165.10,154.89,145.83,132.12,118.88,113.38, 106.00,55.99,47.12,38.96,31.71,29.56,29.21,29.13,26.81,22.56,14.40.

[0082] Example 15: 2-[(6-Nitro-2-benzo[d]thiazolyl)amino]-N-pentylacetamide (Compound SN14)

[0083] Using intermediate 4d (0.60 mmol) and pentylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain a yellow solid, compound SN14, with a yield of 43%. 1 H NMR (400MHz, DMSO-d6) δ9.12–8.92(m,1H),8.70(d,J=13.8Hz,1H),8.10(q,J=11.0,9.7Hz,2H),7.45(dd,J=15.9,8.5Hz,1H ),4.06(d,J=13.8Hz,2H),3.08(dd,J=14.1,7.6Hz,2H),1.46–1.33(m,2H),1.32–1.15(m,4H),0.83(dd,J=14.4,7.2Hz,3H). 13 C NMR (101MHz, DMSO) δ171.50168.20,158.31,141.34,131.93,122.48,118.28,117.75,47.12,39.01,29.18,28.98,22.28,14.36.

[0084] Example 16: 2-[(6-nitro-2-benzo[d]thiazolyl)amino]-N-hexylacetamide (Compound SN15)

[0085] Using intermediate 4d (0.60 mmol) and hexylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain a yellow solid, compound SN15, with a yield of 41%. 1 H NMR(400MHz,DMSO-d6)δ8.96(s,1H),8.71(d,J=2.5Hz,1H),8.15–8.01(m,2H),7.45(d,J=8.9Hz,1H) ,4.07(s,2H),3.08(q,J=6.6Hz,2H),1.40(p,J=7.1,6.4Hz,2H),1.23(s,6H),0.83(d,J=6.8Hz,3H). 13 C NMR (101MHz, DMSO) δ171.45,168.17,158.32,141.33,131.95,122.44,118.28,117.73,47.14,39.01,31.29,29.31,26.60,22.35,14.38.

[0086] Example 17: 2-[(6-Nitro-2-benzo[d]thiazolyl)amino]-N-heptylacetamide (Compound SN16)

[0087] Using intermediate 4d (0.60 mmol) and heptylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain a yellow solid, compound SN16, with a yield of 43%. 1 H NMR(400MHz, DMSO-d6)δ8.96(d,J=6.5Hz,1H),8.70(d,J=13.5Hz,1H),8.14–7.96(m,2H),7.49–7.36(m,1H),4. 07(d,J=5.6Hz,2H),3.08(q,J=6.9Hz,2H),1.39(q,J=7.2Hz,2H),1.21(d,J=10.5Hz,8H),0.83(t,J=7.0Hz,3H). 13 CNMR(101MHz,DMSO)δ168.17,158.32,154.14,141.33,131.95,122.44,118.28,117.73,47.16,39.02,31.71,29.52,28.89,26.75,22.51,14.40.

[0088] Example 18: 2-[(6-Nitro-2-benzo[d]thiazolyl)amino]-N-octylacetamide (Compound SN17)

[0089] Using intermediate 4d (0.60 mmol) and octylamine (0.72 mmol) as raw materials, the preparation method was similar to compound SN1 to obtain a yellow solid, compound SN17, with a yield of 41%. 1 H NMR(400MHz, DMSO-d6)δ8.95(t,J=5.7Hz,1H),8.70(d,J=2.5Hz,1H),8.13–8.01(m,2H),7.45(d,J=8.9Hz,1H), 4.06(d,J=5.5Hz,2H),3.07(q,J=6.5Hz,2H),1.38(q,J=7.0Hz,2H),1.25–1.16(m,10H),0.82(t,J=6.7Hz,3H). 13 CNMR(101MHz,DMSO)δ171.45,168.17,158.32,141.33,131.95,122.44,118. 28,117.73,47.15,39.02,31.69,29.51,29.19,29.13,26.80,22.55,14.39.

[0090] Example 19: Inhibitory activity of compounds against Pseudomonas aeruginosa biofilm

[0091] Experimental method: This experiment uses crystal violet staining to quantitatively determine the biofilm content: the maximum screening concentration of the compound is 10μM, a blank control group and a negative control group are set up, azithromycin is used as the positive control drug, and the compound is diluted into a series of concentration gradients using the two-fold dilution method. Add 75μL of drug-containing culture medium to each 96-well plate, and then inoculate 75μL of bacterial solution. After culturing in a 37°C constant temperature incubator for 24 hours, wash away the planktonic bacteria with PBS buffer solution, add 160μL of methanol to fix at room temperature for 20 minutes, add 150μL of 0.1% crystal violet stain, place at room temperature for 15 minutes, wash away the excess dye with distilled water, add 150μL of 33% glacial acetic acid, shake evenly, and use an enzyme reader to measure the absorbance at a wavelength of 570nm. The experiment was repeated three times to screen out compounds with biofilm inhibitory activity. The results of the biofilm inhibitory activity experiment are shown in Table 1. Calculation method of biofilm inhibition rate:

[0092] Biofilm inhibition rate = [(Control OD值 -Blank OD值 )-(Drug sensitivity group OD值 -Blank OD值 )] / (Control OD值-Blank OD值 )

[0093] ×100%.

[0094] Table 1 Inhibitory effects of all compounds on Pseudomonas aeruginosa biofilm

[0095]

[0096] a IC 50 = inhibitor concentration required to inhibit 50% biofilm formation. b IC of most compounds 50 The screening concentration is 0.001~10μM.

[0097] Experimental results: Most of the 2-(2-benzo[d]thiazolylamino)acetamide compounds of the present invention can inhibit the formation of biofilm at a relatively low concentration. The IC 50 Less than 1μM, better than the IC of the positive control drug azithromycin AZM 50 Among them, compound SN11 had the best activity, inhibiting the biofilm IC 50 It is 0.04±0.02μM.

[0098] Example 20: Study on the synergistic effect of compound SN11 on ciprofloxacin (CIP) in a mouse wound infection model

[0099] Experimental methods: This animal experiment was conducted in accordance with the relevant national regulations on animal experiments. Pseudomonas aeruginosa PAO1 strain was used in this animal experiment, and female 5-week-old Babl / c mice were purchased from SPF (Beijing) Biotechnology.co. Ltd. During the entire experiment, the living environment of the mice was maintained at a constant temperature of 25°C, with a 12-h light / night cycle, and sufficient food and water were provided. First, 20 mice were randomly divided into 4 groups, 5 mice per group. After anesthesia with 4% chloral hydrate, the hair on the back of the mice was shaved, a 4-5 mm circular wound was established on the back of each mouse, and 5×10 8 CFU of PAO1 was used to establish the wound infection model for 24 hours. Then different groups of mice were treated with different drugs (normal saline, 1mg / ml CIP, 0.01mg / ml CIP+10μM SN11, 0.001mg / ml CIP+10μM SN11). After 3 consecutive days of administration, the skin of the mouse wound was taken for CFU counting, and the mouse wound was photographed and monitored every day to calculate the wound area.

[0100] Experimental results: Figure 1As shown in the figure, after three days of continuous administration, the bacteria in the wounds of mice in the combined drug administration group were significantly reduced compared with those in the saline group (Control). By calculating the bacterial survival rate in the wounds, the bacterial survival rate in the saline group was 100%. After three days of treatment with 1mg / ml CIP, the bacteria were basically completely eliminated, with a survival rate of 0%. After the combined treatment of 0.01mg / ml CIP+10μM SN11, very few bacteria survived, and the survival rate approached 0%, indicating that the synergistic effect of SN11 on CIP reached 100 times. In the combined drug group of 0.001mg / ml CIP+50μM SN11, the bacterial survival rate was relatively low compared with the Control group, only about 5%. Subsequently, the monitoring of the wound area of ​​mice also obtained consistent experimental results. After three days of combined administration of SN11 and diluted CIP, the wound area was basically the same as that of the CIP group alone, and both were much smaller than the wound area of ​​the Control group. On the 9th day, the degree of wound healing reached about 80%. In addition, according to the results of H&E staining of mouse organ histology, compound SN11 did not cause damage to the mouse heart, liver, spleen, lung, and kidney. The above results all show that SN11, as a biofilm inhibitor, has a good synergistic effect on CIP, and its synergistic effect is 100-1000 times.

[0101] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof, characterized in that It has a chemical structure as shown in Formula I: ； Formula I Wherein, R1 is one of -H, -Cl, -OCH3, -NO2; When R1 is -H, R2 is a C5 ~ C8 straight chain alkyl group: ； When R1 is one of -Cl, -OCH3, -NO2, and R2 is a C4 ~ C8 straight chain alkyl group: 。 2. The 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that Has the chemical structure shown below: ； ； 。 3. A method for preparing the 2-(2-benzo[d]thiazoleamino)acetamide compound according to claim 1, characterized in that: The following steps are involved: (1.1) reacting 2-aminobenzothiazole substituted with different groups, di-tert-butyl dicarbonate and triethylamine in a solvent, and purifying the reaction solution obtained after the reaction to obtain compound 2; (1.2) Compound 2, methyl bromoacetate and sodium hydride are reacted in a solvent at 0°C, and the obtained reaction solution is purified to obtain compound 3; (1.3) Compound 3 and sodium hydroxide aqueous solution are placed in a solvent for reaction at 50°C, and the obtained reaction solution is purified to obtain compounds 4a-4d; (1.4) Compounds 4a-4d, fatty amine, HOBt and EDCI are reacted in a solvent, and the resulting reaction solution is purified to obtain compounds 5a-5q; (1.5) Compounds 5a-5q are reacted in a methanol solution of hydrochloric acid, and the resulting reaction solution is purified to obtain compounds SN1-SN17; The synthetic route is: 。 4. Use of the 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2 in the preparation of anti-biofilm drugs and antibiotic synergists; wherein, The biofilm is a bacterial biofilm, the bacteria is Pseudomonas aeruginosa, and the antibiotic is ciprofloxacin.

5. Use of the 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2 in the preparation of an antibacterial drug, wherein the bacterium is Pseudomonas aeruginosa.

6. A pharmaceutical composition comprising at least one of the 2-(2-benzo[d]thiazolylamino)acetamide compounds or pharmaceutically acceptable salts thereof according to any one of claims 1 to 2, and further comprising one or more pharmaceutically acceptable carriers or excipients.

7. A combination drug comprising the 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2, and ciprofloxacin.

8. The combination drug according to claim 7, wherein the mass ratio of 2-(2-benzo[d]thiazolylamino)acetamide compound or a pharmaceutically acceptable salt thereof to ciprofloxacin is 50:0.5-20.

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