CN118063434A

CN118063434A - 3- (Indole-3-seleno) benzamide compound and synthetic method and application thereof

Info

Publication number: CN118063434A
Application number: CN202410120276.7A
Authority: CN
Inventors: 侯卫; 庞嘉成; 王鸿; 杨志昆; 罗迪升
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2024-01-29
Filing date: 2024-01-29
Publication date: 2024-05-24

Abstract

The invention discloses a 3- (indole-3-seleno) benzamide compound and a synthesis method and application thereof, wherein the 3- (indole-3-seleno) benzamide compound has good biological activity, and a cancer cell strain showing drug resistance shows obvious sensitization effect when being combined with an anti-tumor drug under the condition of single drug administration without cytotoxicity concentration, can be used as a P-gp inhibitor or tumor multi-drug resistance reversal agent and a biological probe with good tumor metastasis inhibitor or biological inclusion property, and expands the application prospect of a selenium-containing micromolecular structure in the aspect of tumor multi-drug resistance reversal agent.

Description

3- (Indole-3-seleno) benzamide compound and synthetic method and application thereof

Field of the art

The invention belongs to the fields of pharmaceutical chemistry synthesis and pharmacotherapeutics, and in particular relates to a 3- (indole-3-seleno) benzamide compound, a preparation method and application thereof.

(II) background art

Multidrug resistance (Multidrug Resistance, MDR) is a serious problem in the course of chemotherapy of malignant tumors. The multidrug resistance protein P-gp (P-glycoprotein, ABCB1, MDR 1) is one of the major mechanisms responsible for MDR over-expression on tumor cells as a member of the family of ATP-binding transporters. Inhibition of P-gp is a common method for reversing MDR and is one of the research hotspots in the process of overcoming malignant tumor MDR. However, the first-generation P-gp inhibitors still have problems such as poor selectivity, insufficient inhibitory activity, high toxicity, and effects on the pharmacokinetics of chemotherapeutic drugs.

(III) summary of the invention

The invention aims to provide a 3- (indole-3-seleno) benzamide compound, and preparation and application thereof, wherein the compound has good biological activity, has excellent MDR reversing effect and can enhance the sensitivity of malignant tumor cells to an antitumor drug doxorubicin hydrochloride, can be used for developing and utilizing drugs for treating malignant tumor cell multidrug resistance caused by P-gp protein, and is expected to become a potential P-gp inhibitor for treating MDR. To explore the effect of different terminal aromatic rings on the drug effect, we selected 3 reported more structures of 3, 4-dimethoxy tetrahydroisoquinoline, 3, 4-dimethoxy aniline and pyridine-2-methylamine for incorporation. In addition, we have studied the effect of the substitution positions (ortho, meta and para) of indole selenides on the benzene ring on activity, which is of great importance for the geometry of the regulator molecule.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

In a first aspect, the present invention provides a 3- (indol-3-seleno) benzamide compound of formula i:

r ₁ is selected from one of the following: H. halogen, halogen, Wherein Y is C ₁～C₁₀ alkyl, phenyl substituted by halogen or C ₁～C₄ alkoxy, or- (CH ₂)_n-N-(CH₃)₂), wherein n is an integer between 1 and 4.

R ₂ is selected from one of the following:

r ₃ is H or

Further, R ₁ is H, fluorine orWherein Y is methyl, isopropyl, phenyl substituted by fluorine or methoxy or- (CH ₂)₂-N-(CH₃)₂).

Preferably, the R ₁ is hydrogen, 5-fluoro, 7-azaindolyl,

More preferably

In particular, 3- (indol-3-seleno) benzamide compounds of formula I are recommended to be one of the following:

In a second aspect, the present invention also provides a method for preparing two of the 3- (indol-3-seleno) benzamide compounds, scheme 1 is used to examine the effect of substituted indoles on biological activity, scheme 2 is used to examine the effect of amines on biological activity, and all compounds can be prepared by using scheme 1 or 2.

The method of scheme 1 includes the steps of:

S1, adding a compound shown in a formula II and an alkaline substance into an organic solvent A (at-20-0 ℃) (preferably-10 ℃), dropwise adding a 3-nitrobenzoyl chloride solution, and reacting at 20-40 ℃ for 1-4 hours (preferably 25 ℃ for 2 hours) after dropwise adding, and purifying and separating the obtained reaction solution A to obtain an intermediate shown in a formula III; the mol ratio of the compound shown in the formula II, the alkaline substance and the 3-nitrobenzoyl chloride contained in the 3-nitrobenzoyl chloride solution is 1:1-3:1-1.5 (preferably 1:3:1);

R₂-HII

S2: the intermediate shown in the formula III in the step S1 is subjected to reduction reaction for 12-16 h (preferably, the reduction reaction is carried out for 12h at 25 ℃ C.) at 20-40 ℃ under the action of Pd/C catalyst in hydrogen atmosphere and organic solvent B, and the obtained reaction solution B is purified and separated to obtain a compound shown in the formula IV; the mol ratio of the intermediate shown in the formula III to Pd supported on the Pd/C catalyst is 1:0.1-0.5 (preferably 1:0.3);

S3: adding the compound shown in the formula IV in the step S2 and hydrochloric acid into water, dropwise adding an aqueous solution of sodium nitrite at-5 ℃ (preferably 0 ℃), adjusting the pH to 5.5-6 after the dropwise adding, adding an aqueous solution of potassium selenocyanate and sodium bicarbonate, heating to 40-60 ℃ (preferably 55 ℃), reacting for 0.5-1.5 hours (preferably 1 hour), and separating and purifying the obtained reaction solution C to obtain an intermediate shown in the formula V; the molar ratio of potassium selenocyanate in the compound shown in the formula IV, HCl contained in hydrochloric acid, sodium nitrite contained in the aqueous solution of sodium nitrite, potassium selenocyanate and sodium bicarbonate to sodium bicarbonate in the aqueous solution of potassium selenocyanate and sodium bicarbonate is 1:5-8:1-1.5:1-1.5:0.1-0.3 (preferably 1:5.7:1:1:0.25);

in the embodiment of the invention, the slow temperature rising process due to diazotization is to raise the temperature to the room temperature at the room temperature and then to the reaction temperature.

S4: in the step S3, the intermediate shown in the formula V and the compound shown in the formula VI are stirred and reacted for 3-8 hours at 50-120 ℃ in the presence of a catalyst (preferably, the stirring and the reaction are carried out for 3-8 hours at 80-100 ℃ and particularly preferably, the stirring and the reaction are carried out for 3 hours at 100 ℃), and the obtained reaction solution D is purified and separated to obtain the compound shown in the formula I; the catalyst is tris (pentafluorophenyl) borane or cuprous iodide (preferably cuprous iodide); the molar ratio of the intermediate shown in the formula V, the compound shown in the formula VI and the catalyst is 1:1-1.5:0.001-0.1 (preferably 1:1.2:0.1);

The substituents are as defined above.

Further, the organic solvent A in the step S1, the solvent of the 3-nitrobenzoyl chloride solution, the organic solvent B in the step S2 and the organic solvent C in the step S4 are respectively and independently selected from one or a mixture of more than two of the following: benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, 1, 2-dichloroethane, chloroform, carbon tetrachloride, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acetone, butanone, methyl isobutyl ketone, acetonitrile, propionitrile, butyronitrile, N-dimethylformamide, N-dimethylacetamide, N-methyl-formanilide, N-methylpyrrolidone, hexamethylphosphoric triamide, methyl acetate, ethyl acetate, dimethyl sulfoxide, methanol, ethanol, N-propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether. Preferably, the solvent of the organic solvent A, 3-nitrobenzoyl chloride solution is methylene dichloride, the organic solvent B is 1, 2-dichloroethane, and the organic solvent C is 1, 2-dichloroethane.

Furthermore, the volume of the organic solvent A in the step S1 is 1 to 5mL/mmol, preferably 2mL/mmol, based on the amount of the compound represented by the formula II.

Further, the concentration of the 3-nitrobenzoyl chloride solution in the step S1 is 0.5-2.5mmol/mL, and in the embodiment of the invention is 0.5mmol/mL.

Further, the basic substance in the step S1 is one or more than two of pyridine, N-diisopropylethylamine, N-dimethylaniline, N-dimethylbenzylamine, N-methylpiperidine, N-methylmorpholine, N-dimethylaminopyridine, diazabicyclooctane, diazabicyclononene or diazabicycloundecene, sodium hydroxide, sodium ethoxide, trimethylamine or triethylamine; preferably triethylamine.

In the embodiment of the invention, the separation and purification A in the step S1 is as follows: the reaction solution A was concentrated under reduced pressure, and the residue was obtained in a volume ratio of 200:1 of methylene chloride: purifying with silica gel column chromatography (200-300 mesh silica gel, column height of 10cm, diameter of 2 cm) with methanol as eluent, collecting eluent containing target compound, and evaporating solvent to obtain intermediate shown in formula III.

Further, the volume of the organic solvent B in the step S2 is 1 to 5mL/mmol in terms of the amount of the substance of the compound represented by the formula III, and is 4mL/mmol in one embodiment of the present invention.

Further, the active material loading of the Pd/C catalyst in step S2 is 3-10%, and in the embodiment of the present invention, 10%.

In the embodiment of the present invention, the separation and purification step S2 is as follows: the reaction solution B was filtered through celite, the filtrate was concentrated under reduced pressure, and the residue was obtained in the volume ratio of 120:1 of methylene chloride: and (3) performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain the compound shown in the formula IV.

Further, the concentration of the hydrochloric acid in the step S3 is 10-12mol/L, and in the embodiment of the invention, 12mol/L.

Further, the concentration of the aqueous solution of sodium nitrite in the step S3 is 0.5 to 1mol/L, and in the embodiment of the present invention, 1mol/L.

Further, in the step S3, weak base is used for adjusting the pH, and the pH is one or a mixture of two of sodium acetate, potassium carbonate and sodium carbonate, preferably sodium acetate.

Further, in the aqueous solution containing potassium selenocyanate and sodium bicarbonate in the step S3, the concentration of potassium selenocyanate is 1-3mol/L, 2.5mol/L in the embodiment of the invention, and the concentration of sodium bicarbonate aqueous solution is 0.5-1mol/L, and 0.6mol/L in the embodiment of the invention.

Further, the volume of water in step S3 is 1-5mL/mmol, in one embodiment of the invention 2.4mL/mmol, based on the amount of the compound of formula IV.

In the embodiment of the present invention, the separation and purification step S3 is as follows: the reaction solution C was extracted with methylene chloride, the organic layers were combined, washed with saturated brine (2 times), dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure, and the resulting residue was taken up in a volume ratio of 200:1 methylene chloride: and (3) performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain an intermediate shown in a formula V.

Further, the volume of the organic solvent C in the step S4 is 1-7mL/mmol in terms of the amount of the intermediate of formula V, and is 6.7mL/mmol in one embodiment of the present invention.

In the embodiment of the present invention, the separation and purification step S4 is as follows: the reaction solution D was concentrated under reduced pressure, and the resulting residue was petroleum ether in a volume ratio of 3:1: purifying with silica gel column chromatography (200-300 mesh silica gel, column height 10cm, diameter 2 cm) with ethyl acetate as eluent, collecting eluent containing target compound, and evaporating solvent to obtain compound shown in formula I.

The method of route 2 includes the steps of:

(1) Adding 3-methyl aminobenzoate and hydrochloric acid into water, dropwise adding an aqueous solution of sodium nitrite at-5 ℃ (preferably 0 ℃), adjusting the pH to 5.5-6 after the dropwise addition, adding an aqueous solution of potassium selenocyanate and sodium bicarbonate, heating to 40-60 ℃ (preferably 55 ℃) (slowly) and reacting for 0.5-1.5 hours (preferably 1 hour), and separating and purifying the obtained reaction solution E to obtain an intermediate shown in a formula VII; the molar ratio of potassium selenocyanate in the aqueous solution of sodium nitrite, potassium selenocyanate and sodium bicarbonate contained in the aqueous solution of sodium nitrite, HCl contained in hydrochloric acid and 3-aminobenzoate to sodium bicarbonate in the aqueous solution of potassium selenocyanate and sodium bicarbonate is 1:5-8:1-1.5:1-1.5:0.1-0.3 (preferably 1:5.7:1:1:0.25);

(2) The intermediate shown in the formula VII and the compound shown in the formula VI in the step (1) react for 3-8 h (preferably for 6h at 55 ℃ under stirring) at 50-100 ℃ in the presence of a catalyst in an organic solvent D, and the obtained reaction solution F is purified and separated to obtain the compound shown in the formula VIII; the catalyst is tris (pentafluorophenyl) borane or cuprous iodide (preferably tris (pentafluorophenyl) borane); the molar ratio of the intermediate shown in the formula VII, the compound shown in the formula VI and the catalyst is 1:1-1.5:0.001-0.1 (preferably 1:1.2:0.1);

(3) Stirring the compound shown in the formula VIII in the step (2) in an organic solvent E, adding an aqueous solution of an alkaline substance, stirring and reacting for 4-8 hours at 20-40 ℃ (preferably stirring and reacting for 6 hours at 25 ℃), removing the organic solvent under reduced pressure, adjusting the pH value to 2-3 (concentrated hydrochloric acid), filtering, and drying the obtained filter cake to obtain the compound shown in the formula IX; the molar ratio of the compound shown in the formula VIII to the alkaline substance in the aqueous solution of the alkaline substance is 1:50-60 (preferably 1:57);

(4) In the step (3), the compound shown in the formula IX and the compound shown in the formula II react in an organic solvent F at 20-40 ℃ for 1-4h (preferably at 25 ℃ for 4 h) under the action of an alkaline substance, a catalyst and a condensing agent, and the obtained reaction solution G is purified and separated to obtain the compound shown in the formula I; the catalyst is 4-dimethylaminopyridine; the condensing agent is one or more than two of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole, 2- (7-azabenzotriazol) -N, N, N ', N' -tetramethylurea hexafluorophosphate, O-benzotriazol-N, N, N ', N' -tetramethylurea tetrafluoroboric acid, triphenylphosphine-polyhalogenated methane, triphenylphosphine-hexachloroacetone, triphenylphosphine-NBS, 3-acyl-2-thiothiazoline (preferably 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride); the molar ratio of the compound shown in the formula IX, the compound shown in the formula II, the alkaline substance, the catalyst and the condensing agent is 1:1-1.5:1-3:0.1:1-1.5, preferably 1:1.2:3:0.1:1.5;

R₂-HII

the substituents in the above formula are as defined above.

All of the above intermediates or target compounds may be purified by conventional separation techniques such as recrystallization or chromatographic separation.

Further, the concentration of the hydrochloric acid in the step (1) is 10-12mol/L, and in the embodiment of the invention, 12mol/L.

Further, the concentration of the aqueous sodium nitrite solution in the step (1) is 0.5 to 1mol/L, and in the embodiment of the present invention, 1mol/L.

Further, in the step (1), weak base is used for adjusting the pH, and the pH is one or a mixture of two of sodium acetate, potassium carbonate and sodium carbonate, preferably sodium acetate.

Further, in the aqueous solution containing potassium selenocyanate and sodium bicarbonate in the step (1), the concentration of the potassium selenocyanate is 1-3mol/L, 2.5mol/L in the embodiment of the invention, and the concentration of the aqueous solution of sodium bicarbonate is 0.5-1mol/L, and 0.6mol/L in the embodiment of the invention.

Further, the volume of water in step (1) is 1-5mL/mmol, in one embodiment of the invention 2.4mL/mmol, based on the amount of the compound of formula IV.

In an embodiment of the present invention, the separation and purification E in step (1) is: the reaction solution E was extracted with methylene chloride, the organic layers were combined, washed with saturated brine (2 times), dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure, and the resulting residue was taken up in a volume ratio of 200:1 methylene chloride: and (3) performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain an intermediate shown in a formula VII.

In the steps (2) to (4) of the present invention, the diluents may be the same or different, and the organic solvent D in the step (2), the organic solvent E in the step (3) and the organic solvent F in the step (4) are each independently selected from one or a mixture of two or more of the following: benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, methylene chloride, 1, 2-dichloroethane, chloroform, carbon tetrachloride, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acetone, butanone, methyl isobutyl ketone, acetonitrile, propionitrile, butyronitrile, N-dimethylformamide, N-dimethylacetamide, N-methyl-formanilide, N-methylpyrrolidone, hexamethylphosphoric triamide, methyl acetate, ethyl acetate, dimethyl sulfoxide, methanol, ethanol, N-propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether or diethylene glycol monoethyl ether. Preferably, the organic solvent D in the step (2) is 1, 2-dichloroethane, the organic solvent E in the step (3) is tetrahydrofuran, and the organic solvent F in the step (4) is dichloromethane.

Further, the volume of the organic solvent D in the step (2) is 1 to 7mL/mmol in terms of the amount of the substance of the intermediate represented by the formula VII, and 4mL/mmol in one embodiment of the present invention.

In an embodiment of the present invention, the separation and purification F in the step (2) is: the reaction solution F was concentrated under reduced pressure, and the residue was petroleum ether in a volume ratio of 3:1: purifying with silica gel column chromatography (200-300 mesh silica gel, column height of 10cm, diameter of 2 cm) with ethyl acetate as eluent, collecting eluent containing target compound, and evaporating solvent to obtain compound shown in formula VIII.

Further, in the aqueous solution of the alkaline substance in the step (3), the alkaline substance is one or a mixture of more than two of potassium hydroxide, lithium hydroxide and sodium hydroxide, preferably sodium hydroxide.

Further, the concentration of the aqueous alkaline substance solution in the step (3) is 1 to 3mol/L, preferably 2.9mol/L.

Further, the volume of the organic solvent E in the step (3) is 1 to 15mL/mmol in terms of the amount of the substance of the compound represented by the formula VIII, and 10mL/mmol in one embodiment of the present invention.

Further, the alkaline substance in the step (4) is one or a mixture of more than two of pyridine, N-diisopropylethylamine, N-dimethylaniline, N-dimethylbenzylamine, N-methylpiperidine, N-methylmorpholine, N-dimethylaminopyridine, diazabicyclooctane, diazabicyclononene or diazabicycloundecene, sodium hydroxide, sodium ethoxide, trimethylamine and triethylamine. Preferably triethylamine or N, N-diisopropylethylamine, particularly preferably N, N-Diisopropylethylamine (DIPEA).

Further, the volume of the organic solvent F in the step (4) is 1 to 15mL/mmol in terms of the amount of the substance of the intermediate represented by the formula IX, and 15mL/mmol in one embodiment of the present invention.

In an embodiment of the present invention, the separation and purification G in step (4) is: the reaction solution G was concentrated under reduced pressure, and the residue was obtained in a volume ratio of 150:1 of methylene chloride: and (3) performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain the compound shown in the formula I.

In a third aspect, the invention also provides application of the 3- (indole-3-seleno) benzamide compound in preparation of a multi-drug resistant protein P-gp inhibitor.

Preferably, the 3- (indole-3-seleno) benzamide compound is one or a mixture of more than two of compounds I-1, I-13, I-14, I-15 and I-16, and particularly preferably I-13.

In a fourth aspect, the invention also provides an application of the 3- (indole-3-seleno) benzamide compound in preparing a tumor multi-drug resistance reversal agent or a tumor metastasis inhibitor.

The tumor multidrug resistance or the tumor metastasis is caused by the overexpression of the multidrug resistance protein P-gp.

In an embodiment of the invention, the tumor comprises human breast cancer doxorubicin-resistant cell line MCF-7/ADR. The inhibitors also include pharmaceutically acceptable salts.

Further, the invention provides a medicament for preventing or treating multidrug resistant tumors, which comprises the 3- (indole-3-seleno) benzamide compound and an anti-tumor medicament.

Further, the antitumor drug is one or a mixture of more than two antitumor drugs (clinical chemotherapeutics) such as alkylating agents (such as cyclophosphamide or cisplatin), antimetabolites (such as 5-fluorouracil or hydroxyurea), topoisomerase inhibitors (such as camptothecine or topotecan), cell microtubule inhibitors (such as paclitaxel or vinblastine), DNA intercalators (such as doxorubicin or daunorubicin), lysine kinase inhibitors (such as gefitinib) and the like. The sensitivity of the multidrug resistant tumor cells to the antitumor drugs is enhanced by the combined treatment with the antitumor drugs, thereby improving the chemotherapeutic effect. In an embodiment of the invention, the anti-tumor drug is doxorubicin.

Compared with the prior art, the invention has the following beneficial effects:

The invention provides a 3- (indole-3-seleno) benzamide compound, which is simple in preparation method and high in yield. The 3- (indole-3-seleno) benzamide compound has good biological activity, and a cancer cell strain showing drug resistance shows obvious sensitization effect when being combined with an anti-tumor drug under the concentration of no cytotoxicity when being independently used, can be used for a P-gp inhibitor or a tumor multi-drug resistance reversing agent and a tumor metastasis inhibitor or a biological probe with good biological inclusion property, and expands the application prospect of a selenium-containing micromolecular structure in the aspect of the tumor multi-drug resistance reversing agent. The combined use of the 3- (indole-3-seleno) benzamide compound and the doxorubicin hydrochloride can effectively improve the drug effect of the doxorubicin hydrochloride on the doxorubicin-resistant cell line (MCF-7/ADR) of human breast cancer.

(IV) description of the drawings

FIG. 1 shows the calculation of P-gp protein expression levels (A, B) relative to the relative expression of beta-tubulin by treating MCF-7 and MCF-7/ADR cells with 0.5, 2.5, 5.0. Mu.M I-13. Effect of compound i-13 on P-gp mediated accumulation of rhodamine 123 in MCF-7/ADR cells (a) 10.0 μm verapamil or 0.1, 1.0, 10.0 μm i-13 treatment of fluorescent images of rhodamine 123; (B, C) fluorescence intensity of rhodamine 123 in MCF-7/ADR cells. Data are expressed as mean ± SD of three independent experiments. * P <0.001, (/ p <0.01, (/) p < 0.05). Data are expressed as mean ± SD of three independent experiments. * P <0.001 is considered statistically significant.

FIG. 2 shows the calculation of P-gp protein expression levels (A, B) relative to the relative expression of beta-tubulin by treating MCF-7 and MCF-7/ADR cells with 0.5, 2.5, 5.0. Mu.M I-13. Data are expressed as mean ± SD of three independent experiments. * P <0.001 is considered statistically significant.

(Fifth) detailed description of the invention

The present invention will be further illustrated with reference to the following specific examples, which are not intended to limit the present invention in any way. Unless otherwise indicated, all reagents and methods described in the examples are those commonly used in the art.

The room temperature of the invention is 25-30 ℃.

Route 1:

this route is used to prepare compounds I-1 to I-7.

Example 1 preparation of (6, 7-dimethoxy-3, 4-dihydroisoquinolin-2 (1H) -yl) (3- ((5-fluoro-1H-indol-3-yl) selenalkyl) phenyl) methanone (I-1)

S1, adding 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (II) (2.88 g,15.00 mmol), triethylamine (6.26 mL,45.00 mmol) and 30mL of dichloromethane into a round bottom flask, stirring and cooling to-10 ℃, dropwise adding 3-nitrobenzoyl chloride (2.79 g,15.00 mmol) dissolved in dichloromethane (30 mL), controlling the dropwise adding speed to keep the temperature at-10 ℃, slowly rising to room temperature after dropwise adding, reacting for 2 hours at 25 ℃, concentrating the solvent under reduced pressure, purifying the residue by silica gel column chromatography (silica gel 200-300 meshes, column height 10cm, diameter 4 cm), and dichloromethane with the volume ratio of 200:1: methanol is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 50:1 dichloromethane: thin layer chromatography monitoring is carried out by taking methanol as developing agent, and effluent with Rf of 0.5 is collected, and after solvent is distilled off, intermediate (4.41 g,11.25mmol, yield 75%) shown in yellow solid formula III, namely (6, 7-dimethoxy-3, 4-dihydro-isoquinolin-2 (1H) -yl) (3-nitrophenyl) methanone is obtained and used for the next reaction.

S2, (6, 7-dimethoxy-3, 4-dihydroisoquinolin-2 (1H) -yl) (3-nitrophenyl) methanone (III) (3.9 g,10.00 mmol), 10% Pd/C (318 mg,3 mmol) and 40mL of methylene chloride were sequentially added to a round bottom flask, reacted under a hydrogen atmosphere (1 atm) at 25℃for 12 hours, the mixture was filtered over celite, the filtrate obtained was concentrated under reduced pressure, and the residue was purified on silica gel (silica gel 200-300 mesh, column height 10cm, diameter 4 cm) in a volume ratio of 120:1: methanol is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 30:1 dichloromethane: thin layer chromatography monitoring is carried out by taking methanol as developing agent, and effluent with Rf of 0.5 is collected, and solvent is distilled off to obtain yellow oily intermediate (2.65 g,8.50mmol, yield 85%) shown in formula IV, namely (3-aminophenyl) (6, 7-dimethoxy-3, 4-dihydro-isoquinolin-2 (1H) -yl) methanone, which is used for the next reaction.

S3, (3-aminophenyl) (6, 7-dimethoxy-3, 4-dihydroisoquinolin-2 (1H) -yl) methanone (IV) (1.56 g,5.0 mmol), concentrated hydrochloric acid (2.3 mL,28.80 mmol) and 12mL of water are added to a round-bottomed flask, the mixture is cooled to 0℃by ice bath, an aqueous solution of sodium nitrite (0.35 g,5.0mmol,5 mL) is added dropwise, the dropwise acceleration is controlled so that the temperature is maintained at 0℃and the dropwise addition is completed, sodium acetate is added to adjust the pH to 5.5-6, and an aqueous solution (2 mL) of potassium selenocyanate (0.72 g,5.0 mmol) and sodium hydrogencarbonate (0.11 g,1.25 mmol) is added. After stirring at room temperature for 30 minutes, the mixture was warmed to 55℃and reacted for 1 hour. The mixture was extracted several times with dichloromethane, the organic layers were combined, washed 2 times with saturated brine, dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified on silica gel (silica gel 200-300 mesh, column height 10cm, diameter 2 cm), dichloromethane in a volume ratio of 200:1: methanol is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 50:1 dichloromethane: thin layer chromatography monitoring is carried out by taking methanol as developing agent, and effluent with Rf of 0.5 is collected, and solvent is distilled off to obtain intermediate (0.88 g,2.2mmol, yield 44%) shown in yellow solid formula V, namely (6, 7-dimethoxy-3, 4-dihydro-isoquinolin-2 (1H) -yl) (3-selenocyanophenyl) methanone, which is used for the next reaction.

S4, (6, 7-dimethoxy-3, 4-dihydroisoquinolin-2 (1H) -yl) (3-selenocyanophenyl) methanone (V) (60 mg,0.15 mmol), 5-fluoroindole (VI) (24 mg,0.18 mmol), cuprous iodide (2.9 mg,0.015 mmol) and 1mL of 1, 2-dichloroethane were sequentially added to the test tube, the mixture was stirred at 100℃for 3 hours, the solvent was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (silica gel 200-300 mesh, column height 10cm, diameter 2 cm), petroleum ether in a volume ratio of 5:1: ethyl acetate is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 2: petroleum ether of 1: thin layer chromatography monitoring with ethyl acetate as developing agent, collecting effluent with Rf of 0.4, and evaporating solvent to obtain white solid formula I-1 (47 mg,0.09mmol, yield 61%), namely (6, 7-dimethoxy-3, 4-dihydroisoquinolin-2 (1H) -yl) (3- ((5-fluoro-1H-indol-3-yl) seleno) phenyl) methanone .¹H NMR(500MHz,DMSO-d₆)δ11.64(s,1H),7.78(s,1H),7.52(dd,J＝9.0,4.5Hz,1H),7.36(d,J＝8.0Hz,1H),7.29(t,J＝7.5Hz,1H),7.19(d,J＝7.5Hz,1H),7.16(s,1H),7.12(dd,J＝9.5,2.5Hz,1H),7.01(td,J＝9.0,2.5Hz,1H),6.67(s,2H),4.46(s,2H),3.75(s,3H),3.71(s,3H),3.47(s,2H),2.60-2.46(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.30,157.46(d,J＝232.5Hz),147.55(d,J＝3.3Hz),136.69,134.34,133.41,133.07,129.91,129.82,129.87(d,J＝10.0Hz),125.86(d,J＝14.5Hz),124.60,124.01,113.02(d,J＝9.5Hz),112.48,110.31,110.07,109.86,103.26,103.07,94.81(d,J＝4.8Hz),55.57,55.56,27.28.

Route 2:

This route is used to prepare compounds I-8 to I-21.

Example 2 preparation of 3- ((1H-indol-3-yl) seleno-alkyl) -N- (3, 4-dimethoxyphenyl) benzamide (I-8)

(1) To a round bottom flask was added methyl 3-aminobenzoate (755 mg,5.0 mmol), concentrated hydrochloric acid (2.3 mL,28.8 mmol) and 12mL of water, the mixture was cooled to 0℃in an ice bath, an aqueous solution of sodium nitrite (345 mg,5.0mmol,5 mL) was added dropwise, the dropping speed was controlled to maintain the temperature at 0℃and sodium acetate was added to adjust the pH to 5.5-6, and an aqueous solution (2 mL) of potassium selenocyanate (720 mg,5.0 mmol) and sodium hydrogencarbonate (105 mg,1.25 mmol) was added. After stirring at room temperature for 30 minutes, the mixture was warmed to 55℃and reacted for 1 hour. The mixture was extracted several times with dichloromethane, the organic layers were combined, washed 2 times with saturated brine, dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified on silica gel (silica gel 200-300 mesh, column height 10cm, diameter 2 cm), dichloromethane in a volume ratio of 200:1: methanol is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 50:1 dichloromethane: thin layer chromatography monitoring is carried out by taking methanol as developing agent, and effluent with Rf of 0.4 is collected, and after solvent is distilled off, yellow solid intermediate (411 mg,1.7mmol, yield 34%) shown in formula VII is obtained, namely 3-selenium cyano methyl benzoate, which is used for the next reaction.

(2) Methyl 3-selenocyanobenzoate (VII) (241 mg,1.0 mmol), indole (VI) (140 mg,1.2 mmol), tris (pentafluorophenyl) borane (51 mg,0.1 mmol) and 1, 2-dichloroethane (4 mL) were added sequentially to a test tube, the mixture was stirred at 55℃for 6h, the solvent was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (silica gel 200-300 mesh, column height 10cm, diameter 2 cm), petroleum ether in a volume ratio of 3:1: ethyl acetate is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 1: petroleum ether of 1: thin layer chromatography monitoring is carried out by using ethyl acetate as developing agent, effluent with Rf of 0.3 is collected, and after solvent is distilled off, intermediate (228 mg,0.69mmol yield 69%) shown in brown solid formula VIII is obtained, namely 3- ((1H-indol-3-yl) seleno) methyl benzoate which is used for the next reaction.

(3) Methyl 3- ((1H-indol-3-yl) seleno) benzoate (VIII) (165 mg,0.5 mmol) and 5mL tetrahydrofuran are added to a round bottom flask, aqueous sodium hydroxide solution (1144 mg,28.6mmol,10 mL) is added with stirring, stirring is performed for 6H at room temperature, tetrahydrofuran is removed under reduced pressure, concentrated hydrochloric acid is used to adjust the pH of the solution to 2-3, the residue is filtered and dried to give the compound of formula IX, 3- ((1H-indol-3-yl) seleno) benzoic acid, which can be used directly in the next reaction.

(4) 3- ((1H-indol-3-yl) seleno) benzoic acid (IX) (63 mg,0.2 mmol), EDCI (58 mg,0.3 mmol), DMAP (2.4 mg,0.02 mmol), 3, 4-dimethoxyaniline (II) (37 mg,0.24 mmol) and 3mL of dichloromethane were added successively to a round-bottomed flask, DIPEA (0.1 mL,0.6 mmol) was added with stirring, the reaction was carried out at room temperature for 4H, the solvent was concentrated under reduced pressure, and the residue was purified by column chromatography on silica gel (200-300 mesh, column height 10cm, diameter 2 cm), dichloromethane in a volume ratio of 150:1: methanol is used as eluent, the elution speed is 1/10 column reserved volume flowing out per minute, and 3 column volumes are eluted, and the volume ratio is 30:1 dichloromethane: thin layer chromatography monitoring with methanol as developing agent, collecting effluent with Rf of 0.4, and evaporating solvent to obtain pale yellow solid formula I-8 (64 mg,0.14mmol, yield 71%), namely 3- ((1H-indol-3-yl) seleno-alkyl) -N- (3, 4-dimethoxy phenyl) benzamide .¹H NMR(400MHz,DMSO-d₆)δ11.73(s,1H),10.08(s,1H),7.81(d,J＝10.0Hz,2H),7.69(d,J＝7.6Hz,1H),7.55-7.36(m,3H),7.34-7.22(m,3H),7.19(s,1H),7.08(s,1H),6.90(d,J＝8.8Hz,1H),3.74(s,6H).¹³C NMR(150MHz,DMSO-d₆)δ164.48,148.38,145.17,136.67,135.75,134.25,133.01,132.52,130.85,129.39,128.99,127.21,124.74,122.08,120.12,118.91,112.27,112.20,111.83,105.46,94.64,55.69,55.37.

R ₁、R₂ and R ₃ in the compounds of formula II and formula VI are replaced by the corresponding compounds of formula I in a similar manner to examples 1 and 2.

The procedure described in example 1 was followed, except that formula VI was N-methyl-1H-indole-5-carboxamide (31 mg,0.18 mmol) and tris (pentafluorophenyl) borane (7.6 mg,0.015 mmol) was used as the catalyst to give I-2 as a pale yellow solid (40 mg, 48% yield, purity in liquid phase 99％).¹H NMR(500MHz,DMSO-d₆)δ11.77(s,1H),8.12(q,J＝4.5Hz,1H),8.06(d,J＝1.5Hz,1H),7.77(d,J＝2.0Hz 1H),7.74(dd,J＝8.5,1.5Hz,1H),7.54(d,J＝8.5Hz,1H),7.38(d,J＝8.0Hz,1H),7.29(t,J＝7.5Hz,1H),7.18(dt,J＝7.5,1.5Hz,1H),7.13(s,1H),6.66(s,2H),4.45(s,2H),3.75(s,3H),3.71(s,3H),3.45(s,2H),2.80(d,J＝4.5Hz,3H),2.51-2.40(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.43,167.19,147.62,147.57,137.96,136.72,133.89,133.84,129.06,128.85,128.82,126.94,125.90,125.71,124.63,123.98,121.18,118.39,112.53,111.40,110.39,95.90,55.65,27.33,25.86.

According to the method described in example 1, except that pyridine-2-methylamine (1.62 g,15.00 mmol) of formula II and N-methyl-1H-indole-5-carboxamide (31 mg,0.18 mmol) of formula VI, I-3 (45 mg, 65% yield, purity in liquid phase) was obtained as a white solid 99％).¹H NMR(400MHz,DMSO-d₆)δ11.94(s,1H),9.09(t,J＝6.0Hz,1H),8.49(d,J＝4.0Hz,1H),8.35(q,J＝4.4Hz,1H),8.01(d,J＝1.6Hz,1H),7.81(d,J＝2.0Hz,1H),7.75-7.68(m,3H),7.67(dt,J＝7.2,1.6Hz,1H),7.52(d,J＝8.4Hz,1H),7.32-7.21(m,4H),4.51(d,J＝6.0Hz,2H),2.75(d,J＝4.4Hz,3H).¹³C NMR(125MHz,DMSO-d₆)δ167.23,165.78,158.58,148.78,138.13,136.66,134.96,134.54,134.20,130.69,129.11,129.04,127.04,126.86,124.49,122.02,121.40,120.80,118.67,111.72,95.80,44.63,26.26.

According to the method described in example 1, except that pyridine-2-methylamine (1.62 g,15.00 mmol) of formula II and N-methyl-1H-indole-7-carboxamide (31 mg,0.18 mmol) of formula VI, I-4 (34 mg, yield 49% liquid phase purity) was obtained as a white solid 99％).¹H NMR(400MHz,DMSO-d₆)δ12.01(d,J＝2.4Hz,1H),9.09(t,J＝6.0Hz,1H),8.49(dt,J＝4.0,2.0Hz,1H),8.39(q,J＝4.4Hz,1H),8.02(d,J＝1.2Hz,1H),7.92(d,J＝2.4Hz,1H),7.81(t,J＝1.6Hz,1H),7.72(td,J＝7.6,2.0Hz,1H),7.67(dt,J＝6.8,2.0Hz,1H),7.58(dd,J＝8.4,1.6Hz,1H),7.43(d,J＝8.4Hz,1H),7.31-7.21(m,4H),4.51(d,J＝6.0Hz,2H),2.80(d,J＝4.4Hz,3H).¹³C NMR(125MHz,DMSO-d₆)δ167.28,165.77,158.58,148.79,136.65,136.10,135.30,134.97,133.93,131.42,130.91,129.08,128.76,127.26,124.57,122.02,120.82,119.10,118.40,111.75,94.96,44.63,26.32.

The procedure described in example 1 was followed, except that formula VI was N- (4-fluorophenyl) -1H-indole-5-carboxamide (46 mg,0.18 mmol) and catalyst was tris (pentafluorophenyl) borane (7.6 mg,0.015 mmol) to give I-5 as a yellow solid (61 mg, 65% yield, purity in liquid phase 99％).1H NMR(500MHz,DMSO-d₆)δ11.87(s,1H),10.06(s,1H),8.20(d,J＝1.5Hz,1H),7.88(dd,J＝8.5,1.5Hz,1H),7.82(s,1H),7.81-7.73(m,2H),7.61(d,J＝8.5Hz,1H),7.40(d,J＝8.0Hz,1H),7.30(t,J＝7.5Hz,1H),7.22-7.08(m,4H),6.73-6.61(m,2H),4.46(s,2H),3.74(s,3H),3.69(s,3H),3.45(s,2H),2.50-2.41(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.35,165.77,158.87,156.96,147.56,147.53,138.25,136.74,135.49,135.47,134.14,133.73,129.09,128.83,126.80,125.84,124.59,123.98,122.17,122.10,121.56,119.12,114.54,114.36,112.47,111.52,110.35,96.07,55.58,27.35.

The procedure described in example 1 was followed, except that formula VI was N- (2- (dimethylamino) ethyl) -1H-indole-5-carboxamide (42 mg,0.18 mmol) to give I-6 (36 mg, 38% yield, liquid phase purity as a pale yellow solid 99％).¹H NMR(500MHz,DMSO-d₆)δ11.87(s,1H),10.06(s,1H),8.20(d,J＝1.5Hz,1H),7.88(dd,J＝8.5,1.5Hz,1H),7.82(s,1H),7.81-7.73(m,2H),7.61(d,J＝8.5Hz,1H),7.40(d,J＝8.0Hz,1H),7.30(t,J＝7.5Hz,1H),7.22-7.08(m,4H),6.73-6.61(m,2H),4.46(s,2H),3.74(s,3H),3.69(s,3H),3.45(s,2H),2.50-2.41(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.35,165.77,158.87,156.96,147.56,147.53,138.25,136.74,135.49,135.47,134.14,133.73,129.09,128.83,126.80,125.84,124.59,123.98,122.17,122.10,121.56,119.12,114.54,114.36,112.47,111.52,110.35,96.07,55.58,27.35.

The procedure described in example 1 was followed, except that N-isopropyl-1H-indole-5-carboxamide (36 mg,0.18 mmol) of formula VI was used to give I-7 (48 mg, yield 56% as a pale yellow solid, purity of liquid phase 99％).¹H NMR(500MHz,DMSO-d₆)δ11.74(s,1H),8.04(d,J＝1.5Hz,1H),7.86(d,J＝7.5Hz,1H),7.76(d,J＝2.5Hz,1H),7.74(dd,J＝8.5,1.5Hz,1H),7.50(d,J＝8.5Hz,1H),7.36(d,J＝8.0Hz,1H),7.28(t,J＝7.5Hz,1H),7.17(dt,J＝7.5,1.5Hz,1H),7.12(s,1H),6.65(s,2H),4.45(s,2H),4.11(dp,J＝8.0,6.5Hz,1H),3.74(s,3H),3.70(s,3H),3.44(s,2H),2.51-2.39(m,2H),1.17(d,J＝6.5Hz,6H).¹³C NMR(125MHz,DMSO-d₆)δ168.33,165.85,147.57,147.53,137.85,136.70,133.90,133.81,128.95,128.78,128.73,127.27,125.84,125.71,124.60,123.91,121.28,118.50,112.49,111.15,110.37,95.78,55.60,40.62,27.31,21.95.

The procedure described in example 2 was followed except that pyridine-2-diamine of formula II (26 mg,0.24 mmol) was used to give I-9 as a pale yellow solid (59 mg, 73% yield, purity of liquid phase) 99％).¹H NMR(400MHz,CDCl₃)δ8.95(s,1H),8.51(s,1H),7.79(d,J＝2.0Hz,1H),7.65(td,J＝7.6,2.0Hz,1H),7.58(dd,J＝12.4,8.0Hz,2H),7.55-7.48(m,1H),7.44(d,J＝2.4Hz,1H),7.40(d,J＝8.0Hz,1H),7.32(d,J＝7.6Hz,1H),7.29-7.22(m,2H),7.23-7.12(m,4H),4.67(d,J＝4.8Hz,2H).¹³C NMR(150MHz,CDCl₃)δ167.06,156.02,148.80,136.98,136.49,134.93,134.84,131.72,131.58,129.75,129.03,127.27,124.28,122.91,122.47,122.25,120.86,120.11,111.52,97.43,44.65.

The procedure described in example 2 was followed, except that formula VI was 7-azaindolyl (142 mg,1.2 mmol) to give I-10 as a pale grey solid (24 mg, 29% yield, liquid phase purity) 99％).¹H NMR(400MHz,CDCl₃)δ8.95(s,1H),8.51(s,1H),7.79(d,J＝2.0Hz,1H),7.65(td,J＝7.6,2.0Hz,1H),7.58(dd,J＝12.4,8.0Hz,2H),7.55-7.48(m,1H),7.44(d,J＝2.4Hz,1H),7.40(d,J＝8.0Hz,1H),7.32(d,J＝7.6Hz,1H),7.29-7.22(m,2H),7.23-7.12(m,4H),4.67(d,J＝4.8Hz,2H).¹³C NMR(150MHz,CDCl₃)δ167.06,156.02,148.80,136.98,136.49,134.93,134.84,131.72,131.58,129.75,129.03,127.27,124.28,122.91,122.47,122.25,120.86,120.11,111.52,97.43,44.65.

The process as described in example 2 was followed, except that 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (46 mg,0.24 mmol) of formula II and N- (4-methoxyphenyl) -1H-indole-5-carboxamide (319 mg,1.2 mmol) of formula VI gave I-11 as a white solid (64 mg, yield 50% purity in liquid phase) 99％).¹H NMR(500MHz,DMSO-d₆)δ11.78(s,1H),9.87(s,1H),8.20(d,J＝1.5Hz,1H),7.88(dd,J＝8.5,1.5Hz,1H),7.82(d,J＝2.0Hz,1H),7.69-7.62(m,2H),7.60(d,J＝8.5Hz,1H),7.41(d,J＝8.0Hz,1H),7.30(t,J＝7.5Hz,1H),7.21-7.15(m,2H),6.94-6.87(m,2H),6.71-6.60(m,2H),4.47(s,2H),3.75(d,J＝8.0Hz,6H),3.70(s,3H),3.46(s,2H),2.53-2.44(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.35,165.46,155.26,147.54,147.54,138.12,136.74,134.03,133.75,132.29,129.08,128.82,128.80,127.13,125.83,124.59,123.96,121.95,121.53,119.00,113.43,112.46,111.43,110.34,96.07,55.58,55.56,54.99,54.96,54.94,27.36.

Following the procedure described in example 2, except for N- (4-methoxyphenyl) -1H-indole-5-carboxamide of formula VI (319 mg,1.2 mmol), I-12 (64 mg, 53% yield, purity in liquid phase) was obtained as a white solid 99％).¹H NMR(400MHz,DMSO-d₆)δ12.04(d,J＝2.8Hz,1H),10.09(d,J＝2.8Hz,2H),8.14(d,J＝1.6Hz,1H),7.92(d,J＝2.4Hz,1H),7.88-7.78(m,2H),7.70(dt,J＝7.2,1.6Hz,1H),7.65(d,J＝2.4Hz,2H),7.60(d,J＝8.8Hz,1H),7.42(d,J＝2.4Hz,1H),7.37-7.23(m,3H),6.93-6.84(m,3H),3.75-3.70(m,9H).¹³C NMR(150MHz,DMSO-d₆)δ165.71,164.44,155.29,148.37,145.16,138.36,135.83,134.80,134.19,132.50,130.75,129.08,127.20,127.12,124.81,122.04,121.82,119.34,113.58,112.27,111.82,105.46,95.92,55.67,55.35,55.11.

The process as described in example 2, except that 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (46 mg,0.24 mmol) of formula II and 5- (1-methyl-1H-pyrazol-4-yl) -1H-indole (236 mg,1.2 mmol) of formula VI, was obtained as pale brown solid I-13 (54 mg, yield 47% liquid phase purity 99％).¹H NMR(500MHz,DMSO-d₆)δ11.59(s,1H),7.95(s,1H),7.69(s,1H),7.67(d,J＝2.0Hz,1H),7.56(d,J＝15Hz,1H),7.50(d,J＝8.5Hz,1H),7.42-7.36(m,2H),7.28(t,J＝7.5Hz,1H),7.17(d,J＝7.5Hz,2H),6.71-6.52(m,2H),4.44(s,2H),3.83(s,3H),3.75(s,3H),3.69(s,3H),3.43(s,2H),2.51-2.38(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.38,147.55,147.52,136.66,135.30,133.95,132.85,129.72,129.07,128.71,126.70,125.84,124.83,124.59,123.85,122.78,120.20,114.59,112.45,112.17,110.35,55.58,38.02,27.29.

The process as described in example 2 was followed, except that 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (46 mg,0.24 mmol) of formula II and 1- (4-methoxybenzyl) -1H-indole (284 mg,1.2 mmol) of formula VI gave I-14 as a white solid (104 mg, yield 85% purity in liquid phase 99％).¹H NMR(500MHz,DMSO-d₆)δ7.81(s,1H),7.55(d,J＝8.5Hz,1H),7.47(d,J＝8.0Hz,1H),7.38(dt,J＝8.0,1.5Hz,1H),7.28(t,J＝7.5Hz,1H),7.24-7.15(m,4H),7.15-7.08(m,2H),6.85-6.79(m,2H),6.64(s,2H),5.40(s,2H),4.42(s,2H),3.74(s,3H),3.71(s,3H),3.69(s,3H),3.43(s,2H),2.52-2.35(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.42,158.57,147.62,147.60,136.71,136.48,135.56,133.70,129.89,129.18,129.14,128.82,128.17,125.89,124.60,124.08,122.00,120.12,119.08,113.83,112.54,110.59,110.33,94.58,55.66,55.63,54.81,48.77,27.35.

Following the procedure described in example 2, except for the fact that formula VI is 5- (1-methyl-1H-pyrazol-4-yl) -1H-indole (236 mg,1.2 mmol), I-15 (67 mg, 63% yield, purity in liquid phase) is obtained as a white solid 99％).¹H NMR(400MHz,DMSO-d₆)δ11.73(d,J＝2.4Hz,1H),10.09(s,1H),8.06-8.00(m,1H),7.85(d,J＝2.0Hz,1H),7.76(d,J＝2.4Hz,1H),7.74(d,J＝0.8Hz,1H),7.69(dt,J＝6.8,2.0Hz,1H),7.57-7.52(m,1H),7.48(d,J＝8.4Hz,1H),7.45-7.36(m,2H),7.34-7.24(m,3H),6.90(d,J＝8.8Hz,1H),3.82(s,3H),3.72(d,J＝1.2Hz,6H).¹³C NMR(150MHz,DMSO-d₆)δ164.45,148.38,145.16,135.73,135.64,135.43,134.41,133.58,132.51,130.84,129.99,129.02,127.22,127.18,125.00,124.73,122.89,120.43,114.68,112.59,112.28,111.82,105.46,94.59,55.68,55.35,38.47.

Following the procedure described in example 2, except for the fact that formula VI is 1- (4-methoxybenzyl) -1H-indole (284 mg,1.2 mmol), I-16 (102 mg, 89% yield, liquid phase purity) is obtained as a white solid 99％).¹H NMR(400MHz,CDCl₃)δ7.64(t,J＝1.6Hz,1H),7.63-7.54(m,2H),7.53(s,1H),7.41(s,1H),7.41-7.33(m,2H),7.32(d,J＝2.4Hz,1H),7.30-7.14(m,3H),7.11(d,J＝2.0Hz,1H),7.10(d,J＝2.0Hz,1H),6.88-6.76(m,4H),5.30(s,2H),3.86(m,6H),3.73(s,3H).¹³C NMR(150MHz,CDCl₃)δ165.10,159.32,149.03,145.97,137.09,135.65,135.20,135.06,131.58,131.47,130.56,129.23,128.44,128.36,126.47,124.28,122.71,120.77,120.33,114.31,111.92,111.30,110.35,104.90,95.91,56.09,55.91,55.21,49.99.

The process as described in example 2 was followed, except that 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (46 mg,0.24 mmol) of the formula II was obtained as pale yellow solid I-17 (65 mg, yield 66%, purity in liquid phase) 99％).¹H NMR(500MHz,DMSO-d₆)δ11.52(s,1H),7.69(s,1H),7.51(d,J＝8.0Hz,1H),7.46(d,J＝8.0Hz,1H),7.37(d,J＝8.0Hz,1H),7.27(t,J＝7.5Hz,1H),7.22-7.12(m,3H),7.09(t,J＝7.5Hz,1H),6.72-6.62(m,2H),4.45(s,2H),3.76(s,3H),3.72(s,3H),3.45(s,2H),2.53-2.42(m,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.32,147.55,147.52,136.60,136.45,133.81,132.34,129.12,129.08,128.66,125.84,124.59,123.86,121.65,119.70,118.56,112.49,111.75,110.32,94.73,55.59,27.27.

The process as described in example 2 was followed, except that the starting compound was methyl 4-aminobenzoate (755mg, 5.0 mmol), and 6, 7-dimethoxy-1, 2,3, 4-tetrahydroisoquinoline (46 mg,0.24 mmol) of the formula II, to give I-18 (85 mg, yield 86%, liquid phase purity) as a white solid 99％).¹H NMR(500MHz,DMSO-d₆)δ11.51(s,1H),7.70(d,J＝2.0Hz,1H),7.54-7.49(m,1H),7.47(d,J＝8.0Hz,1H),7.29-7.20(m,4H),7.19(t,J＝7.5Hz,1H),7.13-7.06(m,1H),6.71(s,2H),4.54(s,2H),3.78-3.65(m,6H),3.61(s,2H),2.72(t,J＝6.0Hz,2H).¹³C NMR(125MHz,DMSO-d₆)δ168.73,147.56,147.54,136.43,135.71,133.29,132.39,129.22,127.61,127.20,126.00,124.79,121.68,119.73,118.60,112.53,111.76,110.37,94.51,55.57,27.50.

The procedure described in example 2 was followed, except that the starting compound was methyl 4-aminobenzoate (755 mg,5.0 mmol), to give brown solid I-19 (52 mg, yield 58%, purity of liquid phase) 99％).¹H NMR(400MHz,DMSO-d₆)δ11.76(d,J＝2.8Hz,1H),9.96(s,1H),7.79(d,J＝2.4Hz,1H),7.73(d,J＝8.4Hz,2H),7.52(d,J＝8.0Hz,1H),7.43(d,J＝2.4Hz,1H),7.39(d,J＝8.0Hz,1H),7.29-7.23(m,3H),7.20(ddd,J＝8.2,7.0,1.2Hz,1H),7.09(td,J＝8.0,7.2,1.2Hz,1H),6.90(d,J＝8.8Hz,1H),3.72(d,J＝2.8Hz,6H).¹³C NMR(150MHz,DMSO-d₆)δ164.64,148.39,145.06,138.69,136.71,133.05,132.67,132.23,129.30,128.09,127.37,122.12,120.16,118.89,112.22,112.19,111.87,105.41,94.18,55.68,55.34.

The procedure described in example 2 was followed, except that the starting compound was methyl 4-aminobenzoate (755 mg,5.0 mmol) and pyridine-2-methylamine (26 mg,0.24 mmol) was used as the starting compound to give I-20 as a brown solid (39 mg, yield 48%, liquid phase purity 99％).¹H NMR(400MHz,CDCl₃)δ9.02(s,1H),8.51(dt,J＝4.8,1.2Hz,1H),7.65(td,J＝7.6,2.0Hz,1H),7.64-7.53(m,4H),7.47(d,J＝2.5Hz,1H),7.44(d,J＝8.0Hz,1H),7.28(d,J＝8.4Hz,1H),7.26-7.22(m,2H),7.22-7.18(m,2H),7.18-7.13(m,1H),4.71(d,J＝4.8Hz,2H).¹³C NMR(150MHz,CDCl₃)δ167.16,156.09,148.85,139.47,136.89,136.53,131.62,131.27,129.70,128.02,127.46,122.99,122.44,122.21,120.92,120.09,111.56,96.89,44.62.

The procedure described in example 2 was followed except that the starting compound was methyl 2-aminobenzoate (755 mg,5.0 mmol) and pyridine-2-methylamine (26 mg,0.24 mmol) of formula II, to give I-21 (33 mg, yield 41% liquid phase purity) as a white solid 99％).¹H NMR(400MHz,CDCl₃)δ8.82(s,1H),8.58(dt,J＝4.8,1.2Hz,1H),7.70(td,J＝7.6,2.0Hz,1H),7.66-7.60(m,2H),7.58(d,J＝8.0Hz,1H),7.50-7.43(m,2H),7.38(d,J＝8.0Hz,1H),7.29-7.19(m,2H),7.18-7.07(m,2H),7.07-6.96(m,2H),4.84(d,J＝4.8Hz,2H).¹³C NMR(150MHz,CDCl₃)δ168.35,156.09,148.95,137.55,136.90,136.70,132.28,131.99,131.03,130.27,129.49,127.23,124.75,122.78,122.48,122.32,120.69,120.50,111.40,99.36,44.80.

EXAMPLE 3 cytotoxicity of 3- (indol-3-seleno) benzamide compounds of formula I on MCF-7/ADR

Cell lines: MCF-7/ADR (human breast cancer Adriamycin resistant cell line).

Sample test concentration: 5. Mu.M.

Positive control drug: verapamil, cycloporin, tariquidar.

The test method comprises the following steps: cell proliferation activity assay of the compounds was performed using MTT (tetramethylazo salt) method.

MCF-7/ADR cells were cultured in RPMI 1640 medium containing 10% fetal bovine serum and 1% diabody at 37℃under conditions of 5% CO ₂ saturation humidity. Cells in the logarithmic growth phase were inoculated at a density of 1X 10 ⁵/mL into 96-well plates, 100. Mu.L per well, and cultured at 37℃under a saturated humidity of 5% CO ₂, and divided into a blank control group, a test compound group, and a positive control group. The test compound and the positive control medicinal dimethyl sulfoxide (DMSO) are prepared into a solution with the concentration of 10mM for standby. Different test compound solutions are added into the test compound group, and the test compound group is diluted by an RPMI 1640 culture medium containing 10% of fetal bovine serum, and the final concentration is 5 mu mol/L; adding a positive control medicine solution into the positive control group, diluting with an RPMI 1640 culture medium containing 10% of fetal bovine serum and 1% of double antibodies, wherein the final concentration is 5 mu mol/L; the blank group was given an equal volume of PBS. After culturing for 48 hours, MTT solution was added, the culture solution was aspirated after 4 hours, 100. Mu.L of DMSO was added to each well for dissolution, and then absorbance was read at 570nm on a microplate reader to calculate the effect of the compound on cell viability.

Cell viability = (test group OD average/control group OD average) ×100%

The MTT assay measures the cytotoxic effect of test compounds on MCF-7/ADR cells and the results are shown in Table 1. From the data, it can be seen that: the 3- (indole-3-seleno) benzamide compound shown in the formula I has much lower inhibition on cell growth than that of a control medicament, and has no obvious cytotoxicity.

TABLE 1 inhibition of MCF-7/ADR cells at 5. Mu.M test concentration of the compound of formula I

Example 4 multidrug resistance reversal Activity of 3- (indol-3-seleno) benzamide compounds of formula I on MCF-7/ADR cells was studied.

Cell lines: MCF-7/ADR (human breast cancer Adriamycin resistant cell line).

Sample test concentration: 5. Mu.M.

Positive control drug: verapamil, cycloporin, tariquidar.

The test method comprises the following steps: cell proliferation activity assay of the combination of the compound and doxorubicin was performed using MTT (tetramethylazo salt) method.

MCF-7/ADR cells were cultured in RPMI 1640 medium containing 10% calf serum at 37℃under conditions of 5% CO ₂ saturated humidity. Cells in the logarithmic growth phase were inoculated at a density of 1X 10 ⁵/mL into 96-well plates, 100. Mu.L per well, and cultured at 37℃under a saturated humidity of 5% CO ₂, and divided into a blank control group, a test compound group, and a positive control group. The test compound, the positive control drug and doxorubicin were each prepared in a solution of 10mM in dimethyl sulfoxide (DMSO) for use. Different test compound solutions and doxorubicin solutions are added into a test compound group, the test compound group is diluted by an RPMI 1640 culture medium containing 10% calf serum, the final concentration of the doxorubicin is 0 mu mol/L, 0.001 mu mol/L, 0.01 mu mol/L, 0.1 mu mol/L, 1 mu mol/L, 10 mu mol/L positive control group and a positive control medicine solution are added, the test compound group is diluted by an RPMI 1640 culture medium containing 10% calf serum, and the final concentration of the positive control medicine and the doxorubicin are 5 mu mol/L; the blank group was given an equal volume of PBS. After further culturing for 48 hours, MTT solution was added, the culture was aspirated after 4 hours, 100. Mu.L DMSO was added to each well to dissolve, the crystals were gently shaken to dissolve well, and the optical density was read at 570nm on a microplate reader to calculate IC ₅₀ (. Mu.M) and multiple drug Resistance Fold (RF) for the antiproliferative activity of doxorubicin on MCF-7/ADR cells when combined with 5. Mu.M of the compound of formula I, and the effect of the compound on the viability of the cells was examined.

TABLE 2 results of multidrug resistance reversal Activity of Compound 5. Mu.M of formula I on MCF-7/ADR cells

^a IC ₅₀ values for doxorubicin combined with test compound (5. Mu.M). ^b Reverse fold (=ic ₅₀(ADR)/IC₅₀(P-gp inhibitor+ADR).^c doxorubicin alone IC ₅₀ (ADR, 12.66 μm).

As can be seen from Table 2, compounds I-17, I-8 and I-9, in which the indole selenide is located in the meta position, exhibit stronger reversing activity than the ortho-position compound I-21, the para-position compounds I-18, I-19 and I-20. These preliminary results indicate that indole selenides in the meta-position are more favorable for inhibiting P-gp than those in the ortho-and para-positions. For amide groups, C-5 substituted I-2 and I-3 are more effective than C-7 substituted analogues I-4. Notably, the reversing activity of the C-5-fluoro substituted compound i-1 (rf=95.1) was 23-fold improved over i-17 (rf=4.1) and was also more potent than the positive controls verapamil (rf=12.5) and cyclosporine (rf=43.9).

Example 5 formulas I-13 reverse the mode of action of P-gp mediated MDR.

Further evaluation of P-gp mediated substrate accumulation, such as Rhodamine 123 (Rhodamine 123, rh123), is a widely accepted method of evaluating the effects of P-gp modulators against MDR. After treatment with verapamil or I-13, a significant increase in Rh123 accumulation in the cells of MCF-7/ADR was observed, as shown in FIGS. 1A-C. This suggests that I-13 may block P-gp mediated extracellular matrix function of MCF-7/ADR. Notably, I-13 was comparable to verapamil in its ability to elevate Rh123 levels in MCF-7/ADR cells at a concentration of 10. Mu.M. Furthermore, the accumulation of Rh123 in MCF-7/ADR cells increased in a dose-dependent manner with increasing I-13 concentration, indicating that I-13 can inhibit P-gp mediated extracellular drainage activity in a concentration-dependent manner.

To further elucidate the mechanism underlying the reversal of P-gp mediated MDR effects of 3- (indol-3-seleno) benzamides, we selected I-13 for Western blot analysis to assess the effect of I-13 on P-gp expression levels in MCF-7/ADR cells. As shown in FIGS. 2A-B, over-expression of P-gp was seen in doxorubicin-resistant MCF-7/ADR cells, while I-13 had no significant effect on the level of P-gp expression. These findings underscores that the multi-drug resistance reversal potential of I-13 stems from its efficacy in inhibiting P-gp efflux functions, rather than modulating P-gp expression.

In addition, the compounds of formula I generally have better activity in reversing tumor cell multidrug resistance, wherein I-13 is the most potent, and the reversing activity exceeds that of the control drug Tariquidar (RF: 271.7vs 261.6). At the same time, the toxicity to MCF-7 (inhibition rate: 21.1% vs 36.9%) and MCF-7/ADR (inhibition rate: 33.7% vs 45.1%) cell lines was lower than tariquidar. Taken together, these results indicate that I-13 is worth being used as a starting point for developing novel selenium-containing P-gp inhibitors for clinical use.

Claims

1.A 3- (indole-3-seleno) benzamide compound of formula i:

r ₁ is selected from one of the following: H. halogen, halogen, Wherein Y is C ₁～C₁₀ alkyl, phenyl substituted by halogen or C ₁～C₄ alkoxy, or- (CH ₂)_n-N-(CH₃)₂), wherein n is an integer between 1 and 4;

r ₂ is selected from one of the following:

r ₃ is H or

2. A 3- (indol-3-seleno) benzamide compound of formula i according to claim 1, wherein: r ₁ is H, fluorine orWherein Y is methyl, isopropyl, phenyl substituted by fluorine or methoxy or- (CH ₂)₂-N-(CH₃)₂).

3. A 3- (indol-3-seleno) benzamide compound of formula i according to claim 2, wherein: the 3- (indole-3-seleno) benzamide compound shown in the formula I is one of the following:

4. A process for the preparation of 3- (indol-3-seleno) benzamides according to claim 1, characterized in that it comprises the following steps:

S1, adding a compound shown in a formula II and an alkaline substance into an organic solvent A, dropwise adding a 3-nitrobenzoyl chloride solution at a temperature of-20-0 ℃, and reacting for 1-4 hours at a temperature of 20-40 ℃ after the dropwise adding, wherein the obtained reaction solution A is purified and separated to obtain an intermediate shown in a formula III; the mol ratio of the compound shown in the formula II, the alkaline substance and the 3-nitrobenzoyl chloride contained in the 3-nitrobenzoyl chloride solution is 1:1-3:1 to 1.5;

S2: the intermediate shown in the formula III in the step S1 is subjected to reduction reaction for 12-16 hours at 20-40 ℃ under the action of Pd/C catalyst in hydrogen atmosphere and organic solvent B, and the obtained reaction liquid B is purified and separated to obtain a compound shown in the formula IV; the mol ratio of the intermediate shown in the formula III to Pd loaded by the Pd/C catalyst is 1:0.1-0.5;

S3: adding a compound shown in a formula IV in a step S2 and hydrochloric acid into water, dropwise adding an aqueous solution of sodium nitrite at the temperature of minus 5-5 ℃, adjusting the pH to 5.5-6 after the dropwise adding, adding an aqueous solution containing potassium selenocyanate and sodium bicarbonate, heating to the temperature of 40-60 ℃ for reacting for 0.5-1.5 hours, and separating and purifying the obtained reaction solution C to obtain an intermediate shown in a formula V; the molar ratio of potassium selenocyanate in the compound shown in the formula IV to sodium bicarbonate in the aqueous solution of sodium nitrite, potassium selenocyanate and sodium bicarbonate in the aqueous solution of HCl contained in hydrochloric acid and sodium nitrite contained in the aqueous solution of sodium nitrite is 1:5-8:1-1.5:1-1.5:0.1-0.3;

S4: the intermediate shown in the formula V and the compound shown in the formula VI in the step S3 react for 3-8 hours in an organic solvent C at 50-120 ℃ in the presence of a catalyst, and the obtained reaction solution D is purified and separated to obtain the compound shown in the formula I; the catalyst is tris (pentafluorophenyl) borane or cuprous iodide; the mol ratio of the intermediate shown in the formula V, the compound shown in the formula VI and the catalyst is 1:1-1.5:0.001-0.1;

Wherein R ₁ is selected from one of the following: H. halogen, halogen, Wherein Y is C ₁～C₁₀ alkyl, phenyl substituted by halogen or C ₁～C₄ alkoxy, or- (CH ₂)_n-N-(CH₃)₂), wherein n is an integer between 1 and 4;

r ₂ is selected from one of the following:

r ₃ is H or

5. The method for preparing 3- (indole-3-seleno) benzamide compound of claim 4, wherein: the organic solvent A in the step S1, the solvent of the 3-nitrobenzoyl chloride solution, the organic solvent B in the step S2 and the organic solvent C in the step S4 are respectively and independently selected from one or more than two of the following mixtures: benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, 1, 2-dichloroethane, chloroform, carbon tetrachloride, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acetone, butanone, methyl isobutyl ketone, acetonitrile, propionitrile, butyronitrile, N-dimethylformamide, N-dimethylacetamide, N-methyl-formanilide, N-methylpyrrolidone, hexamethylphosphoric triamide, methyl acetate, ethyl acetate, dimethyl sulfoxide, methanol, ethanol, N-propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether;

The volume of the organic solvent A in the step S1 is 1-5mL/mmol based on the mass of the compound shown in the formula II;

The concentration of the 3-nitrobenzoyl chloride solution in the step S1 is 0.5-2.5mmol/mL;

The alkaline substance in the step S1 is one or more than two of pyridine, N-diisopropylethylamine, N-dimethylaniline, N-dimethylbenzylamine, N-methylpiperidine, N-methylmorpholine, N-dimethylaminopyridine, diazabicyclooctane, diazabicyclononene or diazabicycloundecene, sodium hydroxide, sodium ethoxide, trimethylamine or triethylamine;

The separation and purification A in the step S1 is as follows: the reaction solution A was concentrated under reduced pressure, and the residue was obtained in a volume ratio of 200:1 of methylene chloride: purifying by silica gel column chromatography with methanol as eluent, collecting eluent containing target compound, and evaporating solvent to obtain intermediate shown in formula III;

the volume of the organic solvent B in the step S2 is 1-5mL/mmol based on the mass of the compound shown in the formula III;

The active material load of the Pd/C catalyst in the step S2 is 3-10%;

The separation and purification step B in the step S2 is as follows: the reaction solution B was filtered through celite, the filtrate was concentrated under reduced pressure, and the residue was obtained in the volume ratio of 120:1 of methylene chloride: performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing a target compound, and evaporating out a solvent to obtain a compound shown in a formula IV;

the concentration of the hydrochloric acid in the step S3 is 10-12mol/L;

The concentration of the sodium nitrite aqueous solution in the step S3 is 0.5-1mol/L;

In the aqueous solution containing potassium selenocyanate and sodium bicarbonate in the step S3, the concentration of the potassium selenocyanate is 1-3mol/L, and the concentration of the sodium bicarbonate aqueous solution is 0.5-1mol/L;

The volume of water in the step S3 is 1-5mL/mmol based on the mass of the compound shown in the formula IV;

the separation and purification step S3 is as follows: the reaction solution C was extracted with methylene chloride, the organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure, and the resulting residue was taken up in a volume ratio of 200:1 methylene chloride: performing silica gel column chromatography with methanol as eluent, collecting eluent containing target compound, and evaporating solvent to obtain intermediate shown in formula V;

the volume of the organic solvent C in the step S4 is 1-7mL/mmol based on the mass of the intermediate shown in the formula V;

The separation and purification step D in the step S4 is as follows: the reaction solution D was concentrated under reduced pressure, and the resulting residue was petroleum ether in a volume ratio of 3:1: and (3) performing silica gel column chromatography purification by using ethyl acetate as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain the compound shown in the formula I.

6. A process for the preparation of 3- (indol-3-seleno) benzamides according to claim 1, characterized in that it comprises the following steps:

(1) Adding 3-methyl aminobenzoate and hydrochloric acid into water, dropwise adding an aqueous solution of sodium nitrite at the temperature of minus 5-5 ℃, adjusting the pH to 5.5-6 after the dropwise adding, adding an aqueous solution of potassium selenocyanate and sodium bicarbonate, heating to the temperature of 40-60 ℃ for reacting for 0.5-1.5 hours, and separating and purifying the obtained reaction solution E to obtain an intermediate shown in a formula VII; the molar ratio of potassium selenocyanate in the aqueous solution of sodium nitrite, potassium selenocyanate and sodium bicarbonate contained in the aqueous solution of sodium nitrite, HCl contained in hydrochloric acid and 3-aminobenzoate to sodium bicarbonate in the aqueous solution of potassium selenocyanate and sodium bicarbonate is 1:5-8:1-1.5:1-1.5:0.1-0.3;

(2) The intermediate shown in the formula VII and the compound shown in the formula VI in the step (1) react for 3-8 hours in an organic solvent D at 50-100 ℃ in the presence of a catalyst, and the obtained reaction solution F is purified and separated to obtain the compound shown in the formula VIII; the catalyst is tris (pentafluorophenyl) borane or cuprous iodide; the molar ratio of the intermediate shown in the formula VII, the compound shown in the formula VI and the catalyst is 1:1-1.5:0.001-0.1;

(3) Stirring the compound shown in the formula VIII in the step (2) in an organic solvent E, adding an aqueous solution of an alkaline substance, stirring at 20-40 ℃ for reaction for 4-8 hours, removing the organic solvent under reduced pressure, regulating the pH value to 2-3, filtering, and drying the obtained filter cake to obtain the compound shown in the formula IX; the molar ratio of the compound shown in the formula VIII to the alkaline substance in the aqueous solution of the alkaline substance is 1:50-60;

(4) Step (3) reacting the compound shown in the formula IX and the compound shown in the formula II in an organic solvent F at 20-40 ℃ for 1-4 h under the action of an alkaline substance, a catalyst and a condensing agent, and purifying and separating the obtained reaction solution G to obtain the compound shown in the formula I; the catalyst is 4-dimethylaminopyridine; the condensing agent is one or more than two of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole, 2- (7-azabenzotriazol) -N, N, N ', N' -tetramethylurea hexafluorophosphate, O-benzotriazol-N, N, N ', N' -tetramethylurea tetrafluoroboric acid, triphenylphosphine-polyhalogenated methane, triphenylphosphine-hexachloroacetone, triphenylphosphine-NBS and 3-acyl-2-thiothiazoline; the mol ratio of the compound shown in the formula IX, the compound shown in the formula II, the alkaline substance, the catalyst and the condensing agent is 1:1-1.5:1-3:0.1:1-1.5;

r ₂ is selected from one of the following:

r ₃ is H or

7. The method for preparing 3- (indole-3-seleno) benzamide compound of claim 1, wherein: the concentration of the hydrochloric acid in the step (1) is 10-12mol/L;

The concentration of the sodium nitrite aqueous solution in the step (1) is 0.5-1mol/L;

In the step (1), weak base is adopted for regulating the pH value, and the pH value is one or a mixture of two of sodium acetate, potassium carbonate, sodium methoxide and sodium ethoxide;

in the aqueous solution containing potassium selenocyanate and sodium bicarbonate in the step (1), the concentration of the potassium selenocyanate is 1-3mol/L, and the concentration of the sodium bicarbonate aqueous solution is 0.5-1mol/L;

The volume of water in the step (1) is 1-5mL/mmol based on the mass of the compound shown in the formula IV;

The separation and purification E in the step (1) is as follows: the reaction solution E was extracted with methylene chloride, the organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure, and the resulting residue was taken up in a volume ratio of 200:1 methylene chloride: performing silica gel column chromatography with methanol as eluent, collecting eluent containing target compound, and evaporating solvent to obtain intermediate shown in formula VII;

The organic solvent D in the step (2), the organic solvent E in the step (3) and the organic solvent F in the step (4) are respectively and independently selected from one or a mixture of more than two of the following: benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, 1, 2-dichloroethane, chloroform, carbon tetrachloride, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetonitrile, propionitrile, butyronitrile, N-dimethylformamide, N-dimethylacetamide, N-methyl-formanilide, N-methylpyrrolidone, hexamethylphosphoric triamide, methyl acetate, ethyl acetate, dimethyl sulfoxide, methanol, ethanol, N-propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether or diethylene glycol monoethyl ether;

the volume of the organic solvent D in the step (2) is 1-7mL/mmol based on the mass of the intermediate shown in the formula VII;

The separation and purification F in the step (2) is as follows: the reaction solution F was concentrated under reduced pressure, and the residue was petroleum ether in a volume ratio of 3:1: purifying by silica gel column chromatography with ethyl acetate as eluent, collecting eluent containing target compound, and evaporating solvent to obtain compound shown in formula VIII;

The alkaline substance in the aqueous solution of the alkaline substance in the step (3) is one or more than two aqueous solutions of potassium hydroxide, lithium hydroxide and sodium hydroxide;

the concentration of the aqueous solution of the alkaline substance in the step (3) is 1-3mol/L;

the volume of the organic solvent E in the step (3) is 1-15mL/mmol based on the amount of the substance of the compound shown in the formula VIII;

The alkaline substance in the step (4) is one or more than two of pyridine, N-diisopropylethylamine, N-dimethylaniline, N-dimethylbenzylamine, N-methylpiperidine, N-methylmorpholine, N-dimethylaminopyridine, diazabicyclooctane, diazabicyclononene or diazabicycloundecene, sodium hydroxide, sodium ethoxide, trimethylamine and triethylamine;

the volume of the organic solvent F in the step (4) is 1-15mL/mmol based on the mass of the intermediate shown in the formula IX;

the separation and purification G in the step (4) is as follows: the reaction solution G was concentrated under reduced pressure, and the residue was obtained in a volume ratio of 150:1 of methylene chloride: and (3) performing silica gel column chromatography by using methanol as an eluent, collecting eluent containing the target compound, and evaporating the solvent to obtain the compound shown in the formula I.

8. Use of a 3- (indol-3-seleno) benzamide compound according to any one of claims 1 to 3 for the preparation of a multi-drug resistant protein P-gp inhibitor.

9. Use of a 3- (indol-3-seleno) benzamide compound of any one of claims 1 to 3 for the preparation of a tumor multidrug resistance reversal agent or a tumor metastasis inhibitor.

10. The use according to claim 9, characterized in that said medicament comprises said 3- (indol-3-seleno) benzamide compound and an anti-tumour agent;

the antitumor drug is one or more than two of alkylating agent, antimetabolite, topoisomerase inhibitor, cell microtubule inhibitor, DNA intercalator and lysine kinase inhibitor.