3-hydroxy-5-pregnan-20-one derivatives and uses thereof

Abstract

The present invention provides a 3-hydroxy-5-pregnan-20-one derivative represented by Formula I or a pharmaceutically acceptable salt thereof, as well as a pharmaceutical composition comprising the derivative or a pharmaceutically acceptable salt thereof. The derivative or a pharmaceutically acceptable salt thereof of the present invention, or a pharmaceutical composition comprising the derivative or salt thereof, can be used to produce a drug for treating diseases caused by central nervous system abnormalities. [Formula 1] JPEG2022545047000052.jpg4199

Description

[Technical Field]

[0001] The present invention relates to the field of medicinal chemistry, and in particular to 3-hydroxy-5-pregnan-20-one derivatives represented by formula (I) and their use in the manufacture of medicaments for preventing or treating central nervous system disorders and diseases. [Background technology]

[0002] Neuroactive steroids are steroids that have activity in nervous tissue. Neurosteroids that play important regulatory roles in the human body primarily include pregnanes, pregnenolone, and allopregnanolone. Pregnanes, pregnenolone, and allopregnanolone are all produced by the metabolism of cholesterol via different pathways. Cholesterol is transported from the outer to the inner mitochondrial membrane via an 18 kDa transporter protein, where it is metabolized by cytochrome P450 cholesterol side-chain cleavage enzyme to produce pregnenolone, which is then metabolized by 3β-hydroxysteroid dehydrogenase to produce pregnane, which is then metabolized to allopregnanolone through a series of catalytic reactions mediated by 5α-reductase and 3α-hydroxysteroid dehydrogenase. Neuroactive steroids can be used as anesthetics, sedatives, hypnotics, anxiolytics, antidepressants, and antiepileptics. Allopregnanolone has attracted attention in recent research, and as early as 1986, allopregnanolone was shown to inhibit GABA A However, it wasn't until 2006 that allopregnanolone was identified as a positive modulator of GABA receptors. A It has been found that it binds to the α and β subunits of the receptor, increasing the frequency of chloride ion channel opening in the receptor and reducing neural excitability, thereby exerting sedative and anxiolytic effects. There is evidence that the levels of pregnanes and their metabolites in the body vary depending on the stage of the menstrual cycle. Before menstruation begins, pregnane and metabolite levels decrease, which can lead to premenstrual syndrome (PMS), a condition characterized by recurring symptoms such as stress, anxiety, and migraines before the onset of the menstrual cycle, which disappear after menstruation. Postpartum depression is also associated with abnormal levels of pregnanes and their metabolites. As pregnancy progresses, plasma allopregnanolone levels increase in healthy pregnant women, and after delivery, allopregnanolone levels drop sharply.

[0003] Studies have shown that a decrease in allopregnanolone content is closely related to the occurrence and development of many psychiatric disorders, such as anxiety, depression, and tremors, and that the administration of exogenous allopregnanolone can significantly improve the above-mentioned psychiatric symptoms. However, allopregnanolone has low water solubility, poor oral bioavailability, and is rapidly metabolized with a plasma half-life of approximately 45 minutes. Zulresso, a water-soluble, sulfobutyl-β-cyclodextrin-based formulation of allopregnanolone already on the market, achieves stable physiological concentrations of allopregnanolone via intravenous infusion. However, Brexanolone requires intravenous infusion for up to 60 hours, resulting in poor patient compliance. Therefore, in clinical practice, a solution is needed that can improve solubility, reduce administration time, and maintain a stable physiological concentration of allopregnanolone in the body for a long period of time. Summary of the Invention

[0004] The present invention provides a 3-hydroxy-5-pregnan-20-one derivative that can be used to prepare a medicament for preventing or treating central nervous system disorders and diseases, which has improved solubility, stable storage, convenient administration, and good patient compliance.

[0005] In a first aspect, the present invention provides a compound of formula I, or a pharmaceutically acceptable salt thereof. [ka] (In the formula, R 1 and R 2 are each independently H, substituted or unsubstituted C1-C 10 R is an alkyl group, or a substituted or unsubstituted cycloalkyl group. 3 is H, halogen, hydroxy, amino, nitro, or mercapto, or R 2 and R 3 are linked to form a 5-6 membered saturated or unsaturated heterocyclic ring. a and b are each independently an integer of 0 to 3. In specific embodiments, R 3 is an amino group or H.

[0006] In specific embodiments, the compound of formula I is a compound of formula I-1, I-2, I-3, or I-4. [ka] (In the formula, R 1 , R 2 , R 3 , a, and b are defined as above.)

[0007] In a preferred embodiment, R 1 and R 2are each independently H or a substituted or unsubstituted C1-C8 alkyl group, wherein the substituent of the alkyl group is selected from a C1-C6 alkyl group, an aryl group, a hydroxy-substituted aryl group, an amino-substituted aryl group, a halogen-substituted aryl group, a carboxy-substituted aryl group, a heteroaryl group, a hydroxy-substituted heteroaryl group, an amino-substituted heteroaryl group, a halogen-substituted heteroaryl group, a carboxy-substituted heteroaryl group, an amino group, a methylamino group, a dimethylamino group, a hydroxy group, a mercapto group, a methylthio group, an amido group, a guanidyl group, and a carboxy group. In a preferred embodiment, R 1 and R 2 are each independently H, a substituted or unsubstituted C1 alkyl group, a substituted or unsubstituted C2 alkyl group, a substituted or unsubstituted C3 alkyl group, a substituted or unsubstituted C4 alkyl group, a substituted or unsubstituted C5 alkyl group, a substituted or unsubstituted C6 alkyl group, a substituted or unsubstituted C7 alkyl group, or a substituted or unsubstituted C8 alkyl group, wherein the alkyl group substituent is selected from a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, a phenyl group, a phenyl group substituted with a hydroxy group, an indolyl group, an imidazolyl group, an amino group, a hydroxy group, a mercapto group, a methylthio group, an amido group, a guanidyl group, a methylamino group, a dimethylamino group, or a carboxy group.

[0008] In a preferred embodiment, R 1 and R 2are each independently H, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted 2-isobutyl group, or a substituted or unsubstituted 1-isobutyl group, wherein the substituents are selected from a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, a phenyl group, a 2-hydroxyphenyl group, a 3-hydroxyphenyl group, a 4-hydroxyphenyl group, an indolyl group, an imidazolyl group, an amino group, a hydroxy group, a mercapto group, a methylthio group, an amido group, a methylamino group, a dimethylamino group, a guanidyl group, or a carboxy group. In a preferred embodiment, R 1 and R 2 are each independently H, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted 2-isobutyl group, or a substituted or unsubstituted 1-isobutyl group, wherein the substituents are selected from a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, an amino group, a hydroxy group, a mercapto group, a methylthio group, an amido group, a methylamino group, a dimethylamino group, a guanidyl group, or a carboxy group.

[0009] In a preferred embodiment, R 1 and R 2are each independently H, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an isobutyl group, an amido-substituted methyl group, a phenyl-substituted methyl group, a hydroxy-substituted methyl group, a carboxy-substituted methyl group, a mercapto-substituted methyl group, an imidazole-substituted methyl group, an indole-substituted methyl group, a p-hydroxyphenyl-substituted methyl group, a methylthio-substituted methyl group, a guanidyl-substituted methyl group, an amino-substituted methyl group, an amido-substituted ethyl group, a hydroxy-substituted ethyl group, a carboxy-substituted ethyl group, a mercapto-substituted ethyl group, an imidazole-substituted ethyl group, an indole-substituted ethyl group, a p-hydroxyphenyl-substituted ethyl group, a methylthio-substituted ethyl group, a guanidyl-substituted ethyl group, an amino-substituted ethyl group, and methylthio-substituted ethyl groups, amido-substituted propyl groups, hydroxy-substituted propyl groups, carboxy-substituted propyl groups, mercapto-substituted propyl groups, imidazole-substituted propyl groups, indole-substituted propyl groups, p-hydroxyphenyl-substituted propyl groups, methylthio-substituted propyl groups, guanidyl-substituted propyl groups, amino-substituted propyl groups, dimethylamino-substituted propyl groups, methyl-substituted propyl groups, amido-substituted butyl groups, hydroxy-substituted butyl groups, carboxy-substituted butyl groups, mercapto-substituted butyl groups, imidazole-substituted butyl groups, indole-substituted butyl groups, p-hydroxyphenyl-substituted butyl groups, methylthio-substituted butyl groups, guanidyl-substituted butyl groups, and amino-substituted butyl groups.

[0010] In a preferred embodiment, R 1 and R 2each independently represents H, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an isobutyl group, an amido-substituted methyl group, a hydroxy-substituted methyl group, a carboxy-substituted methyl group, a mercapto-substituted methyl group, a methylthio-substituted methyl group, a guanidyl-substituted methyl group, an amino-substituted methyl group, an amido-substituted ethyl group, a hydroxy-substituted ethyl group, a carboxy-substituted ethyl group, a mercapto-substituted ethyl group, a methylthio-substituted ethyl group, a guanidyl-substituted ethyl group, or an amino-substituted ethyl group. group, an amido-substituted propyl group, a hydroxy-substituted propyl group, a carboxy-substituted propyl group, a mercapto-substituted propyl group, a methylthio-substituted propyl group, a guanidyl-substituted propyl group, an amino-substituted propyl group, a dimethylamino-substituted propyl group, a methyl-substituted propyl group, an amido-substituted butyl group, a hydroxy-substituted butyl group, a carboxy-substituted butyl group, a mercapto-substituted butyl group, a methylthio-substituted butyl group, a guanidyl-substituted butyl group, or an amino-substituted butyl group. In specific embodiments, R 1 and R 2 At least one of the groups is an isopropyl group.

[0011] In a preferred embodiment, R 1 and R 2are each independently H, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an isobutyl group, an amido-substituted methyl group, a phenyl-substituted methyl group, a hydroxy-substituted methyl group, a carboxy-substituted methyl group, a mercapto-substituted methyl group, an imidazole-substituted methyl group, an indole-substituted methyl group, a p-hydroxyphenyl-substituted methyl group, a methylthio-substituted methyl group, a guanidyl-substituted methyl group, an amino-substituted methyl group, an amido-substituted ethyl group, a hydroxy-substituted ethyl group, a carboxy-substituted ethyl group, a mercapto-substituted ethyl group, an imidazole-substituted ethyl group, an indole-substituted ethyl group, a p-hydroxyphenyl-substituted ethyl group, a methylthio-substituted ethyl group, a guanidyl-substituted ethyl group, an amino-substituted methyl group, a methyl-substituted ethyl group, an amido-substituted propyl group, a hydroxy-substituted propyl group, a carboxy-substituted propyl group, a mercapto-substituted propyl group, an imidazole-substituted propyl group, an indole-substituted propyl group, a p-hydroxyphenyl-substituted propyl group, a methylthio-substituted propyl group, a guanidyl-substituted propyl group, an amino-substituted propyl group, a dimethylamino-substituted propyl group, a methyl-substituted propyl group, an amido-substituted butyl group, a hydroxy-substituted butyl group, a carboxy-substituted butyl group, a mercapto-substituted butyl group, an imidazole-substituted butyl group, an indole-substituted butyl group, a p-hydroxyphenyl-substituted butyl group, a methylthio-substituted butyl group, a guanidyl-substituted butyl group, or an amino-substituted butyl group, and R 1 , R 2 At least one of R is an isopropyl group. 3 represents H, a halogen, a hydroxy group, an amino group, a nitro group, or a mercapto group; and a and b are each independently selected from 0, 1, 2, or 3.

[0012] In specific embodiments, R 1is an isopropyl group. In a preferred embodiment, R 2 is H, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, amido-substituted methyl, phenyl-substituted methyl, hydroxy-substituted methyl, carboxy-substituted methyl, mercapto-substituted methyl, imidazole-substituted methyl, indole-substituted methyl, p-hydroxyphenyl-substituted methyl, methylthio-substituted methyl, 2-amidoethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-carboxyethyl, mercapto-substituted ethyl, imidazole-substituted ethyl, indole-substituted ethyl, p-hydroxyphenyl-substituted ethyl, 2-methylthioethyl, guanidyl-substituted ethyl, 2-aminoethyl, amido-substituted propyl, hydroxy-substituted propyl, carboxy-substituted propyl, mercapto-substituted propyl and the butyl group is selected from a butyl group, an imidazole-substituted propyl group, an indole-substituted propyl group, a p-hydroxyphenyl-substituted propyl group, a methylthio-substituted propyl group, a 1-guanidylpropyl group, a 2-guanidylpropyl group, a 3-guanidylpropyl group, a 1-aminopropyl group, a 2-aminopropyl group, a 3-aminopropyl group, a 1-dimethylaminopropyl group, a 2-dimethylaminopropyl group, a 3-dimethylaminopropyl group, a 1-methylpropyl group, a 2-methylpropyl group, an amido-substituted butyl group, a hydroxy-substituted butyl group, a carboxy-substituted butyl group, a mercapto-substituted butyl group, an imidazole-substituted butyl group, an indole-substituted butyl group, a p-hydroxyphenyl-substituted butyl group, a methylthio-substituted butyl group, a guanidyl-substituted butyl group, a 1-aminobutyl group, a 2-aminobutyl group, a 3-aminobutyl group, and a 4-aminobutyl group.

[0013] In a preferred embodiment, R 2is selected from H, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, amido-substituted methyl, phenyl-substituted methyl, hydroxy-substituted methyl, carboxy-substituted methyl, mercapto-substituted methyl, imidazole-substituted methyl, indole-substituted methyl, p-hydroxyphenyl-substituted methyl, methylthio-substituted methyl, 2-amidoethyl, 1-hydroxyethyl, 2-carboxyethyl, 2-methylthioethyl, 3-guanidylpropyl, 3-dimethylaminopropyl, 1-methylpropyl, 2-methylpropyl, and 4-aminobutyl. In a preferred embodiment, R 3 is selected from H or an amino group. In a preferred embodiment, R 2 and R 3 are linked to form a 5-6 membered saturated or unsaturated heterocyclic ring, preferably a 5 membered saturated or unsaturated heterocyclic ring containing one heteroatom, more preferably a 5 membered saturated heterocyclic ring containing one heteroatom, and most preferably a pyrrolidyl group. In a preferred embodiment, a and b are each independently selected from 0, 1, 2, or 3. In a preferred embodiment, a is selected from 0 and b is selected from 0 or 1.

[0014] In a preferred embodiment, R 1 is an isopropyl group, and R 2is H, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, amido-substituted methyl, phenyl-substituted methyl, hydroxy-substituted methyl, carboxy-substituted methyl, mercapto-substituted methyl, imidazole-substituted methyl, indole-substituted methyl, p-hydroxyphenyl-substituted methyl, methylthio-substituted methyl, 2-amidoethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-carboxyethyl, mercapto-substituted ethyl, imidazole-substituted ethyl, indole-substituted ethyl, p-hydroxyphenyl-substituted ethyl, 2-methylthioethyl, guanidyl-substituted ethyl, 2-aminoethyl, amido-substituted propyl, hydroxy-substituted propyl, carboxy-substituted propyl, mercapto-substituted propyl R is selected from the group consisting of propyl, imidazole-substituted propyl, indole-substituted propyl, p-hydroxyphenyl-substituted propyl, methylthio-substituted propyl, 1-guanidylpropyl, 2-guanidylpropyl, 3-guanidylpropyl, 1-aminopropyl, 2-aminopropyl, 3-aminopropyl, 1-dimethylaminopropyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 1-methylpropyl, 2-methylpropyl, amido-substituted butyl, hydroxy-substituted butyl, carboxy-substituted butyl, mercapto-substituted butyl, imidazole-substituted butyl, indole-substituted butyl, p-hydroxyphenyl-substituted butyl, methylthio-substituted butyl, guanidyl-substituted butyl, 1-aminobutyl, 2-aminobutyl, 3-aminobutyl, and 4-aminobutyl; 3 is selected from H or an amino group; a and b are each independently selected from 0, 1, 2, or 3;

[0015] In a preferred embodiment, R 1 is an isopropyl group, and R 2is selected from H, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, amido-substituted methyl, phenyl-substituted methyl, hydroxy-substituted methyl, carboxy-substituted methyl, mercapto-substituted methyl, imidazole-substituted methyl, indole-substituted methyl, p-hydroxyphenyl-substituted methyl, methylthio-substituted methyl, 2-amidoethyl, 1-hydroxyethyl, 2-carboxyethyl, 2-methylthioethyl, 3-guanidylpropyl, 3-dimethylaminopropyl, 1-methylpropyl, 2-methylpropyl, and 4-aminobutyl; R 3 is selected from H or an amino group, a is selected from 0, and b is selected from 0 or 1. In a preferred embodiment, R 1 is an isopropyl group, and R 2 and R 3 are linked to form a 5- or 6-membered saturated or unsaturated heterocycle, and a and b are each independently selected from 0, 1, 2, or 3. In a preferred embodiment, R 2 and R 3 are linked to form a 5-membered saturated or unsaturated heterocyclic ring containing one heteroatom, preferably a 5-membered saturated heterocyclic ring containing one heteroatom, more preferably a pyrrolidyl group; a is 0, and b is preferably selected from 0 or 1.

[0016] In a second aspect, the present invention provides a compound selected from the group consisting of: [ka] [ka] [ka] [ka] [ka] [ka]

[0017] In a third aspect, the present invention provides a compound selected from the group consisting of: [ka] In a fourth aspect, the present invention provides a pharmaceutical composition comprising a therapeutically effective dose of a compound according to the first to third aspects, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipient. In a preferred embodiment, the pharmaceutical composition is a pharmaceutical composition for preventing or treating central nervous system disorders or diseases. In a preferred embodiment, the central nervous system disorder or disease includes, but is not limited to, tremors, sleep disorders, depression, depressive disorders, bipolar disorders, anxiety disorders, stress reactions, post-traumatic stress disorders, obsessive-compulsive disorders, schizophrenia, schizoaffective disorders, epilepsy, epileptic seizures, memory and / or cognitive disorders, dementia, movement disorders, personality disorders, autism, monoetiology autism, pain, traumatic brain injury, vascular diseases, substance use disorders and / or withdrawal syndromes or tinnitus; The central nervous system disorders and diseases include, but are not limited to, idiopathic tremor, epilepsy, clinical depression, postpartum or postpartum depression, atypical depression, psychotic major depression, catatonic depression, seasonal affective disorder, dysthymia, bipolar depression, depressive personality disorder, recurrent brief depression, minor depressive disorder, bipolar or manic depression, post-traumatic stress disorder, depression due to a chronic medical condition, treatment-resistant depression, refractory depression, suicidality, suicidal ideation, suicidal behavior, traumatic brain injury, generalized anxiety disorder, social anxiety disorder, attention deficit hyperactivity disorder, dementia, Huntington's disease, Parkinson's disease, neuropathic pain, injury-related pain syndrome, acute pain, long-term pain, stroke, ischemia, vascular malformation, opioid, cocaine and / or alcohol dependence or insomnia.

[0018] In a fifth aspect, the present invention provides the use of a compound according to any one of the first to third aspects, or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition according to the fourth aspect, in the manufacture of a medicament for the prevention or treatment of a central nervous system disorder or disease. In specific embodiments, the central nervous system disorder or disease includes, but is not limited to, tremor, sleep disorder, depression, depressive disorder, bipolar disorder, anxiety disorder, stress reaction, post-traumatic stress disorder, obsessive-compulsive disorder, schizophrenia, schizoaffective disorder, epilepsy, epileptic seizures, memory and / or cognitive impairment, dementia, movement disorder, personality disorder, autism, monoetiology autism, pain, traumatic brain injury, vascular disease, substance use disorder and / or withdrawal syndrome or tinnitus; The central nervous system disorders and diseases include, but are not limited to, idiopathic tremor, epilepsy, clinical depression, postpartum or postpartum depression, atypical depression, psychotic major depression, catatonic depression, seasonal affective disorder, dysthymia, bipolar depression, depressive personality disorder, recurrent brief depression, minor depressive disorder, bipolar or manic depression, post-traumatic stress disorder, depression due to a chronic medical condition, treatment-resistant depression, refractory depression, suicidality, suicidal ideation, suicidal behavior, traumatic brain injury, generalized anxiety disorder, social anxiety disorder, attention deficit hyperactivity disorder, dementia, Huntington's disease, Parkinson's disease, neuropathic pain, injury-related pain syndrome, acute pain, long-term pain, stroke, ischemia, vascular malformation, opioid, cocaine and / or alcohol dependence or insomnia.

[0019] In a sixth aspect, the present invention provides a compound according to any one of the first to third aspects or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition according to the second aspect, for use as a drug for preventing or treating a central nervous system disorder or disease. In a seventh aspect, the present invention provides a method for preventing or treating a central nervous system disorder or disease, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound according to any one of the first to third aspects or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition according to the fourth aspect. In a preferred embodiment, the subject is a mammal, preferably a human. Of course, it is understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (e.g., in the Examples) can be combined with each other to form new or preferred technical solutions, which will not be described here one by one due to space limitations. [Brief explanation of the drawings]

[0020] [Figure 1] Figure 1 shows the pharmacokinetic curves of male rats after oral administration of the compounds of the present invention.

[0021] Through research, the inventors have found that allopregnanolone compounds have poor water solubility, requiring their clinical formulation in cyclodextrin aqueous solution and requiring long-term injections to achieve efficacy. After extensive and in-depth research, the inventors have unexpectedly found that by converting allopregnanolone compounds into specific derivatives, the water solubility of such compounds can be significantly improved, resulting in formulations that have a certain degree of storage stability in aqueous solution, and are sustained-release, with minimal individual variation. Formulations prepared using the derivatives of the present invention have the advantages of maintaining effective physiological concentrations of allopregnanolone in the body for a long period of time, and are conveniently administered, thereby improving patient compliance. Based on this, the present invention has been completed. definition

[0022] Unless stated to the contrary, terms used in the specification and claims have the following meanings. Any carbon, hydrogen, oxygen, sulfur, nitrogen or halogen in the groups and compounds described in the present invention includes their isotopes, and any carbon, hydrogen, oxygen, sulfur, nitrogen or halogen in the groups and compounds described in the present invention is optionally further replaced with one or more of its corresponding isotopes, where the carbon isotope is 12 C. 13C and 14 C, hydrogen isotopes are hydrogen (H), deuterium (D, also called heavy hydrogen), tritium (T, also called tritium), and oxygen isotopes are 16 O. 17 O and 18 O, and sulfur isotopes 32 S, 33 S, 34 S and 36 S, and the nitrogen isotope is 14 N and 15 N, and the isotope of fluorine is 19 F, and the chlorine isotope 35 Cl and 37 Cl, and the isotope of bromine is 79 Br and 81 Contains Br. The term "alkyl group" as used herein has the meaning commonly understood by those skilled in the art, specifically a linear or branched saturated group composed of carbon and hydrogen and having a specified number of carbon atoms. For example, C1-C2 as used herein. 10 An alkyl group refers to a straight or branched chain alkyl group having 1-10 carbon atoms, including, but not limited to, n-methyl, n-ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, n-pentyl, n-hexyl, n-heptyl, and the like.

[0023] As used herein, the term "cycloalkyl group" refers to all carbon monocyclic, fused, spirocyclic, or bridged rings, including, but not limited to, cyclopropane, cyclobutane, cyclopentane, spiro[3.4]octane, bicyclo[3.1.1]hexane, and the like. As used herein, the term "5-6 membered saturated or unsaturated heterocyclic ring" refers to a substituted or unsubstituted, saturated or unsaturated non-aromatic ring system containing at least one or two atoms or groups selected from N, O, S, S(=O), or S(=O)2, wherein the non-aromatic ring system contains 5 or 6 ring atoms, and non-limiting examples include pyrrolidyl, piperidyl, 1,3-dioxolanyl, 1,4-dioxolanyl, 1,3-dioxolanyl, and 1,3-dioxanyl. groups, 1,3-dithianyl groups, morpholyl groups, piperazyl groups, pyridyl groups, furyl groups, thienyl groups, pyrrolyl groups, pyranyl groups, N-alkylpyrrolyl groups, pyrimidinyl groups, pyrazinyl groups, pyridazyl groups, imidazolyl groups, piperidyl groups, thiomorpholyl groups, dihydropyran, thiadiazolyl groups, oxazolyl groups, oxadiazolyl groups, pyrazolyl groups, 1,4-dioxinyl groups, 2H-1,2-oxazinyl groups, and 2,5-dihydrothienyl groups.

[0024] As used herein, the term "halogen" refers to F, Cl, Br, and I. As used herein, the term "pharmaceutically acceptable salt" refers to a salt that is, within the scope of sound medical judgment, suitable for contact with the tissues of humans and lower animals, does not cause excessive toxicity, irritation, allergic reactions, etc., and is consistent with reasonable benefit / risk considerations. Pharmaceutical salts are well known in the art, including those described in detail by Berge et al. in J. Pharmaceutical Sciences (1977) 66:1-19. Pharmaceutical salts of the compounds of the present invention include salts derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, non-toxic acid addition salts include those formed by amino groups with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid, or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, and malonic acid, or by methods used in the art, such as ion exchange methods. Other medicinal salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, hydrogensulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentylpropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, gluconate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxyethanesulfonate, lactobiolate, and benzoate. Pharmaceutically acceptable salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium, and N(C)(OH) salts. 1-4 Alkyl)4 +Representative alkali metal and alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium salts, etc. Where appropriate, pharmaceutically acceptable salts also include non-toxic ammonium salts, quaternary ammonium salts, and amine cations formed with counter ions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkylsulfonate, and arylsulfonate.

[0025] 3-Hydroxy-5-pregnan-20-one derivatives of the present invention and methods for producing the same To achieve the object of the present invention, the inventors have obtained a 3-hydroxy-5-pregnan-20-one derivative represented by formula I by derivatizing 3-hydroxy-5-pregnan-20-one, an allopregnanolone compound. [ka] (In the formula, R 1 and R 2 are each independently H, substituted or unsubstituted C1-C 10 R is an alkyl group, or a substituted or unsubstituted cycloalkyl group. 3 is H, halogen, hydroxy, amino, nitro, or mercapto, or R 2 and R 3 are linked to form a 5-6 membered saturated or unsaturated heterocyclic ring. a and b are each independently an integer of 0 to 3.

[0026] Based on the teachings of the present invention and ordinary skill in the art, it will be understood that the compounds represented by the above formula I can be further divided into compounds represented by formula I-1, I-2, I-3, or I-4. [ka] The compounds described herein may contain one or more asymmetric centers and therefore exist in many isomeric forms, e.g., enantiomeric and / or diastereomeric forms. For example, the compounds described herein may be in the form of a single enantiomer, diastereomer, or geometric isomer, or a mixture of stereoisomers, including racemic mixtures and mixtures enriched in one or more stereoisomers. Isomers can be separated from mixtures by methods known to those skilled in the art, including chiral high-pressure liquid chromatography (HPLC) and the formation and crystallization of chiral salts. Alternatively, preferred isomers can be prepared by asymmetric synthesis. Furthermore, the present invention includes compounds described herein that are single isomers or mixtures of multiple isomers, essentially free of other isomers.

[0027] The present inventors have unexpectedly found that the 3-hydroxy-5-pregnan-20-one derivatives of the present invention have improved water solubility and can maintain a certain degree of stability when stored in an aqueous glucose solution, and in particular, the R 1 or R 2 Further studies have revealed that the 3-hydroxy-5-pregnan-20-one derivatives of the present invention have excellent pharmacokinetic characteristics, and in particular, when R in the 3-hydroxy-5-pregnan-20-one derivatives represented by formula I of the present invention is an isopropyl group, the water solubility is significantly improved. 1 is an isopropyl group, the pharmacokinetic properties of the derivative are found to be better than those of the parent drug and other structurally similar derivatives. As known to those skilled in the art, ester formation is one of the modification methods commonly used in prodrug design. However, a major problem facing ester-based prodrugs is that the pharmacokinetic distribution of ester-based prodrugs is difficult to predict. Since substituted or unsubstituted alkyl esters undergo relatively slow and incomplete biotransformation in human blood, the bioavailability of these ester-based prodrugs is often lower than expected. In other words, it is impossible to predict how to form an ester and whether the prodrug after ester formation has the desired characteristics. Therefore, it is quite unexpected that the 3-hydroxy-5-pregnan-20-one derivatives of the present invention have excellent pharmacokinetic characteristics.

[0028] Based on the teachings of the present invention and common knowledge in the field of chemical synthesis, those skilled in the art will understand how to obtain the 3-hydroxy-5-pregnan-20-one derivatives of the present invention, for example, by reacting the allopregnanolone compound represented by the following formula with the corresponding organic acid to produce the 3-hydroxy-5-pregnan-20-one derivatives: [ka] Allopregnanolone for producing the compounds of the present invention may be commercially available or may be produced by known methods. Pharmaceutical Compositions of the Present Invention

[0029] The present inventors have found that when the 3-hydroxy-5-pregnan-20-one derivatives of the present invention are administered to a recipient, they are hydrolyzed under appropriate conditions, for example, by the action of esterases in the body, to release the more active allopregnanolone. Therefore, the 3-hydroxy-5-pregnan-20-one derivatives of the present invention or compositions containing them can be used to manufacture drugs for diseases caused by central nervous system abnormalities. Such diseases include, but are not limited to, tremors, epilepsy, depression, and anxiety disorders. More specifically, the central nervous system disorders and diseases include, but are not limited to, idiopathic tremor, epilepsy, clinical depression, postpartum or postpartum depression, atypical depression, psychotic major depression, catatonic depression, seasonal affective disorder, dysthymia, bipolar depression, depressive personality disorder, recurrent brief depression, minor depressive disorder, bipolar disorder or manic depression, post-traumatic stress disorder, depression due to a chronic medical condition, treatment-resistant depression, treatment-refractory depression, suicidal tendencies, suicidal ideation, and suicidal behavior. Based on this, the present invention further provides a pharmaceutical composition comprising the above-mentioned 3-hydroxy-5-pregnan-20-one derivative of the present invention and, optionally, a pharmaceutically acceptable carrier. As used herein, the term "composition" is intended to include a product containing specific amounts of specific ingredients, as well as any product that is formed by directly or indirectly combining specific amounts of specific ingredients. Furthermore, a pharmaceutically acceptable carrier refers to a carrier, diluent, or excipient that does not cause significant irritation to the body and does not interfere with the biological activity and properties of the administered compound. In other words, the carrier, diluent, or excipient must be compatible with the other ingredients of the formulation and be harmless to the recipient. The pharmaceutical compositions of the present invention can be prepared by methods known to those skilled in the art. For example, the compounds of the present invention can be mixed with pharmaceutically acceptable carriers, diluents, or excipients to prepare corresponding pharmaceutical compositions. Furthermore, those skilled in the art can formulate the compounds or pharmaceutical compositions of the present invention into various suitable dosage forms, including, but not limited to, rectal administration, transdermal administration, intradermal administration, intrathecal administration, subcutaneous administration, intravenous administration, intramuscular administration, intraarticular cavity administration, oral mucosal administration, vaginal administration, and intranasal administration. Those skilled in the art can also select the appropriate pharmaceutically acceptable carriers, diluents, or excipients depending on the required dosage form. How to prevent and treat disease

[0030] As described above, when the 3-hydroxy-5-pregnan-20-one derivatives of the present invention are administered to a recipient, they can release active allopregnanolone under appropriate conditions. Those skilled in the art will recognize that the 3-hydroxy-5-pregnan-20-one derivatives of the present invention are useful for the prevention or treatment of central nervous system disorders and diseases, including, but not limited to, those listed above. The method for preventing or treating central nervous system disorders or diseases of the present invention comprises administering a therapeutically effective amount of the compound or pharmaceutical composition to a subject in need thereof, including, but not limited to, a human. Advantages of this invention:

[0031] 1. The 3-hydroxy-5-pregnan-20-one derivatives of the present invention have improved solubility; 2. The 3-hydroxy-5-pregnan-20-one derivative of the present invention has a certain degree of storage stability in a glucose solution; 3. The 3-hydroxy-5-pregnan-20-one derivative of the present invention has a sustained effect, can be made into a sustained-release preparation, and has little individual variation after administration; 4. The formulations of the present invention are convenient to administer; and 5. The formulation of the present invention has good patient compliance when administered.

[0032] The present invention will be further described below with reference to specific examples. It is understood that these examples are only used to illustrate the present invention and do not limit the scope of the present invention. In the following examples, experimental methods for which no specific conditions are described were generally carried out under conventional conditions or under conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by weight. All of the reagents and raw materials used in the present invention are commercially available.

[0033] Example 1. Synthesis of Compound 1 Hydrochloride [ka] Preparation of Intermediate 1.2: A 1000 mL three-neck round-bottom reaction flask was charged with compound 1.1 (50.0 g, 157.0 mmol, 1.0 eq), Boc-L-Val-OH (40.9 g, 188.2 mmol), DMAP (1.9 g, 15.5 mmol), and 500 mL of dichloromethane. The reaction mixture was magnetically stirred and cooled to -5 to 10 °C under nitrogen gas protection. A solution of DCC (38.9 g, 188.5 mmol) in 80 mL of dichloromethane was added dropwise. The reaction mixture was then allowed to react at the same temperature for 3 h. The reaction was stopped upon completion of the reaction, monitored by TLC, and the reaction mixture was filtered. The cake was washed with 100 mL of dichloromethane. The filtrate was concentrated under reduced pressure, and a sample was prepared on 100-200 mesh silica gel. The crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 20:1-10:1) to obtain an off-white waxy solid (78.2 g, yield 96.2%). Preparation of Intermediate 1.3: A 1000 mL three-neck round-bottom reaction flask was charged with compound 1.2 (78 g, 150.6 mmol, 1.0 eq) and dichloromethane (320 mL). Under nitrogen gas protection, the system was cooled to 0-10 °C with magnetic stirring, and trifluoroacetic acid (171.8 g, 1510 mmol) was rapidly added dropwise. The reaction was then allowed to proceed at 15-25 °C for 3 h to terminate the reaction. The reaction mixture was quenched by pouring it into a solution of sodium bicarbonate (164.5 g, 1958 mmol) in water (780 mL). The pH was maintained at approximately 8. Dichloromethane (700 mL) was added, and the mixture was stirred and separated to obtain the organic phase. The organic phase was washed with 500 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (59.5 g, 94.6% yield).

[0034] Preparation of Intermediate 1.4: A 250 mL single-neck reaction flask was charged with Boc-L-Val-OH (3.4 g, 15.8 mmol) and dichloromethane (60 mL). After magnetic stirring, N,N-diisopropylethylamine (2.0 g, 15.8 mmol), TBTU (5.1 g, 15.8 mmol), and 1.3 (6.0 g, 14.4 mmol, 1.0 eq) were added and the mixture was allowed to react at room temperature for approximately 1 hour. The reaction mixture was then quenched. The reaction mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 50:1 to 10:1) to give an off-white solid (7.9 g, 96.2% yield). Preparation of Intermediate 1.5: A 250 mL three-necked reaction flask was charged with compound 1.4 (7.9 g, 12.8 mmol, 1.0 eq) and dichloromethane (32 mL). Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (14.6 g, 128.0 mmol) was added at 0-10 °C, and the reaction was then quenched at room temperature for 3 hours. The reaction mixture was concentrated under reduced pressure, and dichloromethane (70 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate solution, and the aqueous phase was extracted with dichloromethane (30 mL). The combined organic phases were washed with an additional 100 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (6.5 g, 98.2% yield).

[0035] Preparation of Compound 1 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 1.5 (6.5 g, 12.6 mmol, 1.0 eq) and ethyl acetate (32 mL). Under nitrogen gas protection, a solution of hydrogen chloride in ethyl acetate (3 M, 5.0 mL, 15.0 mmol) was added at room temperature and stirred for 1 hour. A white gel precipitated, and the reaction mixture was evaporated to remove the solvent. Isopropanol (60 mL) was added, and the mixture was heated to dissolve the solid, then stirred at room temperature for 50 minutes. The solid was filtered and washed with isopropanol (7 mL) to give an off-white solid (3.2 g, 46.0% yield). 1H NMR (400 MHz, CDCl3) δ 8.34 (bs, 3H), 7.80 - 7.59 (m, 1H), 5.21 - 5.01 (m, 1H), 4.54 - 4.41 (m, 1H), 4.36 - 4.20 (m, 1H), 2.53 (t, J = 8.8 Hz, 1H), 2.45 - 2.10 (m, 3H), 2.12 (s, 3H), 2.05 - 1.97 (m, 1H), 1.78 - 0.90 (m, 19H), 1.16 (d, J = 6.9 Hz, 3H), 1.11 (d, J = 6.8 Hz, 3H), 1.05 (d, J = 3.3 Hz, 3H), 1.03 (d, J = 3.2 Hz, 3H),0.86 - 0.73 (m, 1H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 517.6

[0036] Example 2. Synthesis of the hydrochloride salt of compound 2 [ka] Preparation of Intermediate 2.1: A 250 mL single-neck reaction flask was charged with compound 1.3 (5.0 g, 12.0 mmol), Boc-Gly-OH (2.5 g, 14.3 mmol), and dichloromethane (50 mL) under magnetic stirring. N,N-Diisopropylethylamine (3.1 g, 24.0 mmol), HOBT (342 mg, 2.4 mmol), and EDCI (2.8 g, 14.6 mmol) were then added. The reaction mixture was allowed to react at room temperature for 4 hours. The reaction mixture was washed sequentially with HO (50 mL), 1N HCl (50 mL), saturated aqueous NaHCO3, and purified water. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to obtain an off-white solid (5.7 g, 82.8% yield).

[0037] Preparation of Intermediate 2.2: A 250 mL three-necked reaction flask was charged with compound 1.4 (5.5 g, 9.63 mmol, 1.0 eq) and dichloromethane (22 mL). Under nitrogen gas protection, the mixture was magnetically stirred and trifluoroacetic acid (10.9 g, 95.7 mmol) was added at 0 °C. The reaction was allowed to proceed for 3 h at room temperature. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (50 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (30 mL). The combined organic phases were washed with 50 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered, concentrated under reduced pressure, and dried under oil pump vacuum to give an off-white solid (4.5 g, 99.0% yield). Preparation of the hydrochloride salt of compound 2: A 250 mL single-neck reaction flask was charged with compound 1.5 (4.5 g, 9.5 mmol, 1.0 eq) and ethyl acetate (27 mL). Under nitrogen gas protection, magnetic stirring was performed. A solution of hydrogen chloride in ethyl acetate (3 M, 3.8 mL, 11.4 mmol) was added at room temperature, followed by stirring for 1 hour. The mixture was concentrated under reduced pressure, evaporated to remove the solvent, and then acetonitrile (70 mL) was added and stirred at room temperature for 2 hours. After filtration, the solid was washed with acetonitrile (15 mL). The mixture was dried under vacuum at 40 °C with an oil pump for 2 hours to give a white solid (3.5 g, 72.2% yield). 1 H NMR (400 MHz, CDCl3) δ 8.28 (d, J = 8.5 Hz, 1H), 8.16 (bs, 3H), 5.14 - 5.03 (m, 1H), 4.55 (d, J = 4.1 Hz, 1H), 4.27 (d, J = 16.1 Hz, 1H), 4.09 (d, J = 16.0 Hz, 1H), 2.52 (t, J = 8.7 Hz, 1H), 2.40 - 2.07 (m, 2H), 2.11 (s, 3H), 2.05 - 1.96 (m, 1H), 1.82 - 1.08 (m, 18H), 1.08 - 0.89 (m, 7H), 0.85 - 0.71 (m, 1H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 475.3.

[0038] Example 3. Synthesis of Compound 3 Hydrochloride [ka] Preparation of Intermediate 3.1: A 100 mL single-neck reaction flask was charged with Boc-L-Phe-OH (0.96 g, 3.6 mmol), dichloromethane (12 mL), N,N-diisopropylethylamine (0.44 g, 3.6 mmol), TBTU (1.16 g, 3.6 mmol), and 1.3 (1.25 g, 3.0 mmol, 1.0 eq). After magnetic stirring, the mixture was allowed to react for 40 min. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 4:1) to give a pale yellow solid (1.5 g, 75.3% yield). Preparation of Intermediate 3.2: Compound 3.1 (1.5 g, 2.3 mmol, 1.0 eq) and dichloromethane (7.5 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (2.63 g, 23 mmol) was added at 0 °C with magnetic stirring, and the mixture was allowed to react at room temperature for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (50 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (20 mL). The combined organic phases were washed with an additional 50 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (1.1 g, 86.3% yield).

[0039] Preparation of Compound 3 Hydrochloride: A 100 mL single-neck reaction flask was charged with compound 3.2 (1.1 g, 1.95 mmol, 1.0 eq) and ethyl acetate (11 mL). Under nitrogen gas protection, magnetic stirring was performed and a solution of hydrogen chloride in ethyl acetate (3 M, 0.8 mL, 2.4 mmol) was added at room temperature, followed by stirring for 1 h. The mixture was concentrated under reduced pressure to remove the solvent, and the resulting mixture was crystallized with ethanol / water (2:1, 15 mL). The product was filtered and dried under vacuum at 50 °C with an oil pump for 4 h to give a pale yellow solid (620 mg, 52.9% yield). 1 H NMR (400 MHz, CDCl3) δ 7.88 (d, J = 9.2 Hz, 1H), 7.38 - 7.17 (m, 5H), 5.15 - 5.05 (m, 1H), 4.57 (dd, J = 9.2, 4.6 Hz, 1H), 3.67 (dd, J = 9.5, 3.8 Hz, 1H), 3.30 (dd, J = 13.7, 3.8 Hz, 1H), 2.72 (dd, J = 13.7, 9.5 Hz, 1H), 2.53 (t, J = 8.8 Hz, 1H), 2.28 - 2.07 (m, 2H), 2.12 (s, 3H), 2.05 - 1.97 (m, 1H), 1.78 - 1.10 (m, 18H), 1.00 - 0.85 (m, 1H), 0.95 (d, J = 6.9 Hz, 3H), 0.92 (d, J = 6.8 Hz, 3H), 0.83 - 0.72 (m, 1H), 0.80 (s, 3H), 0.61 (s, 3H). MS: [M+H] + 565.40.

[0040] Example 4. Synthesis of Compound 4 Hydrochloride [ka] Preparation of Intermediate 4.1: A 100 mL single-neck reaction flask was charged with Boc-L-Pro-OH (0.77 g, 3.6 mmol), dichloromethane (12 mL), N,N-diisopropylethylamine (0.44 g, 3.6 mmol), TBTU (1.16 g, 3.6 mmol), and 1.3 (1.25 g, 3.0 mmol, 1.0 eq). After magnetic stirring, the mixture was allowed to react at room temperature for 40 min. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to give an off-white solid (1.6 g, 86.9% yield). Preparation of Intermediate 4.2: Compound 4.1 (1.41 g, 2.3 mmol, 1.0 eq) and dichloromethane (7 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (2.63 g, 23 mmol) was added at 0 °C with magnetic stirring, and the mixture was allowed to react at room temperature for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (50 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (20 mL). The combined organic phases were washed with an additional 50 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (1.0 g, 84.7% yield).

[0041] Preparation of Compound 4 Hydrochloride: A 100 mL single-neck reaction flask was charged with compound 3.2 (1.0 g, 1.94 mmol, 1.0 eq) and ethyl acetate (11 mL). Under nitrogen gas protection, a solution of hydrogen chloride in ethyl acetate (3 M, 0.8 mL, 2.4 mmol) was added at room temperature, and the mixture was stirred for 17 hours. A white solid precipitated, which was filtered and washed with ethyl acetate (3 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (560 mg, 52.0% yield). 1H NMR (400 MHz, CDCl3) δ 11.34 (bs, 1H), 8.01 (d, J = 7.7 Hz, 1H), 7.69 - 7.34 (m, 1H), 5.16 - 5.03 (m, 1H), 5.01 - 4.89 (m, 1H), 4.43 (dd, J = 7.7, 4.6 Hz, 1H), 3.62 - 3.49 (m, 1H), 3.48 - 3.37 (m, 1H), 2.72 - 2.58 (m, 1H), 2.53 (t, J = 8.9 Hz, 1H), 2.38 - 2.26 (m, 1H), 2.25 - 2.09 (m, 3H), 2.12 (s, 3H), 2.07 - 1.96 (m, 2H), 1.88 - 1.10 (m, 18H),1.05 (d, J = 2.1 Hz, 3H), 1.09 - 0.88 (m, 1H), 1.03 (d, J = 2.2 Hz, 3H), 0.85 - 0.72 (m, 1H), 0.80 (s, 3H), 0.61 (s, 3H). MS: [M+H] + 515.4.

[0042] Example 5. Synthesis of Compound 5 Hydrochloride [ka] Preparation of Intermediate 5.1: A 100 mL single-neck reaction flask was charged with compound Boc-L-Trp-OH (1.10 g, 3.6 mmol), dichloromethane (12 mL), N,N-diisopropylethylamine (1.16 g, 3.6 mmol), and TBTU (1.16 g, 3.6 mmol). After stirring at room temperature for 6 h, compound 1.3 (1.25 g, 3.0 mmol, 1.0 eq) was added and the mixture was stirred magnetically and then allowed to react at room temperature for 40 min. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to give an off-white solid (1.7 g, 80.7% yield).

[0043] Preparation of Intermediate 5.2: Compound 5.1 (1.58 g, 2.3 mmol, 1.0 eq) and dichloromethane (8 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (2.63 g, 23 mmol) was added at 0 °C and the reaction was allowed to proceed at room temperature for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (50 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (20 mL). The combined organic phases were washed with an additional 50 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (1.20 g, 88.5% yield). Preparation of Compound 5 Hydrochloride: A 100 mL single-neck reaction flask was charged with compound 3.2 (1.15 g, 1.95 mmol, 1.0 eq) and ethyl acetate (11 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 0.8 mL, 2.4 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 hour. The solvent was removed by concentration under reduced pressure, and the mixture was stirred with petroleum ether / ethyl acetate (5:1, 30 mL). The product was filtered and dried under vacuum at 40 °C for 3 hours on an oil pump to give an off-white solid (690 mg, 56.7% yield). 1 H NMR (400 MHz, CDCl3)δ 9.35 (s, 1H), 7.96 (bs, 3H), 7.74 - 7.41 (m, 2H),7.38 - 7.16 (m, 2H), 7.13 - 6.74 (m, 2H), 5.13 - 4.96 (m, 1H), 4.60 - 4.20 (m, 2H), 3.54 - 3.20 (m, 2H), 2.35 - 2.22 (m, 1H), 2.17 - 1.96 (m, 2H), 2.05 (s, 3H), 1.92 - 1.80 (m, 1H), 1.79 - 0.99 (m, 18H), 1.00 - 0.63 (m, 8H), 0.75 (s, 3H), 0.53 (s, 3H). MS: [M+H] + 604.4.

[0044] Example 6. Synthesis of Compound 6 Hydrochloride [ka] Preparation of Intermediate 6.1: A 250 mL single-neck reaction flask was charged with compound 1.3 (6.26 g, 15.0 mmol), Boc-L-Ala-OH (3.41 g, 18 mmol), dichloromethane (60 mL), triethylamine (3.04 g, 30 mmol), HOBT (0.41 g, 3 mmol), and EDCI (3.45 g, 18 mmol) and magnetic stirring. The mixture was stirred at room temperature for 4 hours, then washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO (8 mL). The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to afford an off-white solid (8.20 g, 92.9% yield).

[0045] Preparation of Intermediate 6.2: Compound 6.1 (7.9 g, 13 mmol, 1.0 eq) and dichloromethane (40 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (14.8 g, 130 mmol) was added at 0 °C with magnetic stirring, and the mixture was allowed to react at room temperature for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (100 mL) was added, the solvent was evaporated under reduced pressure, and the mixture was washed with saturated aqueous sodium bicarbonate. The aqueous phase was extracted with dichloromethane (50 mL). The combined organic phases were washed with 100 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered, concentrated under reduced pressure, and dried under oil pump vacuum to give an off-white solid (6.25 g, 95.3% yield). Preparation of Compound 6 Hydrochloride: A 100 mL single-neck reaction flask was charged with compound 6.2 (6.0 g, 12.3 mmol, 1.0 eq) and ethyl acetate (60 mL). Under nitrogen gas protection, a solution of hydrogen chloride in ethyl acetate (3 M, 5 mL, 15 mmol) was added at room temperature, and the mixture was stirred for 6 hours. A white solid precipitated, which was filtered and washed with ethyl acetate (15 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (4.7 g, 72.9% yield). 1 H NMR (400 MHz, CDCl3) δ 8.33 (bs, 3H), 7.96 - 7.67 (m, 1H), 5.20 - 5.00 (m, 1H), 4.76 - 4.36 (m, 2H), 2.53 (t, J = 8.6 Hz, 1H), 2.39 - 2.07 (m, 2H), 2.11 (s, 3H), 2.05 - 1.96 (m, 1H), 1.80 - 0.89 (m, 28H), 0.88 - 0.71 (m, 1H), 0.79 (s, 3H), 0.61 (s, 3H). MS: [M+H] + 489.4.

[0046] Example 7. Synthesis of Compound 7 Hydrochloride [ka] Preparation of Intermediate 7.1: A 250 mL single-neck reaction flask was charged with compound 1.3 (2.09 g, 5.0 mmol), Boc-L-Leu-OH (1.50 g, 6.0 mmol), dichloromethane (20 mL), triethylamine (0.76 g, 7.5 mmol), HOBT (0.14 g, 1 mmol), and EDCI (1.15 g, 18 mmol). The mixture was stirred magnetically at room temperature for 4 hours. The reaction mixture was washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO (1HCO). The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to afford an off-white solid (3.0 g, 95.0% yield). Preparation of Intermediate 7.2: Compound 7.1 (3.0 g, 4.7 mmol, 1.0 eq) and dichloromethane (12 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection and magnetic stirring, trifluoroacetic acid (5.42 g, 47 mmol) was added at 0 °C. After 20 min, the mixture was warmed to room temperature and reacted for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (30 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (10 mL). The combined organic phases were washed with an additional 30 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered, concentrated under reduced pressure, and dried under oil pump vacuum to give an off-white solid (1.30 g, 51.5% yield).

[0047] Preparation of Compound 7 Hydrochloride: A 50 mL single-neck reaction flask was charged with compound 7.2 (1.30 g, 2.5 mmol, 1.0 eq) and ethyl acetate (13 mL). Under nitrogen gas protection, a solution of hydrogen chloride in ethyl acetate (3 M, 5 mL, 15 mmol) was added at room temperature, and the mixture was stirred for 6 hours. A white solid precipitated, which was filtered and washed with ethyl acetate (15 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (0.9 g, 64.8% yield). 1H NMR (400 MHz, CDCl3) δ 8.40 (s, 3H), 7.55 (d, J = 7.9 Hz, 1H), 5.17 - 5.05 (m, 1H), 4.57 - 4.44 (m, 1H), 4.36 - 4.21 (m, 1H), 2.52 (t, J = 8.8 Hz, 1H), 2.35 - 1.97 (m, 3H), 2.11 (s, 3H), 1.96 - 0.73 (m, 35H), 0.80 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 531.4.

[0048] Example 8. Synthesis of Compound 8 Hydrochloride [ka] Preparation of Intermediate 8.1: A 250 mL three-neck reaction flask was charged with compound 1.3 (5.00 g, 11.98 mmol, 1.0 eq), Boc-L-Gln-OH (3.54 g, 14.38 mmol), DMAP (0.15 g, 1.20 mmol), and dichloromethane (40 mL). Under nitrogen gas protection, magnetic stirring was performed. The mixture was cooled in an ice-water bath and a solution of DCC (2.97 g, 14.38 mmol) in dichloromethane (50 mL) was added. After the addition was complete, the reaction mixture was allowed to react at room temperature for 3 h. The reaction mixture was washed sequentially with 1N HCl (50 mL) and saturated aqueous NaHCO3. The mixture was dried over anhydrous Na2SO4 and filtered. The mixture was concentrated under reduced pressure and dried in an oil pump vacuum to give a white solid (4.42 g, 57.2% yield). Preparation of Intermediate 8.2: Compound 8.1 (4.42 g, 6.84 mmol, 1.0 eq) and dichloromethane (22 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (7.80 g, 68.43 mmol) was added at 0 °C with magnetic stirring, and the mixture was allowed to react at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (50 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (3.0 g, 80.3% yield).

[0049] Preparation of Compound 8 Hydrochloride: A 50 mL single-neck reaction flask was charged with compound 8.2 (1.10 g, 2.02 mmol, 1.0 eq) and dichloromethane (12 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 0.8 mL, 2.4 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 h. The mixture was concentrated under reduced pressure to remove the dichloromethane, and methyl tert-butyl ether / isopropanol (4:1, 20 mL) was added and stirred for 2 h. The mixture was filtered and washed with chilled methyl tert-butyl ether / isopropanol (4:1, 5 mL). The mixture was dried under oil pump vacuum at 40 °C for 3 h to give a white solid (0.85 g, 72.4% yield). 1 H NMR (400 MHz, CDCl3) δ 8.67 - 8.59 (m, 1H), 8.36 (bs, 3H), 7.63 (bs, 1H), 6.92 (bs, 1H), 5.30 - 4.96 (m, 1H), 4.80 - 4.31 (m, 2H), 2.80 - 1.94 (m, 6H), 2.52 (t, J = 8.8 Hz, 1H), 2.11 (s, 3H), 1.89 - 0.70 (m, 27H), 0.79 (s, 3H), 0.60 (s, 3H). MS: m / z [M+H] + 546.4.

[0050] Example 9. Synthesis of Compound 9 Hydrochloride [ka] Preparation of Intermediate 9.1: A 250 mL three-neck reaction flask was charged with compound 1.3 (9.60 g, 23.1 mmol, 1.0 eq), Boc-Lys(Boc)-OH (8.00 g, 23.1 mmol), DMAP (0.28 g, 2.3 mmol), and dichloromethane (100 mL). Under nitrogen gas protection, magnetic stirring was performed. The mixture was cooled in an ice-water bath, and a solution of DCC (5.20 g, 25.4 mmol) in dichloromethane (20 mL) was added while maintaining the internal temperature at 3-5 °C. After the addition was complete, the mixture was allowed to react at room temperature for 17 h. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to obtain a white foamy solid (10.0 g, 61.0% yield).

[0051] Preparation of Intermediate 9.2: Compound 9.1 (10.5 g, 14.1 mmol, 1.0 eq) and dichloromethane (50 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (16.0 g, 141.0 mmol) was added at 0 °C and the mixture was allowed to react at room temperature for 3 h. The reaction mixture was added dropwise to a solution of NaHCO3 (28 g) in HO (100 mL) and dichloromethane (150 mL) was added. The layers were separated, and the aqueous phase was extracted with dichloromethane (100 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a pale yellow foamy solid (7.1 g, 92% yield). Preparation of Compound 9 Hydrochloride: A 50 mL single-neck reaction flask was charged with compound 9.2 (7.0 g, 12.8 mmol, 1.0 eq) and ethyl acetate (20 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 5.1 mL, 15.3 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 hour. The ethyl acetate was removed by concentration under reduced pressure, and methyl t-butyl ether (100 mL) was added and stirred for 2 hours. The mixture was filtered and washed with methyl t-butyl ether (20 mL). The mixture was dried under vacuum at 45 °C with an oil pump for 3 hours to give a white solid (7.2 g, 90.7% yield). 1 H NMR (400 MHz, CDCl3) δ 8.30 (bs, 3H), 8.13 - 7.98 (m, 1H), 7.89 (bs, 3H), 5.20 - 4.96 (m, 1H), 4.60 - 4.19 (m, 2H), 3.17 - 2.85 (m, 2H), 2.51 (t, J = 9.1 Hz, 1H), 2.46 - 0.70 (m, 35H), 2.11 (s, 3H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 546.8.

[0052] Example 10. Synthesis of Compound 10 Hydrochloride [ka] Preparation of Intermediate 10.1: A 1000 mL three-necked reaction flask was charged with compound 1.1 (20.0 g, 62.8 mmol, 1.0 eq), Boc-L-Ala-OH (14.3 g, 75.4 mmol), DMAP (0.8 g, 6.3 mmol), and 150 mL of dichloromethane. Under nitrogen gas protection, magnetic stirring was performed. A solution of DCC (15.5 g, 75.4 mmol) in 50 mL of dichloromethane was added at 0 °C and the reaction mixture was allowed to react at room temperature for 6 h. The mixture was filtered and the cake was washed with dichloromethane (100 mL). The filtrate was concentrated, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 4:1) to obtain a white solid (27.3 g, 88.7% yield).

[0053] Preparation of Intermediate 10.2: A 500 mL three-necked reaction flask was charged with compound 10.1 (27.0 g, 55.1 mmol, 1.0 eq) and dichloromethane (135 mL). Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (62.8 g, 551 mmol) was added at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, evaporated to remove the solvent, and then added to dichloromethane (300 mL) and washed with saturated aqueous sodium bicarbonate. The aqueous phase was extracted with dichloromethane (150 mL). The combined organic phases were washed with an additional 300 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (20.9 g, 97.3% yield). Preparation of Intermediate 10.3: A 100 mL single-neck reaction flask was charged with compound 10.2 (5.0 g, 12.8 mmol), Boc-L-Val-OH (3.3 g, 15.4 mmol), dichloromethane (50 mL), triethylamine (1.6 g, 15.4 mmol), HOBT (0.7 g, 5.1 mmol), and EDCI (3.0 g, 15.4 mmol) and magnetic stirring. The mixture was incubated at room temperature for 4 hours, then washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO (7.2 g, 95.6%). The crude product was concentrated under reduced pressure and subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 5:1) to afford an off-white solid (7.2 g, 95.6% yield). Preparation of Intermediate 10.4: A 100 mL three-necked reaction flask was charged with compound 10.3 (6.0 g, 10.2 mmol, 1.0 eq) and dichloromethane (30 mL). Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (11.6 g, 102 mmol) was added at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate solution, and the aqueous phase was extracted with dichloromethane (50 mL). The combined organic phases were washed with an additional 100 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (4.6 g, 92.3% yield).

[0054] Preparation of Compound 10 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 10.3 (4.6 g, 9.4 mmol, 1.0 eq) and ethyl acetate (50 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 3.8 mL, 11.4 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 hour. A white solid precipitated, which was filtered and washed with ethyl acetate (20 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (4.5 g, 86.4% yield). 1H NMR (400 MHz, CDCl3) δ 8.28 (bs, 3H), 8.11 (d, J = 6.2 Hz, 1H), 5.06 (d, J = 3.4 Hz, 1H), 4.51 (p, J = 7.0 Hz, 1H), 4.23 (d, J = 5.6 Hz, 1H), 2.53 (t, J = 8.8 Hz, 1H), 2.40 (q, J = 6.6 Hz, 1H), 2.12 (s, 3H), 2.25-2.09 (m,2H), 2.08-1.06 (m, 18H),1.54-1.50 (m, 3H), 1.22-1.12 (m, 6H)1.05-0.73 (m, 2H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 489.4.

[0055] Example 11. Synthesis of Compound 11 Hydrochloride [ka] Preparation of Intermediate 11.1: A 250 mL single-neck reaction flask was charged with compound 10.1 (5.0 g, 12.8 mmol), Boc-L-Ala-OH (2.9 g, 15.4 mmol), dichloromethane (50 mL), triethylamine (1.6 g, 15.4 mmol), HOBT (0.7 g, 5.1 mmol), and EDCI (3.0 g, 15.4 mmol) and magnetic stirring. The mixture was incubated at room temperature for 4 hours, then washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO (1HCO). The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to afford an off-white solid (6.7 g, 93.5% yield). Preparation of Intermediate 11.2: Compound 11.1 (5.8 g, 10.3 mmol, 1.0 eq) and dichloromethane (30 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (11.8 g, 103 mmol) was added at 0 °C with magnetic stirring, and the mixture was allowed to react at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (50 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (4.5 g, 94.4% yield).

[0056] Preparation of Compound 11 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 11.2 (4.5 g, 9.8 mmol, 1.0 eq) and ethyl acetate (50 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 3.9 mL, 11.7 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 hour. A white solid precipitated, which was filtered and washed with ethyl acetate (20 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (4.2 g, 86.5% yield). 1 H NMR (400 MHz, CDCl3) δ 8.14 (m, 4H), 5.05 (m, 1H), 4.47 (dt, J = 21.0, 6.9 Hz, 1H), 2.53 (t, J = 8.8 Hz, 1H), 2.12 (s, 3H), 2.24-1.97 (m, 2H), 1.94 - 1.07 (m, 19H), 1.69-1.65 (m, 3H), 1.52-1.47 (m, 3H), 0.79 (s,3H), 1.05-0.73 (m, 2H), 0.61(s, 3H). MS: m / z [M+H] + 461.3.

[0057] Example 12. Synthesis of Compound 12 Hydrochloride [ka] Preparation of Intermediate 12.1: A 250 mL single-neck reaction flask was charged with compound 10.1 (5.0 g, 12.8 mmol), Boc-Gly-OH (2.7 g, 15.4 mmol), dichloromethane (50 mL), triethylamine (1.6 g, 15.4 mmol), HOBT (0.7 g, 5.1 mmol), and EDCI (3.0 g, 15.4 mmol). The reaction mixture was stirred at room temperature for 4 hours, then washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 3:1) to afford an off-white solid (6.5 g, 93.1% yield). Preparation of Intermediate 12.2: Compound 11.1 (5.8 g, 10.6 mmol, 1.0 eq) and dichloromethane (30 mL) were placed in a 100 mL three-neck reaction flask. Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (12.1 g, 106 mmol) was added at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate solution, and the aqueous phase was extracted with dichloromethane (50 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a white solid (4.5 g, 95.0% yield). Preparation of Compound 12 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 11.2 (4.5 g, 10.1 mmol, 1.0 eq) and ethyl acetate (50 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 4.0 mL, 12.0 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 1 hour. A white solid precipitated, which was filtered and washed with ethyl acetate (20 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (4.6 g, 94.5% yield). 1H NMR (400 MHz, CDCl3) δ 8.49 (d, J = 7.2 Hz, 1H), 8.08 (bs, 3H), 5.06 (m, 1H), 4.55 (p, J = 7.1 Hz, 1H), 4.35-3.94 (m, 2H), 2.51 (t, J = 8.7 Hz, 1H), 2.11 (s, 3H), 2.17-1.95 (m, 2H) 1.94 - 0.88 (m, 19H), 1.51-1.45(m,3H),0.87-0.72 (m, 1H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 447.3.

[0058] Example 13. Synthesis of Compound 13 Hydrochloride [ka] Preparation of Intermediate 13.2: A 500 mL three-neck reaction flask was charged with compound 13.1 (10.0 g, 55.5 mmol, 1.0 eq), Boc-L-Val-OH (12.0 g, 55.5 mmol), DMAP (1.4 g, 11.5 mmol), and 100 mL of dichloromethane. Under nitrogen gas protection, magnetic stirring was performed. A solution of DCC (13.7 g, 66.6 mmol) in 50 mL of dichloromethane was added at 0 °C and the mixture was allowed to react at room temperature for 6 h. The mixture was filtered and the cake was washed with dichloromethane (100 mL). The filtrate was concentrated, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 20:1 to 6:1) to obtain a colorless oil (20.5 g, 97.3% yield). Preparation of Intermediate 13.3: A 1000 mL single-neck reaction flask was charged with compound 13.2 (20.0 g, 52.7 mmol) and THF (300 mL). After purging with nitrogen gas, 10% Pd / C (2 g) was added. After purging with hydrogen gas, the mixture was hydrogenated at room temperature under atmospheric pressure for 6 hours. After purging with nitrogen gas, the mixture was filtered and washed with THF (50 mL). The filtrate was concentrated and evaporated to remove the solvent, and the mixture was dried under vacuum at room temperature using an oil pump to give a white solid (14.9 g, 97.7% yield).

[0059] Preparation of Intermediate 13.4: A 250 mL three-necked reaction flask was charged with compound 1.1 (5.0 g, 15.7 mmol, 1.0 eq), compound 13.3 (5.4 g, 18.7 mmol), DMAP (0.2 g, 1.6 mmol), and 50 mL of dichloromethane. Under nitrogen gas protection, magnetic stirring was performed. A solution of DCC (3.9 g, 18.9 mmol) in 15 mL of dichloromethane was added at 0 °C and the mixture was allowed to react at room temperature for 2 h. The mixture was filtered and the cake was washed with dichloromethane (20 mL). The filtrate was concentrated, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 20:1 to 3:1) to obtain a white solid (8.7 g, 93.9% yield). Preparation of Intermediate 13.5: Compound 13.4 (8.0 g, 13.6 mmol, 1.0 eq) and dichloromethane (40 mL) were placed in a 250 mL three-neck reaction flask. Trifluoroacetic acid (15.5 g, 136 mmol) was added under nitrogen gas protection at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (150 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate solution, and the aqueous phase was extracted with dichloromethane (50 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a white solid (6.5 g, 97.8% yield).

[0060] Preparation of Compound 13 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 13.4 (6.0 g, 12.3 mmol, 1.0 eq) and ethyl acetate (60 mL). Under nitrogen gas protection, magnetic stirring was performed and a solution of hydrogen chloride in ethyl acetate (3 M, 4.9 mL, 14.7 mmol) was added at room temperature, followed by stirring for 1 hour. A white solid precipitated, which was filtered and washed with ethyl acetate (20 mL). The solid was dried under vacuum at 40 °C with an oil pump for 3 hours to give a white solid (5.2 g, 80.6% yield). 1 H NMR (400 MHz, CDCl3) δ 8.76 (s, 3H), 5.25 (q, J = 7.0 Hz, 1H), 5.08 (q, J = 2.8 Hz, 1H), 4.02 (d, J = 3.9 Hz, 1H), 2.62 - 2.45 (m, 2H), 2.12 (s, 3H), 2.01 (dt, J = 11.9, 3.3 Hz, 1H), 1.78 - 1.63 (m, 5H), 1.63 - 1.58 (m, 1H), 1.56 (d, J = 7.1 Hz, 4H), 1.50 (t, J = 5.1 Hz, 3H), 1.45 - 1.32 (m, 3H), 1.28 (dd, J = 13.2, 3.9 Hz, 2H), 1.22 (dd, J = 7.0, 2.7 Hz, 7H), 1.20 - 1.09 (m, 4H), 0.96 (dd, J = 12.3, 4.6 Hz, 1H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 490.3.

[0061] Example 14. Synthesis of Compound 14 Hydrochloride [ka] Preparation of Intermediate 14.1: A 1000 mL three-necked reaction flask was charged with compound 1.1 (50.0 g, 157.0 mmol, 1.0 eq), Boc-Gly-OH (33.0 g, 188.2 mmol), DMAP (1.9 g, 15.5 mmol), and 500 mL of dichloromethane. Under nitrogen gas protection, magnetic stirring was performed. A solution of DCC (38.9 g, 188.5 mmol) in dichloromethane (80 mL) was added and the reaction was continued at room temperature for 2 hours. The reaction was then quenched by filtration and the cake was washed with dichloromethane (100 mL). The filtrate was concentrated, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 20:1 to 4:1) to obtain a white solid (71.8 g, 95.8% yield).

[0062] Preparation of Intermediate 14.2: Compound 1.2 (30 g, 63.1 mmol, 1.0 eq) and dichloromethane (1200 mL) were placed in a 1000 mL three-neck reaction flask. Under nitrogen gas protection, trifluoroacetic acid (71.9 g, 631 mmol) was added at 0 °C with magnetic stirring, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, evaporated to remove the solvent, and then added to dichloromethane (500 mL) and isopropanol (50 mL). The mixture was washed with saturated aqueous sodium bicarbonate. The organic phase was further washed with 500 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (21.7 g, 91.6% yield). Preparation of Intermediate 14.3: A 250 mL single-neck reaction flask was charged with Boc-L-Val-OH (3.4 g, 15.8 mmol), dichloromethane (60 mL), N,N-diisopropylethylamine (2.0 g, 15.8 mmol), TBTU (5.1 g, 15.8 mmol), and 14.2 (5.4 g, 14.4 mmol, 1.0 eq). The mixture was allowed to react at room temperature for 40 min. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 20:1 to 5:1) to give an off-white solid (7.8 g, 92.6% yield). Preparation of Intermediate 14.4: A 250 mL three-necked reaction flask was charged with compound 1.4 (7.8 g, 13.6 mmol, 1.0 eq) and dichloromethane (32 mL). Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (15.5 g, 135.9 mmol) was added at 0 °C and the reaction was allowed to proceed at room temperature for 3 h. The mixture was concentrated under reduced pressure and evaporated to remove the solvent. Dichloromethane (100 mL) was added and the solvent was evaporated under reduced pressure. The mixture was washed with saturated aqueous sodium bicarbonate, and the aqueous phase was extracted with dichloromethane (50 mL). The combined organic phases were washed with an additional 100 mL of purified water and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give an off-white solid (6.2 g, 96.2% yield).

[0063] Preparation of Compound 14 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 1.5 (6.0 g, 12.6 mmol, 1.0 eq) and ethyl acetate (42 mL). Under nitrogen gas protection and magnetic stirring, a solution of hydrogen chloride in ethyl acetate (3 M, 5.0 mL, 15.0 mmol) and methyl t-butyl ether (42 mL) were added at room temperature. The mixture was stirred at room temperature for 50 minutes and then at 0°C for 1 hour. The mixture was filtered and washed with chilled ethyl acetate (10 mL) to give an off-white solid (5.3 g, 82.0% yield). 1H NMR (400 MHz, CDCl3) δ 8.54 (s, 1H), 8.38 - 8.02 (s, 3H), 5.18 - 4.96 (m, 1H), 4.33 (d, J = 5.3 Hz, 1H), 4.07 (s,2H), 2.52 (t, J = 8.9 Hz, 1H), 2.43 (q, J = 6.5 Hz, 1H), 2.12 (s, 3H), 2.02 (dd, J = 12.3, 3.4 Hz, 1H), 1.82 - 1.56 (m, 6H), 1.56 - 1.32 (m, 6H), 1.32 - 1.20 (m, 4H), 1.16 (d, J = 6.8 Hz, 6H), 1.12 (d, J = 6.7 Hz, 3H), 1.03 - 0.81 (m, 2H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 475.3.

[0064] Example 15. Synthesis of Compound 15 Hydrochloride [ka] Preparation of Intermediate 15.1: A 250 mL single-neck reaction flask was charged with compound 14.2 (5.0 g, 13.3 mmol), Boc-Gly-OH (2.8 g, 16.0 mmol), dichloromethane (50 mL), triethylamine (1.6 g, 16.0 mmol), HOBt (0.7 g, 5.1 mmol), and EDCI (3.1 g, 16.2 mmol). The reaction mixture was stirred at room temperature for 4 hours, and then washed sequentially with HO (50 mL), 1N HCl (50 mL), and saturated aqueous NaHCO. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 2:1) to afford an off-white solid (6.2 g, 87.4% yield). Preparation of Intermediate 15.2: Compound 15.1 (3.0 g, 5.6 mmol, 1.0 eq) and dichloromethane (15 mL) were placed in a 250 mL three-neck reaction flask. Under nitrogen gas protection, magnetic stirring was performed. Trifluoroacetic acid (6.4 g, 56 mmol) was added at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with 100 mL of saturated aqueous sodium bicarbonate solution, and the aqueous phase was extracted with dichloromethane (50 mL). The organic phases were combined, washed with 100 mL of purified water, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a white solid (2.0 g, 82.1% yield).

[0065] Preparation of Compound 15 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 15.2 (2.0 g, 4.6 mmol, 1.0 eq) and ethyl acetate (20 mL). Under nitrogen gas protection, a solution of hydrogen chloride in ethyl acetate (3 M, 1.9 mL, 5.7 mmol) was added at room temperature and stirred for 1 h. After the addition was complete, the mixture was stirred for 1 h. A white solid precipitated and was filtered. The solid was dissolved in MeCN / HO (23 mL) by heating to reflux and stirred at room temperature for 1 h and at 0 °C for 1 h. The solid was filtered and washed with MeCN (5 mL). The mixture was dried under oil pump vacuum at 40 °C for 3 h to give a white solid (1.2 g, 55.3% yield). 1 H NMR (400 MHz, CD3OD) δ 5.10 - 5.02 (m, 1H), 4.03 (s, 2H), 3.74 (s, 2H), 2.63 (t, J = 9.0 Hz, 1H), 2.17 - 2.00 (m, 2H), 2.11 (s, 3H), 1.85 - 1.10 (m, 18H), 1.07 - 0.90 (m, 1H), 0.88 - 0.77 (m, 1H), 0.85 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 433.5.

[0066] Example 16. Synthesis of Compound 16 Hydrochloride [ka] Preparation of Intermediate 16.1 L-OH-Ile-Boc (2.00 g, 8.63 mmol, 1.2 eq), EDCI (1.65 g, 8.63 mmol, 1.2 eq), HOBt (0.2 g, 1.40 mmol, 1.2 eq), and N,N-diisopropylethylamine (1.86 g, 14.38 mmol, 2.0 eq) were added to a 100 mL reaction flask in order. Dichloromethane (25 mL) was added and the mixture was stirred in an ice bath until a homogeneous phase was obtained. Compound 1.3 (3.00 g, 7.19 mmol, 1.0 eq) was then slowly added to the reaction mixture. The mixture was stirred in an ice bath for 1 hour, then transferred to room temperature and stirred for 3 hours. The reaction was confirmed to be complete by TLC. The reaction mixture was adjusted to neutrality with 1.0 M hydrochloric acid, the layers were separated, the organic phase was washed with saturated NaHCO3, the combined organic phase was dried over anhydrous sodium sulfate for 2.0 h, and the solvent was removed by evaporation to give a colorless gel (4.12 g, 90.95% yield).

[0067] Preparation of Intermediate 16.2: Compound 16.1 (4.12 g, 6.53 mmol, 1.0 eq) and dichloromethane (40 mL) were placed in a 100 mL reaction flask and stirred until homogeneous. Trifluoroacetic acid (12 mL) was added, and the reaction mixture gradually turned pale yellow. The mixture was stirred at room temperature for 1 hour. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in dichloromethane and adjusted to a pH of approximately 8 with saturated NaHCO3. The organic phase was separated, and dried over anhydrous sodium sulfate. The solvent was removed by evaporation to give a colorless oil (3.15 g, 90.78% yield). Preparation of Compound 16 Hydrochloride: Compound 16.2 (3.15 g, 5.94 mmol, 1.0 eq) and ethyl acetate (50 mL) were placed in a 50 mL reaction flask and stirred until a homogeneous phase was formed. A solution of hydrogen chloride in ethyl acetate was added to adjust the pH of the reaction mixture to approximately 3-4. Upon addition of the HCl / ethyl acetate solution, a white solid gradually precipitated from the reaction mixture. The mixture was stirred at room temperature and allowed to crystallize for 1.0 h. The resulting mixture was filtered to obtain a white solid (1.82 g, 54.17% yield). 1 H NMR (400 MHz, CDCl3) δ 8.39 (s, 3H), 7.40 (d, J = 7.6 Hz,1H), 5.10 (s,1H), 4.48 (t, J = 6.1 Hz, 1H), 4.25 (s, 1H), 2.53 (t, J = 8.8 Hz, 1H), 2.27 (d, J = 6.0 Hz, 1H), 2.12 (s,3H), 2.01 (d, J = 118 Hz, 1H), 1.81 (s, 5H), 1.69 (d, J = 11.6 Hz, 6H), 1.49 (s, 2H), 1.41 (d, J = 10.3 Hz, 3H), 1.31 - 1.24 (m, 1H), 1.24 - 1.20 (m, 3H), 1.19 (s, 3H), 1.07 (d, J = 6.8 Hz, 3H), 1.06 - 1.00 (m, 6H), 0.98 (t, J = 7.2 Hz, 3H), 0.80 (s, 4H), 0.61 (s, 3H). MS: m / z [M+H] + 531.39.

[0068] Example 17. Synthesis of Compound 17 Hydrochloride [ka] Preparation of Intermediate 17.1 A 100 mL reaction flask was charged with compound 1.3 (3.00 g, 7.19 mmol, 1.0 eq), L-HO-Met-Boc (2.15 g, 8.63 mmol, 1.2 eq), DMAP (0.10 g, 0.72 mmol, 0.1 eq), and 20 mL of dichloromethane and stirred in an ice bath until homogeneous. DCC (1.78 g, 8.63 mmol, 1.2 eq) was dissolved in 10 mL of dichloromethane and added to the reaction mixture, which was then stirred at room temperature for 3 h. TLC confirmed the completion of the reaction. The white solid DCC was removed by filtration, and the organic phase was washed with saturated NaHCO3. The combined organic phases were dried over anhydrous sodium sulfate. The solvent was removed by evaporation to give a white solid mass, which was purified by silica gel column (petroleum ether (60-90) / ethyl acetate = 10:1) to finally give a white solid (3.4 g, yield 72.96%).

[0069] Preparation of Intermediate 17.2: Compound 17.1 (3.4 g, 4.32 mmol, 1.0 eq) and dichloromethane (30 mL) were placed in a 100 mL reaction flask and stirred until homogeneous. Trifluoroacetic acid (9 mL) was added, and the reaction mixture gradually turned pale yellow. The mixture was stirred at room temperature for 1 hour. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in 10 mL of dichloromethane and adjusted to a pH of approximately 8 with saturated NaHCO3. The organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to give a colorless oil (1.82 g, 63.41% yield). Preparation of Compound 17 Hydrochloride: Compound 17.2 (1.82 g, 3.33 mmol, 1.0 eq) and dichloromethane (5 mL) were placed in a 25 mL reaction flask and stirred until a homogeneous phase was formed. A solution of hydrogen chloride in ethyl acetate was added to adjust the pH of the reaction mixture to approximately 3-4, and the solvent was removed by evaporation to obtain a colorless oily liquid. Ethyl acetate (10 mL) was added and stirred, and the reaction mixture gradually became a white suspension. The mixture was stirred for 3 hours and then filtered to obtain a white solid (1.2 g, 61.86% yield). 1H NMR (400 MHz, CDCl3) δ 8.56 (s, 3H), 7.62 (s,1H), 5.10 (s, 1H), 4.53 (s, 2H), 2.77 (s, 2H), 2.53 (t, J = 8.8 Hz, 1H), 2.42 (s, 1H), 2.16 (s, 3H), 2.12 (s, 3H), 2.01 (d, J = 11.9 Hz, 2H), 1.79 (s, 1H), 1.69 (d, J = 11.9 Hz, 4H), 1.66 - 1.58 (m, 2H), 1.54 (d, J = 13.3 Hz, 2H), 1.49 (s, 3H), 1.41 (t, J = 13.0 Hz, 2H), 1.28 (d, J = 12.9 Hz, 4H), 1.19 (d, J = 1.0 Hz, 3H), 1.05 (d, J = 6.8 Hz, 3H), 1.01 (d, J = 6.6 Hz, 3H), 0.80 (s, 4H), 0.61 (s, 3H). MS: m / z [M+H] + 549.4.

[0070] Example 18. Synthesis of compound 18 acid salt

change

[0071] Preparation of Intermediate 18.3: Compound 18.2 (3.0 g, 4.64 mmol, 1.0 eq) and dichloromethane (30 mL) were placed in a 100 mL reaction flask and stirred until homogeneous. Trifluoroacetic acid (9 mL) was added, and the reaction mixture gradually turned pale yellow. The mixture was stirred at room temperature for 1 hour. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in dichloromethane and adjusted to a pH of approximately 8 with saturated NaHCO3. The organic phase was separated, collected, and dried over anhydrous sodium sulfate. The solvent was removed by evaporation to give a colorless oil (1.82 g, 71.65% yield). Preparation of Compound 18 Hydrochloride: A 25 mL reaction flask was charged with intermediate 3 (1.82 g, 3.33 mmol, 1.0 eq) and dichloromethane (5 mL). The mixture was stirred until homogeneous. HCl / ethyl acetate was added to adjust the pH of the reaction mixture to approximately 3-4 and stirred for 10 minutes. The solvent was removed by evaporation to give a colorless oily liquid. Adding ethyl acetate (20 mL) did not completely clear the mixture. Methyl t-butyl ether (20 mL) gradually turned the reaction mixture into a white suspension. The mixture was stirred for 3 hours and filtered to give a white solid (1.33 g, 68.56% yield). 1H NMR (400 MHz, CDCl3) δ 8.39 - 8.23 ​​(d, J = 7.8 Hz, 1H), 8.21 - 8.08 (s, 3H), 5.14 - 5.04 (s, 1H), 4.77 - 4.60 (s, 1H), 4.52 - 4.39 (dd, J = 8.0, 4.5 Hz, 1H), 2.84 - 2.64 (s, 2H), 2.58 - 2.47 (t, J = 8.8 Hz, 1H), 2.44 - 2.33 (s, 1H), 2.33 - 2.21 (dd, J = 11.9, 6.0 Hz, 2H), 2.12 - 2.07 (s, 3H), 2.04 - 1.96 (d, J = 11.1 Hz, 1H), 1.81 - 1.56 (t, J = 15.4 Hz, 7H), 1.56 - 1.32 (m, 7H), 1.31 - 1.07 (m, 6H), 1.05 - 1.00 (d, J = 3.0 Hz, 3H), 1.00 - 0.93 (d, J = 4.7 Hz, 4H), 0.82 - 0.75 (s, 4H), 0.65 - 0.55 (s, 3H). MS: m / z [M+H] + 546.4.

[0072] Example 19. Synthesis of compound 19 acid salt

change

[0073] Preparation of Compound 19 Hydrochloride: Compound 19.2 (3.09 g, 5.57 mmol, 1.0 eq) and ethyl acetate (20 mL) were placed in a 50 mL reaction flask and stirred to dissolve. A solution of hydrogen chloride in ethyl acetate was added to adjust the pH of the reaction solution to about 3-4. A white solid gradually precipitated from the reaction solution. The solution was stirred for 4 hours to crystallize, and the solution was filtered to obtain a white solid (2.11 g, yield 64.33%). 1H NMR (400 MHz, CDCl3) δ 13.88 (s, 1H), 8.88 (s, 1H), 8.58 (s, 3H), 7.56 (d, J = 24.9 Hz, 1H), 5.11 (s, 1H), 4.98 (s, 1H), 4.50 (s, 1H), 3.57 (s, 2H), 2.51 (s, 2H), 2.11 (s, 3H), 2.00 (s, 1H), 1.66 (s, 6H), 1.50 (s, 4H), 1.39 (s, 2H), 1.32 - 1.11 (m, 7H), 1.04 (s, 7H), 0.79 (s, 4H), 0.60 (s, 3H). MS: m / z [M+H] + 555.4.

[0074] Example 20. Synthesis of Compound 20 Hydrochloride [ka] Preparation of Intermediate 20.1: A 100 mL reaction flask was charged with compound 1.3 (3.00 g, 7.19 mmol, 1.0 eq), L-HO-Tyr-Boc-O-Boc (2.74 g, 8.63 mmol, 1.2 eq), DMAP (0.10 g, 0.72 mmol, 0.1 eq), and 20 mL of dichloromethane and stirred in an ice bath until homogeneous. DCC (1.78 g, 8.63 mmol, 1.2 eq) was dissolved in 10 mL of dichloromethane and added to the reaction mixture at 37 °C. The mixture was then stirred at room temperature for 3 h. TLC indicated completion of the reaction. The white solid was removed by filtration, and the organic phase was washed with saturated NaHCO3. The combined organic phases were then dried over anhydrous sodium sulfate. The solvent was removed by evaporation to give a white solid mass, which was purified by silica gel column (petroleum ether (60-90) / ethyl acetate = 10:1 to 5:1) to give a white solid (0.6 g, yield 10.69%). Preparation of Intermediate 20.2: Compound 20.1 (0.60 g, 0.77 mmol, 1.0 eq) and dichloromethane (6.0 mL) were placed in a 25 mL reaction flask and stirred until a homogeneous phase was formed. Trifluoroacetic acid (2.0 mL) was added and stirred at room temperature for 1 h. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in dichloromethane and washed with saturated aqueous NaHCO3 solution until the pH of the aqueous phase reached 7-8. The layers were separated, and the organic phase was dried over anhydrous sodium sulfate. The solvent was removed by evaporation to give a colorless oil (0.43 g, 95.56% yield).

[0075] Preparation of Compound 20 Hydrochloride: Compound 20.2 (0.4 g, 0.68 mmol, 1.0 eq) and ethyl acetate (6.0 mL) were placed in a 25 mL reaction flask and stirred to dissolve. HCl / ethyl acetate was added to adjust the pH of the reaction solution to approximately 3-4, and methyl t-butyl ether (1.5 mL) was added. The mixture was stirred for 1 hour to crystallize. The resulting mixture was filtered and dried to obtain a white solid (0.41 g, 97.62% yield). 1 H NMR (400 MHz, CDCl3) δ 8.11 (s, 5H), 7.19 (d, J = 7.7 Hz, 2H), 6.80 (d, J = 7.6 Hz, 2H), 5.09 (s, 1H), 4.57 (s, 1H), 4.43 (s, 1H), 3.30 (s, 1H), 3.06 (s, 1H), 2.43 (t, J = 8.3 Hz, 1H), 2.24 (s, 1H), 2.09 (s, 3H), 1.90 (s, 1H), 1.82 - 1.56 (m, 5H), 1.49 (s, 5H), 1.38 - 1.20 (m, 4H), 1.22 - 1.07 (m, 4H), 1.07 - 0.86 (m, 8H), 0.77 (s, 3H), 0.70 (s, 1H), 0.56 (s, 3H). MS: m / z [M+H] + 581.4.

[0076] Example 21. Synthesis of Compound 21 Hydrochloride [ka] Preparation of Intermediate 21.1: A 100 mL reaction flask was charged with L-HO-Asn-Boc (2.00 g, 8.63 mmol, 1.2 eq), EDCI (1.65 g, 8.63 mmol, 1.2 eq), HOBt (0.2 g, 1.40 mmol, 1.2 eq), N,N-diisopropylethylamine (1.86 g, 14.38 mmol, 2.0 eq), and dichloromethane (30 mL) and stirred in an ice bath until homogeneous. Compound 1.3 (3.00 g, 7.19 mmol, 1.0 eq) was then added to the reaction mixture and stirred at room temperature for 3 h. Completion was confirmed by TLC. The reaction mixture was neutralized with 1.0 M hydrochloric acid, separated, washed with saturated aqueous NaHCO3, and dried over anhydrous sodium sulfate. Filtration, concentration under reduced pressure and evaporation removed the solvent to give a white chunky solid (4.17 g, 91.85% yield). Preparation of Intermediate 21.2: Compound 21.1 (4.17 g, 6.60 mmol, 1.0 eq) and dichloromethane (40 mL) were placed in a 100 mL reaction flask and stirred until homogeneous. Trifluoroacetic acid (12 mL) was added and stirred at room temperature for 1 hour. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in dichloromethane and adjusted to a pH of approximately 8 with saturated NaHCO3. The organic phase was separated, dried over anhydrous sodium sulfate, and evaporated to give a colorless oil (3.01 g, 86.00% yield).

[0077] Preparation of Compound 21 Hydrochloride: Compound 21.2 (3.00 g, 6.57 mmol, 1.0 eq) and ethyl acetate (30 mL) were placed in a 50 mL reaction flask and stirred to dissolve. Hydrogen chloride in ethyl acetate was added to adjust the pH of the reaction mixture to approximately 3-4. Once the reaction mixture became clear, methyl t-butyl ether was added and stirred to precipitate crystals. The mixture was filtered to obtain a white solid (1.8 g, 56.25% yield). 1 H NMR (400 MHz, CDCl3) δ 8.63 (d, J = 8.1 Hz, 1H), 8.23 ​​(brs, 3H), 7.81 (s, 1H), 7.02 (s, 1H), 5.06 (s, 1H), 4.80 (s, 1H), 4.46 (dd, J = 8.3, 4.2 Hz, 1H), 3.11 (s, 2H), 2.52 (t, J = 8.8 Hz, 1H), 2.28 (d, J = 9.6 Hz, 1H), 2.11 (s, 3H), 2.01 (d, J = 10.8 Hz, 1H), 1.81 - 1.56 (m, 6H), 1.56 - 1.44 (m, 4H), 1.37 (d, J = 21.9 Hz, 1H), 1.26 (qd, J = 6.3, 5.9, 3.3 Hz, 2H), 1.19 (s, 6H), 0.99 (t, J = 7.3 Hz, 7H), 0.79 (s, 4H), 0.61 (s, 3H). MS: m / z [M+H] + 532.4.

[0078] Example 22. Synthesis of Compound 22 Hydrochloride [ka] Preparation of Intermediate 22.1: A 100 mL reaction flask was charged with L-HO-Ar g-Boc (3.23 g, 8.63 mmol, 1.2 eq), EDCI (1.65 g, 8.63 mmol, 1.2 eq), HOBt (0.2 g, 1.40 mmol, 1.2 eq), N,N-diisopropylethylamine (1.86 g, 14.38 mmol, 2.0 eq), and dichloromethane (3 mL). The mixture was stirred in an ice bath until homogeneous. Compound 1.3 (3.00 g, 7.19 mmol, 1.0 eq) was then added to the reaction mixture and stirred at room temperature for 3 h. Completion was confirmed by TLC. The reaction mixture was adjusted to neutral pH with 1.0 M HCl, separated, and the organic phase was washed with saturated NaHCO3 and dried over anhydrous sodium sulfate. The organic phase was concentrated to give a pale yellow oil (4.21 g, 86.98% yield). Preparation of Intermediate 22.2: Compound 22.1 (4.21 g, 6.25 mmol, 1.0 eq) and dichloromethane (40 mL) were placed in a 100 mL reaction flask and stirred until homogeneous. Trifluoroacetic acid (12 mL) was added and stirred at room temperature for 1 h. Completion of the reaction was confirmed by TLC. The solvent was removed by evaporation to give a colorless oil, which was dissolved in dichloromethane and washed with saturated aqueous NaHCO3 solution until the pH of the aqueous phase reached 7-8. The layers were separated, and the organic phase was dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a colorless oil (3.23 g, 90.23% yield).

[0079] Preparation of Compound 22 Hydrochloride: Compound 22.2 (3.23 g, 5.63 mmol, 1.0 eq) and isopropanol (20 mL) were placed in a 100 mL reaction flask and stirred to dissolve. Hydrogen chloride in ethyl acetate was added to adjust the pH of the reaction mixture to approximately 3-4, and the mixture was stirred for 1 hour to allow crystallization. The mixture was filtered and dried under vacuum at 40 °C using an oil pump for 4 hours to obtain a white solid (0.84 g, 22.46% yield). 1H NMR (400 MHz, CDCl3) δ 8.53 (s, 1H), 8.28 (s, 3H), 7.54 (s, 1H), 6.96 (s, 4H), 5.07 (s, 1H), 4.53 (s, 1H), 4.45 (s, 1H), 3.35 (d, J = 28.0 Hz, 2H), 2.51 (s, 1H), 2.29 (s, 1H), 2.11 (s, 3H), 2.02 (s, 1H), 1.87 (s, 2H), 1.67 (s, 6H), 1.48 (s, 5H), 1.41 (s, 2H), 1.33 - 1.23 (m, 2H), 1.23 - 1.08 (m, 5H), 1.00 (d, J = 6.1 Hz, 7H), 0.91 (s, 1H), 0.79 (s, 4H), 0.61 (s, 3H). MS: m / z [M+H] + 574.4.

[0080] Example 23. Synthesis of Compound 23 Hydrochloride [ka] Preparation of Intermediate 23.1: A 250 mL single-neck reaction flask was charged with compound 14.2 (5.0 g, 13.3 mmol), Boc-L-Ala-OH (3.0 g, 15.9 mmol), dichloromethane (50 mL), triethylamine (1.6 g, 16.0 mmol), HOBT (0.7 g, 5.1 mmol), and EDCI (3.1 g, 16.2 mmol). The reaction was allowed to proceed at room temperature for 4 h and then washed with saturated aqueous NaHCO3. The mixture was concentrated under reduced pressure, and the crude product was subjected to column chromatography (petroleum ether (60-90) / ethyl acetate = 10:1 to 2:1) to give an off-white solid (6.5 g, 89.3% yield). Preparation of Intermediate 23.2: Compound 23.1 (3.5 g, 6.4 mmol, 1.0 eq) and dichloromethane (18 mL) were placed in a 250 mL three-neck reaction flask. Under nitrogen gas protection, with magnetic stirring, trifluoroacetic acid (7.3 g, 64 mmol) was added at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. The mixture was concentrated under reduced pressure, and dichloromethane (100 mL) was added. The mixture was washed with saturated aqueous sodium bicarbonate. The combined organic phases were dried over anhydrous sodium sulfate. The mixture was filtered and concentrated to give a white solid (2.6 g, 90.9% yield).

[0081] Preparation of Compound 23 Hydrochloride: A 250 mL single-neck reaction flask was charged with compound 23.2 (2.6 g, 5.85 mmol, 1.0 eq) and ethyl acetate (20 mL). Under nitrogen gas protection and magnetic stirring, HCl / ethyl acetate (3 M, 2.4 mL, 7.2 mmol) was added at room temperature. After the addition was complete, the mixture was stirred for 3 hours. A white solid precipitated, which was filtered and washed with ethyl acetate (5 mL). The mixture was dried under vacuum at 40 °C for 3 hours using an oil pump to obtain a white solid (2.1 g, 74.6% yield). 1 H NMR (400 MHz, CDCl3) δ 8.66 - 8.46 (m, 1H), 8.16 (brs, 3H), 5.18 - 5.02 (m, 1H), 4.70 - 4.52 (m, 1H), 4.44 - 3.78 (m, 2H), 2.53 (d, J = 9.1 Hz, 1H), 2.28 - 1.96 (m, 2H),2.11 (s, 3H), 1.93 - 0.70 (m, 23H), 0.79 (s, 3H), 0.61 (s, 3H). MS: m / z [M+H] + 447.6.

[0082] Example 24. Dissolution performance test Measurement method The appropriate amount of the compound of the present invention was weighed and dissolved in different media. The solution was stirred in a thermostatic water bath at 25°C for about 24 hours, then filtered through a 0.22 μm aqueous filter membrane. An appropriate amount of the filtrate was diluted with methanol to a predetermined concentration to prepare the test solution. Methanol was used as a blank control solution, and the concentration of the test solution was measured by HPLC with a UV detector. (1) Blank solution: Methanol (2) Control solution: 5 mg of the control was weighed accurately, placed in a 10 mL measuring flask, dissolved in methanol, diluted to the mark, and mixed uniformly to obtain the solution. (3) Sample solution: An appropriate amount of sample solution was taken, diluted with methanol to approximately 0.5 mg / mL (determined by the concentration of each sample), and mixed uniformly.

[0083] [Table 1]

[0084] Test results [Table 2]

[0085] " / " indicates not measured. When the solubility is a specific value, it represents "saturated solubility." ">10" indicates that the solubility is greater than 10 mg / mL. Example 25. Stability of compounds of the present invention in glucose solution Measurement method An appropriate amount of each derivative of the present invention was weighed and dissolved in a 5% glucose solution to prepare a solution with a concentration of approximately 1 mg / g. After stirring for approximately 24 hours in a thermostatic water bath magnetic device at 25°C, the solution was filtered through a 0.22 μm aqueous filter membrane, and the clear solution was diluted with methanol to a predetermined concentration to prepare the test sample solution. The sample was left at room temperature for 0, 1, 3, 5, and 8 hours, and the solution stability of the test sample was measured by HPLC with a UV detector using methanol as the blank solvent. (1) Blank solution: methanol. (2) Sample solution: Take an appropriate solution and pass it through a 0.22 μm filter membrane.

[0086] [Table 3]

[0087] Test results [Table 4]

[0088] Conclusion: From the above results, it can be seen that the derivatives of the present invention have a certain degree of stability when stored in a glucose aqueous solution for a certain period of time, and in particular, the R 1 It was shown that when is an isopropyl group, the purity of the derivative in glucose solution remains almost unchanged. Example 26. Pharmacokinetic testing of compounds of the present invention The purpose of this experiment was to orally administer a single dose of each compound of the present invention and allopregnanolone solution to SD rats, detect the active ingredient allopregnanolone in the plasma, and evaluate its pharmacokinetic (PK) characteristics in the SD rats. Each compound was dissolved in an aqueous solution containing 5% Tween 20. The animals used in this study were male SD rats weighing 180-220 g purchased from Shanghai SLAC Laboratory Animal Co., Ltd. All animals were fasted and were deprived of food for 4 hours after administration.

[0089] Using randomly designed groups, the test SD rats were divided into five groups, each containing allopregnanolone, Compound 1 hydrochloride, Compound 2 hydrochloride, Compound 14 hydrochloride, and Compound 15 hydrochloride. Each group was administered intragastrically (ig) at a dose of 20 mg / kg (calculated as allopregnanolone). Approximately 0.6 mL of blood samples were collected from a peripheral vein at 0.0833, 0.25, 0.5, 1, 2, 3, 4, 6, 9, 12, and 24 hours post-dose and transferred to commercially available centrifuge tubes (Jiangsu Kangjian Medical Supplies Co., Ltd.) containing 0.85–1.15 mg of K2 EDTA anticoagulant. Plasma was separated by centrifugation within 30 minutes (10 minutes at 3000 g at approximately 4°C). Plasma was placed in labeled polypropylene tubes, rapidly frozen on dry ice, and stored in an ultra-low temperature refrigerator at or below -60°C for further analysis. Drug concentrations in SD rat plasma were determined using an LCMS / MS bioanalytical method. Plasma drug concentration-time data were analyzed using a non-compartmental model with the WinNonlin software package (version 6.3 or later). Data are shown in Table 3.

[0090] [Table 5] "ND" stands for not quantifiable.

[0091] Conclusion: The above results show that the derivatives of the present invention have significantly improved pharmacokinetic properties compared with the original drug. When the derivatives of the present invention are administered, both AUC and Cmax are significantly improved, and the effect is sustained and has the characteristics of sustained release. In particular, the R 1 When is an isopropyl group, allopregnanolone is maintained at an effective physiological concentration in the body for a long period of time, there is no burst release phenomenon, and the plasma drug concentration curve is gentle and has small fluctuations. All documents related to the present invention are incorporated herein by reference as if each document were individually incorporated by reference. After reading the above content of the present invention, it should be understood that those skilled in the art can make various changes and modifications to the present invention, and that equivalents thereof are within the scope of the claims of the present invention.

Claims

1. A compound selected from the group consisting of: 【Chemistry 1】

2. 10. A pharmaceutical composition comprising a therapeutically effective dose of a compound of claim 1 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipient.

3. Use of the compound of claim 1 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 2, in the manufacture of a medicament for preventing or treating a central nervous system disorder or disease.

4. the central nervous system disorder or disease comprises tremor, sleep disorder, depression, depressive disorder, bipolar disorder, anxiety disorder, stress reaction, post-traumatic stress disorder, obsessive-compulsive disorder, schizophrenia, schizoaffective disorder, epilepsy, epileptic seizures, memory and / or cognitive impairment, dementia, movement disorder, personality disorder, autism, monoetiology autism, pain, traumatic brain injury, vascular disease, substance use disorder and / or withdrawal syndrome or tinnitus; or 4. The use according to claim 3, wherein the central nervous system disorder or disease comprises idiopathic tremor, epilepsy, clinical depression, postpartum or postpartum depression, atypical depression, psychotic major depression, catatonic depression, seasonal affective disorder, dysthymia, bipolar depression, depressive personality disorder, recurrent brief depression, minor depressive disorder, bipolar or manic depression, post-traumatic stress disorder, depression due to a chronic medical condition, treatment-resistant depression, refractory depression, suicidal tendencies, suicidal ideation, suicidal behavior, traumatic brain injury, generalized anxiety disorder, social anxiety disorder, attention deficit hyperactivity disorder, dementia, Huntington's disease, Parkinson's disease, neuropathic pain, injury-related pain syndrome, acute pain, long-term pain, stroke, ischemia, vascular malformation, opioid, cocaine and / or alcohol dependence or insomnia.

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