CN118005654A - Substituted pyridopyrimidinone compounds, compositions containing the same and uses thereof - Google Patents

Abstract

The invention provides a substituted pyridopyrimidinone compound, a composition containing the compound and application thereof, wherein the compound is shown as a formula (I) or a tautomer, stereoisomer, prodrug, crystal form, pharmaceutically acceptable salt, hydrate or solvent compound thereof. The compounds of formula (I) are useful as SMN2 (Survival of motor neuron 2) gene splice modulators for the treatment of spinal muscular atrophy (Spinal Muscular Atrophy, SMA), with high selectivity and good pharmacokinetic properties.

Description

Substituted pyridopyrimidinone compounds, compositions containing the same and uses thereof

Technical Field

The invention belongs to the technical field of biological medicines, and particularly relates to a substituted pyridopyrimidinone compound, a composition containing the compound and application thereof. More particularly, the present invention relates to certain deuterium-substituted 7- (4, 7-diazaspiro [2.5] oct-7-yl) -2- (2, 8-dimethylimidazo [1,2-b ] pyridazin-6-yl) pyrido [1,2-a ] pyrimidin-4-one compounds, and pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates, or solvates thereof. These deuterium substituted compounds and compositions thereof are useful as SMN2 (Survival of motor neuron 2) gene splice modulators for the treatment of spinal muscular atrophy (Spinal Muscular Atrophy, SMA) with high selectivity and good pharmacokinetic properties.

Background

Spinal Muscular Atrophy (SMA) is a variety of hereditary and acquired Central Nervous System (CNS) diseases characterized by progressive motor neuron injury in the spinal cord and brain stem, which causes muscle weakness and atrophy. SMA is most commonly caused by mutations in the motor neuron Survival (SMN) gene and appears to severely affect from infant to adult.

Clinical profiles of SMA disorders have been divided into the following five groups:

(1) Type 0 SMA (intrauterine SMA) is the most severe form of disease and begins before birth. Typically, the first symptom of type 0 SMA is a decrease in fetal movement that can be observed first between 30 and 36 weeks of gestation. After birth, these newborns rarely move and dysphagia and dyspnea.

(2) Type I SMA (infant SMA or wir-Huo Ershi disease) is symptomatic for 0 to 6 months, which is also very severe. The patient is never able to sit up and, due to no respiratory support, death usually occurs in the first 2 years.

(3) The age of onset of type 2 SMA (transitional SMA) is 7-18 months. The patient can sit without support, but cannot stand or walk independently. The prognosis of this group depends largely on the degree of respiratory correlation.

(4) Type 3 SMA (adolescents or ku-wei-di disease (Kugelberg-WELANDER DISEASE)) is usually diagnosed after 18 months. Type 3 SMA individuals are able to walk independently at certain times during the course of the disease, but typically rely on wheelchairs during young or adult life.

(5) Type 4 SMA (adult onset SMA). Symptoms of weakness usually begin in the tongue, hands or feet in the late adolescence and then progress to other areas of the body. Adult SMA processes are slower and have little or no effect on life expectancy.

SMN gene maps have been obtained by linkage analysis of complex regions in chromosome 5 q. In humans, this region contains approximately 50 kilobase pair (kb) inverted copies, resulting in two nearly identical copies of the SMN gene. SMA is caused by an inactivating mutation or deletion of the telomere copy of the gene (SMN 1) on both chromosomes, resulting in loss of SMN1 gene function. However, all patients retained a centromere copy of the gene (SMN 2), and the copy number of the SMN2 gene in SMA patients was generally inversely related to disease severity; i.e. patients with less severe SMA have more copies of SMN 2. Nonetheless, SMN2 cannot fully compensate for the loss of SMN1 function due to alternative splicing of exon 7 caused by a translationally silent C-to-T mutation in exon 7. Thus, most transcripts produced by SMN2 are deleted for exon 7 (Δ7smn2) and encode truncated SMN proteins that have impaired function and are rapidly degraded.

SMN proteins are thought to play a role in RNA processing and metabolism, functioning as a well-identified mediator of the assembly of a specific class of RNA-protein complexes called snrnps. In motor neurons, SMN may have other functions, however, its role in preventing selective degeneration of motor neurons has not been well established.

In most cases, SMA is diagnosed based on clinical symptoms and by the presence of at least one SMN1 gene copy test. However, in about 5% of the conditions SMA is caused by mutations in genes other than SMN1 inactivation, some of which are known and others are not yet established. In some cases, when SMN1 gene testing is not feasible or does not show any abnormalities, other tests such as Electromyography (EMG) or muscle tissue examination may be indicated.

RISDIPLAM (chemical name 7- (4, 7-diazaspiro [2.5] oct-7-yl) -2- (2, 8-dimethylimidazo [1,2-b ] pyridazin-6-yl) pyrido [1,2-a ] pyrimidin-4-one, which has the following structural formula) is the first oral small molecule SMN2 gene splicing modulator to treat SMA worldwide, which can increase functional SMN proteins systemically.

Poor absorption, distribution, metabolism and/or excretion (ADME) properties are known to be the leading cause of failure in many candidate drug clinical trials. Many drugs currently on the market also limit their range of application due to poor ADME properties. Rapid metabolism of drugs can result in many drugs that would otherwise be effective in treating the disease being difficult to formulate due to too rapid clearance from the body's metabolism. Frequent or high dose administration, while potentially solving the problem of rapid drug clearance, can lead to problems such as poor patient compliance, side effects caused by high dose administration, and increased cost of treatment. In addition, rapidly metabolized drugs may also expose the patient to poorly toxic or reactive metabolites.

The discovery of novel potent SMN2 gene splice modulators with good oral bioavailability and patentability is a challenging task. Accordingly, there remains a need in the art to develop compounds having a higher selective inhibitory activity and/or better pharmacodynamics/pharmacokinetics for use as SMN2 gene splice modulators, and the present invention provides such compounds.

Disclosure of Invention

Aiming at the technical problems, the invention discloses a novel deuterium-substituted pyridopyrimidinone compound which is used as a novel and effective SMN2 gene splicing regulator, can increase functional SMN protein and is used for treating SMA. Furthermore, the compounds of the invention also show better metabolic stability and/or pharmacokinetic properties.

In this regard, the present invention adopts the following technical scheme:

in a first aspect of the invention, there is provided a compound of formula (I):

Wherein,

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ And R ₁₆ are each independently selected from hydrogen, deuterium, halogen, or trifluoromethyl;

X ₁ and X ₂ are each independently selected from CH ₃、CD₃、CHD₂ or CH ₂ D;

with the proviso that said compound contains at least one deuterium atom;

Or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystalline form, hydrate, or solvate thereof.

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystalline form, hydrate, or solvate thereof, and a pharmaceutically acceptable excipient. In a specific embodiment, the compounds of the present invention are provided in the pharmaceutical composition in an effective amount. In particular embodiments, the compounds of the present invention are provided in a therapeutically effective amount. In particular embodiments, the compounds of the present invention are provided in a prophylactically effective amount.

In another aspect, the present invention provides a method of preparing a pharmaceutical composition as described above, comprising the steps of: a pharmaceutically acceptable excipient is admixed with a compound of the invention or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, thereby forming a pharmaceutical composition.

In another aspect, the invention provides the use of a compound of the invention, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, or a pharmaceutical composition as described above, in the manufacture of a medicament for the treatment and/or prophylaxis of Spinal Muscular Atrophy (SMA) diseases.

In another aspect, the present invention provides a method of treating and/or preventing Spinal Muscular Atrophy (SMA) disease, the method comprising administering to a subject in need thereof a therapeutically effective amount of a compound of the invention, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystalline form, hydrate, or solvate thereof, or a pharmaceutical composition of the invention.

Other objects and advantages of the present invention will be apparent to those skilled in the art from the detailed description, examples and claims that follow.

Definition of the definition

Herein, "deuterated" refers to a compound or group in which one or more hydrogens are replaced with deuterium, unless otherwise indicated; deuteration may be mono-, di-, poly-or full-substituted. The term "one or more deuterated" is used interchangeably with "one or more deuterated".

Herein, unless otherwise specified, "non-deuterated compound" refers to a compound having a deuterium atom content of not higher than the natural deuterium isotope content (0.015%).

As used herein, the term "subject" includes, but is not limited to: a human (i.e., male or female of any age group, e.g., pediatric subjects (e.g., infants, children, adolescents) or adult subjects (e.g., young adults, middle aged adults, or senior adults)) and/or a non-human animal, e.g., a mammal, e.g., a primate (e.g., cynomolgus monkey, rhesus monkey), cow, pig, horse, sheep, goat, rodent, cat, and/or dog. In some embodiments, the subject is a human. In other embodiments, the subject is a non-human animal.

"Disease," "disorder," and "condition" are used interchangeably herein.

As used herein, unless otherwise indicated, the term "treating" includes an effect that occurs when a subject suffers from a particular disease, disorder or condition, which reduces the severity of the disease, disorder or condition, or delays or slows the progression of the disease, disorder or condition ("therapeutic treatment"), as well as an effect that occurs before the subject begins to suffer from the particular disease, disorder or condition ("prophylactic treatment").

In general, an "effective amount" of a compound refers to an amount sufficient to elicit a biological response of interest. As will be appreciated by those of ordinary skill in the art, the effective amount of the compounds of the present invention may vary depending on the following factors: for example, biological targets, pharmacokinetics of the compound, the disease being treated, the mode of administration, and the age health and symptoms of the subject. Effective amounts include therapeutically and prophylactically therapeutically effective amounts.

As used herein, unless otherwise indicated, a "therapeutically effective amount" of a compound is an amount sufficient to provide a therapeutic benefit in the treatment of a disease, disorder, or condition, or to delay or minimize one or more symptoms associated with a disease, disorder, or condition. A therapeutically effective amount of a compound refers to the amount of therapeutic agent, alone or in combination with other therapies, that provides a therapeutic benefit in the treatment of a disease, disorder or condition. The term "therapeutically effective amount" may include an amount that improves overall treatment, reduces or avoids symptoms or causes of a disease or disorder, or enhances the therapeutic efficacy of other therapeutic agents.

As used herein, unless otherwise indicated, a "prophylactically effective amount" of a compound is an amount sufficient to prevent a disease, disorder, or condition, or to prevent one or more symptoms associated with a disease, disorder, or condition, or to prevent recurrence of a disease, disorder, or condition. A prophylactically effective amount of a compound refers to the amount of therapeutic agent used alone or in combination with other agents, which provides a prophylactic benefit in preventing a disease, disorder or condition. The term "prophylactically effective amount" may include an amount that improves overall prophylaxis, or an amount that enhances the prophylactic efficacy of other prophylactic agents.

"Combination" and related terms refer to the simultaneous or sequential administration of the therapeutic agents of the present invention. For example, the compounds of the invention may be administered simultaneously or sequentially in separate unit dosage forms with another therapeutic agent, or simultaneously in a single unit dosage form with another therapeutic agent.

Detailed Description

Compounds of formula (I)

Herein, "the compound of the present invention" refers to a compound of the following formula (I), or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvent compound thereof.

In one embodiment, the present invention relates to compounds of formula (I):

Wherein,

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ And R ₁₆ are each independently selected from hydrogen, deuterium, halogen, or trifluoromethyl;

X ₁ and X ₂ are each independently selected from CH ₃、CD₃、CHD₂ or CH ₂ D;

with the proviso that said compound contains at least one deuterium atom;

Or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystalline form, hydrate, or solvate thereof.

In a specific embodiment, the deuterium isotope content of deuterium at the deuterated position is at least greater than 0.015%, preferably greater than 30%, more preferably greater than 50%, more preferably greater than 55%, more preferably greater than 60%, more preferably greater than 65%, more preferably greater than 70%, more preferably greater than 75%, more preferably greater than 80%, more preferably greater than 85%, more preferably greater than 90%, more preferably greater than 95%, more preferably greater than 99% of the natural deuterium isotope content.

Specifically, the deuterium isotope content of each deuterated position of R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅、R₁₆、X₁ and X ₂ in the present invention is at least 0.015%, more preferably greater than 1%, more preferably greater than 5%, more preferably greater than 10%, more preferably greater than 15%, more preferably greater than 20%, more preferably greater than 25%, more preferably greater than 30%, more preferably greater than 35%, more preferably greater than 40%, more preferably greater than 45%, more preferably greater than 50%, more preferably greater than 55%, more preferably greater than 60%, more preferably greater than 65%, more preferably greater than 70%, more preferably greater than 75%, more preferably greater than 80%, more preferably greater than 85%, more preferably greater than 90%, more preferably greater than 95%, more preferably greater than 99%.

In another embodiment, the compounds of the present invention contain at least one deuterium atom, more preferably two deuterium atoms, more preferably three deuterium atoms, more preferably four deuterium atoms, more preferably five deuterium atoms, more preferably six deuterium atoms, more preferably seven deuterium atoms, more preferably eight deuterium atoms, more preferably nine deuterium atoms, more preferably ten deuterium atoms, more preferably eleven deuterium atoms, more preferably twelve deuterium atoms, more preferably thirteen deuterium atoms, more preferably fourteen deuterium atoms, more preferably fifteen deuterium atoms, more preferably sixteen deuterium atoms, more preferably seventeen deuterium atoms, more preferably nineteen deuterium atoms, more preferably twenty deuterium atoms.

In another specific embodiment ,"R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen, deuterium, halogen or trifluoromethyl "including the technical scheme that R ₁ is selected from hydrogen, deuterium, halogen or trifluoromethyl, R ₂ is selected from hydrogen, deuterium, halogen or trifluoromethyl, R ₃ is selected from hydrogen, deuterium, halogen or trifluoromethyl, and so on, until R ₁₆ is selected from hydrogen, deuterium, halogen or trifluoromethyl. More specifically, the technical scheme includes that R ₁ is hydrogen, R ₁ is deuterium, R ₁ is halogen (F, cl, br or I) or R ₁ is trifluoromethyl, R ₂ is hydrogen, R ₂ is deuterium, R ₂ is halogen (F, cl, br or I) or R ₂ is trifluoromethyl, R ₃ is hydrogen, R ₃ is deuterium, R ₃ is halogen (F, cl, br or I) or R ₃ is trifluoromethyl, and so on until R ₁₆ is hydrogen, R ₁₆ is deuterium, R ₁₆ is halogen (F, cl, br or I) or R ₁₆ is trifluoromethyl.

In another specific embodiment, "X ₁ and X ₂ are each independently selected from CH ₃、CD₃、CHD₂ or CH ₂ D" includes embodiments in which X ₁ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D, and X ₂ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D. More specifically, the technical scheme includes that X ₁ is CH ₃、X₁, CD ₃、X₁ is CHD ₂ or X ₁ is CH ₂ D, and X ₂ is CH ₃、X₂, CD ₃、X₂ is CHD ₂ or X ₂ is CH ₂ D.

In another specific embodiment ,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium.

In another specific embodiment, R ₁、R₂、R₃、R₄、R₅ and R ₆ are hydrogen.

In another specific embodiment, R ₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are hydrogen.

In another specific embodiment, X ₁ is CD ₃ or CH ₃.

In another specific embodiment, X ₁ is CD ₃.

In another specific embodiment, X ₂ is CD ₃ or CH ₃.

In another specific embodiment, X ₂ is CD ₃.

In another specific embodiment, X ₁ and X ₂ are CD ₃.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates or solvates thereof, wherein X ₁ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅、R₁₆ and X ₂ are as defined above.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvent compound thereof, wherein X ₁ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium, and X ₂ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvent compound thereof, wherein X ₁ is CD ₃,R₁、R₂、R₃、R₄、R₅ and R ₆ is hydrogen, R ₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium, and X ₂ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, wherein X ₁ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ is hydrogen, and X ₂ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates or solvates thereof, wherein X ₂ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅、R₁₆ and X ₁ are as defined above.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvent compound thereof, wherein X ₂ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium, and X ₁ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvent compound thereof, wherein X ₂ is CD ₃,R₁、R₂、R₃、R₄、R₅ and R ₆ is hydrogen, R ₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium, and X ₁ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, wherein X ₂ is CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ is hydrogen, and X ₁ is selected from CH ₃、CD₃、CHD₂ or CH ₂ D.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates or solvates thereof, wherein X ₁ and X ₂ are CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are as defined above.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates, or solvates thereof, wherein X ₁ and X ₂ are CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates, or solvates thereof, wherein X ₁ and X ₂ are CD ₃,R₁、R₂、R₃、R₄、R₅ and R ₆ are hydrogen, R ₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium.

In some embodiments of the compounds of formula (I), preferably, the present invention relates to the above-described compounds, or pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, crystalline forms, hydrates, or solvates thereof, wherein X ₁ and X ₂ are CD₃,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ is hydrogen.

As a preferred embodiment of the present invention, the compound, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, is selected from any one of the following compounds:

The compounds of the invention may include one or more asymmetric centers and thus may exist in a variety of stereoisomeric forms, for example, enantiomeric and/or diastereomeric forms. For example, the compounds of the invention may be individual enantiomers, diastereomers, or geometric isomers (e.g., cis and trans isomers), or may be in the form of mixtures of stereoisomers, including racemic mixtures and mixtures enriched in one or more stereoisomers. The isomers may be separated from the mixtures by methods known to those skilled in the art, including: chiral High Pressure Liquid Chromatography (HPLC), formation and crystallization of chiral salts; alternatively, preferred isomers may be prepared by asymmetric synthesis.

Those skilled in the art will appreciate that the organic compound may form a complex with a solvent in or from which it reacts or from which it precipitates or crystallizes. These complexes are referred to as "solvates". When the solvent is water, the complex is referred to as a "hydrate". The present invention encompasses all solvates of the compounds of the present invention.

The term "solvate" refers to a form of a compound or salt thereof that is bound to a solvent, typically formed by a solvolysis reaction. This physical association may include hydrogen bonding. Conventional solvents include water, methanol, ethanol, acetic acid, DMSO, THF, diethyl ether, and the like. The compounds described herein may be prepared, for example, in crystalline form, and may be solvated. Suitable solvates include pharmaceutically acceptable solvates and further include stoichiometric solvates and non-stoichiometric solvates. In some cases, the solvate will be capable of isolation, for example, when one or more solvent molecules are incorporated into the crystal lattice of a crystalline solid. "solvate" includes both solvates in solution and separable solvates. Representative solvates include hydrates, ethanolates and methanolates.

The term "hydrate" refers to a compound that binds to water. Generally, the ratio of the number of water molecules contained in a hydrate of a compound to the number of molecules of the compound in the hydrate is determined. Thus, the hydrates of the compounds may be represented by, for example, the general formula R x H ₂ O, where R is the compound and x is a number greater than 0. A given compound may form more than one hydrate type, including, for example, monohydrate (x is 1), lower hydrate (x is a number greater than 0 and less than 1, e.g., hemihydrate (r.0.5H ₂ O)), and polyhydrate (x is a number greater than 1, e.g., dihydrate (r.2h ₂ O) and hexahydrate (r.6h ₂ O)).

The compounds of the present invention may be in amorphous or crystalline form (polymorphs). Furthermore, the compounds of the present invention may exist in one or more crystalline forms. Accordingly, the present invention includes within its scope all amorphous or crystalline forms of the compounds of the present invention. The term "polymorph" refers to a crystalline form (or salt, hydrate or solvate thereof) of a compound of a particular crystal stacking arrangement. All polymorphs have the same elemental composition. Different crystalline forms typically have different X-ray diffraction patterns, infrared spectra, melting points, densities, hardness, crystal shapes, optoelectronic properties, stability and solubility. Recrystallization solvent, crystallization rate, storage temperature, and other factors can lead to a crystalline form predominating. Various polymorphs of a compound can be prepared by crystallization under different conditions.

The invention also includes isotopically-labeled compounds, which are identical to those of the compounds of the present invention, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, and chlorine, such as ²H、³H、¹³C、¹¹C、¹⁴C、¹⁵N、¹⁸O、¹⁷O、³¹P、³²P、³⁵S、¹⁸F and ³⁶ Cl, respectively. The compounds of the invention, prodrugs thereof, and pharmaceutically acceptable salts of the compounds or prodrugs thereof, which contain the isotopes described above and/or other isotopes of other atoms, are within the scope of this invention. Certain isotopically-labeled compounds of the present invention, for example those into which radioactive isotopes (e.g., ³ H and ¹⁴ C) are introduced, are useful in drug and/or substrate tissue distribution assays. Tritium, i.e., ³ H, and carbon-14, i.e., ¹⁴ C isotopes are particularly preferred because they are easy to prepare and detect. Further, substitution with heavier isotopes, such as deuterium, i.e., ² H, may be preferred in some circumstances because greater metabolic stability may afford therapeutic benefits such as increased in vivo half-life or reduced dosage requirements. Isotopically-labeled compounds of formula (I) of the present invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the schemes and/or examples and preparations below by substituting a readily available isotopically-labeled reagent for a non-isotopically-labeled reagent.

In addition, prodrugs are also included within the context of the present invention. The term "prodrug" as used herein refers to a compound that is converted in vivo by hydrolysis, e.g. in blood, into its active form having a medical effect. Pharmaceutically acceptable prodrugs are described in t.higuchi and v.stilla, prodrugs as Novel DELIVERY SYSTEMS, A.C.S.SYMPOSIUM Series Vol.14,Edward B.Roche,ed.,Bioreversible Carriers in Drug Design,American Pharmaceutical Association and Pergamon Press,1987, and d.fleisher, s.ramon and H.Barbra"Improved oral drug delivery：solubility limitations overcome by the use of prodrugs",Advanced Drug Delivery Reviews(1996)19(2)115-130, each of which are incorporated herein by reference.

Prodrugs are any covalently bonded compounds of the invention which, when administered to a patient, release the parent compound in vivo. Prodrugs are typically prepared by modifying functional groups in such a way that the modification may be performed by conventional procedures or cleavage in vivo to yield the parent compound. Prodrugs include, for example, compounds of the invention wherein a hydroxy, amino, or sulfhydryl group is bonded to any group that, when administered to a patient, may cleave to form the hydroxy, amino, or sulfhydryl group. Representative examples of prodrugs therefore include, but are not limited to, acetate, formate and benzoate/amide derivatives of hydroxy, mercapto and amino functional groups of compounds of formula (I). In addition, in the case of carboxylic acid (-COOH), esters such as methyl ester, ethyl ester, and the like can be used. The esters themselves may be active and/or may be hydrolysed under in vivo conditions in the human body. Suitable pharmaceutically acceptable in vivo hydrolysable ester groups include those groups which readily decompose in the human body to release the parent acid or salt thereof.

Process for preparing compounds of the invention

The compounds of the present invention (including salts thereof) may be prepared using known organic synthesis techniques and may be synthesized according to any of a number of possible synthetic routes, such as those in the schemes below. The reaction for preparing the compounds of the present invention may be carried out in a suitable solvent, which may be readily selected by those skilled in the art of organic synthesis. Suitable solvents may be substantially unreactive with the starting materials (reactants), intermediates, or products at the temperature at which the reaction is carried out (e.g., at a temperature in the range of the solvent freezing temperature to the solvent boiling temperature). The given reaction may be carried out in one solvent or a mixture of more than one solvent. The skilled artisan can select the solvent for a particular reaction step depending on the particular reaction step.

The preparation of the compounds of the invention may involve protection and deprotection of different chemical groups. One skilled in the art can readily determine whether protection is desired and removal of the protection and selection of the appropriate protecting group. The chemical nature of the protecting groups can be found, for example, in Wuts and Greene, protective Groups in Organic Synthesis, 4 th edition, john Wiley & Sons: new Jersey, (2006), which is incorporated herein by reference in its entirety.

The compounds of the present invention can be prepared as individual stereoisomers thereof by reacting a racemic mixture of the compounds with an optically active resolving agent to form a pair of diastereoisomeric compounds, separating the diastereoisomers and recovering the optically pure enantiomer. Enantiomeric resolution may be carried out using diastereomeric derivatives of the compounds of the invention, preferably dissociable complexes (e.g., crystalline diastereomeric salts). Diastereomers have significantly different physical properties (e.g., melting point, boiling point, solubility, reactivity, etc.), and can be readily separated by the advantages of these dissimilarities. Diastereomers may be separated by chromatography, preferably by separation/resolution techniques based on differences in solubility. The optically pure enantiomer is then recovered by any practical means that does not racemize, along with the resolving agent. A more detailed description of techniques suitable for resolution of stereoisomers of compounds starting from racemic mixtures can be found in Jean Jacques, andre Collet, samue1h.wilen, "enantiomers, racemates and resolution" ("Enantiomers, RACEMATES AND resolution"), john Wiley And Sons, inc.

The reaction may be monitored according to any suitable method known in the art. For example, product formation may be monitored by spectroscopic means, such as Nuclear Magnetic Resonance (NMR) spectroscopy (e.g., ¹ H or ¹³ C), infrared (IR) spectroscopy, spectrophotometry (e.g., UV-visible), mass Spectrometry (MS)), or by chromatographic methods, such as High Performance Liquid Chromatography (HPLC) or Thin Layer Chromatography (TLC).

Pharmaceutical compositions, formulations and kits

In another aspect, the invention provides a pharmaceutical composition comprising a compound of the invention (also referred to as an "active ingredient") and a pharmaceutically acceptable excipient. In some embodiments, the pharmaceutical composition comprises an effective amount of an active ingredient. In some embodiments, the pharmaceutical composition comprises a therapeutically effective amount of an active ingredient. In some embodiments, the pharmaceutical composition comprises a prophylactically effective amount of the active ingredient.

Pharmaceutically acceptable excipients for use in the present invention refer to non-toxic carriers, adjuvants or vehicles that do not destroy the pharmacological activity of the co-formulated compounds. Pharmaceutically acceptable carriers, adjuvants or vehicles that can be used in the compositions of the invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins (e.g., human serum albumin), buffer substances (e.g., phosphates), glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes (e.g., protamine sulfate), disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, silica gel, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethyl cellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol, and lanolin.

The invention also includes kits (e.g., pharmaceutical packages). Kits provided can include a compound of the invention, other therapeutic agent, and first and second containers (e.g., vials, ampoules, bottles, syringes, and/or dispersible packages or other suitable containers) containing a compound of the invention, other therapeutic agent. In some embodiments, the provided kits may also optionally include a third container containing pharmaceutically acceptable excipients for diluting or suspending the compounds of the invention and/or other therapeutic agents. In some embodiments, the compounds of the invention and other therapeutic agents provided in the first and second containers are combined to form one unit dosage form.

The pharmaceutical compositions provided herein may be administered by a number of routes including, but not limited to: oral, parenteral, inhalation, topical, rectal, nasal, buccal, vaginal, by implantation or other means of administration. For example, parenteral administration as used herein includes subcutaneous, intradermal, intravenous, intramuscular, intraarticular, intraarterial, intrasynovial, intrasternal, intramuscularly, and intracranial injection or infusion techniques.

Typically, an effective amount of a compound provided herein is administered. The amount of the compound actually administered may be determined by a physician, according to the circumstances involved, including the condition being treated, the route of administration selected, the compound actually administered, the age, weight and response of the individual patient, the severity of the patient's symptoms, and the like.

When used to prevent a disorder of the present invention, a subject at risk of developing the disorder is administered a compound provided herein, typically based on physician recommendations and administered under the supervision of a physician, at a dosage level as described above. Subjects at risk for developing a particular disorder generally include subjects having a family history of the disorder, or those subjects determined by genetic testing or screening to be particularly susceptible to developing the disorder.

The pharmaceutical compositions provided herein may also be administered chronically ("chronically"). Chronic administration refers to administration of a compound or pharmaceutical composition thereof over a prolonged period of time, e.g., 3 months, 6 months, 1 year, 2 years, 3 years, 5 years, etc., or may continue administration indefinitely, e.g., for the remainder of the subject's life. In some embodiments, chronic administration is intended to provide a constant level of the compound in the blood over a prolonged period of time, e.g., within a therapeutic window.

Various methods of administration may be used to further deliver the pharmaceutical compositions of the present invention. For example, in some embodiments, the pharmaceutical composition may be administered as a bolus, e.g., in order to rapidly increase the concentration of the compound in the blood to an effective level. Bolus doses depend on the targeted systemic level of the active ingredient, e.g., intramuscular or subcutaneous bolus doses cause slow release of the active ingredient, whereas bolus injections delivered directly to veins (e.g., by IV intravenous drip) can be delivered more rapidly, causing the concentration of the active ingredient in the blood to rise rapidly to effective levels. In other embodiments, the pharmaceutical composition may be administered in the form of a continuous infusion, for example, by IV intravenous drip, thereby providing a steady state concentration of the active ingredient in the subject's body. Furthermore, in other embodiments, a bolus dose of the pharmaceutical composition may be administered first, followed by continuous infusion.

Oral compositions may take the form of bulk liquid solutions or suspensions or bulk powders. More typically, however, the compositions are provided in unit dosage form in order to facilitate accurate dosing. The term "unit dosage form" refers to physically discrete units suitable as unitary dosages for human patients and other mammals, each unit containing a predetermined quantity of active material suitable for producing the desired therapeutic effect in association with a suitable pharmaceutical excipient. Typical unit dosage forms include pre-filled, pre-measured ampoules or syringes of liquid compositions, or in the case of solid compositions, pills, tablets, capsules and the like. In such compositions, the compound is typically a minor component (about 0.1 to about 50 wt.%, or preferably about 1 to about 40 wt.%) with the remainder being various carriers or excipients and processing aids useful for forming the desired administration form.

For oral doses, a typical regimen is one to five oral doses per day, especially two to four oral doses, typically three oral doses. Using these modes of dosing, each dose provides from about 0.01 to about 20mg/kg of a compound of the invention, with preferred doses each providing from about 0.1 to about 10mg/kg, especially from about 1 to about 5mg/kg.

In order to provide similar blood levels to, or lower than, the use of an injected dose, a transdermal dose is typically selected in an amount of about 0.01 to about 20% by weight, preferably about 0.1 to about 10% by weight, and more preferably about 0.5 to about 15% by weight.

From about 1 to about 120 hours, especially 24 to 96 hours, the injection dosage level is in the range of about 0.1 mg/kg/hour to at least 10 mg/kg/hour. To achieve adequate steady state levels, a preloaded bolus of about 0.1mg/kg to about 10mg/kg or more may also be administered. For human patients of 40 to 80kg, the maximum total dose cannot exceed about 2 g/day.

Liquid forms suitable for oral administration may include suitable aqueous or nonaqueous carriers, buffers, suspending and dispersing agents, colorants, flavors, and the like. Solid forms may include, for example, any of the following components, or compounds having similar properties: binders, for example microcrystalline cellulose, gum tragacanth or gelatin; excipients, for example starch or lactose, disintegrants, for example alginic acid, primogel or corn starch; lubricants, for example, magnesium stearate; glidants, for example, colloidal silicon dioxide; sweeteners, for example, sucrose or saccharin; or a flavoring agent, for example, peppermint, methyl salicylate, or orange flavoring.

Injectable compositions are typically based on sterile saline or phosphate buffered saline for injectable use, or other injectable excipients known in the art. As previously mentioned, in such compositions, the active compound is typically a minor component, often about 0.05 to 10% by weight, the remainder being an injectable excipient or the like.

Transdermal compositions are typically formulated as topical ointments or creams containing the active ingredient. When formulated as ointments, the active ingredients are typically combined with a paraffinic or a water-miscible ointment base. Alternatively, the active ingredient may be formulated as a cream with, for example, an oil-in-water cream base. Such transdermal formulations are well known in the art and typically include other components for enhancing stable skin penetration of the active ingredient or formulation. All such known transdermal formulations and compositions are included within the scope provided by the present invention.

The compounds of the invention may also be administered via a transdermal device. Transdermal administration may thus be achieved using a reservoir (reservoir) or porous membrane type, or a variety of solid matrix patches.

The above components of the compositions for oral administration, injection or topical administration are merely representative. Other materials and processing techniques, etc. are set forth in Remington's Pharmaceutical Sciences, part 8 of 17th edition,1985,Mack Publishing Company,Easton,Pennsylvania, incorporated herein by reference.

The compounds of the present invention may also be administered in sustained release form, or from a sustained release delivery system. A description of representative sustained release materials can be found in Remington's Pharmaceutical Sciences.

The invention also relates to pharmaceutically acceptable formulations of the compounds of the invention. In one embodiment, the formulation comprises water. In another embodiment, the formulation comprises a cyclodextrin derivative. The most common cyclodextrins are α -, β -and γ -cyclodextrins consisting of 6, 7 and 8 α -1, 4-linked glucose units, respectively, optionally including one or more substituents on the linked sugar moiety, including but not limited to: methylated, hydroxyalkylated, acylated and sulfoalkyl ether substitutions. In some embodiments, the cyclodextrin is a sulfoalkyl ether β -cyclodextrin, e.g., sulfobutyl ether β -cyclodextrin, also known as Captisol. See, for example, U.S.5,376,645. In some embodiments, the formulation comprises hexapropyl- β -cyclodextrin (e.g., 10-50% in water).

Indication of disease

In another aspect, there is provided a compound of formula (I) as disclosed herein (including all individual embodiments and subsets of the classes disclosed herein) or a tautomer, stereoisomer, prodrug, crystal form, pharmaceutically acceptable salt, hydrate or solvate thereof, having valuable pharmacological properties and which is found to enhance the inclusion of exon 7 of SMN1 and/or SMN2 into mRNA transcribed from the SMN1 and/or SMN2 gene, thereby increasing the expression of SMN protein in a human subject in need thereof.

The compounds of the invention may be used alone or in combination with other drugs for the treatment or prevention of diseases caused by inactivating mutations or deletions of the SMN1 gene and/or associated with loss of function or deficiency of the SMN1 gene. These diseases include, but are not limited to, spinal Muscular Atrophy (SMA).

The compounds of the invention may be used alone or in combination with other drugs to treat or prevent Spinal Muscular Atrophy (SMA). Treating SMA includes one or more of the following effects: (1) reducing or improving the severity of SMA; (2) delaying the onset of SMA; (3) inhibiting SMA progression; (4) reducing admission of the subject; (5) reducing the length of time for admission to the subject; (6) increasing survival of the subject; (7) improving the quality of life of the subject; (8) reducing the number of SMA-related symptoms; (9) Reducing or ameliorating the severity of one or more symptoms associated with SMA; (9) inhibiting the development or onset of SMA symptoms; and/or (10) inhibit progression of symptoms associated with SMA.

Symptoms of SMA include muscle weakness, low muscle tension, crying weakness, cough weakness, lameness or tendency to fall, sucking or dysphagia, dyspnea, accumulation of secretions in the lungs or throat, fist held with a sweaty hand, tongue tremor/vibration, frequent tendency to one side of the head (even when lying down), tendency to be weaker than the legs of the arms, frequent legs in the "frog leg" position, difficulty feeding, increased sensitivity to respiratory tract infections, bowel/bladder weakness, less than normal body weight, inability to sit unsupported, inability to walk, inability to crawl, hypotonia, loss of reflex and associated multiple congenital contractures (joint contractures) of the anterior horn cell loss.

The compounds of the invention may be used alone or in combination with other drugs to treat SMA, with one or more of the following beneficial effects: (1) reducing muscle strength injury; (2) increasing muscle strength; (3) reducing muscle atrophy; (4) reducing loss of motor function; (5) increasing motor neurons; (6) reducing motor neuron loss; (7) protecting SMA-deficient motor neurons from degeneration; (8) enhancing athletic performance; (9) increase lung function; and/or (10) reduce loss of lung function.

Examples

The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. The experimental methods, in which specific conditions are not noted in the following examples, are generally conducted under conventional conditions or under conditions recommended by the manufacturer. Parts and percentages are parts by weight and percentages by weight unless otherwise indicated.

Abbreviations:

Pd (dppf) Cl ₂: [1,1' -bis (triphenylphosphine) ferrocene ] palladium dichloride

Pd (OAc) ₂ palladium acetate

PCy ₃: tricyclohexylphosphorus

TsCl: para-toluenesulfonyl chloride

KOAc: potassium acetate

Isopropyl acetate: acetic acid isopropyl ester

TFA: trifluoroacetic acid

DMSO: dimethyl sulfoxide

DMF: n, N-dimethylformamide

EA: acetic acid ethyl ester

Xylene: xylene (P)

MeOH: methanol

Dioxide:1, 4-Dioxahexacyclic ring

DCM: dichloromethane (dichloromethane)

Preparation of intermediate compound A-17- (4-oxo-2- (p-toluenesulfonyloxy) -4H-pyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester

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The following synthetic route was adopted

Step 1 Synthesis of the Compound 7- (6-nitropyridin-3-yl) -4, 7-diazaspiro [2.5] oct-4-carboxylic acid tert-butyl ester

5-Bromo-2-nitropyridine (2.0 g,10 mmol) and tert-butyl 4, 7-diazaspiro [2.5] octa-4-carboxylate (2.23 g,10.5 mmol) were dissolved in 10ml dimethyl sulfoxide, lithium chloride (1.47 g,35 mmol) and tetramethylguanidine (4.4 ml,35 mmol) were added sequentially, the reaction solution was heated to 80℃under nitrogen protection and stirred overnight, TLC monitoring was completed, cooled to room temperature, the reaction solution was slowly added dropwise to ice water, a pale yellow solid was precipitated, filtered, and the filter cake was dried in vacuo to give a yellow solid 2.76g, yield 82.6%. LC-MS (APCI): M/z=335.1 (m+1) ⁺.

Step 2 Synthesis of the Compound 7- (6-aminopyridin-3-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester

7- (6-Nitropyridin-3-yl) -4, 7-diazaspiro [2.5] octane-4-carboxylic acid tert-butyl ester (2.76 g,8.26 mmol) obtained in the previous step was placed in a 100ml flask, 10ml ethyl acetate and 10ml methanol were added for dissolution, 10% wt Pd/C (300 mg) was added under nitrogen protection, three times replaced with hydrogen, stirred at room temperature for 2-4 hours, TLC monitored the reaction was complete, celite was used for filtration, and the filtrate was concentrated to dryness. 2.55g of crude product was obtained and was directly fed to the next reaction without purification. LC-MS (APCI): M/z=305.4 (m+1) ⁺.

Step 3 Synthesis of the Compound 7- (2-hydroxy-4-oxo-4H-pyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octane-4-carboxylic acid tert-butyl ester

7- (6-Aminopyridin-3-yl) -4, 7-diazaspiro [2.5] octyl-4-carboxylate (2.0 g,6.58 mmol) and bis (2, 4, 6-trichlorophenyl) malonate (3.66 g,7.89 mmol) were added to the reaction flask, the reaction mixture was heated to 150℃with the addition of 25ml of xylene and stirred for 1-2 hours under nitrogen protection, TLC monitoring was completed, cooling to room temperature to precipitate a pale yellow solid, filtration, washing the filter cake with a small amount of ethyl acetate, and vacuum drying gave 1.92g of solid, yield 78.4%. LC-MS (APCI) M/z=373.4 (M+1) ⁺.

Step 4 Synthesis of intermediate Compound A-1

7- (2-Hydroxy-4-oxo-4H-pyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octane-4-carboxylic acid tert-butyl ester (1.12 g,3.0 mmol) was dissolved in 40ml of anhydrous dichloromethane, triethylamine (0.54 ml,3.9 mmol) was added thereto under nitrogen protection, tsCl (0.63 g,3.3 mmol) was added thereto in portions, and the reaction was stirred at room temperature for 2 to 4 hours after the addition, and the completion of the reaction was monitored by TLC. 30ml of water is added for quenching reaction, dichloromethane is used for extraction for 3-4 times, the organic phases are combined, saturated saline water is used for washing, anhydrous sodium sulfate is used for drying, filtration is carried out, filtrate is concentrated, and silica gel column chromatography is used for purifying to obtain 1.4g of product, the yield is: 88.7%. LC-MS (APCI): M/z= 527.8 (m+1) ⁺.

Preparation of intermediate B-1 2-methyl-8- (methyl-d ₃) -6- (4, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) imidazo [1,2-B ] pyridazine

The following synthetic route was adopted

Step 1 Synthesis of the Compound 4-bromo-6-chloropyridazine-3-amine

6-Chloropyridazine-3-ammonia (4.0 g,31 mmol), sodium acetate (2.03 g,24.8 mmol) and acetic acid (0.5 g,8.27 mmol) were placed in a 100ml flask, 40ml methanol was added, 1, 3-dibromo-5, 5-dimethylhydantoin (5.3 g,18.5 mmol) was added in portions, stirred overnight at room temperature, TLC monitored, cooled to 0 ℃, quenched by slowly adding 10ml of saturated aqueous sodium sulfite solution, concentrated to remove methanol, diluted with a small amount of water, adjusted to pH 7-8 with 1N sodium hydroxide, a pale yellow solid was precipitated, filtered, the filter cake was washed with water, and 4.5g of the target product was obtained after vacuum drying, yield: 70.1% of the reaction mixture was directly fed to the next reaction without purification. LC-MS (APCI): M/z=208.1 (m+1) ⁺.

Step 2 Synthesis of 6-chloro-4- (methyl-d ₃) pyridazine-3-amine as Compound

4-Bromo-6-chloropyridazine-3-ammonia (2.07 g,10 mmol) obtained in the above step was dissolved in 100ml of anhydrous THF, deuterated methyl magnesium iodide (27 ml,27 mmol) was slowly added dropwise under nitrogen protection, a solution of zinc chloride in 2-methyltetrahydrofuran (2.5 ml,5 mmol) and tetrakis (triphenylphosphine) palladium (116 mg,0.1 mmol) were sequentially added after the addition, and the reaction was stirred for 4-6 hours at 50℃with heating to complete the TLC. The reaction solution was cooled to room temperature, quenched by adding 50ml of saturated ammonium chloride, extracted 3-4 times with ethyl acetate, combined with organic phases, concentrated and purified by silica gel column chromatography to obtain 1.34g of the product, yield: 44.3%. LC-MS (APCI) M/z=147.5 (M+1) ⁺.

Step 3 Synthesis of the Compound 6-chloro-2-methyl-8- (methyl-d ₃) imidazo [1,2-b ] pyridazine

6-Chloro-4- (methyl-d ₃) pyridazine-3-ammonia (194 mg,1.33 mmol) was dissolved in 10ml anhydrous DMF, heated to 100deg.C, and bromoacetone (200 mg,1.46 mmol) was slowly added dropwise to 3ml DMF solution, and the reaction was stirred for 2-3 hours at 110deg.C under nitrogen protection, and TLC monitoring the reaction was complete. After cooling to room temperature, the reaction was quenched by adding 10ml of saturated aqueous sodium bicarbonate, extracted 3-4 times with ethyl acetate, the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and separated by a silica gel column to give 140mg of solid in 57.1% yield. LC-MS (APCI): M/z=185.5 (m+1) ⁺.

Step 4 Synthesis of intermediate Compound B-1

6-Chloro-2-methyl-8- (methyl-d ₃) imidazo [1,2-b ] pyridazine (90 mg,0.5 mmol), pinacol biborate (380 mg,1.5 mmol), pd (OAc) ₂(6mg,0.025mmol)、PCy₃ (14 mg,0.05 mmol) and potassium acetate (100 mg,1.0 mmol) were added to a 20ml microwave tube, 8ml isopropyl acetate was added under nitrogen protection, the reaction was carried out after sealing by microwave heating to 80℃for 1 hour, TLC was monitored to complete the reaction, the solvent was removed by concentration after cooling to room temperature, and silica gel column chromatography was purified to give 108mg solid, yield: 79.1%. LC-MS (APCI): M/z=277.2 (m+1) ⁺.

Preparation of intermediate B-28-methyl-2- (methyl-d ₃) -6- (4, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) imidazo [1,2-B ] pyridazine

The following synthetic route was adopted

Step 1 Synthesis of Compound 1-bromopropane-2-one-1, 3-d ₅

Deuterated acetone (5 g,78.1 mmol) was added to 100ml methanol, cooled to 0 ℃, and a dioxane complex of bromine (19.4 g,78.1 mmol) was added in portions, stirred under ice bath for 3-4 hours, after the reaction was monitored by GC, 80ml water was added for quenching reaction, 80ml diethyl ether was used for extraction 3-4 times, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated at low temperature to remove the solvent to obtain crude product, which was directly put into the next reaction without purification.

Step 2: synthesis of 6-chloro-4-methylpyridazine-3-ammonia as Compound

1-Bromopropane-2-one-1, 3-d ₅ (2.07 g,10 mmol) was dissolved in 100ml anhydrous THF, methyl magnesium iodide (27 ml,27 mmol) was slowly added dropwise under nitrogen protection, a solution of zinc chloride in 2-methyltetrahydrofuran (2.5 ml,5 mmol) and tetrakis (triphenylphosphine) palladium (116 mg,0.1 mmol) were sequentially added after the addition, the temperature was raised to 50℃and the reaction was stirred for 4-6 hours, and TLC was monitored to complete the reaction. The reaction solution was cooled to room temperature, quenched by adding 50ml of saturated ammonium chloride, extracted 3-4 times with ethyl acetate, combined with organic phases, concentrated and purified by silica gel column chromatography to obtain 1.18g of the product, yield: 39.0%. LC-MS (APCI): M/z=144.2 (m+1) ⁺.

Step 3: synthesis of Compound 6-chloro-8-methyl-2- (methyl-d ₃) imidazo [1,2-b ] pyridazine

6-Chloro-4-methylpyridazine-3-ammonia (194 mg,1.34 mmol) was dissolved in 10ml of anhydrous DMF, heated to 100deg.C, 3ml of DMF solution of 1-bromopropane-2-one-1, 3-d ₅ (200 mg,1.40 mmol) was slowly added dropwise, and the reaction was stirred for 2-3 hours while heating to 110deg.C under nitrogen protection, and TLC monitored the reaction. After cooling to room temperature, the reaction was quenched by adding 10ml of saturated aqueous sodium bicarbonate, extracted 3-4 times with ethyl acetate, the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and separated by a silica gel column to give 152mg of solid in 61.9% yield. LC-MS (APCI): M/z=185.5 (m+1) ⁺.

Step 4: synthesis of intermediate compound B-2

6-Chloro-8-methyl-2- (methyl-d ₃) imidazo [1,2-b ] pyridazine (90 mg,0.5 mmol), pinacol biborate (380 mg,1.5 mmol), pd (OAc) ₂(6mg,0.025mmol)、PCy₃ (14 mg,0.05 mmol) and potassium acetate (100 mg,1.0 mmol) were added to a 20ml microwave tube, 8ml isopropyl acetate was added under nitrogen protection, the reaction was carried out after sealing by microwave heating to 80℃for 1 hour, TLC was monitored to complete the reaction, the solvent was removed by concentration after cooling to room temperature, and silica gel column chromatography was purified to give 111mg solid, yield: 81.3 percent. LC-MS (APCI): M/z=277.2 (m+1) ⁺.

Preparation of intermediate compound B-2, 8-bis (methyl-d ₃) -6- (4, 5-tetramethyl-1, 3, 2-dioxaborolan-2-yl) imidazo [1,2-B ] pyridazine

The following synthetic route was adopted

Step 1 Synthesis of 6-chloro-4- (methyl-d ₃) pyridazine-3-amine as Compound

4-Bromo-6-chloropyridazine-3-ammonia (2.07 g,10 mmol) was dissolved in 100ml of anhydrous THF, deuterated methyl magnesium iodide (27 ml,27 mmol) was slowly added dropwise under nitrogen protection, and after the addition, zinc chloride in 2-methyltetrahydrofuran (2.5 ml,5 mmol) and tetrakis (triphenylphosphine) palladium (116 mg,0.1 mmol) were sequentially added, and the temperature was raised to 50℃and stirred for 4-6 hours, after which the reaction was monitored by TLC. The reaction solution was cooled to room temperature, quenched by adding 50ml of saturated ammonium chloride, extracted 3-4 times with ethyl acetate, combined with organic phases, concentrated and purified by silica gel column chromatography to obtain 1.32g of the product, yield: 43.6%. LC-MS (APCI): M/z=144.2 (m+1) ⁺.

Step 2 Synthesis of the Compound 6-chloro-2, 8-bis (methyl-d ₃) imidazo [1,2-b ] pyridazine

6-Chloro-4- (methyl-d ₃) pyridazine-3-ammonia (194 mg,1.32 mmol) was dissolved in 10ml anhydrous DMF, heated to 100deg.C, 3ml DMF solution of 1-bromopropane-2-one-1, 3-d ₅ (200 mg,1.40 mmol) was slowly added dropwise, the temperature was raised to 110deg.C under nitrogen protection, stirred for 2-3 hours, and TLC monitored the reaction was completed. After cooling to room temperature, the reaction was quenched by adding 10ml of saturated aqueous sodium bicarbonate, extracted 3-4 times with ethyl acetate, the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and separated by a silica gel column to give 163mg of solid with a yield of 66.4%. LC-MS (APCI) M/z=188.5 (M+1) ⁺.

Step 3 Synthesis of intermediate Compound B-3

6-Chloro-2, 8-bis (methyl-d ₃) imidazo [1,2-b ] pyridazine (90 mg,0.5 mmol), pinacol biborate (380 mg,1.5 mmol), pd (OAc) ₂(6mg,0.025mmol)、PCy₃ (14 mg,0.05 mmol) and potassium acetate (100 mg,1.0 mmol) were added to a 20ml microwave tube, 8ml isopropyl acetate was added under nitrogen protection, the reaction was carried out after sealing by microwave heating to 80℃for 1 hour, TLC was monitored to complete the reaction, the solvent was removed by concentration after cooling to room temperature, and silica gel column chromatography was purified to give 95mg solid, yield: 69.6%. LC-MS (APCI): M/z=280.2 (m+1) ⁺.

Example 1 7- (4, 7-diazaspiro [2.5] oct-7-yl) -2- (2-methyl-8- (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) pyrido [1,2-a ] pyrimidin-4-one (Compound T-1) preparation

The following synthetic route was adopted

Step 1 Synthesis of the Compound 7- (2- (2-methyl-8- (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester

Intermediate compound a-1 (90 mg,0.17 mmol) and intermediate compound B-1 (52 mg,0.19 mmol) were added to 10ml acetonitrile and 2ml water, pd (dppf) Cl ₂ (12 mg,0.017 mmol) and potassium carbonate (47 mg,0.34 mmol) were added under nitrogen, heated to 80 ℃ and stirred overnight, after TLC monitoring the reaction, cooled to room temperature and concentrated to remove solvent, and purified by silica gel column chromatography to give 69mg of solid, yield: 81.1%. LC-MS (APCI): M/z=505.2 (m+1) ⁺.

Step 2 Synthesis of Compound T-1

7- (2- (2-Methyl-8- (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] oct-4-carboxylic acid tert-butyl ester (69 mg,0.14 mmol) obtained in the above step was added to 5ml of dichloromethane, TFA (0.2 ml,2.8 mmol) was added, the reaction was stirred at room temperature for 0.5-1 hour, TLC was monitored to complete the reaction, 10ml of dichloromethane was added to dilute, and the mixture was washed 2-3 times with 20ml of saturated aqueous sodium bicarbonate solution and saturated brine in sequence, and the organic phase was concentrated and purified by column chromatography on silica gel to give 48mg of off-white solid in yield ：87.2％.LC-MS(APCI):m/z＝405.5(M+1)⁺.¹H NMR(400MHz,CDCl₃)δ8.45(d,J＝2.4Hz,1H),7.92(d,J＝1.0Hz,1H),7.73(d,J＝9.6Hz,1H),7.80(s,1H),7.70(dd,J＝9.7,2.5Hz,1H),7.38(s,1H),3.31-3.22(m,2H),3.20-3.16(m,2H),3.08(s,2H),2.55(s,3H),1.68(br s,1H),0.77-0.75(m,2H),0.67-0.64(m,2H).

Example 2 7- (4, 7-diazaspiro [2.5] oct-7-yl) -2- (8-methyl-2- (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) pyrido [1,2-a ] pyrimidin-4-one (Compound T-2) preparation

The following synthetic route was adopted

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Step 1 Synthesis of the Compound 7- (2- (2- (methyl-d ₃) -8-methylimidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester

Intermediate compound a-1 (90 mg,0.17 mmol) and intermediate compound B-2 (52 mg,0.19 mmol) were added to 10ml acetonitrile and 2ml water, pd (dppf) Cl ₂ (12 mg,0.017 mmol) and potassium carbonate (47 mg,0.34 mmol) were added under nitrogen, heated to 80 ℃ and stirred overnight, after TLC monitoring the reaction, cooled to room temperature and concentrated to remove solvent, and purified by silica gel column chromatography to give 74mg of solid, yield: 87.0%. LC-MS (APCI): M/z=505.2 (m+1) ⁺.

Step 2 Synthesis of Compound T-2

7- (2- (2- (Methyl-d ₃) -8-methylimidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester (74 mg,0.15 mmol) obtained in the above step was added to 5ml of methylene chloride, TFA (0.2 ml,2.8 mmol) was added, stirred at room temperature for 0.5 to 1 hour, TLC was monitored to complete the reaction, 10ml of methylene chloride was added to dilute, and the mixture was washed 2 to 3 times with 20ml of saturated aqueous sodium bicarbonate solution and saturated brine in sequence, and the organic phase was concentrated and purified by silica gel column chromatography to give 51mg of an off-white solid in yield ：92.6％.LC-MS(APCI):m/z＝405.5(M+1)⁺.¹H NMR(400MHz,CDCl₃)δ8.46(d,J＝2.4Hz,1H),7.94(d,J＝1.0Hz,1H),7.73(d,J＝9.6Hz,1H),7.81(s,1H),7.73(dd,J＝9.7,2.5Hz,1H),7.38(s,1H),3.31-3.22(m,2H),3.20-3.16(m,2H),3.09(s,2H),2.74(d,J＝0.9Hz,3H),1.69(br s,1H),0.77-0.75(m,2H),0.68-0.64(m,2H).

Example 3 7- (4, 7-diazaspiro [2.5] oct-7-yl) -2- (2, 8-bis (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) pyrido [1,2-a ] pyrimidin-4-one (Compound T-3) preparation

The following synthetic route was adopted

Step 1 Synthesis of the Compound 7- (2, 8-bis (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] octa-4-carboxylic acid tert-butyl ester

Intermediate compound a-1 (90 mg,0.17 mmol) and intermediate compound B-2 (52 mg,0.19 mmol) were added to 10ml acetonitrile and 2ml water, pd (dppf) Cl ₂ (12 mg,0.017 mmol) and potassium carbonate (47 mg,0.34 mmol) were added under nitrogen protection, heated to 80 ℃ and stirred overnight for reaction, after TLC monitoring the reaction, cooled to room temperature and concentrated to remove solvent, silica gel column chromatography purification gave 58mg of solid, yield: 68.2%. LC-MS (APCI): M/z=508.2 (m+1) ⁺.

Step 2 Synthesis of Compound T-3

7- (2, 8-Bis (methyl-d ₃) imidazo [1,2-b ] pyridazin-6-yl) -4-oxopyrido [1,2-a ] pyrimidin-7-yl) -4, 7-diazaspiro [2.5] oct-4-carboxylic acid tert-butyl ester (58 mg,0.12 mmol) obtained in the above step was added to 5ml of dichloromethane, TFA (0.2 ml,2.8 mmol) was added, the reaction was stirred at room temperature for 0.5-1 hour, TLC was monitored to complete the reaction, 10ml of dichloromethane was added to dilute, and washing with 20ml of saturated aqueous sodium bicarbonate solution and saturated saline was sequentially carried out for 2-3 times, the organic phase was concentrated and purified by silica gel column chromatography to give 35mg of off-white solid in yield ：63.5％.LC-MS(APCI):m/z＝408.5(M+1)⁺.¹H NMR(400MHz,CDCl₃):δ8.45(d,J＝2.4Hz,1H),7.93(d,J＝1.0Hz,1H),7.74(d,J＝9.6Hz,1H),7.81(s,1H),7.70(dd,J＝9.7,2.5Hz,1H),7.39(s,1H),3.30-3.22(m,2H),3.20-3.16(m,2H),3.08(s,2H),1.69(br s,1H),0.78-0.75(m,2H),0.68-0.62(m,2H).

Biological activity testing.

(1) Evaluation of Metabolic stability

Metabolic stability is generally used to describe the rate and extent to which a compound is metabolized and is one of the primary factors affecting pharmacokinetic properties. Many compounds are substrates for CYP450 enzymes and other drug metabolizing enzymes, and liver microsomes are CYP 450-rich systems, and the aim of this experiment was to conduct in vitro stability studies by incubating the compounds of the invention with human and SD rat liver microsomes, respectively, and using LC-MS/MS to detect the remaining proportion of the compounds.

① Preparation of the solution

Phosphate Buffer (PBS): 150mL of a pre-prepared KH ₂PO₄ (0.5M) solution and 700mL of a K ₂HPO₄ (0.5M) solution were mixed, the pH of the mixture was adjusted to 7.4 with a K ₂HPO₄ (0.5M) solution, and the mixture was stored at 4℃as 5-fold concentration PBS for use. Before use, the solution was diluted 5-fold with ultrapure water, and 3.3mM magnesium chloride was added to obtain phosphate buffer PBS (100 mM).

NADPH regeneration system solution: NADPH solution containing 6.5mM NADP,16.5mM G-6-P,3U/mL G-6-P D was formulated with 5mL PBS.

Internal standard stop solution: propranolol hydrochloride (50 ng/mL) and tolbutamide (200 ng/mL) were prepared with acetonitrile as internal standard working solutions.

Human liver microsomal solution: 0.31mL of human liver microsome (25 mg/mL) was added to 0.961mL of PBS (pH 7.4) and mixed to obtain a human liver microsome dilution with a protein concentration of 0.625 mg/mL.

SD rat liver microsomal solution: 0.31mLSD rat liver microsomes (25 mg/mL) were added to 0.961mL PBS (pH 7.4) and mixed to obtain SD rat liver microsome dilution with a protein concentration of 0.625 mg/mL.

Sample working solution: the compound of the present invention and non-deuterated compound powder, positive control dextromethorphan powder and omeprazole powder were formulated with DMSO to 10mM as sample stock solutions. Then, the mixture was diluted with 70% acetonitrile-water to obtain a 0.25mM sample working solution.

② Sample incubation

398 Μl of human liver microsome dilution was added to 96 Kong Fuyo plates (n=2), and 2 μl of 0.25mM test compound and dextromethorphan were added, respectively, and mixed well.

398 Μl of SD rat liver microsome dilution was added to 96 Kong Fuyo plates (N=2), and 2 μl of 0.25mM test compound and omeprazole were added, respectively, and mixed well.

Each well was filled with 300. Mu.L of pre-chilled stop solution into a 96-well deep well plate and placed on ice as a stop plate.

The 96 Kong Fuyo plates and NADPH regeneration system were placed in a 37℃water bath, shaken at 100 revolutions per minute, and pre-incubated for 5min. 80. Mu.L of the incubation solution was removed from each well of the incubation plate, added to the termination plate, mixed well, and supplemented with 20. Mu.L of NADPH regeneration system solution as a 0min sample. Then 80. Mu.L of NADPH regeneration system solution was added to each well of the incubation plate, the reaction was started and timing was started. The reaction concentration of the compound to be tested is 1 mu M, and the protein concentration is 0.5mg/mL.

100. Mu.L of each reaction solution was added to the termination plate at 10, 30 and 90min, and the reaction was terminated by vortexing for 3 min.

The final plates were centrifuged at 5000rpm at 4℃for 15min. 200. Mu.L of the supernatant was mixed with a 96-well plate to which 200. Mu.L of ultrapure water had been added in advance, and the mixture was analyzed by LC-MS/MS to obtain a sample of 10. Mu.L.

③ Sample analysis method

The LC-MS/MS system is used in the experiment to detect the peak areas of the compound to be detected, dextromethorphan, omeprazole and an internal standard, and the ratio of the peak areas of the compound to the internal standard is calculated.

④ Data processing

The peak areas of the sample and the internal standard are obtained by a mass spectrometer and analysis software, and a single-exponential degradation model of GRAPHPAD PRISM 7.0.0 software is used for plotting the residual amount (R%) of the compound with time to obtain a substrate elimination rate constant K

Ct/C0＝exp(-K*t)

And half-life T _1/2 and intrinsic clearance CL _int were calculated according to the following formulas, where V/M is equal to 1/C (protein).

t_1/2(min);CL_int(μL/min/mg)。

Experimental results: the compounds of the present invention and their non-deuterated compounds were simultaneously tested and compared to evaluate their metabolic stability in human and SD rat liver microsomes. The compounds of the invention have a longer half-life T _1/2 and lower clearance CL _int than non-deuterated compounds, which can significantly improve metabolic stability. The results of the compounds of the examples are summarized in Table 1 below.

TABLE 1

(2) Rat pharmacokinetic experiments

6 Male Sprague-Dawley rats, 7-8 weeks old, weighing about 210g, were divided into 2 groups of 3 animals each, and their pharmacokinetic differences were compared by intravenous or oral administration of a single dose of the compound (oral administration 10 mg/kg).

Rats were fed with standard feed and given water. Fasted food was started 16 hours prior to the trial. The drug was dissolved with 10mM ascorbic acid/0.01 mg/mL sodium thiosulfate pentahydrate. The eyebox was sampled at 0.083 hours, 0.25 hours, 0.5 hours, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 12 hours and 24 hours post-administration.

Rats were briefly anesthetized after inhalation of diethyl ether and 300 μl of blood was collected from the orbit in a tube. There was 30. Mu.L of 1% heparin salt solution in the tube. Before use, the tube was baked overnight at 60 ℃. After blood collection was completed at the last time point, rats were sacrificed after ether anesthesia.

Immediately after blood sample collection, the tube was gently inverted at least 5 times, ensuring that the mix was well placed on ice. The blood sample was centrifuged at 5000rpm at 4℃for 5 minutes to separate the plasma from the erythrocytes. 100. Mu.L of plasma was aspirated with a pipette into a clean plastic centrifuge tube, indicating the name and time point of the compound. Plasma was stored at-80 ℃ prior to analysis. The concentration of the compounds of the invention in plasma was determined by LC-MS/MS. Pharmacokinetic parameters were calculated based on the blood concentration of each animal at different time points.

Experiments show that the compound has better pharmacokinetic properties in animals, thus having better pharmacodynamics and treatment effect. The results of the compounds of the examples are summarized in Table 2 below.

TABLE 2

The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.

Claims (11)

1. A compound of formula (I), or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof:

Wherein,

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ And R ₁₆ are each independently selected from hydrogen, deuterium, halogen, or trifluoromethyl;

X ₁ and X ₂ are each independently selected from CH ₃、CD₃、CHD₂ or CH ₂ D;

with the proviso that the above-mentioned compounds contain at least one deuterium atom.

2. The compound of claim 1, wherein ,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are each independently selected from hydrogen or deuterium.

3. The compound of claim 1 or 2, wherein R ₁、R₂、R₃、R₄、R₅ and R ₆ are hydrogen.

4. A compound according to any one of claims 1-3, wherein R ₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅ and R ₁₆ are hydrogen.

5. The compound of any one of claims 1-4, wherein X ₁ is CD ₃ or CH ₃.

6. The compound of any one of claims 1-5, wherein X ₁ is CD ₃.

7. The compound of any one of claims 1-6, wherein X ₂ is CD ₃ or CH ₃.

8. The compound of any one of claims 1-7, wherein X ₂ is CD ₃.

9. The compound of claim 1, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal form, hydrate, or solvate thereof, wherein the compound is selected from the group consisting of:

10. A pharmaceutical composition comprising a pharmaceutically acceptable excipient and a compound of any one of claims 1-9, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystal, hydrate, or solvate thereof.

11. Use of a compound according to any one of claims 1-9, or a pharmaceutically acceptable salt, tautomer, stereoisomer, prodrug, crystalline form, hydrate, or solvate thereof, or a pharmaceutical composition according to claim 10, for the manufacture of a medicament for the treatment and/or prevention of Spinal Muscular Atrophy (SMA) disease.