Use of α-chromene spiropiperidine compounds in the preparation of serotonin 2C receptor agonists

Abstract

The present invention discloses the use of α-chromene spiropiperidine compounds in the preparation of 5-hydroxytryptamine 2C receptor agonists. These compounds exhibit excellent activation effects and good selectivity for the 5-HT 2C receptor, have complete G protein signaling pathway bias and low hERG inhibitory activity, and can be used for the prevention and treatment of obesity, urinary incontinence, depression, anxiety disorder, obsessive-compulsive disorder, epilepsy, schizophrenia, pain, diabetes, drug addiction and other diseases with the 5-HT 2C receptor as the therapeutic target, providing new theoretical and technical support for the development of drugs for the treatment and / or prevention of diseases with the 5-HT 2C receptor as the therapeutic target.

Description

Technical Field

[0001] The present invention relates to the field of pharmacology, and particularly to the use of α-chromene spiro-piperidine compounds in the preparation of 5-hydroxytryptamine 2C receptor agonists. Background Art

[0002] 5-Hydroxytryptamine 2C (5-HT 2C ) receptor is a GPCR receptor that has been widely studied in recent years. It belongs to the 5-hydroxytryptamine receptor family and is the only 5-hydroxytryptamine receptor subtype that undergoes RNA editing. Since it is mainly expressed in the central nervous system and has a low risk of peripheral side effects, the 5-HT 2C receptor has become an ideal target for treating central nervous system diseases, such as childhood refractory epilepsy Dravet syndrome, obesity, schizophrenia, addiction, and drug abuse. It is generally believed that GPCR receptors only mediate downstream complex signal transduction pathways through G proteins. However, more and more recent studies have found that GPCR receptors can also activate non-G protein-dependent signal pathways through G protein-coupled receptor kinases (GRKs) and β-arrestins (β-arrestin), mediating desensitization, internalization, and recycling of GPCRs. Because GPCR agonists unevenly activate these two signal pathways, they exhibit different degrees of "bias", namely "G protein-biased agonists" and "β-arrestin-biased agonists". Among them, G protein-biased agonists have become a new focus of research recently because they can avoid drug resistance induced by desensitization mediated by the β-arrestin pathway and show a longer-lasting therapeutic effect.

[0003] Compared with other GPCR receptors, the research on biased agonists targeting the 5-HT 2C receptor is still in its initial stage and was not reported until 2016. One type is that the University of Illinois at Chicago (UIC) in the United States confirmed that the (2-phenylcyclopropyl) methylamine-based G protein-biased 5-HT 2C receptor agonist (+)-7e can delay the desensitization reaction of the 5-HT 2C receptor and prolong the downstream effects mediated by the receptor (JMed Chem, 2016, 59, 9866-80). Another type is a series of aporphine-based fully G protein-biased 5-HT 2C receptor agonists discovered by our team previously, which have in vivo anti-obesity activity and anti-schizophrenia activity (ACSCentSci, 2020, 6, 213-25; Bioorganic Chemistry 123 (2022) 105795).

[0004] However, the existing G protein-biased 5-HT 2C receptor agonists have a certain affinity for 5-HT 2CLow receptor selectivity [such as (+)-7e (JMed Chem, 2016, 59, 9866 - 80), (+)-15a and (+)-19 (JMed Chem, 2017, 60, 6273 - 88), 11b and 11f (Bioorganic Chemistry 123(2022)105795)]. When activating the 5-HT 2C receptor, it will also activate its highly homologous 5-HT2 receptor subtype, 5-HT 2A and 5-HT 2B , thereby triggering hallucinogenic effects, as well as the occurrence of pulmonary hypertension and cardiac valvular disease, which may lead to the occurrence of side effects. In addition, the compound also has poor bias (such as (+)-7e, (+)-19), weak 5-HT 2C receptor agonist activity [such as 1857 (ACS Cent Sci, 2020, 6, 213 - 25)] or high hERG inhibition rate [MQ02 - 439 (ACS Chem Neurosci, 2020, 11, 549 - 59)] and other defects, which limit the further clinical development of the above compounds. Therefore, it is still necessary to develop 5-HT 2C receptor agonists with unique structures, high selectivity, high bias, high activity and good drug-likeness.

[0005] α-Chromene spiropiperidine is obtained by introducing a spiropiperidine ring at the C-2 position of chroman-4-one and reducing the carbonyl group at the C-4 position to a double bond. As an important structural skeleton in organic synthesis and drug design, it has been widely used in drug research and development. By acting on important drug targets such as acetyl-CoA carboxylase (ACC), transient receptor potential TRPM8, GPR119 and 5-HT 2A etc. (Journal of Medicinal Chemistry, 2015, 26:539–563; Bioorganic&MedicinalChemistry, 2020, 28:115813), it is used as a metabolic regulator, anti-inflammatory, antioxidant, anti-diabetic, anti-tumor, antipsychotic, anti-epileptic and anti-dementia drug for the potential treatment of diseases. There is currently no report on α-chromene spiropiperidine derivatives activating the 5-HT 2C receptor. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide the use of α-chromene spiropiperidine compounds in the preparation of 5-hydroxytryptamine 2C receptor agonists. The α-chromene spiropiperidine compounds exhibit high 5-HT 2C receptor selectivity and complete G protein bias, and significantly reduce the hERG inhibition rate.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] The present invention provides the use of an α-chromene spiropiperidine compound or a pharmaceutically acceptable salt thereof in the preparation of a serotonin 2C receptor agonist, and the general structural formula M of the α-chromene spiropiperidine compound is shown as follows:

[0009]

[0010] Wherein, is an aryl or heteroaryl, the aryl is phenyl, naphthyl or biphenyl, and the heteroaryl is a nitrogen-containing aromatic heterocycle or a fused aromatic ring substituent, such as: pyridine ring, pyrrole ring, pyrazole ring, thiazole ring, quinoline, isoquinoline, indole, benzofuran ring, furan ring, benzofuran ring, benzothiophene ring or thiophene ring;

[0011] R is selected from one or more of hydrogen, halogen, cyano, C1-C8 alkyl, C1-C8 alkoxy, C1-C8 haloalkyl, or forms a dihydrofuran ring with ;

[0012] X is -O-, -S- or -SO2-;

[0013] R1 is selected from one of hydrogen, cyano, C1-C8 alkyl, aryl;

[0014] m and n independently selected from 0, 1 or 2;

[0015] R2, R3, R4, R5, R6, R7, R8, R9 are independently selected from one of hydrogen, halogen, cyano, C1-C8 alkyl, C1-C8 haloalkyl, C1-C8 alkoxycarbonyl, C1-C8 alkoxyamide, C1-C8 alkanoyloxy, C1-C8 alkoxy, or any two of R2, R3, R4, R5, R6, R7, R8, R9 form a fused ring or a spiro ring.

[0016] Further, the pharmaceutically acceptable salt is a salt formed by the compound represented by the general formula M and an inorganic acid or an organic acid, such as hydrochloride.

[0017] Further, the C1-C8 haloalkyl is an alkyl containing 1-8 carbons with halogen, preferably one of trifluoromethyl, difluoromethyl, monofluoromethyl, trifluoroethyl.

[0018] Further, the C1-C8 alkyl (structural formula: R 10 -*), C1-C8 alkoxy (structural formula: R 10 O-*), C1-C8 alkoxycarbonyl (structural formula: ), C1-C8 alkoxyamide (structural formula: ), C1-C8 alkanoyloxy (structural formula: ), where R 10 , R 11 is an aliphatic alkyl group or an aromatic alkyl group.

[0019] Further, the aliphatic alkyl group includes one of a straight-chain alkyl group, a branched-chain alkyl group, a spirocyclic alkyl group, a bridged-ring alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkynyl group, an alkoxyalkyl group, an alkoxyacylalkyl group, a cycloalkylalkyl group, preferably one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, allyl, propargyl, cyclobutenyl, cyclohexenyl.

[0020] Further, the aromatic alkyl group is a substituted or unsubstituted aralkyl group or heteroaralkyl group, including a substituted or unsubstituted aryloxy group, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenethyl group.

[0021] Further, preferably is a benzene ring; X is -O-; R is selected from a halogen, a C1-C8 alkyl group, a C1-C8 alkoxy group, or forms a dihydrofuran ring with ; R1 is selected from one of hydrogen, a cyano group, a C1-C8 alkyl group;

[0022] R2, R3, R4, R5, R6, R7, R8, R9 are independently selected from hydrogen, a C1-C8 alkyl group, a halogen, or any two substituents form a fused ring or a spiro ring.

[0023] Further, the α-chromene spiropiperidine compound is one of the following structural formulas:

[0024]

[0025]

[0026] Further, preferably is a benzene ring; X is -O-; R is selected from one of hydrogen, a halogen, a C1-C8 alkyl group, a C1-C8 alkoxy group; m and n are both 1; R1 to R9 are all hydrogen.

[0027] Further, the α-chromene spiropiperidine compound is selected from one of the compounds shown in Formula S1, S2, S4, S5, S8, S16, S18.

[0028] Further, when is a benzene ring; X is -O-; R is selected from hydrogen, a halogen, a C1-C8 alkyl group, a C1-C8 alkoxy group, or forms a dihydrofuran ring with ; when R1 to R5 are all hydrogen; the preparation method of the α-chromene spiropiperidine compound includes the following steps:

[0029] (1) React the compound shown by formula M1 with the compound shown by formula M2 under an organic solvent and basic conditions to prepare the compound shown by formula M3;

[0030] (2) React the compound shown by formula M3 in the presence of an organic solvent and a reducing agent to obtain the compound shown by formula M4; React the compound shown by formula M4 in the presence of a dehydrating agent, a reducing agent and an organic solvent to remove water and a protecting agent to obtain the compound shown by formula M5; or,

[0031] React the compound shown by formula M3 in the presence of a base, a trifluoromethanesulfonylation reagent and an organic solvent to isomerize to obtain the compound shown by formula M6; React the compound shown by formula M6 in the presence of a metal catalyst, phenylboronic acid, a basic solution and an organic solvent, introduce the R1 fragment and then deprotect to obtain the compound shown by formula M7.

[0032] The structural formulas and reaction routes of the above M1 - M7 are as follows:

[0033]

[0034] Among them, the reaction conditions: (a) pyrrole, ethanol, rt (room temperature); (b) NaBH4 (sodium borohydride), MeOH (methanol), 0 °C - rt; (c) TsOH (p - toluenesulfonic acid), toluene, 130 °C; (d) C6H5N(SO2CF3)2 ((trifluoromethanesulfonyl)aniline), LiHMDS (lithium bis - (trimethylsilyl)amide), THF (tetrahydrofuran), - 78 °C - 25 °C; (e) phenylboronic acid, Pd[P(C6H5)3]4, LiCl (lithium chloride), aq.Na2CO3 (sodium carbonate), dimethyl ether, reflux.

[0035] Furthermore, the 5 - hydroxytryptamine 2C receptor agonist is used for preventing and / or treating diseases targeted at the 5 - hydroxytryptamine 2C receptor.

[0036] Furthermore, the diseases are one or more of obesity, urinary incontinence, depression, anxiety disorder, obsessive - compulsive disorder, epilepsy, schizophrenia, pain, diabetes and drug addiction.

[0037] The beneficial effects of the present invention are as follows:

[0038] 1. The present invention designs α - chromene spiro - piperidine compounds with a general formula M structure and discovers that the compounds with such a structure have an effect on 5 - HT 2CThe receptor exhibits excellent activation, good receptor selectivity, complete G-protein signaling pathway bias, low hERG inhibitory activity, no effect on the β-arrestin signaling pathway, and low side effects and drug resistance. In addition, the present invention further studies the relationship between the α-chromene spiroperidine structure and activity efficacy, providing new theoretical and technical support for the development of drugs for the treatment and / or prevention of diseases targeting the 5-HT 2C receptor as a therapeutic target.

[0039] 2. The α-chromene spiroperidine compound described in the present invention can be used as a live 5-HT 2C receptor agonist for preventing or treating diseases targeting the 5-HT 2C receptor, such as obesity, urinary incontinence, depression, anxiety, obsessive-compulsive disorder, epilepsy, schizophrenia, pain, diabetes, and drug addiction. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Fig. is the dose-effect curves of lorcaserin and α-chromene spiroperidine compounds on the G q signaling pathway and the β-arrestin-2 signaling pathway; Figure 1 A: Lorcaserin, Figure 1 B: Compound S1, Figure 1 C: Compound S4. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments given are not intended to limit the present invention.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] In the following embodiments of the present invention, the structure of the compound is determined by nuclear magnetic resonance (NMR) or mass spectrometry (MS). NMR is measured using an Agilent 400 MHz or 600 MHz instrument, the measurement solvent is deuterated dimethyl sulfoxide (DMSO-d6), deuterated chloroform (CDCl3), and the internal standard is tetramethylsilane (TMS). MS is measured using a GCT PremierTM (CI) mass spectrometer, and the CI source (70 ev) is used unless otherwise specified.

[0044] For thin-layer chromatography silica gel plates, Yantai Huanghai HSGF254 or Qingdao GF254 silica gel plates are used. The specifications of the silica gel plates used in thin-layer chromatography (TLC) are 0.15 mm - 0.2 mm. For column chromatography, silica gel with 100 - 200 mesh or 200 - 300 mesh from Yantai Huanghai is generally used as the carrier.

[0045] When the reaction condition is to fill with nitrogen, it means connecting a nitrogen balloon with a volume of about 1 L to the reaction flask. When the reaction condition is to fill with hydrogen, it means connecting a hydrogen balloon with a volume of about 1 L to the reaction flask. The reaction condition is room temperature (rt), and the temperature range is 20 - 30 °C.

[0046] In the following examples of the present invention, all solvents were redistilled before use, and the anhydrous solvents used were all obtained by drying treatment according to standard methods.

[0047] Example 1: Synthesis of Compound S1

[0048] The synthesis route of Compound S1 is as follows:

[0049]

[0050] Among them, the reaction conditions are: (a) pyrrole, ethanol, rt (room temperature); (b) NaBH4 (sodium borohydride), MeOH (methanol), 0 °C - rt; (c) TsOH (p-toluenesulfonic acid), toluene, 130 °C.

[0051] Synthesis of Compound S1-3: Dissolve 0.25 mL (3.25 mmol) of commercially available 2-hydroxyacetophenone (S1-1) in 20 mL of anhydrous methanol solution, add 345 mg (4.87 mmol) of pyrrolidine, stir for 5 min, then add 969.16 mg (4.87 mmol) of commercially available 1-Boc-4-piperidone (S1-2), and stir at room temperature for 2 h. Concentrate methanol under reduced pressure, extract and separate with dichloromethane and saturated sodium chloride solution, dry the organic phase with anhydrous sodium sulfate, and concentrate under reduced pressure. The obtained crude product is purified by silica gel column chromatography (PE / EA = 10 / 1) to obtain 976 mg of white solid.

[0052] Synthesis of Compound S1-4: Dissolve 634 mg of Compound S1-3 (2 mmol) in 15 mL of anhydrous methanol, add 380 mg (10 mmol) of NaBH4 to the mixture under ice bath, after adding, transfer to room temperature, after 2 h, concentrate methanol under reduced pressure, extract and separate with dichloromethane and saturated sodium chloride solution, dry the organic phase with anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the crude product. The obtained crude product is purified by silica gel column chromatography (PE / EA = 4 / 1) to obtain 437 mg of pure product.

[0053] Synthesis of Compound S1: Dissolve 319 mg of Compound S1-4 (1 mmol) in 10 mL of toluene, add 209 mg (1.1 mmol) of TsOH, and reflux overnight at 130 °C. After cooling, add an excess of TEA, concentrate the mixture, and obtain the crude product. Separate it by column chromatography on basic alumina with PE:EA = 1:1, and then use the eluent DCM:MeOH:NH3·H2O = 70:1:0.1 to obtain 140 mg of a white solid. 1 H NMR (400 MHz, CDCl3) δ 7.13 (t, J = 7.6 Hz, 1H), 6.99 (d, J = 7.2 Hz, 1H), 6.87 (t, J = 7.6 Hz, 2H), 6.38 (d, J = 9.8 Hz, 1H), 5.62 (d, J = 9.7 Hz, 1H), 3.13 (t, J = 11.4 Hz, 2H), 2.88 (d, J = 12.3 Hz, 2H), 2.20 (s, 1H), 1.99 (d, J = 13.4 Hz, 2H), 1.72–1.59 (m, 2H).

[0054] Example 2: Synthesis of Compound S2

[0055] The synthesis method of Compound S2 is the same as that of Compound S1, except that the starting material of Compound S2 is 2-hydroxy-3-chloroacetophenone. 1 H NMR (400 MHz, DMSO) δ 7.13 (d, J = 7.9 Hz, 1H), 6.84 (d, J = 7.2 Hz, 1H), 6.74 (t, J = 7.6 Hz, 1H), 6.31 (d, J = 9.8 Hz, 1H), 5.59 (d, J = 9.8 Hz, 1H), 3.17 (t, J = 11.8 Hz, 2H), 2.84 (d, J = 12.0 Hz, 2H), 1.98 (s, 2H), 1.95 (s, 1H), 1.66–1.54 (m, 2H). 13 C NMR (101 MHz, CDCl3) δ 148.27 (s), 130.73 (s), 129.59 (s), 124.67 (s), 123.40 (s), 122.71 (s), 121.72 (s), 121.19 (s), 76.47 (s), 41.61 (s), 36.08 (s).

[0056] Example 3: Synthesis of Compound S3

[0057] The synthesis method of Compound S3 is the same as that of Compound S1, except that the starting material of Compound S3 is 2-hydroxy-5-chloroacetophenone. 11H NMR (400 MHz, CDCl3) δ 7.02 (d, J = 8.5 Hz, 1H), 6.92 (s, 1H), 6.73 (d, J = 8.5 Hz, 1H), 6.26 (d, J = 9.8 Hz, 1H), 5.62 (d, J = 9.8 Hz, 1H), 3.04 (t, J = 11.4 Hz, 2H), 2.85–2.77 (m, 2H), 1.91 (d, J = 13.5 Hz, 2H), 1.85 (s, 1H), 1.65–1.55 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 151.01 (s), 131.01 (s), 128.63 (s), 125.95 (s), 125.59 (s), 123.26 (s), 122.26 (s), 117.70 (s), 75.55 (s), 41.64 (s), 36.20 (s).

[0058] Example 4: Synthesis of Compound S4

[0059] Compound S4 was synthesized in the same manner as Compound S1, except that the starting material for Compound S4 was 4-chloro-2-hydroxy-acetophenone. 1 1H NMR (400 MHz, CDCl3) δ 6.80 (d, J = 9.2 Hz, 2H), 6.74 (d, J = 7.9 Hz, 1H), 6.23 (d, J = 9.8 Hz, 1H), 5.52 (d, J = 9.8 Hz, 1H), 2.99 (t, J = 11.2 Hz, 2H), 2.75 (d, J = 12.4 Hz, 2H), 1.86 (d, J = 13.4 Hz, 2H), 1.64 (s, 1H), 1.59–1.51 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 153.21 (s), 133.81 (s), 129.78 (s), 127.03 (s), 122.25 (s), 120.99 (s), 120.47 (s), 116.82 (s), 75.77 (s), 41.62 (s), 36.32 (s).

[0060] Example 5: Synthesis of Compound S5

[0061] Compound S5 was synthesized in the same manner as Compound S1, except that the starting material for Compound S5 was 2-hydroxy-6-chloro-acetophenone. 11H NMR (400 MHz, CDCl3) δ 7.01 (t, J = 8.0 Hz, 1H), 6.89 (d, J = 7.9 Hz, 1H), 6.78–6.69 (m, 2H), 5.71 (d, J = 9.9 Hz, 1H), 3.07 (t, J = 10.9 Hz, 2H), 2.88–2.82 (m, 2H), 1.99 (s, 1H), 1.95 (d, J = 13.6 Hz, 2H), 1.70–1.62 (m, 2H). 13 13C NMR (101 MHz, CDCl3) δ 153.53 (s), 131.20 (s), 130.83 (s), 129.08 (s), 121.75 (s), 120.20 (s), 119.61 (s), 115.25 (s), 75.25 (s), 41.66 (s), 36.08 (s).

[0062] Example 6: Synthesis of Compound S6

[0063]

[0064] Among them, the reaction conditions: (a) pyridine, acetyl chloride, dichloromethane, nitrogen, rt (room temperature); (b) aluminum trichloride, 150 °C.

[0065] Synthesis of Compound S6-2: Dissolve 1.6 g (10 mmol) of commercially available S9-1 in 45 mL of anhydrous dichloromethane, add 6.8 mL (85 mmol) of anhydrous pyridine under stirring at room temperature, add 0.86 mL (12 mmol) of acetyl chloride after 5 min, charge N2, and stir at room temperature. Distill the mixture under reduced pressure, add 1N dilute hydrochloric acid, separate with dichloromethane and saturated sodium chloride solution, dry the organic phase with anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the crude product. The obtained crude product is purified by silica gel column chromatography to obtain 1.7 g of white solid.

[0066] Synthesis of Compound S6-3: Mix 650 mg of Compound S6-2 (3 mmol) with 600 mg (4.5 mmol) of AlCl3, stir at 150 °C for 1 h and then solidify. After cooling to room temperature, dissolve the mixture with ethyl acetate, add an appropriate amount of 1N dilute hydrochloric acid, separate with ethyl acetate and saturated sodium chloride solution, dry the organic phase with anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the crude product. The obtained crude product is purified by silica gel column chromatography to obtain 450 mg of white solid.

[0067] The synthesis method of Compound S6 is the same as that of Compound S1, except that the starting material of S6 is S6-3. 1HNMR(400MHz,CDCl3)δ6.96(t,J=12.3Hz,1H),6.81(d,J=8.1Hz,1H),6.31(d,J=9.8Hz,1H),5.62(d,J=9.8Hz,1H),3.18(t,J=11.7Hz,2H),2.86(d,J=12.1Hz,2H),1.98(d,J=13.3Hz,2H),1.73(s,1H),1.68–1.58(m,2H). 13 C NMR(151MHz,cdcl3)δ149.61(s),132.54(s),130.54(s),124.37(s),122.11(s),122.31–119.29(m),120.80(s),120.80(s),77.43–77.02(m),76.91(d,J=32.0Hz),41.54(s),36.09(s),35.37(s).

[0068] Example 7: Synthesis of Compound S7

[0069] Compound S7 was synthesized in the same manner as Compound S1, except that the starting materials for S7 were synthesized by the same method as S6-3. 1 H NMR(400MHz,DMSO)δ6.91(s,1H),6.78(s,1H),6.66(d,J=10.0Hz,1H),5.72(d,J=10.0Hz,1H),3.05(t,J=11.0Hz,2H),2.90–2.80(m,2H),1.93(d,J=13.3Hz,2H),1.70–1.57(m,3H). 13 C NMR(151MHz,cdcl3)δ153.95(s),133.80(s),131.52(s),130.85(s),121.61(s),118.85(d,J=8.3Hz),115.81(s),77.21(s),76.93(d,J=20.9Hz),76.79(s),76.10(s),41.63(s),36.18(s).

[0070] Example 8: Synthesis of Compound S8

[0071] Compound S8 was synthesized in the same manner as Compound S1, except that the starting material for Compound S8 was 2-hydroxy-3-fluoroacetophenone. 11H NMR (400 MHz, Chloroform-d) δ 7.17–7.08 (m, 3H), 6.31–6.25 (m, 1H), 5.78 (d, J=9.3 Hz, 1H), 3.17 (p, J=3.7 Hz, 1H), 2.92–2.78 (m, 4H), 2.06–2.00 (m, 1H), 2.03–1.98 (m, 1H), 1.94 (ddd, J=12.5, 5.7, 3.3 Hz, 2H).

[0072] Example 9: Synthesis of Compound S9

[0073] Compound S9 was synthesized in the same manner as Compound S1, except that the starting material was 2-hydroxy-4-fluoroacetophenone. 1 1H NMR (400 MHz, CDCl3) δ 7.53 (ddd, J=8.4, 5.1, 0.7 Hz, 1H), 7.00 (td, J=8.2, 2.4 Hz, 1H), 6.57 (dd, J=8.0, 2.3 Hz, 1H), 6.32 (dd, J=9.4, 0.7 Hz, 1H), 5.80 (d, J=9.3 Hz, 1H), 3.17 (q, J=3.7 Hz, 1H), 2.92–2.79 (m, 4H), 2.01 (ddd, J=12.5, 5.7, 3.4 Hz, 2H), 1.92 (ddd, J=12.4, 5.7, 3.4 Hz, 2H).

[0074] Example 10: Synthesis of Compound S10

[0075] Compound S10 was synthesized in the same manner as Compound S1, except that the starting material for Compound S10 was 2-hydroxy-5-fluoroacetophenone. 1 1H NMR (400 MHz, Chloroform-d) δ 7.13 (dd, J=8.0, 2.2 Hz, 1H), 7.02 (td, J=8.0, 2.3 Hz, 1H), 6.79 (dd, J=7.9, 5.0 Hz, 1H), 6.28 (d, J=9.1 Hz, 1H), 5.80 (d, J=9.2 Hz, 1H), 3.17 (p, J=3.7 Hz, 1H), 2.92–2.79 (m, 4H), 2.01 (ddd, J=12.5, 5.7, 3.4 Hz, 2H), 1.91 (ddd, J=12.5, 5.6, 3.4 Hz, 2H).

[0076] Example 11: Synthesis of Compound S11

[0077] Compound S11 was synthesized in the same manner as Compound S1, except that the starting material for Compound S11 was 2-hydroxy-6-fluoroacetophenone. 1 H NMR(500MHz,Chloroform-d)δ7.28(ddd,J=8.1,7.1,4.9Hz,1H),7.00(td,J=8.0,1.1Hz,1H),6.72(dd,J=7.1,1.1Hz,1H),6.63(d,J=9.2Hz,1H),5.90(d,J=9.2Hz,1H),3.17(p,J=3.7Hz,1H),2.92–2.79(m,4H),2.01(ddd,J=12.5,5.7,3.4Hz,2H),1.92(ddd,J=12.4,5.7,3.4Hz,2H).

[0078] Example 12: Synthesis of Compound S12

[0079] Compound S12 was synthesized in the same manner as Compound S1, except that the starting material for Compound S12 was 2-hydroxy-3-methylacetophenone. 1 H NMR(400MHz,Chloroform-d)δ7.33–7.28(m,1H),7.11–7.03(m,2H),6.23–6.18(m,1H),5.77(d,J=9.3Hz,1H),3.20–3.14(m,1H),2.91–2.79(m,4H),2.05(ddd,J=12.5,5.7,3.4Hz,2H),1.94(ddd,J=12.3,5.7,3.4Hz,2H).

[0080] Example 13: Synthesis of Compound S13

[0081] Compound S13 was synthesized in the same manner as Compound S1, except that the starting material for Compound S13 was 2-hydroxy-4-methylacetophenone. 1 H NMR(400MHz,Chloroform-d)δ7.38(dd,J=8.2,0.7Hz,1H),6.84(ddd,J=8.5,1.9,0.8Hz,1H),6.61(dd,J=2.2,0.7Hz,1H),6.32(dd,J=9.3,0.7Hz,1H),5.79(d,J=9.3Hz,1H),3.20–3.14(m,1H),2.91–2.79(m,4H),2.33(s,2H),2.01(ddd,J=12.3,5.7,3.4Hz,2H),1.92(ddd,J=12.4,5.7,3.4Hz,2H).

[0082] Example 14: Synthesis of Compound S14

[0083] Compound S14 was synthesized in the same manner as Compound S1, except that the starting material for Compound S14 was 2-hydroxy-5-methylacetophenone. 1 H NMR(400MHz,Chloroform-d)δ7.16–7.12(m,1H),7.09–7.04(m,1H),6.78(d,J=7.8Hz,1H),6.20(d,J=9.3Hz,1H),5.76(d,J=9.3Hz,1H),3.20–3.14(m,1H),2.91–2.79(m,4H),2.38(s,2H),2.01(ddd,J=12.5,5.7,3.4Hz,2H),1.91(ddd,J=12.5,5.6,3.4Hz,2H).

[0084] Example 15: Synthesis of Compound S15

[0085] Compound S15 was synthesized in the same manner as Compound S1, except that the starting material for Compound S15 was 2-hydroxy-6-methylacetophenone. 1 H NMR(400MHz,Chloroform-d)δ7.12(dd,J=7.9,7.1Hz,1H),6.87–6.81(m,1H),6.72(dd,J=7.1,1.1Hz,1H),6.56(d,J=9.1Hz,1H),5.82(d,J=9.1Hz,1H),3.17(p,J=3.7Hz,1H),2.92–2.79(m,4H),2.47(d,J=0.7Hz,3H),2.01(ddd,J=12.3,5.7,3.4Hz,2H),1.92(ddd,J=12.4,5.7,3.4Hz,2H).

[0086] Example 16: Synthesis of Compound S16

[0087] Compound S16 was synthesized in the same manner as compound S1, except that the starting material for compound S16 was 2-hydroxy-4-methylacetophenone, and the product was then salted out by dissolving it in an ethyl acetate solution of hydrochloric acid, concentrating under reduced pressure, and repeating three times to obtain the hydrochloride salt of compound S16. 1H NMR (500 MHz, Chloroform-d) δ 7.39 (dd, J = 9.0, 0.7 Hz, 1H), 6.71 (dd, J = 9.0, 2.4 Hz, 1H), 6.38 (d, J = 2.4 Hz, 1H), 6.32 (dd, J = 9.4, 0.8 Hz, 1H), 5.78 (d, J = 9.3 Hz, 1H), 3.82 (s, 2H), 3.17 (p, J = 3.7 Hz, 1H), 2.92–2.79 (m, 4H), 2.01 (ddd, J = 12.3, 5.7, 3.4 Hz, 2H), 1.91 (ddd, J = 12.4, 5.7, 3.5 Hz, 2H).

[0088] Example 17: Synthesis of Compound S17

[0089] Compound S17 was synthesized in the same manner as compound S16, except that the starting material for compound S17 was 2-hydroxy-5-methoxyacetophenone. 1 1H NMR (400 MHz, Chloroform-d) δ 6.84–6.79 (m, 1H), 6.78–6.73 (m, 2H), 6.30 (d, J = 9.1 Hz, 1H), 5.80 (d, J = 9.2 Hz, 1H), 3.81 (s, 3H), 3.20–3.14 (m, 1H), 2.85 (ddt, J = 10.9, 5.6, 3.6 Hz, 4H), 2.05–1.97 (m, 2H), 1.96–1.88 (m, 2H).

[0090] Example 18: Synthesis of Compound S18

[0091] Compound S18 was synthesized in the same manner as compound S16, except that the starting material for compound S18 was 2-hydroxy-6-methoxyacetophenone. 1H NMR (500 MHz, Chloroform-d) δ 7.09–7.03 (m, 1H), 6.75–6.68 (m, 2H), 6.62 (d, J = 9.5 Hz, 1H), 5.81 (d, J = 9.3 Hz, 1H), 3.88 (s, 2H), 3.20–3.14 (m, 1H), 2.89–2.82 (m, 2H), 2.03–1.98 (m, 1H), 1.92 (dd, J = 5.7, 3.5 Hz, 1H).

[0092] Example 19: Synthesis of Compound S19

[0093]

[0094] Among them, the reaction conditions are as follows: (a) pyrrole, methanol, rt (room temperature); (b) benzyl bromide, potassium carbonate, DMF (N,N-dimethylformamide); (c) sodium borohydride, methanol, 0 °C - rt; (d) TsOH (p-toluenesulfonic acid), toluene, 130 °C.

[0095] The synthesis method of Compound S19 is the same as that of Compound S1, except for the synthesis of the starting material S19-3.

[0096] Synthesis of Compound S19-3: Dissolve Compound S19-2 in a DMF solution. After adding K2CO3, the mixture is transferred to 0 °C and stirred, and benzyl bromide is added dropwise. After addition, it is refluxed and stirred overnight at 70 °C. After cooling to room temperature, it is concentrated and separated with ethyl acetate and saturated sodium chloride solution. The organic phase is dried with anhydrous sodium sulfate and concentrated under reduced pressure to obtain the crude product. The obtained crude product is purified by silica gel column chromatography to obtain the pure product.

[0097] The subsequent synthesis method of Compound S19 is the same as that of Compound S1. 1 H NMR(400MHz,Chloroform-d)δ7.45–7.40(m,1H),7.35(d,J=6.9Hz,1H),6.92(s,1H),6.43(s,1H),6.34(d,J=9.1Hz,1H),5.79(d,J=9.2Hz,1H),5.14(d,J=1.1Hz,2H),3.88(s,2H),3.17(d,J=3.8Hz,1H),2.85(dd,J=10.9,5.7Hz,2H),2.00(dd,J=5.7,3.3Hz,1H),1.95–1.90(m,1H).

[0098] Example 20: Synthesis of Compound S20

[0099] The synthesis method of Compound S20 is the same as that of Compound S1, except that the starting materials of Compound S20 are 2-hydroxy-4-chloro-acetophenone and 3-nitromethyl ketone. 11H NMR (400 MHz, Chloroform-d) δ 7.49 (dd, J = 8.4, 0.6 Hz, 1H), 7.25 (dd, J = 8.4, 2.2 Hz, 1H), 6.93 (d, J = 2.3 Hz, 1H), 6.36–6.31 (m, 1H), 5.89 (d, J = 9.2 Hz, 1H), 3.90 (dd, J = 12.4, 3.8 Hz, 2H), 3.69 (dd, J = 12.4, 3.8 Hz, 2H), 3.34 (p, J = 3.7 Hz, 1H).

[0100] Example 21: Synthesis of Compound S21

[0101] Compound S21 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S21 were 2-hydroxy-4-chloroacetophenone and 3-pyrrolidone. 1 1H NMR (400 MHz, Chloroform-d) δ 7.49 (dd, J = 8.4, 0.6 Hz, 1H), 7.25 (dd, J = 8.4, 2.2 Hz, 1H), 6.92 (d, J = 2.2 Hz, 1H), 6.35–6.30 (m, 1H), 5.77 (d, J = 9.3 Hz, 1H), 3.74 (p, J = 3.4 Hz, 1H), 3.37–3.27 (m, 2H), 2.94 (q, J = 3.6 Hz, 2H), 2.11 (dt, J = 12.5, 3.4 Hz, 1H), 2.07–2.00 (m, 1H).

[0102] Example 22: Synthesis of Compound S22

[0103] Compound S22 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S22 were 2-hydroxy-4-chloroacetophenone and 3-piperidone. 1 1H NMR (400 MHz, Chloroform-d) δ 7.49 (dd, J = 8.4, 0.6 Hz, 1H), 7.25 (dd, J = 8.4, 2.2 Hz, 1H), 6.91 (d, J = 2.2 Hz, 1H), 6.35–6.30 (m, 1H), 5.74 (d, J = 9.3 Hz, 1H), 3.31–3.22 (m, 3H), 2.85–2.78 (m, 2H), 2.01 (dt, J = 7.0, 5.7 Hz, 2H), 1.69–1.60 (m, 2H).

[0104] Example 23: Synthesis of Compound S23

[0105] Compound S23 was synthesized in the same manner as compound S1, except that the starting materials for compound S23 were 2-hydroxy-4-chloroacetophenone and nortropin-3-one. 1 H NMR(400MHz,Chloroform-d)δ7.49(dd,J=8.4,0.6Hz,1H),7.25(dd,J=8.4,2.2Hz,1H),6.91(d,J=2.3Hz,1H),6.33(dd,J=9.9,0.7Hz,1H),5.76(d,J=9.9Hz,1H),3.48(t,J=5.0Hz,1H),3.22(dddd,J=6.8,4.5,2.5,1.4Hz,2H),1.98(dd,J=12.4,3.9Hz,2H),1.87–1.81(m,1H),1.78–1.70(m,2H),1.64–1.57(m,2H).

[0106] Example 24: Synthesis of Compound S24

[0107] Compound S24 was synthesized in the same manner as compound S1, except that the starting materials for compound S24 were 2-hydroxy-4-chloroacetophenone and 4-ketoazepine. 1 H NMR(400MHz,Chloroform-d)δ7.49(dd,J=8.4,0.6Hz,1H),7.25(dd,J=8.4,2.2Hz,1H),6.91(d,J=2.3Hz,1H),6.32(dd,J=9.3,0.7Hz,1H),5.78(d,J=9.3Hz,1H),3.76(tt,J=4.9,3.5Hz,1H),2.87–2.75(m,4H),1.98(dt,J=12.3,6.1Hz,1H),1.90(dt,J=12.5,6.1Hz,1H),1.89–1.74(m,2H),1.70–1.61(m,2H).

[0108] Example 25: Synthesis of Compound S25

[0109]

[0110] Among them, the reaction conditions were as follows: (a) tetrahydrofuran, triethylamine, reflux, 5 h; (b) NaBH4, EtOH; (c) TsOH, toluene, reflux, 72 h; (d) 6N HCl, 90 °C, 12 h.

[0111] Compound S25 was synthesized by referring to the method in J.Med.Chem.2002,45,492-503.

[0112] Synthesis of Compound S25-3; The synthesis of Compound S25-3 was carried out by referring to the method in Patent EP 431943, June 12, 1991. Compound S25-2 (1 eq) was dissolved in tetrahydrofuran, triethylamine (0.5 eq) was added, and the mixture was refluxed at heating for 5 hours. It was extracted and separated with 0.5N HCl and ethyl acetate. The organic layer was washed with sodium chloride, dried with anhydrous sodium sulfate, and concentrated under reduced pressure. Compound S25-3 was obtained by crystallization with ethyl acetate.

[0113] Synthesis of Compound S25-4: Compound S25-3 was dissolved in methanol, NaBH4 was added under N2, and the mixture was stirred at room temperature for 12 h. It was extracted and separated with saturated ammonium chloride and dichloromethane. The organic layer was washed with saturated sodium chloride, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to obtain Compound S25-4.

[0114] Synthesis of Compound S25-5; Compound S25-4 was dissolved in toluene, p-toluenesulfonic acid was added, and the mixture was refluxed for 72 h. Then it was extracted and separated with saturated sodium carbonate and dichloromethane. The organic layer was washed with saturated sodium chloride, dried with anhydrous sodium sulfate, and concentrated under reduced pressure to obtain Compound S25-5.

[0115] Synthesis of Compound S25; Compound S25-5 was dissolved in ethanol, 6N HCl was added, and the mixture was refluxed at 90 °C for 12 h. It was cooled to room temperature, the mixture was azeotroped with toluene, and then purified with methanol to obtain white solid S25. 1 H NMR (400 MHz, Chloroform-d) δ 7.27 (s, 1H), 7.05 (d, J = 2.8 Hz, 1H), 6.89–6.84 (m, 1H), 6.36 (d, J = 8.2 Hz, 1H), 6.18 (d, J = 8.2 Hz, 1H), 3.81 (s, 3H), 2.87 (q, J = 3.7 Hz, 4H), 2.07–1.97 (m, 4H).

[0116] Example 26: Synthesis of Compound S26

[0117]

[0118] Among them, the reaction conditions: (a) 30% H2O2 (hydrogen peroxide), HOAc (acetic acid), 90 °C, 2 h.

[0119] Synthesis of Compound S26: The synthesis method of Compound S26 is the same as that of S25, except for the synthesis of intermediate Compound S26-1. The synthesis of Compound S26 was carried out by referring to the method in J.Med.Chem.2002, 45, 492-503.

[0120] Synthesis of Compound S26-1: Dissolve Compound S25-1 in glacial acetic acid, then add 30% H2O2. Heat the mixture to 90 °C and stir for 2 h. After the reaction is completed, cool and concentrate to contain an appropriate amount of solvent. Extract and separate with water and dichloromethane. Wash the organic layer with sodium chloride, dry with anhydrous sodium sulfate, and concentrate under reduced pressure to obtain Compound S26-1.

[0121] The synthesis method after Compound S26 is the same as that of Compound S25. 1 H NMR(400MHz,Chloroform-d)δ7.76(d,J=8.8Hz,1H),7.11(d,J=2.7Hz,1H),6.98(dd,J=8.8,2.8Hz,1H),6.74(d,J=9.6Hz,1H),5.99(d,J=9.7Hz,1H),3.81(s,2H),3.17–3.12(m,1H),2.88(dddd,J=5.6,4.6,3.8,0.8Hz,4H),2.12(td,J=5.2,3.8Hz,4H).

[0122] Example 27: Synthesis of Compound S27

[0123] The synthesis of Compound S27 is the same as that of Compound S25, except that the starting material is 2-mercapto-5-chloroacetophenone. 1 H NMR(500MHz,Chloroform-d)δ7.47(d,J=2.3Hz,1H),7.34(d,J=7.2Hz,1H),7.30(dd,J=7.2,2.1Hz,1H),6.42(d,J=8.2Hz,1H),6.18(d,J=8.2Hz,1H),2.87(q,J=3.7Hz,4H),2.45–2.40(m,1H),2.09–1.97(m,4H).

[0124] Example 28: Synthesis of Compound S28

[0125] The synthesis of Compound S28 is the same as that of Compound S26, except that the starting material is 2-mercapto-5-chloroacetophenone. 11H NMR (500 MHz, Chloroform-d) δ 7.87 (d, J = 8.8 Hz, 1H), 7.63 (d, J = 2.2 Hz, 1H), 7.46 (dd, J = 8.8, 2.2 Hz, 1H), 6.80 (d, J = 9.6 Hz, 1H), 5.99 (d, J = 9.7 Hz, 1H), 3.14 (q, J = 3.7 Hz, 1H), 2.88 (dddd, J = 5.6, 4.6, 3.7, 0.8 Hz, 4H), 2.18–2.08 (m, 4H).

[0126] Example 29: Synthesis of Compound S29

[0127]

[0128] Among them, the reaction conditions are: (a) ammonium acetate, water, room temperature; (b) pyrrole, ethanol, rt (room temperature); (c) C6H5N(SO2CF3)2 (N-phenylbis(trifluoromethanesulfonimide)), LiHMDS (lithium bis(trimethylsilylamide)), THF (tetrahydrofuran), -78 °C - rt; (d) 4-ethylphenylboronic acid, Pd[P(C6H5)3]4 (tetrakis(triphenylphosphine)palladium), LiCl (lithium chloride), aqNa2CO3 (sodium carbonate), DME (dimethyl ether), reflux; (e) TsOH, toluene, 130 °C.

[0129] Synthesis of Compound S29-1: Compound S29-1 was synthesized by referring to the method of J. Org. Chem. 2008, 73, 6, 2090-2095. Commercially available 2,4-pentanedione (1 eq) was dissolved in water (5 mL), ammonium acetate (5 eq) was added, and commercially available phenylglyoxal monohydrate (1 eq) was slowly added dropwise, and stirred at room temperature. After the raw materials reacted completely, a solid was produced, filtered, the filter cake was washed three times with water, and purified with ethanol to obtain Compound S29-1.

[0130] Synthesis of Compound S29-2: The synthesis of Compound S29-2 was the same as the synthesis process of Compound S1-3.

[0131] Synthesis of Compound S29-3: Compound S29-3 was synthesized by referring to the method of J.Med.Chem.2009,52,18,5685–5702. Compound S29-2 (1eq) was dissolved in tetrahydrofuran, purged with nitrogen, and then placed at -78 °C. 1N LiHMDS (1.2eq) diluted with tetrahydrofuran was slowly added dropwise, and the mixture was stirred for 1 h. A solution of C6H5N(SO2CF3)2 (1.2eq) in tetrahydrofuran was added dropwise, and the temperature was slowly raised to room temperature, followed by stirring for 12 h. After the reaction was completed, the mixture was poured into ice water. The organic phase was washed successively with 1N aqueous hydrochloric acid, 1N aqueous sodium hydroxide, and sodium chloride solution, then dried over anhydrous sodium sulfate, concentrated, and purified by silica gel column chromatography to obtain Compound S29-3.

[0132] Synthesis of Compound S29: Compound S29 was synthesized by Suzuki coupling reaction, referring to J.Org.Chem.2008,73,6,2090–2095. Compound S29-3 was dissolved in DME, and Pd[P(C6H5)3]4 (0.02eq), 2N Na2CO3 (3eq), LiCl (3eq), and 4-ethylphenylboronic acid (1.1eq) were added to the solution. The mixture was purged with nitrogen and refluxed for 12 h. After cooling to room temperature, it was extracted with water and ethyl acetate. The organic layer was washed with brine and dried over anhydrous sodium sulfate. The crude product was purified by column chromatography to obtain Compound S29. 1 H NMR(400MHz,Chloroform-d)δ8.70(s,1H),7.44–7.39(m,2H),7.35–7.30(m,3H),7.26–7.21(m,1H),5.71(s,1H),2.90–2.83(m,2H),2.69(d,J=7.3Hz,1H),2.07(dd,J=6.0,3.8Hz,1H),1.97(dd,J=6.1,3.9Hz,1H),1.23(t,J=7.2Hz,2H).

[0133] Example 30: Synthesis of Compound S30

[0134]

[0135] Among them, the reaction conditions are: (a) 2-oxopropanal, acetic acid, water, room temperature; (b) glyoxal, water, reflux.

[0136] The synthesis method of Compound S30 is the same as that of Compound S29, except for the synthesis of the starting material S30-1.

[0137] Synthesis of Compound S30-1: Compound S30-1 was synthesized by referring to the method in J.Med.Chem.2012,55,2,935–942. Acetic acid was slowly added dropwise to an aqueous solution of hydrazine (1 eq), and then 2-oxopropanal (1 eq) was slowly added dropwise. The mixture was stirred overnight at room temperature. Dichloromethane was added to the mixture, and the mixture was extracted and separated. The organic phase was dried and concentrated, and purified by column chromatography to obtain the hydrazone S30-1. An aqueous solution of 40% hydrazone (1 eq) was prepared and glyoxal (1 eq) was slowly added. The mixture was refluxed for 1 h. It was extracted and separated with dichloromethane. The organic layer was dried with anhydrous sodium sulfate, concentrated, and purified using column chromatography.

[0138] Synthesis of Compound S30: The synthesis process of Compound S30 was the same as that of S29. 1 H NMR(400MHz,Chloroform-d)δ7.33–7.22(m,3H),6.26(s,1H),3.80(s,2H),3.17(d,J=3.8Hz,1H),2.90–2.83(m,2H),2.69(d,J=7.3Hz,1H),2.08(dd,J=6.0,3.8Hz,1H),1.98(dd,J=6.0,3.8Hz,1H),1.23(d,J=14.5Hz,1H),1.23(s,1H).

[0139] Example 31: Synthesis of Compound S31

[0140]

[0141] Among them, the reaction conditions are: (a) BnOH (benzyl alcohol), NaH (sodium hydride), DMF, 0 °C, 72%; (b) NaOMe, MeOH, Toluene, 70 °C, 56%; (c) n-BuLi (n-butyllithium), THF, -75 °C, Acetaldehyde, 65%; (d) DMP (Dess-Martin reagent), DCM, 75%; (e) H2, Cat.Pd / C, EtOAc, 88%.

[0142] Compound S31 was synthesized in the same way as Compound S29. The difference lies in the synthesis of the raw material S31-6, which was synthesized by referring to the method in J.Med.Chem.2020,63,5879-5955.

[0143] Synthesis of Compound S31-2: Dissolve commercially available 2,4-dichloropyridine (1 eq) in DMF, place it at 0 °C, add NaH (1.1 eq) under N2 protection, and stir at this temperature for 20 min. Then add benzyl alcohol (1 eq), and continue to stir the mixture at this temperature for 1 h. After the reaction is completed, pour it into ice water, filter to obtain the filter cake, and then wash it with water. Stir the solid in n-hexane, collect the solid again, and dry it to obtain Compound S31-2.

[0144] Synthesis of Compound S31-3: Dissolve Compound S31-2 (1 eq) in toluene, add a methanol solution of NaOMe (2 eq), and stir at 60 °C for 5 h. After the reaction, remove the solvent, extract and separate with ethyl acetate and water, wash the organic layer with sodium chloride and dry it with anhydrous sodium sulfate, concentrate under reduced pressure, and crystallize with n-hexane to obtain white solid S31-3.

[0145] Synthesis of Compound S31-4: Dissolve Compound S31-3 (1 eq) in tetrahydrofuran, place it at -78 °C, then add a hexane solution of n-butyllithium (1.2 eq), and stir at this temperature for 30 min. Add acetaldehyde, and continue to stir at this temperature for 2 h. After the reaction is completed, quench the reaction with saturated ammonium chloride solution, extract with ethyl acetate, wash the organic phase with sodium chloride, then dry it with anhydrous sodium sulfate, concentrate under reduced pressure, and then purify by column chromatography to obtain white solid S31-4.

[0146] Synthesis of Compound S31-5: Dissolve Compound S31-4 (1 eq) in dichloromethane at room temperature, add DMP (1.2 eq) dropwise, then add water dropwise, and stir for 10 min. After the reaction is completed, filter the mixture through diatomaceous earth, wash the filter cake with dichloromethane, extract the filtrate with saturated sodium bicarbonate, wash the organic phase with saturated sodium chloride and dry it with anhydrous sodium sulfate, concentrate, and purify by column chromatography to obtain Compound S31-5.

[0147] Synthesis of Compound S31-6: Dissolve Compound S31-5 in ethyl acetate, add Pd / C, replace the air with N2, and then replace it with H2, and stir at room temperature for 3 h. Filter the mixture through diatomaceous earth, wash the filter cake with ethyl acetate, then concentrate the filtrate under reduced pressure, and purify by column chromatography to obtain Compound S31-6.

[0148] Synthesis of Compound S31: The synthesis process of Compound S31 is the same as that of S29, except that the raw material is S31-6. 1HNMR(400MHz,Chloroform-d)δ8.31(d,J=1.8Hz,1H),7.62(d,J=1.8Hz,1H),7.37–7.32(m,2H),7.28(dt,J=8.1,1.0Hz,2H),5.86(s,1H),3.20–3.14(m,1H),2.87(ddt,J=9.8,6.0,3.7Hz,4H),2.73–2.65(m,2H),2.06(ddd,J=12.4,6.1,3.8Hz,2H),1.95(ddd,J=12.3,6.0,3.9Hz,2H),1.23(t,J=7.2Hz,3H).

[0149] Example 32: Synthesis of Compound S32

[0150] Compound S32 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S32 were 4-chloro-2-hydroxy-acetophenone and N-Boc-3-methyl-piperidin-4-one. 1 H NMR(500MHz,Chloroform-d)δ7.52(dd,J=7.5,1.0Hz,1H),7.35(dd,J=7.5,1.8Hz,1H),7.21(dt,J=2.0,1.0Hz,1H),7.02(d,J=0.9Hz,1H),6.21(s,1H),2.89(d,J=16.5Hz,2H),2.76(d,J=0.9Hz,1H),2.68(d,J=15.9Hz,2H),2.41(s,1H),2.30(d,J=0.9Hz,1H),1.90(s,1H),1.81(s,1H),0.95(s,2H).

[0151] Example 33: Synthesis of Compound S33

[0152] Compound S33 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S33 were 4-chloro-2-hydroxy-acetophenone and N-Boc-(S)-2-methyl-piperidin-4-one. 11H NMR (500 MHz, Chloroform-d) δ 7.50 (dd, J = 7.5, 1.1 Hz, 1H), 7.35 (dd, J = 7.4, 1.9 Hz, 1H), 7.22 (dt, J = 2.0, 1.0 Hz, 1H), 6.93 (d, J = 0.9 Hz, 1H), 6.25 (s, 1H), 2.98 (s, 1H), 2.93 (s, 1H), 2.71 (d, J = 0.9 Hz, 1H), 2.58 (s, 1H), 2.46 (d, J = 0.9 Hz, 1H), 2.05 (s, 1H), 1.89 (s, 1H), 1.83 (s, 1H), 1.40 (s, 1H), 1.14 (s, 3H).

[0153] Example 34: Synthesis of Compound S34

[0154] Compound S34 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S34 were 4-chloro-2-hydroxy-acetophenone and N-Boc-(S)-2-methylpiperidin-4-one. 1 1H NMR (500 MHz, Chloroform-d) δ 7.50 (dd, J = 7.5, 1.1 Hz, 1H), 7.35 (dd, J = 7.4, 1.9 Hz, 1H), 7.22 (dt, J = 2.0, 1.0 Hz, 1H), 6.93 (d, J = 0.9 Hz, 1H), 6.25 (s, 1H), 2.98 (s, 1H), 2.93 (s, 1H), 2.71 (d, J = 0.9 Hz, 1H), 2.58 (s, 1H), 2.46 (d, J = 0.9 Hz, 1H), 2.05 (s, 1H), 1.89 (s, 1H), 1.83 (s, 1H), 1.40 (s, 1H), 1.14 (s, 3H).

[0155] Example 35: Synthesis of Compound S35

[0156] Compound S35 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S35 were 4-chloro-2-hydroxy-acetophenone and N-Boc-2,6-dimethylpiperidin-4-one. 11H NMR (500 MHz, Chloroform-d) δ 7.50 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.4, 1.9 Hz, 1H), 7.22 (dt, J = 2.0, 1.0 Hz, 1H), 6.96 (d, J = 0.9 Hz, 1H), 6.30 (s, 1H), 3.04 (s, 2H), 2.73 (d, J = 1.1 Hz, 1H), 2.55 (d, J = 0.9 Hz, 1H), 2.40 (s, 1H), 2.04 (s, 2H), 1.14 (s, 5H).

[0157] Example 36: Synthesis of Compound S36

[0158] Compound S36 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S36 were 4-chloro-2-hydroxy-acetophenone and N-Boc-2,5-dimethylpiperidin-4-one. 1 1H NMR (500 MHz, Chloroform-d) δ 7.52 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.5, 1.8 Hz, 1H), 7.21 (dt, J = 2.0, 1.0 Hz, 1H), 6.98 (d, J = 0.9 Hz, 1H), 6.21 (s, 1H), 3.22 (s, 1H), 2.85 (s, 1H), 2.73 (d, J = 1.1 Hz, 1H), 2.54–2.47 (m, 2H), 1.95 (s, 1H), 1.80 (s, 1H), 1.76 (s, 1H), 1.15 (s, 3H), 0.95 (s, 3H).

[0159] Example 37: Synthesis of Compound S37

[0160] Compound S37 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S37 were 4-chloro-2-hydroxy-acetophenone and N-Boc-2-isopropylpiperidin-4-one. 11H NMR (500 MHz, Chloroform-d) δ 7.50 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.4, 1.9 Hz, 1H), 7.22 (dt, J = 2.0, 1.0 Hz, 1H), 6.93 (d, J = 0.9 Hz, 1H), 6.23 (s, 1H), 3.00 (s, 1H), 2.93 (s, 1H), 2.78 (d, J = 1.1 Hz, 1H), 2.70 (s, 1H), 2.66 (d, J = 0.9 Hz, 1H), 2.40 (s, 1H), 1.88 (d, J = 15.8 Hz, 2H), 1.69 (d, J = 3.1 Hz, 2H), 0.90 (s, 2H), 0.85 (s, 2H).

[0161] Example 38: Synthesis of Compound S38

[0162] Compound S38 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S38 were 4-chloro-2-hydroxy-acetophenone and N-Boc-3-ethylpiperidin-4-one. 1 1H NMR (500 MHz, Chloroform-d) δ 7.52 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.5, 1.8 Hz, 1H), 7.21 (dt, J = 2.0, 1.0 Hz, 1H), 6.92 (d, J = 1.0 Hz, 1H), 6.17 (s, 1H), 2.91 (s, 1H), 2.86 (s, 1H), 2.76 (d, J = 1.1 Hz, 1H), 2.64 (s, 1H), 2.55–2.49 (m, 2H), 2.39 (d, J = 1.1 Hz, 1H), 1.78 (s, 1H), 1.50–1.44 (m, 2H), 1.36 (d, J = 12.3 Hz, 1H), 0.91 (s, 2H).

[0163] Example 39: Synthesis of Compound S39

[0164] Compound S39 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S39 were 4-chloro-2-hydroxy-acetophenone and tert-butyl 4-oxooctahydroquinoline-1(2H)-carboxylate. 11H NMR (500 MHz, Chloroform-d) δ 7.52 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.5, 1.8 Hz, 1H), 7.21 (dt, J = 2.0, 1.0 Hz, 1H), 6.91 (d, J = 1.0 Hz, 1H), 6.50 (s, 1H), 2.97 (d, J = 17.2 Hz, 2H), 2.89 (d, J = 1.1 Hz, 1H), 2.66–2.60 (m, 3H), 1.75–1.61 (m, 4H), 1.57 (d, J = 13.0 Hz, 1H), 1.47 (d, J = 13.0 Hz, 1H), 1.40 (d, J = 13.0 Hz, 1H), 1.31 (dd, J = 13.0, 8.6 Hz, 2H), 1.25 (d, J = 13.0 Hz, 1H).

[0165] Example 40: Synthesis of Compound S40

[0166] Compound S40 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S40 were 4-chloro-2-hydroxy-acetophenone and N-Boc-3,3-difluoropiperidin-4-one. 1 1H NMR (500 MHz, Chloroform-d) δ 7.52 (dd, J = 7.5, 0.9 Hz, 1H), 7.35 (dd, J = 7.5, 2.0 Hz, 1H), 7.24 (dt, J = 2.1, 1.0 Hz, 1H), 7.07 (d, J = 1.0 Hz, 1H), 6.54 (s, 1H), 3.83 (d, J = 0.8 Hz, 1H), 3.42 (s, 1H), 3.36 (s, 1H), 2.90–2.84 (m, 2H), 2.75 (s, 1H), 2.61 (d, J = 1.1 Hz, 1H), 2.09 (s, 1H).

[0167] Example 41: Synthesis of Compound S41

[0168] Compound S41 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S41 were 4-chloro-2-hydroxy-acetophenone and N-Boc-2-(fluoromethyl)piperidin-4-one. 11H NMR (500 MHz, Chloroform-d) δ 7.50 (dd, J = 7.5, 1.1 Hz, 1H), 7.35 (dd, J = 7.4, 1.9 Hz, 1H), 7.22 (dt, J = 2.0, 1.0 Hz, 1H), 6.93 (d, J = 1.0 Hz, 1H), 6.27 (s, 1H), 4.44–4.34 (m, 2H), 3.24 (s, 1H), 3.01 (s, 1H), 2.78 (d, J = 1.0 Hz, 1H), 2.69–2.62 (m, 2H), 2.52 (s, 1H), 1.99 (s, 1H), 1.83 (s, 1H), 1.50 (s, 1H).

[0169] Example 42: Synthesis of Compound S42

[0170] Compound S42 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S42 were 4-chloro-2-hydroxy-acetophenone and N-Boc-3-methoxypiperidin-4-one. 1 1H NMR (500 MHz, Chloroform-d) δ 7.51 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.5, 1.9 Hz, 1H), 7.21 (dt, J = 2.0, 1.0 Hz, 1H), 6.87 (d, J = 1.1 Hz, 1H), 6.26 (s, 1H), 3.65 (s, 1H), 3.28 (s, 2H), 2.94 (s, 1H), 2.83 (s, 1H), 2.79–2.73 (m, 2H), 2.65 (d, J = 11.7 Hz, 2H), 2.49 (d, J = 1.1 Hz, 1H), 1.91 (s, 1H).

[0171] Example 43: Synthesis of Compound S43

[0172] Compound S43 was synthesized in the same manner as Compound S1, except that the starting materials for Compound S43 were 4-chloro-2-hydroxy-acetophenone and N-Boc-3-chloropiperidin-4-one. 11H NMR (500 MHz, Chloroform-d) δ 7.52 (dd, J = 7.5, 1.0 Hz, 1H), 7.35 (dd, J = 7.5, 1.8 Hz, 1H), 7.21 (dt, J = 2.1, 1.0 Hz, 1H), 6.91 (d, J = 1.0 Hz, 1H), 6.20 (s, 1H), 4.10 (s, 1H), 2.94 (d, J = 12.6 Hz, 2H), 2.80–2.74 (m, 2H), 2.69 (s, 1H), 2.61 (d, J = 1.1 Hz, 1H), 2.44 (d, J = 0.7 Hz, 1H), 1.94 (s, 1H).

[0173] Example 44: Determination of Calcium Ion Flux

[0174] Select some of the compounds in the above examples and the control compounds shown in Formulas B1 - B3 as experimental subjects. The structural formulas of B1 - B3 are as follows:

[0175]

[0176] Test the activity of the above compounds on the calcium ion flux of 5HT receptors. The specific operation is as follows: 8 hours before the calcium flux determination experiment, seed HEK 293T cells stably transfected with 5-HT 2A / 2B / 2C receptors at a density of 15,000 cells / well in a 384-well plate containing DMEM with 1% dialyzed FBS. After removing the culture medium, then incubate the cells (20 μL / well) with Fluo-4 direct dye (Invitrogen) reconstituted in FLIPR buffer (19 HBSS, 2.5 mmol / L probenecid and 20 mmol / L HEPES, pH 7.4) at 37 °C for 1 hour. After loading the dye, place the cells in a FLIPR TETRA fluorescence imaging plate reader (Molecular Devices); prepare a drug dilution in FLIPR buffer at 3-fold concentration and aliquot it into the 384-well plate, and also add it to the FLIPR. The fluid module and plate reader of the FLIPR TETRA are programmed to read the baseline fluorescence for 10 seconds (1 reading / second), then add 10 μL of the drug / well and read for 6 minutes (1 reading / second). Normalize the fluorescence in each well to the average of the first 10 readings before the start (i.e., the baseline fluorescence). Then, determine the maximum fold increase that occurs within 60 s after drug addition, above the baseline fluorescence caused by the vehicle or drug.

[0177] Table 1 Results of the determination of the calcium ion flux activity of representative α-chromene spiropiperidine derivatives and reference compounds on 5HT2 receptors

[0178]

[0179]

[0180] NA: indicates inactivity, ND: indicates no activity assay was performed.

[0181] Compared with the two existing classes of G-protein biased 5-HT 2C receptor agonists, the α-chromene spiroperidine has a unique structure and is reported for the first time in this invention. Representative compounds such as compounds S1, S2, S4, S5, S8, S16, S32, and S33 have activities comparable to those of aporphine 1857 [EC 50 (E max ) = 308 nM (86.1%), ACS Cent Sci, 2020, 6, 213 - 25] or 18b [EC 50 (E max ) = 103 nM (95.9%), ACS Chem Neurosci, 2020, 11, 549 - 59; ZL201910594756.6]; its 5-HT 2C receptor selectivity is significantly better than that of aporphine 11b [5-HT 2C :EC 50 (E max ) = 51 nM (93.6%); 5-HT 2B :EC 50 (E max ) = 794.3 nM (25.4%); 5-HT 2A :EC 50 (E max ) = 317.7 nM (55.2%)] and 11f [5-HT 2C :EC 50 (E max ) = 23.6 nM (101.8%); 5-HT 2B :EC 50 (E max ) = 278.4 nM (63.5%); 5-HT 2A :EC 50 (E max ) = 596.4 nM (44.9%)] (Bioorganic Chemistry 123 (2022) 105795; ZL201910594756.6), and has almost no agonist activity on 5-HT 2A and / or 5-HT 2B receptors.

[0182] Compared with the 5-HT 2C receptor agonist lorcaserin that has been approved for marketing, lorcaserin has an impact on 5-HT2A 、5-HT 2C receptors all have strong activities, and the activity against the 5-HT 2B receptor reaches 136 nM, and it is a full agonist. Although some of the α-chromene spiropiperidine compounds (such as S1, S2, S4, S5, S8, S16, S32, and S33, etc.) screened in this application have weaker activities against the 5HT 2C receptor than lorcaserin, they have weak partial activities or even no activities against the 5HT 2B receptor, so they have better safety.

[0183] In addition, the control compounds B1 - B3 in which the double bond of the α-chromene spiropiperidine ring is reduced have no activities against the 5-HT 2C receptor. From this, it can be known that the double bond in the α-chromene spiropiperidine ring has a certain correlation with the activity against the 5-HT 2C receptor.

[0184] Example 45: Determination of Tango β-arrestin recruitment experiment

[0185] Select the above compounds S1, S4, and lorcaserin as experimental objects to study the effects of different compounds on the β-arrestin signaling pathway. Use HTLA cells with the 5-HT 2C Tango plasmid to detect the β-arrestin-2 recruitment activity. The specific operations are as follows: The cells are plated (40 μL / well) in the same method as the calcium flux experiment, and then the test compound solution consistent with the calcium flux experiment is added and incubated for 20 hours (37 °C, 5% CO2). After that, the compound solution is poured out, and Bright-Glo reagent (20 μL / well) is added and incubated for 20 minutes. Finally, the luminescence is detected using an Envision counter (PerkinElmer). Similarly, the activity intensity of 5-HT is normalized to 100%, and the dose-effect curve is fitted using GraphPad Prism 7.0. The data of all compounds are independently tested at least 2 times and averaged.

[0186] The test results are as Figure 1 shown( Figure 1 A: lorcaserin, Figure 1 B: Compound S1, Figure 1 C: Compound S4), lorcaserin activates both the G q signaling pathway and the β-arrestin signaling pathway, while compounds S1 and S4 completely and preferentially activate the G q signaling pathway and have no effect on the β-arrestin signaling pathway, that is, the α-chromene spiropiperidine derivative is a completely G protein-biased 5-HT 2C receptor selective agonist.

[0187] Example 46: Determination of the Inhibition Rate Experiment of hERG Potassium Ion Channels

[0188] The inhibition effect of compound S4 on hERG potassium ion channels was detected using the fully automated electrophysiological patch clamp QPatch (Sophion, Denmark). The specific operation is as follows: The cells used in this experiment were CHO cell lines transfected with hERG cDNA and stably expressing hERG channels (provided by Sophion Bioscience, Denmark), and the cell passage number was P30. After achieving the whole-cell configuration state of membrane rupture in the initial stage, the cells were recorded for at least 120 seconds to reach stability. Then, throughout the process, the cells were clamped at a voltage of -80 mV. The cell clamping voltage was depolarized to +20 mV to activate the hERG potassium channel, and then clamped to -50 mV 2.5 seconds later to eliminate inactivation and generate an outward tail current. The above voltage pattern was applied to the cells every 15 seconds. Only stable cells were allowed to enter the drug treatment process in the above parameter threshold recording. The external solution containing 0.1% dimethyl sulfoxide (solvent) was applied to the cells to establish a baseline, and then the current was allowed to stabilize for 3 minutes. After adding the compound solution, the cells were maintained in the test environment until the effect of the compound reached a stable state or within 4 minutes. In the test experiments with different concentration gradients of the compound, the compound was added to the clamped cells from low to high concentration. After completing the compound test, the cells were washed with the external solution until the current returned to a stable state. A positive control (cisapride) was used in the experiment to ensure normal cell responses and reliable cell quality. Unless otherwise specified, the experiments were carried out at room temperature (~25℃). The test data were analyzed using the Qpatch analysis software provided by Sophion, Excel, etc.

[0189] The test results showed that the α-chromene spiropiperidine derivative S4 had an inhibition rate of only 43.9% on hERG potassium ion channels at a concentration of 10 μM, which also indicated that the α-chromene spiropiperidine derivative S4 had a lower risk of cardiotoxicity and showed good cardiac safety.

[0190] The above-described embodiments are only preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. Use of an α-chromene spiro-piperidine compound or a pharmaceutically acceptable salt thereof in the preparation of a serotonin 2C receptor agonist, characterized in that, The general structural formula M of the α-chromene spiropiperidine compounds is as follows: ， Among them, is phenyl; R is selected from one or more of hydrogen, halogen, cyano, C1-C8 straight-chain alkyl, C1-C8 branched-chain alkyl, C1-C8 straight-chain alkoxy, C1-C8 branched-chain alkoxy, -O-R 10 , and C1-C8 haloalkyl; X is -O-; R1 is selected from one of hydrogen, cyano, C1-C8 straight-chain alkyl, and C1-C8 branched-chain alkyl; m and n are independently selected from 1; R2, R3, R4, R5, R6, R7, R8, R9 are independently selected from one of hydrogen, halogen, cyano, C1-C8 straight-chain alkyl, C1-C8 branched-chain alkyl, C1-C8 haloalkyl, C1-C8 straight-chain alkoxy, C1-C8 branched-chain alkoxy, -O-R 10 ; R 10 is benzyl or phenethyl; The 5-hydroxytryptamine 2C receptor agonist is used for preventing and / or treating diseases targeted at the 5-hydroxytryptamine 2C receptor; the diseases are one or more of obesity, urinary incontinence, depression, anxiety disorder, obsessive-compulsive disorder, epilepsy, schizophrenia, pain, diabetes, and drug addiction.

2. The application according to claim 1, wherein The pharmaceutically acceptable salt is a salt formed by the compound shown in the general formula M and an inorganic acid or an organic acid.

3. The application according to claim 1, wherein The C1-C8 haloalkyl is selected from one of trifluoromethyl, difluoromethyl, monofluoromethyl, and trifluoroethyl.

4. The application according to claim 1, wherein The α-chromene spiropiperidine compound is one of the following structural formulas: ， 。 5. The application according to claim 1, wherein is a benzene ring; X is -O-; R is selected from one of hydrogen, halogen, C1-C8 straight-chain alkyl, C1-C8 branched-chain alkyl, C1-C8 straight-chain alkoxy, and C1-C8 branched-chain alkoxy; m and n are both 1; R1 to R9 are all hydrogen.

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