A benzothiazole derivative and its application

Abstract

The present invention discloses a benzothiazole derivative, the structure of which is shown in Formula I below. By modifying the amide group on the benzothiazole skeleton and splicing it with amino acid fragments, a series of acylhydrazone and acylhydrazide derivatives were designed and synthesized based on this structure. Tumor inhibition tests have shown that these derivatives have certain inhibitory activity against liver cancer cells and melanoma cells and can be used to prepare anti-tumor drugs, thereby providing more candidate compounds for the development of new drugs.

Description

Technical Field

[0001] The present invention belongs to the pharmaceutical field, and in particular relates to a benzothiazole derivative and an application thereof in the preparation of an anti-tumor drug. Background Art

[0002] The incidence and mortality of cancer are increasing worldwide, and in many countries, cancer has surpassed cardiovascular disease as the cause of death.

[0003] Benzothiazoles are an important class of heterocyclic alkaloids, found in numerous natural products and as potential synthetic drug molecules. Benzothiazole derivatives exhibit diverse biological functions, such as antiviral, antibacterial, and anticancer properties, with minimal toxic side effects. Amino acids and amide units are key building blocks of polypeptides, and a large body of literature demonstrates that compounds containing these units often exhibit a wide range of biological activities, including antibacterial, antioxidant, anti-inflammatory, analgesic, antitumor, and antiviral pharmacological activities. Furthermore, some amide derivatives exhibit a wide range of pesticide activities, including fungicidal, insecticidal, acaricidal, herbicidal, and plant growth regulatory activities.

[0004] Based on this, in order to further develop benzothiazole drug molecules with novel structures and improve their activity, we tried to combine the benzothiazole skeleton with natural amino acid fragments to design and prepare a series of novel benzothiazole amide derivatives. At the same time, we also further introduced active units such as acylhydrazone and acylhydrazide on the basis of introducing amino acid fragments and verified their activity, providing more candidate compounds for the development of new drugs. Summary of the Invention

[0005] The present invention aims to screen a novel benzothiazole derivative and improve its anti-tumor activity.

[0006] The structure of the benzothiazole derivative provided by the present invention is shown in the following formula I:

[0007]

[0008] Among them, the R 1 、R 2 is H or a conventional substituent on the benzene ring;

[0009] The R 3 is a substituent containing a carboxylic acid, and the R 3 Connected with the amino group in formula I to form an amide compound with the structure shown in formula II below;

[0010]

[0011] Or, the R 3 is a substituent containing an amino group, and the R 3Connected with the amino group in formula I to form a hydrazide compound with the structure shown in formula III below;

[0012]

[0013] Or, the R 3 is a substituent containing a nitrilo group, and the R 3 Connected with the amino group in formula I to form an acylhydrazone compound with the structure shown in formula IV below;

[0014]

[0015] Wherein, the conventional substituent on the benzene ring is nitro or trifluoromethyl.

[0016] Among them, the R 4 is H or alkyl.

[0017] Among them, the R 5 It is pyrazole or substituted pyrazole, benzene or substituted benzene.

[0018] Among them, the R 6 It is benzene or substituted benzene or indole.

[0019] Furthermore, the preferred derivatives of the present invention are the six compounds with the following structural formulas:

[0020]

[0021] Among these six derivatives, they are divided into two categories, acylhydrazone and acylhydrazone, according to the substitution type of the amide group. Among them, four compounds belong to the acylhydrazone category and two compounds belong to the acylhydrazone category. Tumor inhibition experiments showed that the half-maximal inhibitory concentration (IC50) of these six derivatives on liver cancer cells and melanoma cells 50 ) were all lower than 20 μg / mL, and their activities were higher than most other derivatives.

[0022] The above compounds can all be synthesized using ethyl benzothiazole-2-carboxylate as a raw material using hydrolysis, condensation, and substitution reactions well known in the art.

[0023] The derivatives provided by the present invention have a significant inhibitory effect on the growth of tumor cells, especially human liver cancer cells and human melanoma cells, and can be used to develop anti-tumor drugs. In addition, the synthesis process of such compounds is simple and easy, the raw materials are readily available, and they have great industrial application prospects. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below by means of specific examples, but the present invention is not limited to the following examples.

[0025] Example 1 Compound Type

[0026] The structures of some compounds provided by the present invention are shown in Tables 1-3.

[0027] Table 1 Structure list and physical properties of acylhydrazone compounds

[0028]

[0029]

[0030] Table 2 Structure list and physical properties of representative hydrazide compounds

[0031]

[0032]

[0033] Table 3 Structure list and physical properties of representative amide compounds

[0034]

[0035]

[0036] Example 2 Preparation of Compound

[0037] The target compounds in Tables 1-3 were synthesized using ethyl benzothiazole-2-carboxylate as the raw material.

[0038] 1. Synthesis of amide compounds

[0039] First, benzothiazole-2-carboxylic acid ethyl ester is hydrolyzed, and the hydrolysis product is subjected to an amidation reaction with amino acid methyl ester hydrochloride. Finally, the methyl ester is hydrolyzed again to reduce it to formic acid to obtain the target compound.

[0040]

[0041] Take the target compound 3c as an example:

[0042] (1) Add 1.56mmol of the raw material drug benzothiazole-2-carboxylic acid ethyl ester and 6mL of methanol to a round-bottom single-necked flask, dissolve 2.34mmol of sodium hydroxide in 3mL of water, add the above reactants to the flask and add a magnet, place the flask on a stirrer, stir at room temperature for 5h, and monitor the reaction by TLC. After the reaction is completed, take a clean beaker, add 50mL of water and place it in an ice water bath, pour the liquid into the beaker containing water, slowly add hydrochloric acid until the pH value of the solution is between 1 and 2, and stir continuously. After the addition is complete, continue stirring for 10min, filter, rinse the solid with a small amount of water, and place it in a fume hood to dry.

[0043]

[0044] (2) 0.51 mmol of the hydrolysis product and 3 mL of DMF were added to a round-bottomed single-necked flask, followed by 1.29 mmol of glycine methyl ester hydrochloride, 0.77 mmol of EDCI, and 0.77 mmol of HOBt. A magnetic rod was added and the flask was placed on a stirrer. The mixture was stirred at room temperature for 3 h and the reaction was monitored by TLC. After the reaction, 20 mL of water and 20 mL of ethyl acetate were added to the reaction system. The mixture was shaken in a separatory funnel for separation. The aqueous phase was extracted twice with 20 mL of ethyl acetate. The organic phases were combined and washed with 30 mL of 1N hydrochloric acid, 20 mL of saturated sodium chloride solution, and 30 mL of water in sequence. The organic phases were dried over anhydrous sodium sulfate and the solvent was removed by rotary evaporation. The product was a liquid. The product was dissolved in 6 mL of methanol for subsequent hydrolysis.

[0045]

[0046] (3) Weigh 1.025 mmol of sodium hydroxide solid, dissolve it in 3 mL of water and add it to the above system. Stir at room temperature for 4 h and monitor the reaction by TLC. After the reaction is completed, remove part of the methanol by rotary evaporation. Take a clean beaker, add 50 mL of water and place it in an ice water bath. Pour the liquid into the beaker containing water and slowly add hydrochloric acid until the pH value of the solution is between 1 and 2 while stirring continuously. Continue stirring for 10 min after the addition is completed. Filter with suction, rinse the solid with a small amount of water and place it in a fume hood to dry.

[0047]

[0048] 2. Synthesis of hydrazide compounds

[0049] The raw material drug benzothiazole-2-carboxylic acid ethyl ester is condensed with hydrazine hydrate to obtain an intermediate, and the intermediate is substituted to obtain the target compound.

[0050]

[0051] Take target compound 2a as an example:

[0052] (1) Add 2 mmol of ethyl 7-nitro-5-trifluoromethyl-1,3-benzothiazole-2-carboxylate and 10 mL of anhydrous ethanol to a round-bottomed single-necked flask, then add 20 mmol of hydrazine hydrate. Add a magnetic bar and place the flask in a constant temperature oil bath with stirring. The reaction temperature is 40°C and the temperature is kept constant for 2 h. The reaction is monitored by TLC. When the reaction is complete, the flask is filtered and the solid is rinsed with a small amount of anhydrous ethanol. The solid is then placed in a fume hood to dry for subsequent use.

[0053]

[0054] (2) 0.33 mmol of the intermediate, 0.33 mmol of 1-methyl-3-(difluoromethyl)-1H-pyrazole-4-carboxylic acid, and 3 mL of DMF were added to a round-bottomed single-necked flask. 0.49 mmol of TBTU and 0.65 mmol of triethylamine were then added. A magnetic bar was added and the flask was placed on a stirrer. The mixture was stirred at room temperature for 3 h and monitored by TLC. After the reaction was completed, the liquid was slowly dripped into a beaker containing ice water while stirring continuously. Solid precipitated. After the dripping was completed, stirring was continued for 5 min. The mixture was filtered and the solid was rinsed with a small amount of water. The solid was then placed in a fume hood to dry.

[0055]

[0056] 3. Synthesis of acylhydrazone compounds

[0057] The raw material drug benzothiazole-2-carboxylic acid ethyl ester is condensed with hydrazine hydrate to obtain an intermediate, and the intermediate is condensed with a substituted aldehyde (ArCHO) to obtain the target compound.

[0058]

[0059] Take target compound 1j as an example:

[0060] The first step of the hydrazine hydrate condensation reaction is the same as that of compound 2a.

[0061] 1.3 mmol of the intermediate and 10 mL of anhydrous ethanol were added to a round-bottomed single-necked flask, followed by 1.3 mmol of vanillin. A magnetic bar was added and the flask was placed in a constant temperature oil bath with stirring. The reaction temperature was 50 ° C. The temperature was kept constant and stirred for 20 h. The reaction was monitored by TLC. After the reaction was complete, the product was filtered and the solid was rinsed with a small amount of anhydrous ethanol. It was placed in a fume hood to dry for subsequent use.

[0062]

[0063] By referring to the above synthesis method and selecting different conventional chemical raw materials in combination with the structural characteristics of the target compound, the other compounds in Tables 1-3 can be prepared. The mass spectrometry data of some of the compounds are as follows:

[0064] Compound 1a: N′-(4-hydroxy-3-methoxybenzylidene)benzo[d]thiazole-2-carbohydrazide: 11H NMR (600 MHz, DMSO-d6) δ 12.53 (s, 1H), 9.68 (s, 1H), 8.59 (s, 1H), 8.30 - 8.26 (m, 1H), 8.22 - 8.17 (m, 1H), 7.68 (ddd, J = 8.3, 7.1, 1.2 Hz, 1H), 7.65 - 7.60 (m, 1H), 7.35 (d, J = 1.9 Hz, 1H), 7.14 (dd, J = 8.2, 1.9 Hz, 1H), 6.90 (d, J = 8.1 Hz, 1H), 3.87 (s, 3H). 13 13C NMR (151 MHz, DMSO-d6) δ 164.48, 156.33, 153.22, 151.53, 149.95, 148.56, 136.51, 127.72, 127.51, 125.87, 124.51, 123.51, 123.13, 115.98, 109.63, 56.05. MS (ESI) m / z 328.23 [M + H] + , calcd. for C 16 H 13 N3O3S m / z = 327.07.

[0065] Compound 1b: N'-(2-hydroxy-3-methoxybenzylidene)benzo[d]thiazole-2-carbohydrazide: 1 1H NMR (600 MHz, DMSO-d6) δ 12.96 (s, 1H), 10.76 - 10.71 (m, 1H), 8.90 (s, 1H), 8.30 - 8.27 (m, 1H), 8.21 (dt, J = 8.1, 1.1 Hz, 1H), 7.71 - 7.66 (m, 1H), 7.66 - 7.61 (m, 1H), 7.17 (dd, J = 7.9, 1.4 Hz, 1H), 7.07 (dt, J = 8.0, 1.3 Hz, 1H), 6.89 (td, J = 7.9, 0.9 Hz, 1H), 3.83 (s, 3H). 13 13C NMR (151 MHz, DMSO-d6) δ 163.76, 156.54, 153.19, 150.98, 148.48, 147.82, 136.56, 127.81, 127.67, 124.61, 123.59, 121.19, 119.63, 119.42, 114.62, 56.34. MS (ESI) m / z 328.23 [M + H] + , calcd. for C 16 H 13N3O3S m / z = 327.07.

[0066] Compound 1c: N'-(2-fluorobenzylidene)benzo[d]thiazole-2-carbohydrazide: 1 HNMR(600MHz, DMSO-d6) δ12.92(s, 1H), 8.97(s, 1H), 8.30(ddd, J = 8.0, 1.3, 0.7Hz, 1H), 8.24 - 8.21(m, 1H), 8.02 - 7.97(m, 1H), 7.69(ddd, J = 8.3, 7.1, 1.3Hz, 1H), 7.64(ddd, J = 8.3, 7.1, 1.3Hz, 1H), 7.57 - 7.52(m, 1H), 7.36 - 7.31(m, 2H). 13 C NMR(151MHz, DMSO-d6) δ164.00, 162.27, 160.61, 156.77, 153.17, 143.77, 143.74, 136.57, 133.03, 132.97, 127.81, 127.68, 12,6.98, 126.96, 125.50, 125.48, 124.61, 123.59, 122.15, 122.09, 116.63, 116.49.MS(ESI)m / z 300.32[M + H] + , calcd. for C 15 H 10 FN3OS m / z = 299,05.

[0067] Compound 1d: N'-(2-(trifluoromethyl)benzylidene)benzo[d]thiazole-2-carbohydrazide: 1 H NMR(600MHz, CDCl3) δ10.59(s, 1H), 8.66(s, 1H), 8.45(d, J = 7.9Hz, 1H), 8.15(d, J = 8.2Hz, 1H), 8.03(d, J = 8.1Hz, 1H), 7.72(d, J = 7.8Hz, 1H), 7.66 - 7.57(m, 2H), 7.57 - 7.50(m, 2H). 1313C NMR(151MHz,CDCl3)δ162.23,156.04,152.62,145.27,137.15,132.18,131.29,130.36,128.75,128.54,128.17,127.29,127.26,125.84,125.80,124.98,124.47,122.53.MS(ESI)m / z 350.29[M+H] + ,calcd.for C 16 H 10 F3N3OS m / z=349.05.

[0068] Compound 1e: N′-((1H-indol-2-yl)methylene)benzo[d]thiazole-2-carbohydrazide: 1 1H NMR(600MHz,DMSO-d6)δ12.39(s,1H),11.68(s,1H),8.83(s,1H),8.29(dd,J = 19.9,7.9Hz,2H),8.20(d,J = 8.1Hz,1H),7.87(s,1H),7.66(t,J = 7.6Hz,1H),7.61(t,J = 7.6Hz,1H),7.46(d,J = 7.9Hz,1H),7.22(t,J = 7.6Hz,1H),7.19(t,J = 7.5Hz,1H). 13 13C NMR(151MHz,DMSO-d6)δ165.03,155.90,153.31,147.91,137.54,136.48,131.61,127.66,127.38,124.81,124.45,123.51,123.24,122.48,121.10,112.39,112.06.MS(ESI)m / z 321.30[M+H] + ,calcd.for C 17 H 12 N4OS m / z = 320.07.

[0069] Compound 1f: N′-(2-hydroxybenzylidene)benzo[d]thiazole-2-carbohydrazide: 11H NMR (600 MHz, CDCl3) δ 10.43 (s, 1H), 8.57 (s, 1H), 8.12 (d, J = 8.3 Hz, 1H), 8.03 (d, J = 6.2 Hz, 1H), 7.65 - 7.52 (m, 3H), 7.39 - 7.32 (m, 1H), 7.30 - 7.27 (m, 1H), 7.05 (d, J = 9.3 Hz, 1H), 6.95 (t, J = 8.0 Hz, 1H). 13 13C NMR (151 MHz, CDCl3) δ 152.32, 132.53, 131.27, 127.35, 127.33, 124.39, 122.57, 119.55, 117.47, 117.14. MS (ESI) m / z 298.25 [M + H] + , calcd. for C 15 H 11 N3O2S m / z = 297.06.

[0070] Compound 1g: N'-(2,4-dichlorobenzylidene)benzo[d]thiazole-2-carbohydrazide: 1 1H NMR (600 MHz, CDCl3) δ 10.57 (s, 1H), 8.71 (s, 1H), 8.19 (d, J = 6.6 Hz, 1H), 8.11 (d, J = 8.0 Hz, 1H), 8.02 (d, 1H), 7.62 - 7.51 (m, 2H), 7.31 (d, J = 8.2 Hz, 1H), 7.26 (s, 1H). 13 13C NMR (151 MHz, CDCl3) δ 162.23, 156.01, 152.66, 145.05, 137.21, 137.18, 135.03, 129.67, 129.45, 128.93, 127.79, 127.28, 127.23, 124.47, 122.53. MS (ESI) m / z 350.20 [M + H] + , calcd. for C 15 H9Cl2N3OS m / z = 348.98.

[0071] Compound 1h: N'-(4-bromobenzylidene)benzo[d]thiazole-2-carbohydrazide: 1HNMR(600MHz,CDCl3)δ10.45(s,1H),8.35(s,1H),8.10(d,J=8.2Hz,1H),8.02(d,J=8.1Hz,1H),7.70(d,J=9.1Hz,2H),7.62 - 7.52(m,4H),7.26(s,1H). 13 C NMR(151MHz,CDCl3)δ162.47,155.93,152.65,148.61,137.15,132.24,132.10,129.31,127.20,127.18,125.38,124.41,122.53.MS(ESI)m / z360.19[M + H] + ,calcd.for C 15 H9Cl2N3OS m / z=358.97.

[0072] Compound 1i: N′ - 3-(4 - chlorophenyl)allylidene)benzo[d]thiazole - 2 - carbohydrazide: 1 H NMR(600MHz,DMSO - d6)δ12.68(s,1H),8.47(d,J=8.9Hz,1H),8.28(d,J=7.8Hz,1H),8.21(d,J=8.1Hz,1H),7.71(d,J=8.2Hz,2H),7.67(d,J=7.7Hz,1H),7.64(d,J=7.8Hz,1H),7.​​​​​​​​​​​​1H NMR (600 MHz, DMSO-d6) δ 9.72 (s, 1H), 8.93 (s, 1H), 8.82 (s, 1H), 8.57 (s, 1H), 7.33 (s, 1H), 7.13 (d, J = 8.0 Hz, 1H), 6.87 (d, J = 8.1 Hz, 1H), 3.85 (s, 3H). 13 13C NMR (151 MHz, DMSO-d6) δ 170.46, 155.65, 152.43, 150.19, 148.58, 143.77, 123.36, 115.98, 109.65, 56.05. MS (ESI) m / z 441.22 [M+H] + , calcd. for C 17 H 11 F3N4O5S m / z = 440.04.

[0074] Compound 1l: N'-(2-fluorobenzylidene)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 1H NMR (600 MHz, DMSO-d6) δ 13.11 (s, 1H), 8.95 (d, J = 13.3 Hz, 2H), 8.83 (s, 1H), 7.98 (t, J = 7.6 Hz, 1H), 7.61 - 7.50 (m, 1H), 7.34 (t, J = 8.3 Hz, 2H). 13 13C NMR (600 MHz, DMSO-d6) δ: 154.91, 144.90, 144.83, 143.79, 134.76, 133.99, 133.17, 128.67, 127.94, 127.06, 125.59, 123.67, 120.87, 119.84, 116.82, 116.49. MS (ESI) m / z 413.14 [M+H] + , calcd. for C 16 H8F4N4O3S m / z = 412.03.

[0075] Compound 1m: 7-nitro-5-(trifluoromethyl)-N'-(2-(trifluoromethyl)benzylidene)benzo[d]thiazole-2-carbohydrazide: 11H NMR (600 MHz, DMSO-d6) δ 9.15 (s, 1H), 8.94 (s, 1H), 8.84 (s, 1H), 8.26 (d, J = 7.9 Hz, 1H), 7.88 - 7.79 (m, 2H), 7.74 - 7.67 (m, 1H).

[0076] Compound 1n: N′-((1H-indol-3-yl)methylene)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 1H NMR (600 MHz, DMSO-d6) δ 12.63 (s, 1H), 11.73 (s, 1H), 8.92 (s, 1H), 8.84 (s, 1H), 8.79 (s, 1H), 8.28 (d, J = 8.7 Hz, 1H), 7.90 (d, J =​​​​​​​​​​​​​​​​​​​Compound 2b: N′-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 HNMR(600MHz, DMSO-d6) δ8.99(s, 1H), 8.82(s, 1H), 8.52(s, 1H), 8.22(d, J = 8.1Hz, 1H), 7.70 - 7.62(m, 1H), 7.34(s, 1H). MS(ESI) m / z 590.40[M + H] + , calcd. for C 18 H8BrClF3N7O4S m / z = 588.92.

[0079] Compound 2c: N′-(2-methyl-[1,1′-biphenyl]-3-carbonyl)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 H NMR(600MHz, CDCl3) δ8.79(s, 1H), 8.72(s, 1H), 7.54(d, J = 7.4Hz, 1H), 7.45 - 7.27(m, 9H), 2.40 - 2.34(m, 3H). MS(ESI) m / z501.45[M + H] + , calcd. for C 23 H 15 F3N4O4S m / z = 500.08.

[0080] Compound 2d: N′-(3,5-dimethylbenzoyl)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 H NMR(600MHz, DMSO-d6) δ8.82(s, 1H), �.60(s, 1H), 7.46 - 7.28(m, 2H), 7.26 - 7.02(m, 1H), 2.34(s, 6H). MS(ESI) m / z 439.51[M + H] + , calcd. for C 18 H 13 F3N4O4S m / z = 438.06. <0, span style="font-size: 10pt; line-height: 12pt; font-family: Courier New; color: black;">

[0081] Compound 2e: N′,N′-bis(3,5-dimethylbenzoyl)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 H NMR(600MHz, DMSO-d6) δ9.01(s, 1H), 8.81(s, 1H), 7.54(d, J=14.1Hz, 5H), 7.24(s, 2H), 2.36 - 2.31(m, 12H). MS(ESI) m / z 571.58[M + H] + , calcd. for C 27 H 21 F3N4O5S m / z=570.12.

[0082] Compound 2f: N′-(4-ethylbenzoyl)-7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbohydrazide: 1 H NMR(600MHz, DMSO-d6) δ8.86(s, 1H), 8.65(s, 1H), 7.88 - 7.64(m, 2H), 7.38 - 7.19(m, 2H), 2.71 - 2.61(m, 2H), 1.27 - 1.14(m, 3H). MS(ESI) m / z 571.58[M + H] + , calcd. for C 18 H 13 F3N4O4S m / z=438.06.

[0083] Compound 3a: (7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbonyl)alanine: 1 H NMR(600MHz, CDCl3) δ8.75(s, 1H), 8.73 - 8.69(m, 1H), 7.91(d, J=7.6Hz, 1H), 4.92 - 4.85(m, 1H), 1.69(d, J=7.2Hz, 3H). 13 C NMR(151MHz, CDCl3) δ175.58, 170.45, 161.83, 159.03, 154.74, 143.26, 136.40, 127.81, 119.99, 47.55, 29.21, 19.09. MS(ESI) m / z364.42[M + H] + , calcd. for C12 H8F3N3O5S m / z=363.01.

[0084] Compound 3c: (7-nitro-5-(trifluoromethyl)benzo[d]thiazole-2-carbonyl)glycine: 1 H NMR (600MHz, DMSO-d6) δ9.57(t,J=6.1Hz,1H),9.03-8.99(m,1H),8.84-8.79(m,1H),4.03(d,J=6.0Hz,2H),1.23(s,1H). 13 C NMR(151MHz,DMSO-d6)δ170.73,170.07,159.52,154.93,143.76,135.19,129.08,128.75,128.19,120.14,41.81.MS(ESI)m / z350.20[M+H] + ,calcd.for C 11 H6F3N3O5Sm / z=349.00.

[0085] Compound 3e: (benzo[d]thiazole-2-carbonyl)glycine: 1 H NMR (600MHz, DMSO-d6) δ9.36(t,J=6.1Hz,1H),8.25(d,J=8.0Hz,1H),8.16(d,J=8.1Hz,1H),7.63(dt,J=30.2,7.5Hz,2H),3.98(d,J=6.1Hz,2H). 13 C NMR(151MHz,DMSO-d6)δ170.98,164.36,160.24,153.13,136.58,127.69,127.50,124.51,123.59,41.66.MS(ESI)m / z 237.30[M+H] + ,calcd.for C 10 H8N2O3S m / z=236.03.

[0086] Inhibitory effect of the compound of Example 2 on the growth of tumor cells in vitro

[0087] To demonstrate the effectiveness of the present invention, the growth inhibitory effects of different compounds on human hepatoma cells (Huh7) and human melanoma cells (A875) were determined using an in vitro MTT assay with 5-fluorouracil as a positive control. The specific test method is as follows: After preparing a single-cell suspension, gently mix it and add 100 μl of cells to each well of a 96-well plate. Three parallel samples are set up for each experimental group. The inoculated 96-well plate is placed in an incubator and cultured. After the cells adhere for 2-4 hours, the old culture medium is removed and different concentrations of the drug (0, 0.1, 1, 5, 10, 20 μM) are added. The remaining volume is supplemented to 100 μl with fresh culture medium. Remove the culture medium from the cell culture plate, wash twice with PBS, add 30 μL of 5 mg / ml MTT solution to each well, incubate at 37°C in a cell culture incubator for 2-4 hours, then remove the MTT, add 30 μL of DMSO to dissolve and mix, and read the light absorption value (OD) at 492 nm on an enzyme-linked immunosorbent assay (ELISA) 492 ).

[0088] The IC values ​​of the tested compounds on Huh7 and A875 tumor cells were 50 The inhibitory effect of the compound on tumor cells was expressed as the tumor cell growth inhibition concentration IC 50 , which represents the concentration of compound that reduces cell growth by 50%. All data were processed using SPSS software to calculate the half-inhibitory concentration (IC) of each compound on different tumor cell lines. 50 , taking the mean of three independent repeated experiments, the data results are as follows:

[0089] Table 4 Effects of some compounds of the present invention on cell viability of different tumor cells

[0090]

[0091]

[0092] The results showed that the antitumor activity of acylhydrazones and acylhydrazides was generally higher than that of amides. Among them, 1b, 1f, 1k, 1n, 2b, and 2c had better antitumor activity, with the half-maximal inhibitory concentration for human hepatoma cells and human melanoma cells lower than 20 μg / mL. Among them, 1b and 1k had the best effects.

[0093] In summary, the present invention modifies the amide group on the benzothiazole skeleton and splices it with amino acid fragments. On this basis, a series of acylhydrazone and acylhydrazide derivatives are designed and synthesized, and the anti-tumor activity of the derivatives is verified, thereby providing more candidate compounds for the development of new drugs.

Claims

1. Use of a benzothiazole derivative in the preparation of an anti-tumor drug, wherein the structure of the benzothiazole derivative is as follows: ， The tumor is melanoma.

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