Amino amide alkyl thioester compound as well as preparation method and application thereof

Abstract

The invention discloses an aminoamide alkyl thioester compound (I), pharmaceutically acceptable salts thereof, a preparation method of the aminoamide alkyl thioester compound, a pharmaceutical composition of the aminoamide alkyl thioester compound and application of the aminoamide alkyl thioester compound in preparation of drugs for treating and / or preventing nervous system related diseases. Comprising but not limited to vascular dementia, Alzheimer's disease, frontotemporal dementia, Prion disease, dementia with Lewy bodies, Parkinson's disease, Huntington's disease, HIV-related dementia, multiple sclerosis, amyotrophic lateral sclerosis, neuropathic pain, cerebral arterial thrombosis, hemorrhagic stroke, nerve injury caused by cerebral trauma and other diseases; # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical chemistry and relates to a class of aminoamide alkylthioester compounds (I) and pharmaceutically acceptable salts thereof, a preparation method thereof, a pharmaceutical composition thereof, and use thereof in preparing drugs for treating and / or preventing diseases related to the nervous system, including but not limited to vascular dementia, Alzheimer's disease, frontotemporal dementia, prion disease, Lewy body dementia, Parkinson's disease, Huntington's disease, HIV-related dementia, multiple sclerosis, amyotrophic lateral sclerosis, neuropathic pain, ischemic stroke, hemorrhagic stroke, and nerve damage caused by brain trauma. Background Art

[0002] Neurodegenerative diseases are a general term for diseases caused by the chronic, progressive degeneration of central nervous system tissues, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Their pathogenesis is closely linked to oxidative stress, neuroinflammation, and the resulting damage. Oxidative stress is mediated by reactive oxygen species (ROS) free radicals, including superoxide anions, hydrogen peroxide, and hydroxyl radicals. Under normal physiological conditions, ROS production levels are in a dynamic equilibrium with the body's antioxidant capacity. When ROS production exceeds cellular antioxidant capacity, oxidative stress occurs. The brain is particularly sensitive to oxidative stress, which can trigger a variety of neurological diseases. Other studies have found that vascular dementia, HIV-related dementia, neuropathic pain, ischemic stroke, hemorrhagic stroke, and nerve damage caused by brain trauma are also closely related to the body's oxidative stress and neuroinflammation.

[0003] Vascular dementia (VD) is a clinical syndrome characterized by intellectual and cognitive impairment caused by various types of cerebrovascular disease, including ischemic cerebrovascular disease, hemorrhagic cerebrovascular disease, and acute and chronic hypoxic cerebrovascular disease. Due to its complex pathogenesis, there are currently no medications that can halt its progression. Clinical treatment focuses on improving cerebral blood circulation, brain metabolism, and enhancing brain nutrition.

[0004] Alzheimer's disease (AD) is a degenerative disease of the central nervous system characterized by progressive cognitive impairment and memory loss. Its incidence is increasing annually, making it second only to cardiovascular disease and cancer in terms of prevalence. With the accelerating aging of the global population, its incidence is showing a significant upward trend. It is estimated that over 50 million people worldwide suffer from dementia, with the total cost of treatment and care exceeding US$1 trillion in 2018. The number of patients is projected to increase to 152 million by 2050. AD manifests itself in clinical manifestations such as decreased memory, orientation, thinking, and judgment, as well as impaired daily living abilities, and can even lead to abnormal psychiatric and behavioral symptoms. This makes patient care challenging and places a heavy burden on society and families. Currently approved drugs for the treatment of mild / moderate AD include acetylcholinesterase (AChE) inhibitors and, for severe AD, N-methyl-D-aspartate (NMDA) receptor antagonists. However, clinical use has shown that these drugs can alleviate AD symptoms by increasing acetylcholine levels in patients or inhibiting the excitotoxicity of excitatory amino acids, but they cannot effectively prevent or reverse the course of the disease. In addition, they can cause serious side effects such as hallucinations, confusion, dizziness, nausea, liver toxicity, loss of appetite, and frequent bowel movements, resulting in less than ideal long-term efficacy. Therefore, there is an urgent need to develop new AD treatment drugs that can both improve AD symptoms and change the course of the disease.

[0005] AD is a disease caused by multiple factors, and its pathogenesis is complex and has not yet been fully elucidated. However, studies have shown that the decrease in acetylcholine levels in the patient's brain, excessive production and deposition of β-amyloid protein, platelet aggregation in cerebral blood vessels, metal ion metabolism disorders, Ca 2+ Multiple factors play a key role in the pathogenesis of AD, including imbalanced homeostasis, neurofibrillary tangles caused by tau protein hyperphosphorylation, excessive glutamate receptor activity, oxidative stress producing large amounts of reactive oxygen species (ROS) and free radicals, and neuroinflammatory responses. To address these pathogenic factors, researchers have employed a traditional "one-drug, one-target" drug design strategy, discovering a large number of highly active and selective drugs for a specific target, such as cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists. However, these drugs suffer from a single target, numerous toxic side effects during clinical use, and poor long-term efficacy in AD patients.

[0006] In recent years, as the pathogenic mechanisms of neurodegenerative diseases have been elucidated, it has been discovered that the onset and progression of neurodegenerative diseases are characterized by multiple mechanisms and factors. These mechanisms are interconnected and mutually influential, forming a complex network regulatory system in the onset and progression of these diseases. Clearly, the development of therapeutic agents that can simultaneously target multiple pathways in the pathological process of neurodegenerative diseases is a necessary step. Based on these findings, researchers have proposed a "multi-target drug" strategy for the development of anti-neurodegenerative disease drugs. A "multi-target drug" refers to a single chemical entity that simultaneously acts on multiple targets within the disease network, generating synergistic effects on each target, resulting in a total effect greater than the sum of the individual effects. The key differences between multi-target drugs and multidrug combinations and combination drugs include reduced dosage, improved therapeutic efficacy, avoidance of drug interactions and the resulting toxic side effects, uniform pharmacokinetic properties, and ease of use. Therefore, the development of anti-neurodegenerative disease drugs with novel chemical structures, novel mechanisms of action, multi-target effects, and reduced toxicity and side effects is a key focus. Summary of the Invention

[0007] The present invention aims to disclose a class of aminoamide alkylthioester compounds (I) and pharmaceutically acceptable salts thereof.

[0008] Another object of the present invention is to disclose a method for preparing the aminoamide alkylthioester compound (I) and its pharmaceutically acceptable salt.

[0009] Another object of the present invention is to disclose a pharmaceutical composition comprising the aminoamide alkylthioester compound (I) and a pharmaceutically acceptable salt thereof.

[0010] Another object of the present invention is to disclose that the aminoamide alkylthioester compound (I) and its pharmaceutically acceptable salt have multi-target effects and can be used to prepare drugs for treating and / or preventing diseases related to the nervous system, including but not limited to vascular dementia, Alzheimer's disease, frontotemporal dementia, prion disease, Lewy body dementia, Parkinson's disease, Huntington's disease, HIV-related dementia, multiple sclerosis, amyotrophic lateral sclerosis, neuropathic pain, ischemic stroke, hemorrhagic stroke, and nerve damage caused by brain trauma.

[0011] The general chemical structure of the aminoamide alkylthioester compound (I) provided by the present invention is: In the formula: R1 represents a C1 to C5 alkyl group, 2-pyridyl, 3-pyridyl, 4-pyridyl, R5O-, R6NH- or R6R7N-; m represents 0-4; n represents 1-5; represents the residue of L-alanine, L-valine, L-leucine, L-phenylalanine or L-proline; R3 and R4 each independently represent H, C1-C6 alkyl, C1-C6 alkoxy, OH, acetoxy, dimethylamino or halogen, and R3 and R4 are at any possible position on their corresponding phenyl rings; R5, R6 and R7 each independently represent C1-C6 alkyl, benzyl, substituted benzyl, R5O also represents (+)-bornyl, (-)-bornyl, and fenchol; when R6R7N- forms a ring, it represents tetrahydropyrrolyl, morpholinyl, piperidinyl, piperazinyl, piperazinyl substituted at the 4-position by a C1-C6 alkyl, or piperazinyl substituted at the 4-position by a benzyl or substituted benzyl; the "halogen" refers to F, Cl, Br, or I; the "substituted benzyl" refers to a benzyl group substituted on the benzene ring by 1-4 groups selected from the group consisting of F, Cl, Br, I, C 1-4 Alkyl, C 1-4 Alkoxy, trifluoromethyl, trifluoromethoxy, dimethylamino, these substituents can be at any possible position on the phenyl ring of the benzyl group.

[0012] The aminoamide alkylthioester compound (I) disclosed in the present invention can be prepared by the following method: (1) When R1 represents a C1-C5 alkyl group, In the case of 2-pyridyl, 3-pyridyl, or 4-pyridyl, an amide alkanethiolate compound (1) in which the corresponding amino group is protected by Boc (tert-butyloxycarbonyl) and a corresponding acid chloride (2) are used as starting materials, and condensation is carried out in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (3) (step A); then, the Boc protecting group is removed under acidic conditions to obtain an aminoamide alkylthioester compound (I) (step C); the reaction formula is as follows: In the formula: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R1, R2 and n are the same as those in the general chemical structure formula of the aminoamide alkylthioester compound (I).

[0013] (2) When R1 represents R5O, the corresponding amino group is protected by Boc (tert-butyloxycarbonyl) and the corresponding chloroformate (4) are used as starting materials, and condensed in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (5) (step A). ​​The Boc protecting group is then removed under acidic conditions to obtain the aminoamide alkylthioester compound (I) (step C). The reaction formula is as follows: In the formula: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R5 and n are the same as those in the general chemical structure formula of the aminoamide alkylthioester compound (I).

[0014] (3) When R1 represents R6NH, the corresponding amino group is protected by Boc (tert-butyloxycarbonyl) and the corresponding isocyanate (6) are used as starting materials, and condensed in a solvent to obtain the corresponding amide alkylthioester intermediate (7) (step B). The Boc protecting group is then removed under acidic conditions to obtain the aminoamide alkylthioester compound (I) (step C). The reaction formula is as follows: In the formula: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R6 and n are the same as those in the general chemical structure formula of the aminoamide alkylthioester compound (I).

[0015] (4) When R1 represents R6R7N, the corresponding amino group is protected by Boc (tert-butyloxycarbonyl) and the corresponding carbamoyl chloride (8) are used as starting materials, and condensed in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (9) (step A). ​​The Boc protecting group is then removed under acidic conditions to obtain the aminoamide alkylthioester compound (I) (step C). The reaction formula is as follows: In the formula: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R6, R7 and n are the same as those in the general chemical structure formula of the aminoamide alkylthioester compound (I).

[0016] For the above-mentioned synthetic route, its specific preparation method is described as follows: Step A): The amino group of the amide alkanethiols (1) is protected by Boc and condensed with the corresponding acyl chloride (2) or chloroformate (4) or carbamoyl chloride (8) in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediates (3), (5) or (9); wherein the solvent used is: diethyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, C 5-10 Aliphatic alkanes or C 5-10 Cycloalkanes (such as n-hexane, n-heptane, cyclohexane, etc.), N,N-dimethylformamide, C 1-6 Fatty acids and C 1-6The ester formed by the fatty alcohol, dichloromethane, chloroform, 1,2-dichloroethane, o-dichlorobenzene, benzene, toluene or acetonitrile, preferably the solvent is: diethyl ether, tetrahydrofuran, N,N-dimethylformamide, dichloromethane, chloroform, ethyl acetate, acetonitrile or toluene; the base used in the reaction is: alkali metal carbonate, alkaline earth metal carbonate, alkali metal bicarbonate, alkaline earth metal bicarbonate, triethylamine, diisopropylethylamine, tributylamine, pyridine, N-methylmorpholine, N-methylpiperidine or triethylenediamine, preferably the base is : sodium bicarbonate, potassium carbonate, triethylamine, N-methylmorpholine or pyridine; the molar feed ratio of amide alkanethiol compound (1): acyl chloride (2) or chloroformate (4) or carbamoyl chloride (8): base is 1.0:1.0~5.0:1.0~5.0, preferably 1.0:1.0~2.5:1.0~2.5; the reaction temperature is -20℃~120℃, preferably 0~100℃; the reaction time is 20 minutes~20 hours, preferably 30 minutes~12 hours.

[0017] Step B): The amino group of the amide alkanethiols (1) is protected by Boc and the corresponding isocyanate (6) is directly condensed in a solvent to obtain the corresponding amide alkanethioester intermediate (7); wherein the solvent used is: isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, C 5-10 Aliphatic alkanes or C 5-10 Cycloalkanes (such as n-hexane, n-heptane, cyclohexane, etc.), N,N-dimethylformamide, C 1-6 Fatty acids and C 1-6 The ester formed by the fatty alcohol, dichloromethane, chloroform, o-dichlorobenzene, benzene, toluene or acetonitrile, preferably the solvent is: tetrahydrofuran, N,N-dimethylformamide, chloroform, isopropyl acetate, toluene or acetonitrile; the molar feed ratio of the amide alkanethiol compound (1): isocyanate (6) is 1.0:1.0~4.0, preferably 1.0:1.0~2.0; the reaction temperature is 0℃~120℃, preferably 20~100℃; the reaction time is 30 minutes~20 hours, preferably 1 hour~15 hours.

[0018] Step C): The amide alkylthioester intermediate (3), (5) or (9) obtained in step A), or the amide alkylthioester intermediate (7) obtained in step B) is subjected to removal of the Boc protecting group under acidic conditions to obtain the corresponding aminoamide alkylthioester compound (I); wherein the acid used in the reaction is: hydrochloric acid, sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid, C 1-6Alkylsulfonic acid, phosphoric acid, perchloric acid, trifluoroacetic acid, trifluoromethanesulfonic acid or nitric acid, preferably the acid is hydrochloric acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid or ethanesulfonic acid; the molar feed ratio of the amide alkylthioester intermediate (3), (5), (7) or (9): the acid is 1.0:0.1-10.0, preferably the molar feed ratio is 1.0:0.3-5.0; the reaction temperature is 0-100°C, preferably the reaction temperature is room temperature to 70°C; the reaction time is 1-60 hours, preferably the reaction time is 2-48 hours.

[0019] The aminoamide alkylthioester compound (I) obtained by the above method can be reacted with any suitable acid by a conventional pharmaceutical salt-forming method to obtain its pharmaceutically acceptable salt, wherein the acid is hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, aminosulfonic acid, C 1-6 Fatty carboxylic acids (such as formic acid, acetic acid, propionic acid, etc.), trifluoroacetic acid, stearic acid, pamoic acid, oxalic acid, benzoic acid, phenylacetic acid, salicylic acid, maleic acid, fumaric acid, succinic acid, tartaric acid, citric acid, malic acid, lactic acid, hydroxymaleic acid, pyruvic acid, glutamic acid, ascorbic acid, lipoic acid, C 1-6 Alkylsulfonic acid (such as methanesulfonic acid, ethylsulfonic acid, etc.), camphorsulfonic acid, naphthalenesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or 1,4-butanedisulfonic acid.

[0020] The pharmaceutical composition disclosed herein comprises a therapeutically effective amount of one or more aminoamide alkylthioester compounds (I) or pharmaceutically acceptable salts thereof, and may further contain one or more pharmaceutically acceptable carriers or excipients. The term "therapeutically effective amount" refers to the amount of a drug or agent that elicits a biological or medical response in a tissue, system, or animal targeted by a researcher or physician; the term "composition" refers to a product formed by mixing one or more substances or components; and the term "pharmaceutically acceptable carrier" refers to a pharmaceutically acceptable substance, composition, or carrier, such as a liquid or solid filler, diluent, excipient, solvent, or encapsulating material, that carries or transports a chemical substance. The pharmaceutical composition provided herein ideally comprises 2% to 99.5% by weight of the aminoamide alkylthioester compound (I) or pharmaceutically acceptable salt thereof as the active ingredient.

[0021] The aminoamide alkylthioester compounds (I) and pharmaceutically acceptable salts thereof disclosed in the present invention were screened for the following biological activities: (1) Antioxidant activity of aminoamide alkylthioester compounds (I) (ORAC-FL method) The determination was performed according to the method reported in the literature (Qiang, XM et al. Eur. J Med. Chem. 2014, 76, 314-331), namely: 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) was prepared into a 10-80 μmol / L solution in PBS buffer at pH 7.4, fluorescein was prepared into a 250 nmol / L solution in PBS buffer at pH 7.4, and 2,2'-azobisisobutylamidine dihydrochloride (AAPH) was prepared into a 40 mmol / L solution in PBS buffer at pH 7.4 before use. Compound solution and fluorescein solution were added to a 96-well plate at 50-10 μmol / L, mixed, and incubated at 37°C for 15 min. AAPH solution was added to a total volume of 200 μL per well, mixed, and immediately placed in a Varioskan Flash Multimode Reader (ThermoScientific). Fluorescence was measured continuously for 90 min at an excitation wavelength of 485 nm and an emission wavelength of 535 nm. The area under the fluorescence decay curve (AUC) was calculated using 1-8 μmol / L Trolox as the standard and a blank without the test sample. The antioxidant activity of the compound was expressed as Trolox equivalents using the following formula: [(AUC Sample - AUC Blank) / (AUCTrolox - AUC Blank)] × [(Concentration of Trolox / Concentration of Sample)]. Three replicate wells were measured for each compound, and each experiment was repeated three times. The test results show that the antioxidant activity of the aminoamide alkylthioester compound (I) disclosed in the examples of the present invention is 0.45 to 2.6 times that of Trolox, indicating that this type of compound has strong antioxidant activity. The test results also found that when the S atom in the aminoamide alkylthioester compound (I) is replaced with O or NH, the antioxidant activity of the corresponding compound obtained is significantly reduced (the antioxidant activity is reduced by about 2-5 times).

[0022] (2) Effects of aminoamide alkylthioester compounds (I) on Aβ 1-42 Inhibitory activity of oligomers The determination was carried out according to the method reported in the literature (Qiang, XM et al. Eur. J Med. Chem. 2014, 76, 314-331), namely: the pretreated Aβ1-42 was prepared into a stock solution with DMSO and diluted to 50 μM with pH 7.4 PBS buffer before use; the test compound was prepared into a 2.5 mM stock solution with DMSO and diluted to the corresponding concentration with pH 7.4 PBS buffer before use, and 20 μL of Aβ was taken. 1-42solution + 20 μL of test compound solution, 20 μL of Aβ 1-42 The solution was added with 20 μL of PBS buffer (containing 2% DMSO) in a 96-well plate and incubated at 37°C for 24 h. Then, 160 μL of 50 mM glycine-NaOH buffer (pH = 8.5) containing 5 μM thioflavin T was added. After shaking for 5 seconds, the fluorescence value was immediately measured using a multifunctional microplate reader at an excitation wavelength of 446 nm and an emission wavelength of 490 nm. 1-42 The fluorescence value of the compound to be tested is recorded as IF i , Aβ 1-42 The fluorescence value of the buffer solution containing PBS was recorded as IFc, and the fluorescence value of the buffer solution containing only PBS was recorded as IF0. 1-42 The inhibition rate of oligomers is: 100-(IF i -IF0) / (IFc-IF0)*100; select five to six concentrations of the compound and determine their inhibition rate; each compound and each concentration are repeated three times, with curcumin as a positive control. The results show that the aminoamide alkylthioester compound (I) disclosed in the embodiment of the present invention has an inhibitory effect on Aβ 1-42 The oligomer formation was significantly inhibited at a concentration of 20.0 μM. 1-42 The inhibition rate of oligomer formation was between 28.2% and 78.0%. The inhibition rate of curcumin at this concentration was 28.0%. The control drugs: donepezil, ibuprofen, aspirin, (+)-bornyl alcohol, (-)-bornyl alcohol, amino Boc-protected amide alkanethiols (1) and their corresponding de-Boc protected products had no significant effect on Aβ at a concentration of 25.0 μM. 1-42 The inhibition rates of oligomer formation were all less than 18.3%.

[0023] (3) Inhibitory activity of aminoamide alkylthioester compound (I) on neuroinflammation (a) Effects of compound and lipopolysaccharide (LPS) on BV-2 cell activity BV-2 cells in the logarithmic growth phase were prepared into a cell suspension and inoculated into a 96-well plate. The cells were cultured in a 37°C, 5% CO2 cell culture incubator for 24 h. After the cells attached, 90 μL of fresh serum-free culture medium was replaced. 10 μL of the test compound at each concentration was added and pre-incubated for 30 min. Three parallel wells were set up for each concentration, and a blank control group was set up. LPS was then added or not, and the cells were cultured in a 37°C, 5% CO2 cell culture incubator for another 24 h. MTT solution was added and incubated at 37°C for 4 h. The supernatant was discarded, and 200 μL of DMSO solution was added to each well. After gentle shaking for 10 min, the OD value was measured at 490 nm using a microplate reader. The mean OD value of each test sample at different concentrations was calculated, and the cell viability was calculated as follows: Cell viability (%) = mean OD value of the treatment group / mean OD value of the control group × 100%. The test results show that all aminoamide alkylthioester compounds (I), amino-Boc-protected amide alkylthiol compounds (1) and their corresponding de-Boc-protected products disclosed in the examples of the present invention showed no cytotoxicity (inhibition rate less than <15.0%) at a concentration not exceeding 25 μM.

[0024] (b) Effects of aminoamide alkylthioester compounds (I) on LPS-induced NO release in BV-2 cells BV-2 cells in the logarithmic growth phase were prepared into a cell suspension and inoculated into a 96-well plate. The cells were cultured in a 37°C, 5% CO2 cell culture incubator for 24 h. After the cells adhered, 90 μL of fresh serum-free culture medium was replaced. 10 μL of the test compound at each concentration was added and pre-incubated for 30 min. Three parallel wells were set for each concentration, and a blank control group was also set up. LPS was then added for stimulation, and the cells were cultured in a 37°C, 5% CO2 cell culture incubator for another 24 h. The cell culture supernatant of the different treatment groups was taken, and an equal volume of Griess reagent I and an equal volume of Griess reagent II were added. The cells were reacted at room temperature in the dark for 10 min, and the absorbance was measured at 540 nm to detect the NO level in the cell supernatant (the specific operation was carried out according to the instructions of the NO detection kit). Test results showed that all aminoamide alkylthioester compounds (I) disclosed in the examples of the present invention exhibited strong inhibition of LPS-induced NO production in BV-2 cells within a concentration range of 0.5 μM to 25 μM (inhibition rates exceeded 42.0% at a concentration of 10.0 μM), with a clear dose-response relationship, indicating that the aminoamide alkylthioester compounds (I) disclosed in the examples of the present invention have significant anti-neuroinflammatory activity. The study also found that replacing the S atom in the aminoamide alkylthioester compound (I) with O or NH significantly reduced the anti-neuroinflammatory activity of the corresponding compound (the percentage of inhibition of NO production in BV-2 cells at a concentration of 10.0 μM was less than 21.0%).

[0025] (4) Effects of aminoamide alkylthioester compounds (I) on NaNO2-induced learning and memory consolidation impairment in mice Sodium nitrite (NaNO2) can oxidize hemoglobin in red blood cells into methemoglobin, and high doses of NaNO2 can significantly reduce the content of reduced small molecules (GSH) and reductase systems (SOD, GPx, GR) in the body, thereby causing lipid peroxidation and protein carbonylation, leading to oxidative stress. Therefore, NaNO2-induced mouse models are often used to screen the in vivo activity of candidate anti-oxidative stress drugs.

[0026] SPF-grade ICR mice, half male and half female, with an initial body weight of 18-22 grams, were randomly divided into: normal group, model group, positive control group (donepezil hydrochloride), and test drug high, medium and low dose groups, with 8 mice in each group. Before the platform jumping test, mice in each group were gavaged with the corresponding compound (twice a day, with an interval of 12 hours, for 4 days). The normal group and model group mice were gavaged with the same volume of 0.5% CMC-Na solution, and the high, medium and low dose groups of the test drug were gavaged with the corresponding drug saline solution (45.0 mg / kg, 15.0 mg / kg, and 5.0 mg / kg). One hour after the second administration on the third day, the mice were placed on the platform jumping apparatus to adapt for 3 minutes, and then placed on the circular platform and trained with 36V AC for 5 minutes. The time when the mice first jumped off the platform was recorded as the training latency. After training, NaNO2 saline solution (90.0 mg / kg) was subcutaneously injected into the mice in each group except the normal group. One hour after the last administration on the next day, the mice were tested again using the platform jumping apparatus. The time when the mice first jumped off the platform was recorded as the test latency, and the number of times they were shocked after jumping off the platform within 5 minutes was recorded as the number of errors. After the behavioral test, the mice were decapitated and their brains were removed. The cerebral cortex of the mice was separated on ice and then homogenized according to the test requirements. The homogenate supernatant was used to determine the malondialdehyde (MDA) and SOD contents in the cerebral cortex of the mice.

[0027] The results of the assay showed that the aminoamide alkylthioester compounds (I) tested (Example compounds 2-2-6, 2-2-10, 2-2-13, 2-2-15, 2-2-30, 2-2-31) had an improving effect on NaNO2-induced learning and memory consolidation disorders in mice (prolonging the latency period and reducing the number of errors) at high, medium and low doses, and there were statistical differences compared with the model group (p<0.01). In addition, the activity was significantly higher than that of the de-Boc protected product of the corresponding compound (1) at the same dose (p<0.01), and was also stronger than that of the clinical drug donepezil hydrochloride at the same dose (p<0.01). In addition, the test results also showed that the aminoamide alkylthioester compound (I) tested at high, medium and low doses could reduce the MDA content in the mouse cerebral cortex to varying degrees and increase the SOD activity in a dose-dependent manner. Its effect was also significantly higher than that of the de-Boc protected product of the corresponding compound (1) at the same dose (p<0.01); therefore, the aminoamide alkylthioester compound (I) disclosed in the embodiment of the present invention can alleviate the central oxidative stress in mice caused by NaNO2. DETAILED DESCRIPTION

[0028] The present invention will be further described by the following examples, however, the scope of the present invention is not limited to the following examples. Those skilled in the art will appreciate that various changes and modifications can be made to the present invention without departing from the spirit and scope of the present invention.

[0029] Example 1 General method for preparing amide alkylthioester intermediates (3), (5) or (9) In a reaction flask, add 3.0 mmol of an amide alkanethiolate compound (1) whose amino group is protected by Boc, 6.0 mmol of triethylamine, and 30 ml of tetrahydrofuran. After stirring at room temperature, add 4.0 mmol of the corresponding acyl chloride (2) or chloroformate (4) or carbamoyl chloride (8). Continue stirring at room temperature for 2 to 12 hours (the reaction progress is monitored by TLC). After the reaction is completed, the solvent is evaporated under reduced pressure, 100 mL of dichloromethane is added to the residue, and the mixture is washed with 40 mL of deionized water, 40 mL of a saturated sodium bicarbonate aqueous solution, and 40 mL of a saturated NaCl aqueous solution in sequence. The organic layer is dried over anhydrous sodium sulfate and filtered. The solvent is evaporated under reduced pressure. The residue is the amide alkanethioester intermediate (3), (5), or (9), which can be used in the next step without purification.

[0030] Example 2 General method for preparing amide alkylthioester intermediate (7) In a reaction flask, 3.0 mmol of an amide alkanethiolate compound (1) whose amino group is protected by Boc, 3.6 mmol of the corresponding isocyanate (6), and 40 ml of tetrahydrofuran were added. The temperature was raised to 40-60°C and stirred for 2-12 hours (the reaction progress was monitored by TLC). After the reaction, the solvent was evaporated under reduced pressure, 100 mL of dichloromethane was added to the residue, and the mixture was washed with 35 mL of deionized water, 35 mL of a saturated sodium bicarbonate aqueous solution, and 50 mL of a saturated NaCl aqueous solution in sequence. The organic layer was dried over anhydrous sodium sulfate and filtered, and the solvent was evaporated under reduced pressure. The residue was the amide alkanethioester intermediate (7), which was used in the next step without purification.

[0031] Example 3 General method for preparing aminoamide alkylthioester compound (I) The amide alkylthioester intermediate (3), (5), (7) or (9) (about 3.0 mmol) obtained according to Example 1 or Example 2 was dissolved in 30 ml of dichloromethane, and 9.0 mmol of trifluoroacetic acid was added under cooling, and the reaction was stirred at room temperature for 2 to 24.0 hours (the reaction progress was monitored by TLC); after the reaction, 60 mL of deionized water was added, and the pH of the reaction solution was adjusted to alkaline with sodium bicarbonate, and then extracted three times with 120 mL of dichloromethane. The organic layers were combined and washed with saturated sodium chloride aqueous solution, dried over anhydrous Na2SO4, and then filtered. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (eluent: dichloromethane / methanol = 20 to 70 / 1 v / v) to obtain the corresponding target compound (total yield of two steps: 40.3% to 73.5%). 1 H-NMR, 13 C-NMR and ESI-MS confirmed that the purity of the obtained target product was greater than 96.5% as determined by HPLC. The structure of the target product prepared by the above general method is as follows: Some compounds 1 H-NMR and 13 The C-NMR data are as follows: 1 HNMR(400MHz,D2O):3.74(d,J=6.0Hz,1H),3.39-3.35(m,1H),3.26-3.24(m,1H),2.90(t,J=7.2 Hz,2H),2.37(s,3H),2.22-2.18(m,1H),1.82-1.80(m,2H),1.03(dd,J1=7.2Hz,J2=2.8Hz,6H); 13 CNMR(101MHz,D2O):201.6,169.0,58.7,38.2,29.9,29.8,28.1,26.1,17.6,16.9; 1 HNMR (400MHz, CDCl3): 7.96 (dd, J1=7.6Hz, J2=2.4Hz, 2H), 7.65 (brs, 1H), 7.57 (t, J=7.6Hz, 1H), 7.45 (t, J=7.6Hz, 2H), 3.39-3.37 (m, 2H), 3. 34(d,J=4.0Hz,1H),3.11(t,J=6.8Hz,2H),2.43(brs,2H),2.33-2.30(m,1H),1.91-1.89(m,2H),1.00(d,J=6.8Hz,3H),0.87(d,J=6.8Hz,3H); 13 CNMR(101MHz, CDCl3):192.4,174.0,137.0,133.6,128.8,127.4,60.2,37.7,30.9,29.9,26.3,19.7,16.5; 1HNMR(400MHz,CDCl3):7.65(brs,1H),7.29-7.27(m,2H),7.20-7.16(m,3H),3.41(d,J=4.0Hz,1H),3.32-3.28(m,2H),3.24(brs,2H),2.90(t,J=7.2Hz,2H),2.64(t,J=7.6Hz,2H),2.57(t,J=7.6Hz,2H),2.31-2.29(m,1H),2.00-1.96(m,2H),1.81-1.77(m,2H),1.00(d,J=6.8Hz,3H),0.88(d,J=6.8Hz,3H); 13 CNMR(101MHz,CDCl3):199.8,173.2,141.1,128.5,128.4,126.1,59.9,43.4,37.6,34.9,30.8,29.7,27.2,26.1,19.5,16.6; 1 HNMR(400MHz,D2O):3.74(d,J=6.0Hz,1H),3.41-3.39(m,1H),3.30-3.26(m,1H),3.00(s,6H),2.90(t,J=7.2Hz,2H),2.20-2.18(m,1H),1.86-1.82(m,2H),1.02(dd,J1=6.8Hz,J2=3.2Hz,6H); 13 CNMR(101MHz,D2O):170.7,168.9,58.7,38.0,36.6,36.3,29.8,28.9,27.2,17.5,16.9; 1 HNMR(400MHz,CDCl3):7.51(brs,1H),4.28(q,J=7.2Hz,2H),3.37-3.33(m,2H),3.25(d,J=4.0Hz,1H),2.89(t,J=6.8Hz,2H),2.31-2.27(m,1H),1.89-1.86(m,2H),1.67(brs,2H),1.31(t,J=7.2Hz,3H),0.99(d,J=6.8Hz,3H),0.84(d,J=6.8Hz,3H); 13CNMR(101MHz, CDCl3):174.4,171.2,63.6,60.2,37.4,30.8,30.0,28.2,19.7,16.1,14.3; 1 HNMR (400MHz, D2O): 7.86 (dd, J1=7.6Hz, J2=2.4Hz, 1H), 7.60 (td, J1=7.6Hz, J2=1.6 Hz,1H),7.36(td,J1=7.6Hz,J2=1.2Hz,1H),7.16(dd,J1=8.0Hz,J2=1.2Hz,1H),3.7 4(d,J=6.0Hz,1H),3.42-3.38(m,1H),3.24-3.22(m,1H),2.98(t,J=7.2Hz,2H),2.3 1(s,3H),2.19-2.17(m,1H),1.85-1.82(m,2H),1.00(dd,J1=7.2Hz,J2=3.2Hz,6H); 13 CNMR(101MHz,D2O):193.6,172.7,168.9,146.6,134.5,129.7,129.4,126.9,123.5,58.6,38.2,29.8,28.0,26.5,20.4,17.5,16.9.

[0032] Example 4 General method for preparing aminoamide alkylthioester compound (I) by acid salt formation In a reaction flask, 1.0 mmol of the aminoamide alkylthioester compound (I) obtained in Example 3 and 40 ml of dichloromethane were added, stirred evenly, and then 2.0 mmol of the corresponding acid was added. The mixture was stirred at room temperature for 30 minutes. After the reaction was completed, the solvent was evaporated under reduced pressure, and the residue was crystallized to obtain the salt of the corresponding aminoamide alkylthioester compound. Its chemical structure is shown in FIG. 1 The results were confirmed by HNMR and ESI-MS.

Claims

1. An aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof, characterized in that The chemical structure of this type of compound is shown in the formula (I): In the formula: R1 represents a C1 to C5 alkyl group, 2-pyridyl, 3-pyridyl, 4-pyridyl, R5O-, R6NH- or R6R7N-; m represents 0-4; n represents 1-5; represents the residue of L-alanine, L-valine, L-leucine, L-phenylalanine or L-proline; R3 and R4 each independently represent H, C1-C6 alkyl, C1-C6 alkoxy, OH, acetoxy, dimethylamino or halogen, and R3 and R4 are at any possible position on their corresponding phenyl rings; R5, R6 and R7 each independently represent C1-C6 alkyl, benzyl, substituted benzyl, R5O also represents (+)-bornyl, (-)-bornyl, and fenchol; when R6R7N- forms a ring, it represents tetrahydropyrrolyl, morpholinyl, piperidinyl, piperazinyl, piperazinyl substituted at the 4-position by a C1-C6 alkyl, or piperazinyl substituted at the 4-position by a benzyl or substituted benzyl; the "halogen" refers to F, Cl, Br, or I; the "substituted benzyl" refers to a benzyl group substituted on the benzene ring by 1-4 groups selected from the group consisting of F, Cl, Br, I, C 1-4 Alkyl, C 1-4 Alkoxy, trifluoromethyl, trifluoromethoxy, dimethylamino, these substituents can be at any possible position on the phenyl ring of the benzyl group.

2. The aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that R1 is selected from methyl, propyl, pentyl, phenyl, (2-hydroxy)phenyl, (2-acetoxy)phenyl, phenethyl, (4-methoxy)phenethyl, 4-chlorophenethyl, phenylpropyl, 4-fluorophenylpropyl, (4-dimethylamino)phenylpropyl, 1-(4-isobutylphenyl)ethyl, phenylvinyl, (3-hydroxy-4-methoxy)phenylvinyl, (3-methoxy-4-hydroxy)phenylvinyl, (3,4-dihydroxy)phenylvinyl, (4-dimethylamino)phenylvinyl, 3-pyridyl, 4-pyridyl 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 1-Hydroxy, 3. The aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that A residue selected from L-alanine, L-valine, L-phenylalanine or L-proline; n is selected from 1, 2 or 3.

4. The aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 3, characterized in that The pharmaceutically acceptable salts are prepared by reacting such aminoamide alkylthioester compounds with hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, aminosulfonic acid, C 1-6 Fatty carboxylic acid, trifluoroacetic acid, stearic acid, pamoic acid, oxalic acid, benzoic acid, phenylacetic acid, salicylic acid, maleic acid, fumaric acid, succinic acid, tartaric acid, citric acid, malic acid, lactic acid, hydroxymaleic acid, pyruvic acid, glutamic acid, ascorbic acid, lipoic acid, C 1-6 Salts of alkylsulfonic acid, camphorsulfonic acid, naphthalenesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid or 1,4-butanedisulfonic acid.

5. The method for preparing the aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 4, characterized in that The compound can be prepared by the following method: (1) When R1 represents a C1-C5 alkyl group, In the case of 2-pyridyl, 3-pyridyl, or 4-pyridyl, the corresponding amino group is protected by Boc (tert-butyloxycarbonyl) and the corresponding acid chloride (2) are used as starting materials, and condensed in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (3); the Boc protecting group is then removed under acidic conditions to obtain the aminoamide alkylthioester compound (I); the reaction formula is as follows: Wherein: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R1, R2 and n are the same as the general chemical structure formula of aminoamide alkylthioester compound (I); (2) When R1 represents R5O, the corresponding amino group of the amide alkanethiols (1) protected by Boc (tert-butyloxycarbonyl) and the corresponding chloroformate (4) are used as starting materials, and condensed in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (5); then, the Boc protecting group is removed under acidic conditions to obtain the aminoamide alkylthioester compound (I); the reaction formula is as follows: Wherein: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R5 and n are the same as the general chemical structure formula of aminoamide alkylthioester compound (I); (3) When R1 represents R6NH, the corresponding amino group of the amide alkanethiols (1) protected by Boc (tert-butyloxycarbonyl) and the corresponding isocyanate (6) are used as starting materials and condensed in a solvent to obtain the corresponding amide alkylthioester intermediate (7); then, the Boc protecting group is removed under acidic conditions to obtain the amino amide alkylthioester compound (I); the reaction formula is as follows: Wherein: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R6 and n are the same as the general chemical structure formula of aminoamide alkylthioester compound (I); (4) When R1 represents R6R7N, the corresponding amino group of the amide alkanethiols (1) protected by Boc (tert-butyloxycarbonyl) and the corresponding carbamoyl chloride (8) are used as starting materials, and condensed in a solvent under alkaline conditions to obtain the corresponding amide alkylthioester intermediate (9); then, the Boc protecting group is removed under acidic conditions to obtain the aminoamide alkylthioester compound (I); the reaction formula is as follows: Wherein: R8 represents a substituent after the amino group in R2 is protected by Boc; the definitions of R2, R6, R7 and n are the same as those in the general chemical structure formula of aminoamide alkylthioester compound (I); The aminoamide alkylthioester compound (I) obtained by the above method can be reacted with an acid through a conventional pharmaceutical salt-forming method to obtain a pharmaceutically acceptable salt thereof.

6. The method for preparing the aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof as claimed in claim 5, characterized in that The solvents used in step A are: diethyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, C 5-10 Aliphatic alkanes or C 5-10 Cycloalkanes, N,N-dimethylformamide, C 1-6 Fatty acids and C 1-6 The ester formed by the fatty alcohol, dichloromethane, chloroform, 1,2-dichloroethane, o-dichlorobenzene, benzene, toluene or acetonitrile; the base used in the reaction is: alkali metal carbonate, alkaline earth metal carbonate, alkali metal bicarbonate, alkaline earth metal bicarbonate, triethylamine, diisopropylethylamine, tributylamine, pyridine, N-methylmorpholine, N-methylpiperidine or triethylenediamine; the molar feed ratio of amide alkanethiol compound (1): acid chloride (2) or chloroformate (4) or carbamoyl chloride (8): base is 1.0:1.0~5.0:1.0~5.0; the reaction temperature is -20℃~120℃; the reaction time is 20 minutes~20 hours; The solvents used in step B are: isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, C 5-10 Aliphatic alkanes or C 5-10 Cycloalkanes, N,N-dimethylformamide, C 1-6 Fatty acids and C 1-6 The ester formed by the fatty alcohol, dichloromethane, chloroform, o-dichlorobenzene, benzene, toluene or acetonitrile; the molar feed ratio of the amide alkanethiol compound (1): isocyanate (6) is 1.0:1.0-4.0; the reaction temperature is 0°C-120°C; the reaction time is 30 minutes-20 hours; The acid used in step C is: hydrochloric acid, sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid, C 1-6 Alkylsulfonic acid, phosphoric acid, perchloric acid, trifluoroacetic acid, trifluoromethanesulfonic acid or nitric acid; the molar feed ratio of amide alkylthioester intermediate (3), (5), (7) or (9): acid is 1.0:0.1-10.0; the reaction temperature is 0-100°C; and the reaction time is 1-60 hours.

7. A pharmaceutical composition characterized in that The invention comprises the aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 4, and one or more pharmaceutically acceptable carriers or excipients.

8. Use of the aminoamide alkylthioester compound or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 4 in the preparation of a medicament for treating and / or preventing nervous system diseases, characterized in that The neurological diseases are: vascular dementia, Alzheimer's disease, frontotemporal dementia, prion disease, Lewy body dementia, Parkinson's disease, Huntington's disease, HIV-related dementia, multiple sclerosis, amyotrophic lateral sclerosis, neuropathic pain, ischemic stroke, hemorrhagic stroke and nerve damage caused by brain trauma.

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