Indole derivatives, and preparation method, pharmaceutical composition and application thereof

Abstract

The invention provides indole derivatives as well as a preparation method, a pharmaceutical composition and application thereof. Specifically provided is a compound represented by formula I or a pharmaceutically acceptable salt thereof. The compound provided by the invention is good in activity, high in medication safety and wide in application prospect. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of pharmaceuticals, and particularly relates to a class of indole derivatives, a preparation method thereof, a pharmaceutical composition thereof, and an application thereof. Background Art

[0002] Currently, the first-line antidepressant drugs in clinical practice are mainly selective serotonin (5-HT) reuptake inhibitors (SSRI), such as Fluoxetine and Citalopram. They generally have the defects of slow onset (usually taking three to four weeks to take effect), low efficiency (the drugs are ineffective for one-third to one-half of the patients, and more patients only partially relieve symptoms), large side effects (sexual dysfunction, weight gain, gastrointestinal and cardiovascular side effects, etc.), and inability to improve the cognitive impairment of patients.

[0003] In 2011, the US FDA approved the drug vilazodone with the mechanism of action of serotonin reuptake inhibition and 5-HT1a partial agonism. In 2013, the FDA approved the drug vortioxetine with the effects on serotonin reuptake inhibition and multiple serotonin receptor subtypes (5-HT1a, 5-HT1b, 5-HT1d, 5-HT3, 5-HT7), verifying the druggability of multi-mechanism drugs with serotonin reuptake inhibition plus serotonin receptor subtype effects.

[0004] Serotonin reuptake inhibition (SSRI) combined with 5-HT1a receptor can accelerate the onset of antidepressant drugs and reduce the side effects of drugs (Current Drug Targets, 2006, 7: 139-47.). The marketed drugs vilazodone and vortioxetine both have the dual-target effect of (serotonin reuptake inhibition) SSRI / 5-HT1a. 5-HT7 receptor antagonists are generally reported to show antidepressant activity in animals (ACS chemical neuroscience, 2019, 10(1): 89-119.). Some antipsychotics such as amisulpride and lurasidone have antidepressant effects, which are related to their antagonism of 5-HT7 receptor (Neuropharmacology, 2013, 70: 211-7.). The SSRI antidepressant citalopram combined with the 5-HT7 receptor antagonist SB269970 shows better activity in an antidepressant animal model (The Journal of pharmacology and experimental therapeutics, 2007, 321(2): 690-8.). 5-HT7 antagonism shows good cognitive improvement in animal experiments (Frontiers in psychiatry, 2021, 12: 623684).

[0005] CN109467554A discloses a class of indole-aryl heterocyclic piperazine (pyridine) derivatives, compounds acting on serotonin transporter, 5-HT1a receptor and 5-HT7 receptor, which are expected to solve the defects of existing drugs. It is very necessary to further develop other serotonin (5-HT) reuptake inhibitors and optimize their drug properties. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defect in the prior art that there are few types of drugs with inhibitory activity against the three targets of 5-HT reuptake, 5-HT1a and 5-HT7. Therefore, the present application provides a class of indole derivatives, their preparation methods, pharmaceutical compositions and their applications. The indole derivatives provided by the present application have good activity and low side effects, and have broad application prospects.

[0007] The present invention provides a compound of formula I or a pharmaceutically acceptable salt thereof,

[0008]

[0009] Wherein:

[0010] n is 0, 1 or 2;

[0011] k is 0, 1 or 2;

[0012] R 1 Each independently is halogen, hydroxy, C1-C6 alkoxy, C1-C6 alkyl or cyano;

[0013] R 2 Each independently is halogen, C1-C6 alkoxy or C1-C6 alkyl;

[0014] L is -C(=O)- or -CH(OH)-

[0015] m is 1, 2 or 3;

[0016] X is CH or N;

[0017] Y is O or S.

[0018] In certain embodiments of the present invention, some groups in the compound of formula I and its pharmaceutically acceptable salts are defined as follows. For groups not mentioned, they are the same as those described in any embodiment of the present invention (abbreviated as "in a certain embodiment"),

[0019] In a certain embodiment, R 1 and R 2 Among them, the halogen is each independently fluorine, chlorine or bromine, for example, fluorine.

[0020] In a certain embodiment, R 1 and R 2 Among them, the C1-C6 alkyl is each independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

[0021] In a certain embodiment, R 1 and R 2 Among them, the C1-C6 alkoxy is each independently methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy.

[0022] In a certain embodiment, n is 0 or 1, for example, 1.

[0023] In a certain embodiment, k is 0 or 1.

[0024] In a certain embodiment, R 1 Each independently is halogen or cyano.

[0025] In a certain embodiment, R 2 Each independently is halogen.

[0026] In a certain embodiment, the compound of formula I is the compound of formula I-1;

[0027]

[0028] Among them, R 1, m, X, L, Y, R 2 and k are each independently as described in any one of the present inventions.

[0029] In one embodiment, the compound of formula I is the compound of formula I-2;

[0030]

[0031] wherein, R 1 , m, L, X, Y, R 2 and k are each independently as described in any one of the present inventions.

[0032] In one embodiment, in the compound of formula I or a pharmaceutically acceptable salt thereof,

[0033] n is 1;

[0034] k is 0 or 1;

[0035] R 1 is halogen or cyano;

[0036] R 2 is halogen;

[0037] L is -C(=O)- or -CH(OH)-;

[0038] m is 1, 2 or 3;

[0039] X is CH or N;

[0040] Y is O or S.

[0041] In one embodiment, R 1 is F or cyano.

[0042] In one embodiment, R 2 is F.

[0043] In one embodiment, is

[0044] In one embodiment, is

[0045] In one embodiment, the compound of formula I is any one of the following compounds:

[0046] 3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-one (Compound I);

[0047] 1-(5-Fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (Compound II);

[0048] 3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-ol (Compound III);

[0049] 1-(5-Fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-ol (Compound IV);

[0050] 3-(3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)propanoyl)-1H-indole-5-carbonitrile (Compound V);

[0051] 3-(3-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile (Compound VI);

[0052] 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one (Compound VII);

[0053] 1-(5-Fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (Compound VII).

[0054] In one embodiment, the pharmaceutically acceptable salt of the compound represented by Formula I is hydrochloride, hydrobromide, sulfate, mesylate or oxalate, such as hydrochloride.

[0055] In one embodiment, the pharmaceutically acceptable salt of the compound represented by Formula I is:

[0056] 1-(5-Fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one monohydrochloride;

[0057] 3-(3-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile monohydrochloride;

[0058] 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one monohydrochloride; or

[0059] 1-(5-Fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one monohydrochloride.

[0060] The present invention also provides a pharmaceutical composition, which comprises:

[0061] (1) A compound represented by formula I as described in any one of the present inventions, its pharmaceutically acceptable salts, and

[0062] (2) Pharmaceutically acceptable excipients.

[0063] The present invention also provides the use of a compound represented by formula I as described in any one of the present inventions, its pharmaceutically acceptable salts or the pharmaceutical composition as described above, and the uses are selected from:

[0064] (5) Preparing a 5-HT reuptake inhibitor;

[0065] (6) Preparing a 5-HT1a receptor binder;

[0066] (7) Preparing a 5-HT7 receptor binder;

[0067] (8) Preparing a drug for treating and / or preventing diseases related to 5-HT reuptake, 5-HT1a or 5-HT7;

[0068] (9) Preparing a drug for treating and / or preventing central nervous system diseases.

[0069] In one embodiment, in the said use, the disease is a central nervous system disease, such as depression and / or anxiety disorder.

[0070] In one embodiment, in the said use, the central nervous system disease is depression and / or anxiety disorder.

[0071] The present invention provides a preparation method of a compound represented by formula I-3 or I-4,

[0072] The preparation method of the compound represented by formula I-3 includes the following steps: the compound represented by formula I-5 (for example, under the action of a base) is hydrolyzed to obtain the compound represented by formula I-3;

[0073]

[0074] R 3 is an amino protecting group, such as p-toluenesulfonyl or tert-butoxycarbonyl, preferably p-toluenesulfonyl;

[0075] R 1 , n, m, X, Y, R 2 and k are each independently as described in any one of the present inventions;

[0076] The preparation method of the compound represented by formula I-4 includes the following steps: the compound represented by formula I-3 reacts with a reducing reagent (such as sodium borohydride) to carry out a reduction reaction to obtain the compound represented by formula I-4;

[0077]

[0078] Among them, R 1 , n, m, X, Y, R 2 and k are each independently as described in any one of the present invention;

[0079] Alternatively, the method for preparing the compound represented by Formula I-4 includes the following steps: hydrolyzing the compound represented by Formula I-6 to obtain the compound represented by Formula I-4;

[0080]

[0081] R 4 is an amino protecting group, such as p-toluenesulfonyl or tert-butoxycarbonyl, preferably p-toluenesulfonyl;

[0082] R 1 , n, m, X, Y, R 2 and k are each independently as described in any one of the present invention.

[0083] The present invention provides compounds represented by Formula I-5 and I-6;

[0084]

[0085] Among them, R 1 , n, m, X, Y, R 2 , R 3 , R 4 and k are each independently as described in any one of the present invention.

[0086] In one embodiment, the compound represented by Formula I-5 is

[0087] In one embodiment, the compound represented by Formula I-6 is

[0088] Unless otherwise specified, the terms used in the present invention have the following meanings:

[0089] Those skilled in the art can understand that, according to the convention used in the art, the used in the structural formula of the group described in the present invention means that the corresponding group is connected to other fragments and groups in the compound through this site.

[0090] The term "pharmaceutically acceptable" means relatively non-toxic, safe and suitable for use by patients.

[0091] The term "pharmaceutically acceptable salt" refers to a salt obtained by reacting a compound with a pharmaceutically acceptable acid or base. When a compound contains a relatively basic functional group, an acid addition salt can be obtained by contacting the compound with a sufficient amount of a pharmaceutically acceptable acid in a suitable inert solvent. For details, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use (P. Heinrich Stahl, Camille G. Wermuth, 2011, 2nd Revised Edition).

[0092] The term "halogen" refers to fluorine, chlorine, bromine, or iodine.

[0093] The term "alkyl" refers to a straight-chain or branched-chain, saturated monovalent hydrocarbon group having a specified number of carbon atoms (e.g., C1-C6 or C1-C4). Alkyl groups include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, etc.

[0094] The term "alkoxy" refers to the group -O-R X , R X is defined in the same way as the term "alkyl". Alkoxy groups include, but are not limited to: methoxy, ethoxy, n-propoxy, isopropoxy, etc.

[0095] The term "pharmaceutically acceptable excipient" refers to excipients and additives used in the production of drugs and the formulation of prescriptions; it is all substances contained in a pharmaceutical preparation except the active ingredient. See the fourth part of the Pharmacopoeia of the People's Republic of China (2020 Edition), or Handbook of Pharmaceutical Excipients (Raymond C Rowe, 2009 Sixth Edition).

[0096] On the basis of not violating the common knowledge in this field, the above preferred conditions can be arbitrarily combined to obtain various preferred examples of the present invention.

[0097] The reagents and raw materials used in the present invention are all commercially available.

[0098] The positive and progressive effects of the present invention are as follows: The compounds or their pharmaceutically acceptable salts provided by the present invention have one or more of the following effects:

[0099] (1) It has good binding activity to 5-HT reuptake, 5-HT1a, and 5-HT7 receptors;

[0100] (2) It has good antidepressant activity.

[0101] (3) It has good safety, shows weak inhibitory effect on hERG ion channels, and demonstrates good application prospects. Detailed implementation manners

[0102] The present invention will be further illustrated by way of examples below, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions noted in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0103] Example 1

[0104] Preparation of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-one (Compound I)

[0105]

[0106] Step 1: Synthesis of 5-fluoro-1-tosyl-1H-indole (2-I)

[0107] 60% sodium hydride (4.44 g, 110.99 mmol) was slowly added to a solution of 5-fluoroindole (1-I) (10 g, 74.00 mmol) in tetrahydrofuran (100 mL) at 0 °C, and the reaction solution was stirred at 0 - 20 °C for 2 hours. Then, p-toluenesulfonyl chloride (21.16 g, 110.99 mmol) was added to the reaction solution. After addition, the reaction solution was continuously stirred at 20 °C for 12 hours. Saturated ammonium chloride solution (100 mL) was added to the reaction solution, and the reaction solution was extracted with ethyl acetate (100 mL × 3). The organic phases were combined, washed with saturated brine (150 mL), the organic layer was collected, dried over anhydrous sodium sulfate and then filtered and concentrated, and purified by silica gel column chromatography (petroleum ether:ethyl acetate (V:V) = 15:1 - 5:1) to obtain 20.5 g of the title compound with a yield of 96%.

[0108] MS(ESI) m / z: 290.1 [M + H] + ;

[0109] 1 H NMR(600 MHz, Chloroform-d) δ 7.92 (dd, J = 9.1, 4.4 Hz, 1H), 7.76–7.71 (m, 2H), 7.59 (d, J = 3.7 Hz, 1H), 7.23 (s, 1H), 7.22 (d, J = 2.0 Hz, 1H), 7.17 (dd, J = 8.7, 2.5 Hz, 1H), 7.03 (td, J = 9.1, 2.5 Hz, 1H), 6.61 (dd, J = 3.6, 0.8 Hz, 1H), 2.34 (s, 3H).

[0110] Step 2: Synthesis of 3-chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (3-I)

[0111] 5-Fluoro-1-tosyl-1H-indole (2-I) (8 g, 27.65 mmol) and aluminum trichloride (4.06 g, 30.42 mmol) were successively added to dichloromethane (80 mL). Under stirring at 0 °C, a solution of 3-chloropropionyl chloride (2.6 mL, 30.42 mmol) in dichloromethane (20 mL) was slowly added dropwise thereto. After the addition was completed, the reaction solution was continued to react at 0 - 20 °C for 3 hours. The reaction mixture was slowly poured into ice water (150 mL), stirred for 0.5 hour, and allowed to stand for liquid separation. The organic layer was washed once with water (100 mL) and saturated brine (150 mL), dried over anhydrous sodium sulfate, filtered and concentrated, and purified by silica gel column chromatography (petroleum ether:ethyl acetate (V:V) = 15:1 - 5:1) to obtain 6.2 g of the title compound, with a yield of 59%.

[0112] MS(ESI) m / z: 380.10 [M + H] + ;

[0113] 1 H NMR(600 MHz, Chloroform-d) δ 8.19 (s, 1H), 7.94 (dd, J = 9.0, 2.6 Hz, 1H), 7.80 (dd, J = 9.1, 4.3 Hz, 1H), 7.77–7.72 (m, 2H), 7.23 (dd, J = 7.4, 1.3 Hz, 2H), 7.04 (td, J = 8.9, 2.7 Hz, 1H), 3.86 (t, J = 6.6 Hz, 2H), 3.28 (t, J = 6.6 Hz, 2H), 2.31 (s, 3H).

[0114] Step 3: Synthesis of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (4-I)

[0115] 3-Chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (3-I) (2 g, 5.27 mmol), 3-(piperazin-1-yl)benzo[d]isothiazole (1.05 g, 4.79 mmol), triethylamine (1.33 mL, 9.57 mmol), and potassium iodide (0.08 g, 0.48 mmol) were added to acetonitrile (20 mL), and the mixture was refluxed for 24 h. The reaction system was cooled to room temperature, quenched with water (40 mL), extracted with ethyl acetate (40 mL×3), the organic phases were combined, washed with saturated brine (100 mL), the organic layer was collected, dried over anhydrous sodium sulfate, filtered, and concentrated. Purification by silica gel column chromatography (dichloromethane:methanol (V:V) = 20:1 - 10:1) gave 1.1 g of the title compound with a yield of 41%.

[0116] MS(ESI) m / z: 563.40 [M+H] + ;

[0117] Step 4: Synthesis of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-one (I)

[0118] To 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (4-I) (1.10 g, 1.95 mmol), ethanol (33 mL), and tetrahydrofuran (5.5 mL) was added sodium hydroxide solution (4.9 mL, 4 mol / L), and the mixture was heated to 80 °C and reacted for 12 h. The reaction system was cooled to room temperature, water (50 mL) was added, and the mixture was extracted with ethyl acetate (50 mL×3). The organic phases were combined, washed with saturated brine (100 mL), the organic layer was collected, dried over anhydrous sodium sulfate, filtered, and concentrated. Purification by silica gel column chromatography (dichloromethane:methanol (V:V) = 20:1 - 10:1) gave 0.6 g of the title compound with a yield of 75%.

[0119] MS(ESI) m / z: 409.18 [M+H] + ;

[0120] 11H NMR (400 MHz, DMSO-d6) δ 12.09 (d, J = 3.1 Hz, 1H), 8.50 (d, J = 3.1 Hz, 1H), 8.05 (d, J = 8.2 Hz, 2H), 7.87 (dd, J = 9.9, 2.7 Hz, 1H), 7.56 (dd, J = 8.4, 6.9 Hz, 1H), 7.45 (ddd, J = 20.8, 8.5, 5.6 Hz, 2H), 7.07 (td, J = 9.2, 2.7 Hz, 1H), 3.44 (m, 4H), 3.10 (t, J = 7.4 Hz, 2H), 2.81 (m, 2H), 2.70 (m, 4H).

[0121] Example 2

[0122] Preparation of 1-(5-Fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (Compound II)

[0123]

[0124] Step 1: Synthesis of 1-(5-Fluoro-1-tosyl-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (4-II)

[0125] The title compound of this step was prepared according to the method described in Step 3 of Example 1, that is, 3-chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (3-I) (2 g, 5.27 mmol), 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole (1.05 g, 4.79 mmol), triethylamine (1.33 mL, 9.57 mmol), and potassium iodide (0.08 g, 0.48 mmol) were added to acetonitrile (20 mL), and the mixture was refluxed for 24 hours to obtain 1.6 g of the title compound with a yield of 59%.

[0126] MS (ESI) m / z: 564.40 [M+H] + ;

[0127] Step 2: Synthesis of 1-(5-Fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one

[0128] The title compound was prepared according to the method described in Step 4 of Example 1, that is, 1-(5-fluoro-1-tosyl-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (4-II) (1.6 g, 2.84 mmol) and sodium hydroxide solution (7.1 mL, 4 mol / L) were reacted in a mixed solution of ethanol (48 mL) and tetrahydrofuran (8 mL) at 80 °C for 12 hours to obtain 0.9 g of the title compound with a yield of 77%.

[0129] MS(ESI) m / z: 410.20 [M+H] + ;

[0130] 1 H NMR(400 MHz, DMSO-d6) δ 12.07(s, 1H), 8.47(d, J = 3.1 Hz, 1H), 7.99(dd, J = 8.9, 5.4 Hz, 1H), 7.85(dd, J = 10.0, 2.7 Hz, 1H), 7.68(dd, J = 9.1, 2.1 Hz, 1H), 7.47(dd, J = 8.9, 4.6 Hz, 1H), 7.26(t, J = 9.0 Hz, 1H), 7.06(td, J = 9.1, 2.7 Hz, 1H), 3.05(m, 5H), 2.75(m, 2H), 2.17(m, 2H), 2.02(m, 2H), 1.81(m, 2H).

[0131] Example 3

[0132] Synthetic Route 1:

[0133] Preparation of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-ol (Compound III)

[0134]

[0135] Step 1: Synthesis of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-ol (III)

[0136] At 0 °C, sodium borohydride (1.67 g, 44.06 mmol) was slowly added portionwise to a mixed system of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-one (I) (0.6 g, 1.47 mmol) (I), methanol (100 mL) and tetrahydrofuran (10 mL). The reaction was carried out at 0 - 25 °C under nitrogen protection for 13 hours. Water (100 mL) was slowly added to quench the reaction, and the mixture was extracted with ethyl acetate (100 mL × 3). The organic phases were combined, washed with saturated brine (100 mL), the organic layer was collected, dried over anhydrous sodium sulfate, filtered and concentrated, and purified by silica gel column chromatography (methylene chloride:methanol (V:V) = 20:1 - 10:1) to obtain 0.2 g of the title compound with a yield of 33%.

[0137] MS(ESI) m / z: 411.15 [M + H] + ;

[0138] 1 1H NMR (600 MHz, DMSO-d6) δ 10.97 (d, J = 2.5 Hz, 1H), 8.03 (dd, J = 8.2, 3.2 Hz, 2H), 7.54 (t, J = 7.6 Hz, 1H), 7.44–7.37 (m, 2H), 7.34 (dd, J = 8.8, 4.6 Hz, 1H), 7.31 (d, J = 2.5 Hz, 1H), 6.91 (td, J = 9.1, 2.6 Hz, 1H), 5.19 (s, 1H), 4.91 (dd, J = 7.7, 5.2 Hz, 1H), 3.45 (d, J = 10.0 Hz, 4H), 2.60 (dtd, J = 20.2, 10.8, 4.6 Hz, 4H), 2.56–2.51 (m, 1H), 2.48–2.42 (m, 1H), 2.06–2.00 (m, 1H), 1.99–1.95 (m, 1H).

[0139] Synthetic Route 2:

[0140] Step 1: Synthesis of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-ol (7-III)

[0141] At 0 °C, sodium borohydride (2.0 g, 53.32 mmol) was slowly added portionwise to a mixed system of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-one (4-I) (1.0 g, 1.78 mmol), methanol (100 mL) and tetrahydrofuran (10 mL). The reaction was carried out at 0 - 25 °C under nitrogen protection for 14 hours. Water (100 mL) was slowly added to quench the reaction, and the mixture was extracted with ethyl acetate (100 mL × 3). The organic phases were combined, washed with saturated brine (100 mL), the organic layer was collected, dried over anhydrous sodium sulfate, filtered and concentrated, and purified by silica gel column chromatography (methylene chloride:methanol (V:V) = 20:1 - 10:1) to obtain 0.3 g of the title compound with a yield of 30%.

[0142] MS(ESI) m / z: 565.20 [M+H] + ;

[0143] Step 2: Synthesis of 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-ol (III)

[0144] To 3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)propan-1-ol (7-III) (0.8 g, 1.42 mmol), ethanol (24 mL) and tetrahydrofuran (4 mL) was added sodium hydroxide solution (3.5 mL, 4 mol / L), and the mixture was heated to 80 °C and reacted for 10 hours. The reaction system was cooled to room temperature, water (50 mL) was added, and the mixture was extracted with ethyl acetate (50 mL × 3). The organic phases were combined, washed with saturated brine (100 mL), the organic layer was collected, dried over anhydrous sodium sulfate, filtered and concentrated, and purified by silica gel column chromatography (methylene chloride:methanol (V:V) = 20:1 - 10:1) to obtain 0.3 g of the title compound with a yield of 52%.

[0145] The spectral data is the same as above.

[0146] Example 4

[0147] Preparation of 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-ol (Compound IV)

[0148]

[0149] Step 1: Synthesis of 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (IV)

[0150] The title compound of this step was prepared according to the method described in Step 1 of Example 3, that is, 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one (II) (0.9 g, 2.20 mmol) and sodium borohydride (2.49 g, 65.94 mmol) were reacted in a mixed solution of methanol (200 mL) and tetrahydrofuran (20 mL) at 0-25 °C under nitrogen protection for 48 hours to obtain 0.2 g of the title compound with a yield of 22%.

[0151] MS(ESI) m / z: 412.13 [M+H] + ;

[0152] 1 H NMR(600 MHz, Methanol-d4) δ 7.89 (dd, J = 8.8, 5.1 Hz, 1H), 7.38 (ddd, J = 15.7, 9.4, 2.3 Hz, 2H), 7.33–7.28 (m, 2H), 7.17 (td, J = 9.0, 2.2 Hz, 1H), 6.87 (td, J = 9.1, 2.5 Hz, 1H), 5.05 (dd, J = 7.7, 5.4 Hz, 1H), 3.24 (m, 1H), 2.85–2.78 (m, 1H), 2.72–2.62 (m, 1H), 2.45 (m, 2H), 2.31–2.23 (m, 1H), 2.23–2.13 (m, 4H), 2.11–2.03 (m, 2H), 1.65–1.55 (m, 1H).

[0153] Example 5

[0154] Preparation of 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propanoyl)-1H-indole-5-carbonitrile (Compound V)

[0155]

[0156] Step 1: Synthesis of 1-tosyl-1H-indole-5-carbonitrile (2-V)

[0157] The title compound of this step was prepared according to the method described in Step 1 of Example 1, that is, 1H-indole-5-carbonitrile (1-V) (5 g, 35.17 mmol), 60% sodium hydride (2.11 g, 52.76 mmol) and p-toluenesulfonyl chloride (7.38 g, 38.69 mmol) were reacted in tetrahydrofuran (50 mL) for 18 hours to obtain 10.2 g of the title compound with a yield of 98%.

[0158] MS(ESI) m / z: 297.10 [M+H] + ;

[0159] Step 2: Synthesis of 3-(3-chloropropionyl)-1-tosyl-1H-indole-5-carbonitrile (3-V)

[0160] The title compound of this step was prepared by referring to the method described in Step 2 of Example 1, that is, 1-tosyl-1H-indole-5-carbonitrile (2-V) (10 g, 33.74 mmol), 3-chloropropionyl chloride (3.2 mL, 37.12 mmol), and aluminum trichloride (4.95 g, 37.12 mmol) were reacted in dichloromethane (120 mL) for 4 hours to obtain 7.1 g of the title compound with a yield of 54%.

[0161] MS(ESI) m / z: 387.00 [M+H] + ;

[0162] Step 3: Synthesis of 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propionyl)-1-tosyl-1H-indole-5-carbonitrile (4-V)

[0163] The title compound of this step was prepared by referring to the method described in Step 3 of Example 1, that is, 3-(3-chloropropionyl)-1-tosyl-1H-indole-5-carbonitrile (3-V) (2 g, 5.17 mmol), 3-(piperazin-1-yl)benzo[d]isothiazole (1.03 g, 4.70 mmol), triethylamine (1.3 mL, 9.40 mmol), and potassium iodide (0.08 g, 0.47 mmol) were reacted in acetonitrile (20 mL) for 24 hours to obtain 1.1 g of the title compound with a yield of 41%.

[0164] MS(ESI) m / z: 570.20 [M+H] + ;

[0165] Step 4: Synthesis of 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propionyl)-1H-indole-5-carbonitrile (V)

[0166] The title compound of this step was prepared by referring to the method described in Step 4 of Example 1, that is, 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propionyl)-1-tosyl-1H-indole-5-carbonitrile (4-V) (1 g, 1.76 mmol) and sodium hydroxide (4.4 mL, 4 mol / L) were reacted in ethanol (30 mL) and tetrahydrofuran (5 mL) at 30 °C for 24 hours to obtain 0.2 g of the title compound with a yield of 27%.

[0167] MS(ESI) m / z: 416.18 [M+H] + ;

[0168] 1 H NMR (400 MHz, DMSO-d6) δ 12.50 (s, 1H), 8.64 (s, 1H), 8.60–8.54 (m, 1H), 8.08–8.01 (m, 2H), 7.66 (d, J = 8.4 Hz, 1H), 7.62–7.52 (m, 2H), 7.46–7.40 (m, 1H), 3.48–3.38 (m, 4H), 3.13 (t, J = 7.2 Hz, 2H), 2.81 (t, J = 7.2 Hz, 2H), 2.68 (t, J = 4.8 Hz, 4H).

[0169] Example 6

[0170] Preparation of 3-(3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile (Compound VI) Hydrochloride

[0171]

[0172] Step 1: Synthesis of 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propanoyl)-1-tosyl-1H-indole-5-carbonitrile (4-VI)

[0173] The title compound of this step was prepared according to the method described in Step 3 of Example 1, that is, 3-(3-chloropropanoyl)-1-tosyl-1H-indole-5-carbonitrile (3-V) (2 g, 5.17 mmol), 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole (1.04 g, 4.70 mmol), triethylamine (1.30 mL, 9.40 mmol), and potassium iodide (0.08 g, 0.47 mmol) were added to acetonitrile (20 mL), and the mixture was refluxed for 24 hours to prepare the title compound 0.9 g, with a yield of 34%.

[0174] MS(ESI) m / z: 571.20 [M+H] + ;

[0175] Step 2: Synthesis of 3-(3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile (Compound VI)

[0176] The title compound of this step was prepared according to the method described in Step 4 of Example 1, that is, 3-(3-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)propanoyl)-1-toluenesulfonyl-1H-indole-5-carbonitrile (4-VI) (0.9 g, 1.58 mmol) and sodium hydroxide (3.9 mL, 4 mol / L) were reacted in ethanol (27 mL) and tetrahydrofuran (4.5 mL) at 30 °C for 24 hours to obtain 0.3 g of the title compound with a yield of 46%.

[0177] MS(ESI) m / z: 416.96 [M+H] + ;

[0178] 1 H NMR(400 MHz, DMSO-d6) δ 12.57(s, 1H), 8.66(s, 1H), 8.56(d, J = 1.5 Hz, 1H), 8.07(dt, J = 8.9, 4.0 Hz, 1H), 7.77–7.66(m, 2H), 7.62(dd, J = 8.4, 1.7 Hz, 1H), 7.31(td, J = 9.0, 2.3 Hz, 1H), 3.42–3.26(m, 5H), 3.16(d, J = 8.1 Hz, 2H), 2.73(s, 2H), 2.18(d, J = 13.1 Hz, 2H), 2.02(p, J = 12.8 Hz, 2H).

[0179] Step 3: Preparation of 3-(3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile (VI) hydrochloride

[0180] 3-(3-(4-(6-Fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile (VI) (0.25 g, 0.6 mmol) was dissolved in a mixed solution of methanol (70 mL) and acetone (30 mL), and then a solution of hydrogen chloride in ethyl acetate (0.9 mL, 2 mol / L) was added dropwise. After the addition, the reaction solution was stirred at 25 °C for 12 hours, and a white solid precipitated. The solid was filtered to obtain a filter cake, which was recrystallized from methanol (75 mL) to obtain 0.15 g of the white title compound with a yield of 55%.

[0181] MS(ESI) m / z: 416.96 [M+H] + ;

[0182] 11H NMR (600 MHz, DMSO-d6) δ 12.74 (d, J = 3.1 Hz, 1H), 11.08 (s, 1H), 8.67 (d, J = 3.1 Hz, 1H), 8.53 (d, J = 1.6 Hz, 1H), 8.21 (dd, J = 8.8, 5.2 Hz, 1H), 7.74–7.68 (m, 2H), 7.66–7.59 (m, 1H), 7.33 (td, J = 9.1, 2.2 Hz, 1H), 3.75–3.69 (m, 2H), 3.61 (t, J = 7.3 Hz, 2H), 3.56 - 3.48 (m, 3H), 3.27–3.16 (m, 2H), 2.44–2.33 (m, 2H), 2.29–2.22 (m, 2H).

[0183] Example 7

[0184] Preparation of 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one (Compound VII) Hydrochloride

[0185]

[0186] Step 1: Synthesis of 4-chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)butan-1-one (3-VII)

[0187] The title compound of this step was prepared according to the method described in Step 2 of Example 1, that is, 5-fluoro-1-tosyl-1H-indole (2-I) (3.3 g, 11.41 mmol), 4-chlorobutyryl chloride (1.6 mL, 14.83 mmol), and aluminum trichloride (3.0 g, 22.81 mmol) were reacted in dichloromethane (80 mL) at 0 - 30 °C for 5 hours to obtain 2.2 g of the title compound with a yield of 49%.

[0188] MS (ESI) m / z: 394.20 [M + H] + ;

[0189] Step 2: Synthesis of 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)butan-1-one (4-VII)

[0190] The title compound of this step was prepared according to the method described in Step 3 of Example 1, that is, 4-chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)butan-1-one (3-VII) (0.6 g, 1.52 mmol), 3-(piperazin-1-yl)benzo[d]isothiazole (0.3 g, 1.38 mmol), triethylamine (0.6 mL, 4.15 mmol), and potassium iodide (0.02 g, 0.14 mmol) were added to acetonitrile (10 mL), and the mixture was refluxed for 24 hours to obtain 0.2 g of the title compound with a yield of 25%.

[0191] MS(ESI) m / z: 577.20 [M+H] + ;

[0192] Step 3: Synthesis of 4-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one (Compound VII)

[0193] The title compound of this step was prepared according to the method described in Step 4 of Example 1, that is, 4-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1-tosyl-1H-indol-3-yl)butan-1-one (4-VII) (0.2 g, 0.35 mmol) and sodium hydroxide solution (0.9 mL, 4 mol / L) were reacted in a mixed solution of ethanol (6 mL) and tetrahydrofuran (1 mL) at 70 °C for 10 hours to obtain 0.14 g of the title compound with a yield of 96%.

[0194] MS(ESI) m / z: 423.30 [M+H] + ;

[0195] Step 4: Synthesis of 4-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one (VII) hydrochloride

[0196] The title compound of this step was prepared according to the method described in Step 3 of Example 6, that is, 4-(4-(benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one (VII) (0.14 g, 0.3 mmol) and ethyl acetate solution of hydrogen chloride (0.5 mL, 2 mol / L) were stirred in ethyl acetate (5 mL) at 30 °C for 11 hours to obtain 0.09 g of the title compound with a yield of 59%.

[0197] MS(ESI) m / z: 423.30 [M+H] + ;

[0198] 1 1H NMR (400 MHz, DMSO-d6) δ 12.23 (d, J = 3.1 Hz, 1H), 10.98 (s, 1H), 8.48 (d, J = 3.2 Hz, 1H), 8.16 (dd, J = 14.4, 8.2 Hz, 2H), 7.91 (dd, J = 9.9, 2.7 Hz, 1H), 7.67–7.60 (m, 1H), 7.58–7.48 (m, 2H), 7.11 (td, J = 9.1, 2.7 Hz, 1H), 4.12 (d, J = 13.5 Hz, 2H), 3.72–3.63 (m, 2H), 3.56 (t, J = 12.7 Hz, 2H), 3.33 (m, 2H), 3.29 (m, 2H), 3.09 (t, J = 7.1 Hz, 2H), 2.17 (p, J = 7.3 Hz, 2H).

[0199] Example 8

[0200] Preparation of 1-(5-Fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (Compound VIII) Hydrochloride

[0201]

[0202] Step 1: Synthesis of 5-Chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)pentan-1-one (3-VIII)

[0203] The title compound of this step was prepared according to the method described in Step 2 of Example 1, that is, 5-Fluoro-1-tosyl-1H-indole (2-I) (8 g, 27.65 mmol), 5-Chlorovaleryl chloride (4.6 mL, 35.95 mmol), and aluminum trichloride (7.4 g, 55.30 mmol) were reacted in dichloromethane (160 mL) at 0 - 30 °C for 6 hours to obtain 11 g of the title compound with a yield of 98%.

[0204] MS (ESI) m / z: 408.20 [M+H] + ;

[0205] Step 2: Synthesis of 1-(5-Fluoro-1-tosyl-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (4-VIII)

[0206] The title compound of this step was prepared according to the method described in Step 3 of Example 1, that is, 5-chloro-1-(5-fluoro-1-tosyl-1H-indol-3-yl)pentan-1-one (3-VIII) (2 g, 4.90 mmol), 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole (0.98 g, 4.46 mmol), triethylamine (1.2 mL, 8.92 mmol), and potassium iodide (0.07 g, 0.44 mmol) were added to acetonitrile (20 mL), and the mixture was refluxed for 24 hours to obtain 1 g of the title compound with a yield of 38%.

[0207] MS(ESI) m / z: 592.30 [M+H] + ;

[0208] Step 3: Synthesis of 1-(5-fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (Compound VIII)

[0209] The title compound of this step was prepared according to the method described in Step 4 of Example 1, that is, 1-(5-fluoro-1-tosyl-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (4-VIII) (0.5 g, 0.84 mmol) and sodium hydroxide solution (2.1 mL, 4 mol / L) were reacted in a mixed solution of ethanol (15 mL) and tetrahydrofuran (2.5 mL) at 70 °C for 15 hours to obtain 0.16 g of the title compound with a yield of 43%.

[0210] MS(ESI) m / z: 438.20 [M+H] + ;

[0211] Step 4: Synthesis of 1-(5-fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (VIII) hydrochloride

[0212] The title compound of this step was prepared according to the method described in Step 3 of Example 6, that is, 1-(5-fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one (VIII) (0.1 g, 0.23 mmol) and ethyl acetate solution of hydrogen chloride (0.3 mL, 2 mol / L) were stirred in tetrahydrofuran (5 mL) at 30 °C for 11 hours to obtain 0.05 g of the title compound with a yield of 46%.

[0213] MS(ESI) m / z: 438.62 [M+H] + ;

[0214] 1H NMR (600 MHz, Methanol-d4) δ 8.26 (s, 1H), 7.91 (dd, J = 9.9, 2.6 Hz, 2H), 7.44 (dt, J = 8.9, 3.2 Hz, 2H), 7.21 (td, J = 9.0, 2.2 Hz, 1H), 7.02 (td, J = 9.1, 2.6 Hz, 1H), 3.77 (m, 2H), 3.53 (m, 1H), 3.26 (m, 4H), 3.04 (t, J = 6.4 Hz, 2H), 2.44 (m, 2H), 2.21 (m, 2H), 1.88 (m, 4H).

[0215] Activity test section

[0216] The inhibitory effect of the compound of Example 9 on 5-HT reuptake, 5-HT 1A and 5-HT7 receptor binding experiments

[0217] Using compound A in the patent (CN109467554A) as a control

[0218] 1. 5-HT reuptake inhibition experiment of the compound

[0219] Cell culture: HEK293 cells stably expressing human serotonin transporter (hSERT) (purchased from WuXi AppTec) were passaged more than twice to stabilize cell viability. The cells were digested with trypsin-EDTA and collected by centrifugation at 1000 rpm for 5 minutes. The cell pellet was resuspended in 10 mL of medium, and the cell clumps were dispersed by pipetting up and down using a sterile pipette. Cell viability was measured using a Vi-CELL cell counter. The cell suspension was diluted with medium to 1×106 cells per milliliter (2×104 cells per 20 μL well), and then added to a 384-well cell plate. The cell plate was placed in an incubator at 37 °C and 5% CO2 for 16 - 20 hours.

[0220] 5 - Hydroxytryptamine Reuptake Experiment: Using a Bravo automated liquid handling workstation, the control compound (citalopram) was serially diluted into 10 concentrations in buffer (HBSS solution with 20 mM HEPES, containing 0.1% BSA) in duplicate for each concentration. The highest concentration was set at 1 μM, and the dilution factor was 3. Using the Bravo instrument, the test compound was serially diluted into 10 concentrations in buffer (HBSS solution with 20 mM HEPES, containing 0.1% BSA) in duplicate for each concentration. The highest concentration was set at 10 μM, and the dilution factor was 5. The culture medium was aspirated from the 384 - well cell plate by Bravo, and then the compound dilution was transferred to the cell plate at a rate of 25 μL / well by Bravo. For the high control group (blank control group), a 25 - μL 0.25% DMSO solution containing BSA prepared with experimental buffer was used. For the low control group, a 25 - μL 1 - μM citalopram solution was used. Then the cell plate was centrifuged at 300 rpm for 15 seconds and then incubated at 37°C for 30 minutes. After incubation with the compound, 25 μL of the dye solution was added to each well, and then incubated at 37°C for 30 minutes. The cell plate was read using an EnVision multimode microplate reader platform.

[0221] The experiment can be divided into: high control group (High control, abbreviated as HC), low control group (Low control, abbreviated as LC), and compound group. Two replicates were measured for each concentration. Calculate the percentage of reuptake inhibition of each compound according to the following formula:

[0222]

[0223] Non - linear regression analysis was performed on the competitive curves fitted to the reuptake inhibition rates (averages) of the compound at multiple concentrations to obtain the IC 50 value.

[0224] 2.5 - HT 1A Receptor Binding Experiment

[0225] Radioligand binding experiments were performed using the membranes of HEK293 cells stably transfected with the human 5-HT1a receptor (purchased from WuXi AppTec). Prepare Tris-HCl reaction buffer (50 mM Tris-HCl, 10 mM MgSO4, 0.5 mM EDTA, pH 7.4) and eluent (50 mM Tris-HCl, pH 7.4) for the experiment. The test compound was serially diluted into 8 concentrations, with the highest concentration set at 1 μM and a dilution factor of 4. The control compound (8-OH-DPAT) was serially diluted into 8 concentrations, with the highest concentration set at 0.1 μM and a dilution factor of 4. Both were prepared with the reaction buffer. Two replicates were measured for each concentration. 8-OH-DPAT (100 nM) was used to test non-specific binding, i.e., the low control group (LC), and 1 μL of DMSO was used as the high control group (HC). Transfer 1 μL of the compound / high control / low control group solution to the pre-set positions on the microplate. Then, add 100 μL of the membrane stock solution (15 μg / well) to the microplate, and then add 100 μL of the radioactive ligand 3 [3H]-8-OH-DPAT solution (final concentration 0.3 nM), seal the microplate, and incubate at room temperature for 1 hour. Add 50 μL of 0.3% PEI (polyethyleneimine) to each well of the Unifilter-96GF / C filter plate and soak at room temperature for at least 0.5 hours. When the binding reaction is complete, use the Filtermate cell harvester from PerkinElmer to filter the reaction mixture through the GF / C filter plate, and then wash each plate 4 times with cold eluent. Dry the filter plate at 50 °C for 1 hour. After drying, seal the bottom of the filter plate wells with the Perkin Elmer Unifilter-96 backing seal tape, add 50 μL of Perkin Elmer's Microscint-O scintillation fluid, and seal the top of the filter plate with the Perkin Elmer TopSeal-A sealing film. Use the Perkin Elmer MicroBeta2 counter to count the 3 [3H] captured on the filter plate. The percentage inhibition rate of each compound on radioligand binding was calculated according to the aforementioned formula.

[0226]

[0227] The obtained inhibition rate data were analyzed using GraphPad Prism software. The data were fitted to a single-point curve fitting equation, and the Ki value was calculated according to the Cheng-Prusoff equation.

[0228] 3. 5-HT7 Receptor Binding Experiment

[0229] Using a multi-channel pipette, transfer 1 μL of serial dilutions of the reference compound (serotonin) and the test compound onto the cell plate. According to the preset positions, transfer 1 μL of the non-specific binding compound (10 μM serotonin) onto the cell plate (as the low control group, abbreviated as LC). According to the preset positions, transfer 1 μL of DMSO onto the assay plate (as the high control group, abbreviated as HC). Then, add 100 μL of the membrane stock solution (10 μg / well) into the microplate, and then add 100 μL of the radioactive ligand 3 [3H]-LSD solution (final concentration of 4 nM), seal the microplate, and shake the microplate at a speed of 300 rpm under specific conditions. Soak each well of the Unifilter-96 GF / C filter plate with 50 μL of 0.3% PEI at room temperature for at least 0.5 hours. When the binding experiment is completed, use a Filtermate cell harvester from Perkin Elmer to filter the reaction mixture through the GF / C plate, and then wash each plate 4 times with cold eluent. Dry the filter plate at 50 °C for 1 hour. After drying, seal the bottom of the filter plate wells with a Perkin Elmer Unifilter-96 backing sealing tape, add 50 μL of PerkinElmer Microscint 20 scintillation fluid, and then seal the top of the filter plate with a Perkin Elmer TopSeal-A sealing film. Use a Perkin Elmer MicroBeta2 counter to count the 3 3H captured on the filter plate. Calculate the inhibition rate using the following equation:

[0230]

[0231] Analyze the data using Prism 5 software, fit the data using the "log(inhibitor) vs. response--Variable slope" model, and calculate the Ki value according to the Cheng-Prusoff equation.

[0232] 4. Experimental results of compound 5-HT reuptake inhibition, 5-HT 1A receptor binding, and 5-HT7 receptor binding

[0233] Table 1. Experimental results of compound 5-HT reuptake inhibition, 5-HT 1A receptor binding, and 5-HT7 receptor binding

[0234]

[0235]

[0236] As shown in Table 1, under the same test conditions, the compounds I-VIII of the present invention show extremely strong activities of 5-HT reuptake inhibition, 5-HT1a binding and 5-HT7 binding, and are equivalent to or superior to compound A and the positive drug vortioxetine in activity. The activities of some compounds such as III against three targets are superior to those of compound A and vortioxetine.

[0237] hERG potassium channel inhibition experiment of the compound in Example 10

[0238] Experimental method:

[0239] Dissolve the compound in DMSO to prepare a 10 mM stock solution. The stock solution was successively diluted 3-fold with DMSO to the corresponding secondary stock solutions. Take 60 μL of each concentration of the secondary stock solution and dilute it to 20 mL of extracellular fluid to obtain the final concentration for electrophysiological detection. At least 2 cells were tested for each concentration (n≥2). The final concentration of DMSO was 3:1000. HEK293 cells overexpressing the hERG potassium channel (purchased from Corebio) were used. The cells were cultured in an incubator at 37°C and 5% CO2. When the cell density reached 80% of the culture dish, they were first pre-washed with phosphate buffer (PBS), then digested with trypsin / EDTA for 2-3 minutes, and the digestion was stopped by adding cell culture medium. The cells were gently pipetted and transferred to a centrifuge tube, centrifuged at 1000 rpm for 3 minutes, the supernatant was discarded, cell culture medium was added, and the cells were gently pipetted to mix them evenly, and then transferred to a culture dish for subculture, or the cells were dropped onto a round glass slide and cultured in cell culture medium until the cells adhered for experiments. The composition of the cell culture medium was DMEM, 15% fetal bovine serum, and 1% 100x penicillin-streptomycin. The stably transfected cells were dropped onto a round glass slide and placed in a culture dish with a cell density of less than 50%, and cultured overnight. The experimental cells were transferred to a cell bath embedded in the platform of an inverted microscope, and the extracellular fluid was perfused at a perfusion rate of 2.7 ml / min. The experiment could be started after 5 minutes of stabilization. The HEKA EPC-10 patch clamp amplifier and PATCHMASTER acquisition system were used to record the membrane current (HEKA Instruments Inc., D-67466 Lambrecht, Pfalz, Germany). All experiments were completed at room temperature (22-24°C). In the experiment, a P-97 microelectrode puller (Sutter Instrument Company, One Digital Drive, Novato, CA94949) was used to pull the electrode (BF150-110-10). The inner diameter of the electrode was 1-1.5 mm, and the access resistance after being filled with the internal solution was 2-4 MΩ. The electrophysiological stimulation protocol for the hERG potassium channel was to first clamp the membrane voltage at -80 mV, apply a +20 mV voltage stimulation to the cells for 2 s to activate the hERG potassium channel, and then repolarize to -50 mV for 5 s to generate an outward tail current, with a stimulation frequency of once every 15 s. The current value was the peak value of the tail current. The whole-cell recording mode was used to record the channel current in the experiment. First, the extracellular fluid was perfused (about 2 ml per minute) and continuously recorded, and waited for the current to stabilize (the current decay (Run-Down) was less than 5% within 5 minutes). At this time, the peak value of the tail current was the control current value. Then, the extracellular fluid containing the drug to be tested was perfused and continuously recorded until the inhibitory effect of the drug on the hERG current reached a steady state. At this time, the peak value of the tail current was the current value after adding the drug. The standard of the steady state was judged by whether the last 3 consecutive current recording lines coincided.After reaching a stable state, if the hERG current recovers or approaches the level before drug addition after perfusion and rinsing with extracellular fluid, perfusion can continue to test other concentrations or drugs. 30 μM Quinidine was used as a positive control in the experiment to ensure normal cell responses. By measuring the maximum current values of the control group and the drug-treated group, calculating the ratio of the maximum current value of the treated group to that of the control group, the effect of the test compound on the hERG potassium channel at the test concentration was evaluated (Mean ± SE). Experimental data were collected using PATCHMASTER V2X60 (HEKA Instruments Inc., D-67466 Lambrecht, Pfalz, Germany) and analyzed and statistically processed using Origin 8.5 (OriginLab Corporation, Northampton, MA) software and Microsoft Excel. Nonlinear regression analysis was performed on the competitive curves fitted to the hERG inhibition rates (averages) of the compound at multiple concentrations to obtain the IC of the compound's hERG inhibition. 50 value.

[0240] The experimental results of the compound's inhibition of the hERG potassium channel are shown in Table 2 below:

[0241] Table 2. Inhibition rate and inhibition IC of the compound on the hERG potassium channel at 1 μM 50 value

[0242] Compound Number hERG Inhibition Rate (1 μM) <![CDATA[hERG inhibitory IC 50 > I 50.01％±1.82％ > 1 μM III 40.08％±0.73％ > 1 μM IV 38.05％±0.95％ 5.2 μM Compound A 95.12％±1.22％ 0.01 μM Vortioxetine 55.43％±0.49％ 3.2 μM

[0243] Using the "gold standard" test method, the hERG manual patch clamp experiment, under the same test conditions, the inhibition rates of Compounds I, III, and IV of the present invention on the hERG channel at a concentration of 1 μM were significantly lower than that of Compound A, comparable to or better than that of the positive drug vortioxetine, and the measured IC 50 value was at least 100 times that of Compound A, showing a significant improvement in the inhibition of the hERG channel, reducing the potential risk of cardiac toxicity, and also demonstrating better safety in electrocardiogram experiments.

[0244] In-vivo antidepressant activity experiment of the compound in Example 11

[0245] The tail suspension test and forced swimming test of mice in the "behavioral despair model" were used, with vilazodone and vortioxetine as positive control drugs respectively, to preliminarily study the in-vivo antidepressant effects of some of the inventive compounds.

[0246] 1. Tail suspension test of mice

[0247] Experimental method:

[0248] Ten male ICR mice were evenly and randomly divided into the following groups according to body weight: blank control group, positive drug group (vilazodone), and compound test group. They were gavaged at a dose of 0.2 ml / 10 g, and the blank control group was given the same volume of normal saline. One hour after administration, about 2 cm from the end of the mouse's tail was fixed with medical tape, and the mouse was hung upside down in the tail suspension box, with its head about 5 cm from the bottom of the box. After the mouse was hung, observation began and lasted for 6 minutes. The immobility time of the mouse within these 6 minutes was accumulated (the mouse stopped struggling in the air or only had slight limb movements).

[0249] The results of the mouse tail suspension experiment of Compounds I, IV, and A under the same test conditions are shown in Table 3:

[0250] Table 3. Results of the mouse tail suspension experiment after gavage administration of Compounds I, IV, and A

[0251] Group Dose (mg / kg) Immobility Time (s) Blank Control Group - 178.0±31.8 I 3 172.5±60.5 I 10 99.5±40.1** I 30 69.5±34.9** IV 3 168.5±67.2 IV 10 100.3±50.2** IV 30 80.3±45.2** Compound A 3 175.2±60.2 Compound A 10 145.2±56.7 Compound A 30 72.5±33.2** Vilazodone 30 81.0±42.3**

[0252] The experimental data were statistically analyzed by the T-test. *Compared with the blank control group, P < 0.05, indicating a significant difference; **compared with the blank control group, P < 0.01, indicating a highly significant difference.

[0253] In the mouse tail suspension experiment, Compounds I, IV, and Compound A all showed a trend of dose-dependently reducing the immobility time of mice. Compounds I and IV could highly significantly reduce the immobility time of mice at doses of 10 mg / kg and 30 mg / kg, with a lower effective dose compared to Compound A. And at a dose of 30 mg / kg, the immobility time of mice was less than that of the positive drug vilazodone, showing stronger antidepressant activity.

[0254] 2. Mouse forced swimming experiment

[0255] Experimental method:

[0256] Ten male ICR mice were evenly and randomly divided into the following groups according to body weight: blank control group, vortioxetine group (20.0 mg / kg), and compound test group (5.0 mg / kg). They were gavaged at a dose of 0.2 ml / 10 g, and the blank control group was given the same volume of normal saline. The mice were pre-screened by pre-swimming one day before the experiment. The mice were placed in a glass cylinder with a water depth of 15 cm (height 25 cm, diameter 20 cm), and the water temperature was 25 °C, and they were allowed to swim for 6 minutes. Animals with a stop-swimming immobility time between 70 - 160 seconds were selected for the formal experiment. The next day, the formal experiment was carried out, and each group of mice was given the corresponding drug according to the group. One hour after administration, the mouse swimming experiment was carried out. The animals were placed in the above environment to swim for 6 minutes, and the cumulative stop-swimming immobility time of the mice in the last 4 minutes within 6 minutes was recorded.

[0257] The results of the forced swimming test in mice for Compounds I, IV, and A under the same test conditions are shown in Table 4:

[0258] Table 4. Results of the forced swimming test in mice administered Compounds I, IV, and A by gavage

[0259] Group Dose (mg / kg) Immobility Time (s) Blank Control Group - 134.9±38.7 I 3 141.0±60.2 I 10 92.2±39.2* I 30 60.5±24.9** IV 3 121.5±57.4 IV 10 88.3±40.2* IV 30 58.3±35.2** Compound A 3 127.1±50.1 Compound A 10 100.5±60.1 Compound A 30 60.5±33.2** Vortioxetine 30 73.1±21.5**

[0260] The experimental data were subjected to a statistical T - test. *, compared with the blank control group, P < 0.05, showing a significant difference; **, compared with the blank control group, P < 0.01, showing a highly significant difference.

[0261] In the forced swimming test in mice, Compounds I, IV, and Compound A all showed a tendency to dose - dependently reduce the immobility time of mice. Compounds I and IV could significantly reduce the immobility time of mice at a dose of 10 mg / kg and highly significantly reduce the immobility time at a dose of 30 mg / kg. Their effective doses were lower than that of Compound A. At a dose of 30 mg / kg, the immobility time of mice was less than that of the positive drug, vortioxetine, indicating stronger antidepressant activity.

[0262] The above - mentioned embodiments are preferred embodiments of the present invention. However, the embodiments of the present invention are not limited to the above - mentioned embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included within the scope of the present invention.

Claims

1. A compound of formula I or a pharmaceutically acceptable salt thereof, wherein: n is 0, 1 or 2; k is 0, 1 or 2; R 1 each independently represents a halogen, a hydroxyl group, a C1-C6 alkoxy group, a C1-C6 alkyl group or a cyano group; R 2 each independently represents a halogen, a C1-C6 alkoxy group or a C1-C6 alkyl group; L is -C(=O)- or -CH(OH)-; m is 1, 2 or 3; X is CH or N; Y is O or S.

2. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1, wherein, It satisfies one or more of the following conditions: (1)R 1 and R 2 wherein each of the halogens is independently fluorine, chlorine or bromine, such as fluorine; (2)R 1 and R 2 wherein each of the C1-C6 alkyl groups is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; (3)R 1 and R 2 wherein each of the C1-C6 alkoxy groups is independently methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy; and (4) the pharmaceutically acceptable salt of the compound of formula I is hydrochloride, hydrobromide, sulfate, mesylate or oxalate of the compound of formula I, such as hydrochloride of the compound of formula I.

3. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1, wherein, It satisfies one or more of the following conditions: (1) n is 0 or 1, such as 1; (2) k is 0 or 1; (3)R 1 Each independently is a halogen or a cyano group; and (4)R 2 Each is independently a halogen.

4. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, The compound of formula I satisfies one or more of the following conditions: (1)R 1 is F or cyano; (2)R 2 is F; (3) For and (4) is 5. The compound of formula I or a pharmaceutically acceptable salt thereof according to any one of claims 1-4, characterized in that, The compound of formula I is the compound of formula I-1; wherein, R 1 , m, X, L, Y, R 2 and k are each independently as described in any one of claims 1-4.

6. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 5, characterized in that, The compound of formula I is the compound of formula I-2; wherein, R 1 、m, L, X, Y, R 2 and k are each independently as defined in claim 5.

7. The compound of formula I or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, The compound of formula I is: 3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-one; 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one; 3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)propan-1-ol; 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-ol; 3-(3-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)propanoyl)-1H-indole-5-carbonitrile; 3-(3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile; 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one; or 1-(5-fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one; The pharmaceutically acceptable salt of the compound of formula I is: 1-(5-fluoro-1H-indol-3-yl)-3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propan-1-one monohydrochloride; 3-(3-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)propanoyl)-1H-indole-5-carbonitrile monohydrochloride; 4-(4-(Benzo[d]isothiazol-3-yl)piperazin-1-yl)-1-(5-fluoro-1H-indol-3-yl)butan-1-one monohydrochloride; or 1-(5-fluoro-1H-indol-3-yl)-5-(4-(6-fluorobenzo[d]isoxazol-3-yl)piperidin-1-yl)pentan-1-one monohydrochloride.

8. A pharmaceutical composition comprising the compound of formula I or a pharmaceutically acceptable salt thereof according to any one of claims 1-7, and a pharmaceutically acceptable excipient.

9. Use of a compound of formula I as described in any one of claims 1-7 or a pharmaceutically acceptable salt thereof or a pharmaceutical composition as described in claim 8, said use being selected from: (1) Preparing a 5-HT reuptake inhibitor; (2) Preparing a 5-HT1a receptor binder; (3) Preparing a 5-HT7 receptor binder; (4) Preparing a drug for treating and / or preventing diseases related to 5-HT reuptake, 5-HT1a or 5-HT7; preferably, said diseases are central nervous system diseases, such as depression and / or anxiety disorder; and (5) Preparing a drug for treating and / or preventing central nervous system diseases, preferably, said central nervous system diseases are depression and / or anxiety disorder.

10. A method for preparing a compound represented by Formula I-3 or I-4, characterized in that, The preparation method of the compound of formula I-3 comprises the following steps: The compound of formula I-5 is hydrolyzed to obtain the compound of formula I-3; R 3 is an amino protecting group, such as tosyl or tert-butoxycarbonyl, preferably tosyl; R 1 、n、m、X、Y, R 2 and k are each independently as described in any one of claims 1-7; The preparation method of the compound of formula I-4 comprises the following Method 1 or Method 2: Method 1 comprises the following steps: The compound of formula I-3 reacts with a reducing agent in a reduction reaction to obtain the compound of formula I-4; wherein, R 1 , n, m, X, Y, R 2 and k are each independently as described in any one of claims 1-7; Method 2 comprises the following steps: The compound of formula I-6 is hydrolyzed to obtain the compound of formula I-4; R 4 is an amino protecting group, such as tosyl or tert-butoxycarbonyl, preferably tosyl; R 1 , n, m, X, Y, R 2 and k are each independently as described in any one of claims 1-7.

11. Compounds of formula I-5 and I-6; Among them, R 1 , n, m, X, Y, R 2 , R 3 , R 4 and k are each independently as described in any one of claims 1-7; for example, the compound represented by Formula I-5 is For example, the compound represented by Formula I-6 is

Images