CN115703792B - Tricycle derivative and preparation method and medical application thereof - Google Patents

Abstract

The invention belongs to the technical field of chemical medicaments, and relates to a compound shown in a general formula (I), or a tautomer, a meso form, a racemic form, an enantiomer, a diastereomer or a mixture thereof or pharmaceutically acceptable salt thereof, a preparation method and application thereof in medicines. These compounds are agonists of the glucagon-like peptide-1 receptor (GLP-1R). The invention also relates to a pharmaceutical composition containing the compounds and application of the compounds in medicines for treating diseases such as diabetes and the like.

Description

A tricyclic derivative and its preparation method and medical use

Technical Field

The present invention belongs to the technical field of chemical medicines, and provides a series of agonists of glucagon-like peptide-1 receptor (GLP-1R). The present invention also relates to pharmaceutical compositions containing these compounds and the use of the compounds in medicines for treating diseases such as diabetes.

Background Art

Diabetes affects millions of people worldwide and is considered one of the leading threats to human mortality in the 21st century. Over time, uncontrolled diabetes can damage body systems, including the heart, blood vessels, eyes, kidneys, and nerves. The socioeconomic burden of diabetes is high worldwide.

There are two main types of diabetes, named type I and type II, of which type II diabetes (T2DM) accounts for more than 90% of all diabetes worldwide. Type I diabetes is characterized by insulin deficiency, mainly caused by autoimmune-mediated destruction of pancreatic β cells, and type II diabetes is characterized by abnormal insulin secretion and subsequent insulin resistance. To prevent ketoacidosis, patients with type I diabetes must take exogenous insulin to survive. Although patients with type II diabetes are not as dependent on exogenous insulin as patients with type I diabetes, they may need exogenous insulin to control blood sugar levels.

Glucagon-like peptide-1 (GLP-1) is a type of incretin secreted by intestinal epithelial L cells and exerts physiological effects by binding to its receptor. GLP-1 receptor (GLP-1R) belongs to the G protein-coupled receptor subfamily. When GLP-1 binds to the GLP-1 receptor, it triggers a series of biological effects. Studies have shown that GLP-1 promotes insulin secretion in a glucose-dependent manner, that is, when the blood glucose concentration in the human body increases, GLP-1 stimulates pancreatic cells, increases insulin secretion, and lowers blood sugar. GLP-1 receptor agonists are a new type of hypoglycemic drug that can effectively control blood sugar levels without causing hypoglycemia; they can also effectively reduce body weight by increasing satiety, delaying gastric emptying, suppressing appetite, and reducing fat accumulation, thereby achieving the purpose of weight loss.

At present, peptide drugs based on GLP-1 receptor agonists such as liraglutide, exenatide, and semaglutide have been used in obese patients with type II diabetes and simple obese or overweight patients, and have shown a significant effect in reducing body weight, but are often accompanied by gastrointestinal adverse reactions such as nausea and vomiting. Oral non-peptide drugs have always been the drugs that research institutions have tried to use for the treatment of type II diabetes and weight loss, but because small molecules are difficult to simulate the interaction between receptors and peptides, the discovery of small molecule drugs for glucagon-like peptide-1 receptors is limited.

At present, the patent applications for non-peptide GLP-1 receptor agonists are WO2009/111700, WO2010/114824, WO2011/114271, WO2013/090454, WO2018/056453, WO2018/109607, WO2019239319, WO2019239371, WO2020103815, etc. Among them, only vTv's TTP-273 and Pfizer's PF-06882961 have entered the Phase II clinical study.

Therefore, the present invention aims to discover new non-peptide GLP-1 receptor agonists, especially new compounds with good biological properties that can be safely applied to the human body. The present invention also provides the necessary tools for preventing and/or treating GLP-1 related diseases, especially diabetes related diseases.

Summary of the invention

The present invention provides a series of tricyclic derivatives, preparation methods thereof and medical applications thereof.

Specifically, the present invention provides compounds represented by general formula (I), or tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof, wherein all variables are as defined herein.

These compounds are agonists of glucagon-like peptide 1 receptor (GLP-1R). The present invention also relates to pharmaceutical compositions containing these compounds and the use of the compounds in drugs for treating diseases such as diabetes.

Specifically, the present invention is implemented through the following technical solutions:

The compound represented by general formula (I), or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof or pharmaceutically acceptable salt thereof:

in:

A is selected from an aromatic ring, a heteroaromatic ring, and an 8- to 10-membered fused aromatic ring;

B is selected from a non-aromatic 6- to 8-membered ring;

R ¹ is selected from hydrogen, halogen, cyano, alkyl, alkoxy, haloalkyl, haloalkoxy, alkoxyalkyl, cycloalkyl, heterocycloalkyl, alkyl substituted with one or more R ⁷ , aryl substituted with one or more R ⁸ , and heteroaryl;

m is 0, 1, 2 or 3;

W is selected from O or NH;

^R2 is selected from hydrogen, halogen, cyano, alkyl, haloalkyl, alkoxy, alkoxyalkyl;

n is 0, 1, 2 or 3;

R ³ is selected from fluorine, hydroxyl, cyano, oxo (=O), C _1-3 alkyl, OC _1-3 alkyl, C _3-4 cycloalkyl, or two R ³ are cyclized together to form a C _3-4 spirocycloalkyl, wherein the C _1-3 alkyl, OC _1-3 alkyl, C _3-4 cycloalkyl or C _3-4 spirocycloalkyl may be substituted by 0 to 3 fluorine atoms or by 0 to 1 hydroxyl groups when valence permits;

X is CH or N;

Y is -CR ¹⁰ ₂ (CR ¹⁰ ₂ ) _q -, -O(CR ¹⁰ ₂ ) _q -, -NR ¹¹ (CH ₂ ) _q -, -CR ¹⁰ ₂ O-, -CR ¹⁰ ₂ NR ¹¹ -;

R ¹⁰ is independently selected from hydrogen, fluorine, hydroxyl, cyano, C _1-3 alkyl, OC _1-3 alkyl, C _3-4 cycloalkyl, or 2 R ¹⁰ together form oxo (=O), or 2 R ¹⁰ together cyclize to form C _3-4 spirocycloalkyl, wherein C _1-3 alkyl, OC _1-3 alkyl, C _3-4 cycloalkyl or C _3-4 spirocycloalkyl may be substituted by 0 to 3 fluorine atoms or by 0 to 1 hydroxyl groups when valence permits;

R ¹¹ is selected from hydrogen, alkyl, cycloalkyl, heterocycloalkyl, alkylcycloalkyl, alkylheterocycloalkyl;

q is 0 or 1;

R ⁴ is -C _1-3 alkyl, -C _0-3 alkylene-C _3-6 cycloalkyl, -C _0-3 alkylene-R ⁹ or -C _1-3 alkylene-R ⁶ , wherein the alkyl group may be substituted with 0 to 3 substituents independently selected from 0 to 3 F atoms or with 0 to 1 substituent selected from -C _0-1 alkylene-CN, -C _0-1 alkylene-OR ^O or -N( ^RN ) ₂ when valence permits, and wherein the alkylene and cycloalkyl group may be substituted with 0 to 2 substituents independently selected from 0 to 2 F atoms or with 0 to 1 substituent selected from -C _0-1 alkylene-CN, -C _0-1 alkylene-OR ^O or -N( ^RN ) ₂ when valence permits;

R ⁹ is a 4- to 6-membered heterocycloalkyl group, wherein the heterocycloalkyl group may be substituted with 0 to 2 substituents independently selected from the following when valence permits:

0 to 1 oxo (=O),

0 to 1 -CN,

0 to 2 F atoms, or

0 to 2 substituents independently selected from -C _1-3 alkyl or -OC _1-3 alkyl, wherein the alkyl of C _1-3 alkyl and OC _1-3 alkyl may be substituted with 0 to 3 substituents independently selected from the following when valence permits:

0 to 3 F atoms,

0 to 1 -CN, or

0 to 1 -OR ^O ;

^R6 is a 5- to 6-membered heteroaryl group, wherein the heteroaryl group may be substituted with 0 to 2 substituents independently selected from the following when valence permits:

0 to 2 halogens,

0 to 1 substituents selected from -OR ^O and -N( ^RN ) ₂ , or

0 to 2 -C _1-3 alkyl groups, wherein the alkyl group may be substituted with 0 to 3 substituents independently selected from the following groups when valence permits:

0 to 3 F atoms, or

0 to 1 -OR ^O ;

Each R ^O is independently H or -C _1-3 alkyl, wherein the C _1-3 alkyl may be substituted by 0 to 3 F atoms;

Each ^RN is independently H or -C _1-3 alkyl;

Z ¹ , Z ² and Z ³ are each independently -CR ^Z or N, and each R ^Z is independently H, F, Cl or -CH ₃ ;

R ⁷ is selected from halogen, cyano, hydroxy, cycloalkyl, heterocycloalkyl, sulfone;

^R8 is selected from halogen, cyano, alkyl, haloalkyl, alkoxy, haloalkoxy, alkoxyalkyl, cycloalkyl, heterocycloalkyl, and sulfone.

As a preferred embodiment of the present invention, the alkyl group refers to a branched, unbranched and cyclic saturated hydrocarbon chain containing a specified number of carbon atoms, preferably a _C1-6 alkyl group, and the _C1-6 alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, 1-ethylpropyl, 2-methylbutyl, tert-pentyl, 1,2-dimethylpropyl, isopentyl, neopentyl, n-hexyl, isohexyl, sec-hexyl, tert-hexyl, neohexyl, 2-methylpentyl, 1,2-dimethylbutyl, and 1-ethylbutyl.

As a preferred embodiment of the present invention, the alkoxy group refers to an alkyl ether free radical, preferably a C _1-6 alkoxy group, and the C _1-6 alkoxy group is selected from methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 1-ethylpropoxy, 2-methylbutoxy, tert-pentoxy, 1,2-dimethylpropoxy, isopentyl, neopentyl, n-hexyl, isohexyl, sec-hexyl, tert-hexyl, neohexyl, 2-methylpentyl, 1,2-dimethylbutoxy, and 1-ethylbutoxy.

As a preferred embodiment of the present invention, the alkoxyalkyl group refers to an alkyl group in which one or more hydrogen atoms are substituted by an alkoxy group, preferably selected from _C1-4 alkoxy _C1-4 alkyl, and further selected from methoxymethyl, methoxyethyl, methoxypropyl, methoxybutyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, propoxymethyl, propoxyethyl, propoxypropyl, propoxybutyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl and the like.

As a preferred embodiment of the present invention, the halogen is selected from fluorine, chlorine, bromine and iodine; a haloalkyl group refers to one or more hydrogen atoms of an alkyl group being replaced by a halogen; a haloalkoxy group refers to one or more hydrogen atoms of an alkoxy group being replaced by a halogen; a hydroxyalkyl group refers to one or more hydrogen atoms of an alkyl group being replaced by a hydroxyl group; a heterocycloalkyl group refers to one or more hydrogen atoms of an alkyl group being replaced by a heterocycle; and a cycloalkyl methylene group refers to one or more hydrogen atoms of an alkyl group being replaced by a cycloalkane.

As a preferred embodiment of the present invention, the aromatic ring is selected from a four-membered ring, a condensed ring containing a four-membered ring, a five-membered ring, a condensed ring containing a five-membered ring, a six-membered ring, a condensed ring containing a six-membered ring, and a biphenyl-type aromatic ring; the condensed aromatic ring is selected from naphthalene or a condensed aromatic heterocycle, the condensed aromatic heterocycle refers to an aromatic ring or a heteroaromatic ring fused with a heteroaromatic ring, the heteroatoms on the heteroaromatic ring are selected from nitrogen, oxygen, and sulfur, and the heteroatoms are one or more.

As a preferred embodiment of the present invention, the fused aromatic heterocycle is selected from indazole, quinoline, isoquinoline, quinoxaline, indole, isoindole, cinnoline, quinazoline, phthalazine, purine, naphthyridine, pteridine, benzofuran, benzothiophene, benzoxazole, benzothiazole, benzisoxazole, benzisothiazole, benzoxadiazole, benzothiadiazole, benzotriazole, benzotriazine, benzimidazole, pyrazinopyrazole, pyrazinopyrimidine, pyrazinopyridazine, pyrazinotriazine, pyrimidinopyrazole, pyrimidinotriazole, pyrimidinotriazine, pyrimidinopyridazine, pyridazinimidazole, pyridazinopyrazole, pyridazinotriazole, pyridazinotriazine, triazinimidazole, triazinopyrazole, triazinotriazole, pyridinotriazine ... isothiazole, pyridoxadiazole, pyridothiadiazole, pyridofuran, pyridopyrrole, pyrazinoxazole, pyrazinothiazole, pyrazinoisoxazole, pyrazinoisothiazole, pyrazinooxadiazole, pyrazinothiadiazole, pyrazinofuran, pyrazinopyrrole, pyrimidoxazole, pyrimidothiazole, pyrimidisoxazole, pyrimidisothiazole, pyrimidoxadiazole, pyrimidothiadiazole, pyrimidofuran, pyrimidopyrrole, pyridazinooxazole, pyridazinothiazole, pyridazinoisoxazole, pyridazinoisothiazole, pyridazinooxadiazole, pyridazinothiadiazole, pyridazinofuran, pyridazinopyrrole, triazinooxazole, triazinothiazole, triazinoisoxazole, triazinoisothiazole, triazinooxadiazole, triazinothiadiazole, triazinofuran, triazinopyrrole. wherein the naphthyridine is selected from The pyridoimidazole is selected from The pyrazinoimidazole is selected from The pyrazinotriazole is selected from The pyrimidopyrazole is selected from The pyrimidoimidazole is selected from The pyrimidotriazole is selected from The pyridazine imidazole is selected from The pyridazinetriazole is selected from The triazinoimidazole is selected from The pyridopyridazine is selected from The pyridopyrazole is selected from The pyridopyrimidine is selected from The pyridotriazine is selected from The pyrimidotriazine is selected from

As a preferred embodiment of the present invention, the heterocyclic ring of the heterocycloalkyl is selected from a 4- to 10-membered heterocyclic ring, and the 4- to 10-membered heterocyclic ring is selected from The aryl group is selected from phenyl; the heteroaryl group is selected from 5 to 12-membered heteroaryl groups, and the 5 to 12-membered heteroaryl groups are selected from

As a preferred embodiment of the present invention, the "alkylene group" refers to an alkyl group which can be independently substituted by 0 to 2 substituents when the valence permits.

As a preferred embodiment of the present invention, the "heterocycle" refers to a saturated or unsaturated heterocycle containing one or more heteroatoms (nitrogen, oxygen, sulfur); the "aromatic ring" refers to a benzene ring; the "heteroaromatic ring" refers to a heterocycle with a closed conjugated system of 4n+2 π electrons, such as furan, thiophene, tetrahydropyrrole, dihydropyrazole, imidazole, thiazole, isothiazole, thiadiazole, oxazole, oxadiazole, isoxazole, piperidine, piperazine, pyridazine, pyrazine, triazine, pyrimidine, morpholine or pyridine, etc.; the "plurality" refers to two, three, or four.

As a preferred embodiment of the present invention, the cycloalkane is selected from C _3-6 cycloalkane, and the C _3-6 cycloalkane is selected from cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

As a preferred embodiment of the present invention, A is selected from a benzene ring and a pyridine ring.

As a preferred embodiment of the present invention, Selected from

As a preferred embodiment of the present invention, Selected from

As a preferred embodiment of the present invention, A is selected from a benzene ring and a pyridine ring;

_R1 is selected from cyano, fluorine, and chlorine;

Selected from

W is -O-;

^R2 is hydrogen;

^R3 is hydrogen or methyl;

^R4 is oxetan-2-ylmethyl;

Z ¹ , Z ² and Z ³ are CH or N.

As a preferred embodiment of the present invention, the compound, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof or its pharmaceutically acceptable salt, is selected from the following compounds:

As a preferred embodiment of the present invention, the pharmaceutically acceptable salt refers to a salt prepared from a compound and a pharmaceutically acceptable acid or base.

As a preferred embodiment of the present invention, one or more hydrogen atoms in the compound are substituted by deuterium isotope.

Another object of the present invention is to provide a pharmaceutical composition comprising the aforementioned compound of formula (I), or its tautomer, mesomer, racemate, enantiomer, diastereomer, or a mixture thereof or a pharmaceutically acceptable salt thereof and one or more pharmaceutically acceptable carriers.

Another object of the present invention is to provide the use of the compound of formula (I), or its tautomer, mesomer, racemate, enantiomer, diastereoisomer, or mixture thereof or its pharmaceutically acceptable salt in the preparation of a drug for treating GLP-1 related diseases, specifically, the use of a drug for diabetes related diseases.

Unless otherwise indicated, the following terms and phrases used herein are intended to have the following meanings. A particular term or phrase should not be considered to be uncertain or unclear in the absence of a special definition, but should be understood in accordance with the ordinary meaning. When a trade name appears in this article, it is intended to refer to its corresponding commercial product or its active ingredient. The term "pharmaceutically acceptable" used here refers to those compounds, materials, compositions and/or dosage forms that are within the scope of reliable medical judgment and are suitable for use in contact with human and animal tissues without excessive toxicity, irritation, allergic reactions or other problems or complications, and are commensurate with a reasonable benefit/risk ratio.

The term "pharmaceutically acceptable salt" refers to salts of the compounds of the present invention, which are prepared from the compounds having specified substituents discovered in the present invention and pharmaceutically acceptable acids or bases.

In addition to the form of salts, compounds provided by the present invention also exist in prodrug form. Prodrugs of compounds described herein easily undergo chemical changes under physiological conditions to be converted into compounds of the present invention. In addition, prodrugs can be converted to compounds of the present invention by chemical or biochemical methods in an in vivo environment.

Certain compounds of the present invention may exist in unsolvated forms as well as solvated forms, including hydrated forms. In general, the solvated forms are equivalent to the unsolvated forms and are encompassed within the scope of the present invention.

The compounds of the present invention may exist in specific geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis and trans isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, and racemic mixtures and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the present invention. Additional asymmetric carbon atoms may be present in substituents such as alkyl. All of these isomers and their mixtures are included within the scope of the present invention.

Optically active (R)- and (S)-isomers, as well as D and L isomers, can be prepared by chiral synthesis or chiral reagents or other conventional techniques. If one enantiomer of a compound of the present invention is desired, it can be prepared by asymmetric synthesis or derivatization with a chiral auxiliary, wherein the resulting diastereomeric mixture is separated and the auxiliary group is cleaved to provide the pure desired enantiomer. Alternatively, when the molecule contains a basic functional group (such as an amino group) or an acidic functional group (such as a carboxyl group), a diastereomeric salt is formed with an appropriate optically active acid or base, and then the diastereoisomers are separated by conventional methods known in the art, and then the pure enantiomer is recovered. In addition, the separation of enantiomers and diastereomers is usually accomplished by using chromatography, which uses a chiral stationary phase and is optionally combined with a chemical derivatization method (for example, a carbamate is generated from an amine).

The atom of the compound of the present invention molecule is an isotope, and isotope derivatization can generally extend the half-life, reduce the clearance rate, stabilize metabolism and improve the effects of in vivo activity. And, include an embodiment, wherein at least one atom is replaced by an atom with the same atomic number (proton number) and different mass numbers (protons and neutrons). The example of the isotope included in the compound of the present invention includes hydrogen atom, carbon atom, nitrogen atom, oxygen atom, phosphorus atom, sulfur atom, fluorine atom, chlorine atom, which includes ² H, ³ H, ¹³ C, ¹⁴ C, ¹⁵ N, ¹⁷ O, ¹⁸ O, ³¹ P, ³² P, ³⁵ S, ¹⁸ F, ³⁶ Cl respectively. In particular, the radioactive isotope such as ³ H or ¹⁴ C that emits radiation with its decay can be used for local anatomy inspection of pharmaceutical preparations or compounds in vivo. Stable isotopes neither decay or change with their amount, nor have radioactivity, so they can be used safely. When atoms constituting molecules of the compounds of the present invention are isotopes, the isotopes can be converted according to a common method by replacing the reagent used in the synthesis with a reagent containing the corresponding isotope.

The compounds of the present invention may contain unnatural proportions of atomic isotopes on one or more of the atoms constituting the compounds. For example, compounds may be labeled with radioactive isotopes, such as deuterium ( ^2H ), iodine-125 ( ^125I ) or C-14 ( ^14C ). All isotopic changes in the compounds of the present invention, whether radioactive or not, are included within the scope of the present invention.

Furthermore, one or more hydrogen atoms of the compounds of the present invention are replaced by the isotope deuterium ( ^2H ). After deuteration, the compounds of the present invention have the effects of extending half-life, reducing clearance rate, stabilizing metabolism and improving in vivo activity.

The preparation method of the isotopic derivative generally includes: a phase transfer catalytic method. For example, a preferred deuteration method uses a phase transfer catalyst (e.g., a tetraalkylammonium salt, NBu ₄ HSO ₄ ). The use of a phase transfer catalyst to exchange the methylene protons of the diphenylmethane compound results in a higher deuterium introduction than reduction with deuterated silane (e.g., triethyldeuterated silane) or with a Lewis acid such as aluminum trichloride using sodium deuterated borate in the presence of an acid (e.g., methanesulfonic acid).

The term "pharmaceutically acceptable carrier" refers to any formulation carrier or medium that can deliver an effective amount of the active substance of the present invention, does not interfere with the biological activity of the active substance, and has no toxic side effects on the host or patient. Representative carriers include water, oil, vegetables and minerals, cream bases, lotion bases, ointment bases, etc. These bases include suspending agents, viscosity enhancers, transdermal enhancers, etc. Their preparations are well known to those skilled in the art of cosmetics or topical drugs. For additional information about the carrier, reference can be made to Remington: The Science and Practice of Pharmacy, 21st Ed., Lippincott, Williams & Wilkins (2005), the contents of which are incorporated herein by reference.

The term "excipient" generally refers to carriers, diluents and/or vehicles required to formulate an effective pharmaceutical composition.

With respect to a drug or pharmacologically active agent, the term "effective amount" or "therapeutically effective amount" refers to a sufficient amount of a drug or agent that is non-toxic but can achieve the desired effect. For oral dosage forms of the present invention, an "effective amount" of an active substance in a composition refers to the amount required to achieve the desired effect when used in combination with another active substance in the composition. The determination of the effective amount varies from person to person, depending on the age and general condition of the recipient, and also on the specific active substance. The appropriate effective amount in each case can be determined by a person skilled in the art based on routine experiments.

The terms "active ingredient," "therapeutic agent," "active substance," or "active agent" refer to a chemical entity that is effective in treating a target disorder, disease, or condition.

"Optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

Indicates a connection key.

The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthetic methods, and equivalent substitutions well known to those skilled in the art. Preferred embodiments include but are not limited to the embodiments of the present invention.

DETAILED DESCRIPTION

The present invention is further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

The structures of the compounds were determined by nuclear magnetic resonance (NMR) or mass spectrometry (MS). NMR shifts (δ) are given in units of 10 ^-6 (ppm). NMR measurements were performed using a Bruker AVANCE-III NMR spectrometer, with deuterated dimethyl sulfoxide (DMSO-d ₆ ) and deuterated chloroform (CDCl ₃ ) as solvents and tetramethylsilane (TMS) as the internal standard.

MS was measured using ISQ EC mass spectrometer (manufacturer: Thermo, model: ISQ EC).

High performance liquid chromatography (HPLC) analysis was performed using a Thermo U3000 HPLC DAD and an Agilent 1260 HPLC.

The CombiFlash rapid preparation instrument uses CombiFlash Rf+LUMEN (TELEDYNE ISCO).

The thin layer chromatography silica gel plate uses Yantai Yinlong HSGF ₂₅₄ or GF ₂₅₄ silica gel plate. The silica gel plate used in thin layer chromatography (TLC) adopts a specification of 0.17mm-0.23mm, and the specification used for thin layer chromatography separation and purification products is 0.4mm-0.5mm.

Silica gel column chromatography generally uses Rushan Shangbang silica gel 100-200 mesh silica gel as the carrier.

Reagents: LDA-lithium diisopropylamide, THF-tetrahydrofuran, TEA-triethylamine, Dioxane-1,4-dioxane, BH ₃ -borane, EDCl-1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, HOBT-1-hydroxybenzotriazole, DIPEA-N,N-diisopropylethylamine, DMF-N,N-dimethylformamide, K ₂ CO ₃ -potassium carbonate, DMSO-dimethyl sulfoxide, EtOH-ethanol, NaH-sodium hydride, toluene-toluene, rt-room temperature, PdCl ₂ (dppf)-[1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium, Pd(OAc)2-palladium acetate, PhMe-toluene, HCl-dioxane-hydrochloric acid, NaCO ₃ -sodium carbonate, MeOH-methanol, DCE-dichloroethane, NCS-N-chlorosuccinimide, TfOH-trifluoromethanesulfonic acid, TFA-trifluoroacetic acid, AcOH-acetic acid, (CH ₂ O)n-paraformaldehyde, CDI-N,N'-carbonyldiimidazole, LAH-lithium aluminum hydride, PPA-polyphosphoric acid, TsOH-toluenesulfonic acid, NBS-N-bromosuccinimide, BPO-benzoyl peroxide.

abs means absolute configuration.

Example 1

Synthesis of 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of tert-butyl 3-(((tert-butyldimethylsilyl)oxy)methyl)piperazine-1-carboxylate

At room temperature, tert-butyl 3-hydroxymethylpiperazine-1-carboxylate (1.0 g, 4.6 mmol) was dissolved in N,N-dimethylformamide (15 ml), and imidazole (947.6 mg, 13.9 mmol) and tert-butyldimethylsilyl chloride (1.4 g, 9.3 mmol) were added. The mixture was reacted at room temperature for 2 hours. After the reaction was complete, the mixture was diluted with ethyl acetate (200 ml), washed with hydrochloric acid (40 × 3 times) and saturated brine (40 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 1/1) to obtain 1.2 g of yellow oily tert-butyl 3-(((tert-butyldimethylsilyl)oxy)methyl)piperazine-1-carboxylate (yield: 70.1%). LC-MS: RT = 2.23 min, [M+H] ⁺ = 331.06.

Step B: Synthesis of 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluorocarbaldehyde

At room temperature, 2,6-difluoropyridine-3-carboxaldehyde (1.0 g, 7.0 mmol), 4-chloro-2-fluorobenzyl alcohol (1.35 g, 8.4 mmol) and potassium carbonate (2.9 g, 20.9 mmol) were dissolved in N,N-dimethylformamide (15 ml) and heated to 100 degrees Celsius for 6 hours. After the reaction was complete, it was diluted with ethyl acetate (200 ml), washed with water (40 ml × 3 times) and saturated brine (40 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 10/1) to obtain 850.5 mg of white powder 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluorocarboxaldehyde (yield: 50.7%). ¹ H NMR (400MHz, CDCl ₃ ) δ10.34(d,J＝5.0Hz,1H),10.24(d,J＝5.0Hz,2H),8.32(dt,J＝8.1,4.1Hz,1H),8.24(dt,J＝8.8,4.4Hz,2H),7.56–7.47(m,4H),7.22 (tq,J＝8.2,4.8,3.6Hz,8H),5.57(d,J＝5.1Hz,2H),5.51(d,J＝5.0Hz,4H).

Step C: Synthesis of tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-pyridinecarboxaldehyde-2-yl)piperazine-1-carboxylate

At room temperature, 6-((4-chloro-2-fluorobenzyl)oxy-2-fluoroformaldehyde (850.0 mg, 3.7 mmol), tert-butyl 3-(((tert-butyldimethylsilyl)oxy)methyl)piperazine-1-carboxylate (1.4 g, 4.1 mmol) and potassium carbonate (1.5 g, 11.1 mmol) were dissolved in N,N-dimethylformamide (15 ml) and heated to 100 degrees Celsius for 6 hours. After the reaction was complete, ethyl acetate (200 ml) was diluted and water (40 ml × 3 times) was added. , washed with saturated brine (40 ml x 1 time), dried over anhydrous sodium sulfate and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 180.2 mg of white powder 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-pyridinecarboxaldehyde-2-yl)piperazine-1-carboxylic acid tert-butyl ester (yield: 10.1%). LC-MS: RT = 4.37 min. [M+H] ⁺ = 594.17. ¹ HNMR (400 MHz, CDCl ₃ )δ7.54(s,1H),7.43(d,J＝8.2Hz,1H),7.17(d,J＝2.8Hz,2H),6.58(d,J＝8.2Hz,1H),5.39(d,J＝6.4Hz,2H),4.80(d,J＝12.6Hz,1H),4.48(d,J＝12.7Hz,1H) ,3.87(d,J＝1 3.1Hz,1H),3.80–3.71(m,1H),3.56–3.51(m,2H),3.50(d,J＝6.8Hz,1H),3.43(dt,J＝12.4,5.4Hz,2H),3.08(d,J＝16.7Hz,2H),1.54(s,9H),1.30(s,9H ),0.86(s,6H).

Step D: Synthesis of tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)piperidin-2-yl)piperazine-1-carboxylate

Under ice bath, tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-6((4-chloro-2-fluorophenyl)oxy)-3-pyridinecarboxaldehyde-2-yl)piperazine-1-carboxylate (47.6 mg, 757.3 μmol) was dissolved in methanol (10 ml), cooled to zero degrees Celsius, and sodium cyanoborohydride (180.2 mg, 302.9 μmol) was added to react for 2 hours. After the reaction was complete, it was diluted with ethyl acetate (50 ml), washed with water (20 ml × 3 times) and saturated brine (20 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. (Eluent: petroleum ether/ethyl acetate = 6/1) 143.5 mg of tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)piperidin-2-yl)piperazine-1-carboxylate was obtained (yield: 79.6%). LC-MS: RT = 4.26 min, [M+H] ⁺ = 596.6.

Step E: Synthesis of tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

At room temperature, tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorophenyl)oxy)-3-(hydroxymethyl)piperidin-2-yl)piperazine-1-carboxylate (143.5 mg, 240.8 μmol) was dissolved in tetrahydrofuran solution, and tetrabutylammonium fluoride (228 μl, 722.3 μmol) was added and reacted at room temperature for 2 hours. After the reaction was complete, it was diluted with ethyl acetate (50 ml), washed with water (20 ml × 3 times) and saturated brine (20 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. (Eluent: petroleum ether/ethyl acetate = 1/1) to obtain 106.2 mg of yellow oily tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate (yield: 92.1%). LC-MS: RT=3.67min, [M+H] ⁺ =482.1.

Step F: Synthesis of 2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-tert-Butyl formate

At room temperature, tert-butyl 3-(((tert-butyldimethylsilyloxy)oxy)methyl)-4-(6-((4-chloro-2-fluorophenyl)oxy)-3-(hydroxymethyl)piperidin-2-yl)piperazine-1-carboxylate (106.2 mg, 229.3 μmol) was dissolved in carbon tetrachloride (10 ml), zinc chloride (56.2 mg, 412.7 μmol) was added, and the temperature was raised to reflux for 4 hours. After the reaction was complete, it was diluted with ethyl acetate (50 ml), washed with water (20 ml × 3 times) and saturated brine (20 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. (Eluent: petroleum ether/ethyl acetate = 1/1) to obtain 47.8 mg of 2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -tert-Butyl 9(7H)-formate (yield: 46.4%). LC-MS: RT = 4.95 min, [M+H] ⁺ = 464.19.

Step G: Synthesis of 2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine

At room temperature, 2-((4-chloro-2-fluorophenoxy)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-tert-butyl formate (47.8 mg, 470.6 μmol) was dissolved in dichloromethane (7 ml), trifluoroacetic acid (3 ml) was added, and the reaction was carried out at room temperature for 1 hour. After the reaction was complete, the product was concentrated and used directly in the next step without purification. 37.5 mg of 2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine was obtained. LC-MS: RT=2.56min, [M+H] ⁺ =364.19.

Step H: Synthesis of 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -tert-Butyl-9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine was reacted with (37.5 mg, 103.2 μmol), (S)-2-(chloromethyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (41.8 mg, 123.9 μmol) and potassium carbonate (43.1 mg, 309.6 μmol) were dissolved in N,N-dimethylformamide (5 ml), heated to 50 degrees Celsius and reacted for 6 hours. After the reaction was complete, it was diluted with ethyl acetate (50 ml), washed with water (20 ml × 3 times), saturated brine (20 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. (Eluent: petroleum ether/ethyl acetate = 1/1 to dichloromethane/methanol = 10/1) to obtain 48.1 mg of light yellow oily 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -tert-butyl 9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (yield: 70.1%). LC-MS: RT = 3.77 min, [M+H] ⁺ = 644.32.

Step I: Synthesis of 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The compound 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine was reacted at room temperature. tert-Butyl-9(7H)-yl)methyl)-1-(((S)-oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (48.1 mg, 72.4 μmol) was dissolved in dichloromethane (7 ml), trifluoroacetic acid (3 ml) was added, and the mixture was reacted at room temperature for 2 hours. After the reaction was completed, the pH was adjusted to 7 with aqueous sodium carbonate solution, and the mixture was extracted with ethyl acetate (25 ml × 3 times), the organic layers were combined, washed with saturated brine (25 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The resulting residue was further purified by reverse phase HPLC (mobile phase: water/acetonitrile = 90/10 to 5/95) and lyophilized to give 21.5 mg of a white solid 2-((2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 47.6%). LC-MS: RT = 2.48 min, [M+H] ⁺ = 608.31.

Example 2

Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepan-9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluoronicotinaldehyde

At room temperature, 2,6-difluoronicotinaldehyde (5.8 g, 40.6 mmol) was dissolved in N,N-dimethylformamide (100 ml), potassium carbonate (13 g, 93.8 mmol) and (4-chloro-2-fluorophenyl)methanol (5 g, 31.3 mmol) were added, and the temperature was raised to 100 degrees Celsius for 16 hours. After the reaction was completed, saturated sodium chloride was used for quenching, ethyl acetate was extracted (20 ml × 3 times), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/10) to obtain 2.9 g of white solid 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluoronicotinaldehyde (yield: 33%).

Step B: Synthesis of (R)-tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

At room temperature, 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluoronicotinaldehyde (1 g, 3.55 mmol) was dissolved in N,N-dimethylformamide (15 ml), potassium carbonate (1.5 g, 10.7 mmol) and (R)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (0.9 g, 4.26 mmol) were added, and the temperature was raised to 100 °C for 16 hours. After the reaction was completed, the reaction was quenched with saturated sodium chloride, extracted with ethyl acetate (10 ml × 3 times), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/10) to give 360 mg of white solid (R)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 21%).

Step C: Synthesis of (R)-tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

Under ice-water bath, (R)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (360 mg, 0.75 mmol) was dissolved in methanol (5 ml), sodium borohydride (60 mg, 1.5 mmol) was added, and the mixture was reacted at zero degrees Celsius for 0.5 hours. After the reaction was completed, 0.5 ml of water was added to quench the reaction, and the reaction was dried. The crude product was purified by column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 320 mg of yellow solid (R)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 89%). LC-MS: RT = 1.98 min, [M+H] ⁺ = 482.21

Step D: Synthesis of (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester

At room temperature, (R)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (100 mg, 0.21 mmol) was dissolved in dichloromethane (3 ml), p-toluenesulfonic acid (17 mg, 0.1 mmol) was added, and the mixture was reacted at room temperature for 3 hours. After the reaction was completed, water was added to quench the mixture, and ethyl acetate (3 ml × 3 times) was extracted. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 80 mg of colorless oily liquid (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester (yield: 82%). LC-MS: RT = 1.95 min, [M+H] ⁺ = 464.35

Step E: Synthesis of (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine

At room temperature, (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-C]pyridino[2,3-e][1,4]oxazepine-9(7H)-carboxylic acid tert-butyl ester (80 mg, 0.17 mmol) was dissolved in dioxane (2 ml), and hydrogen chloride dioxane solution (2 ml) was added under ice-water bath, and the mixture was reacted at room temperature for 0.5 hours. After the reaction was completed, the mixture was concentrated to obtain crude (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-C]pyridino[2,3-e][1,4]oxazepine. LC-MS: RT = 1.67 min, [M+H] ⁺ = 364.25.

Step F: Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester

At room temperature, (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (0.17 mmol) was dissolved in N,N-dimethylformamide (2 ml), and (S)-2-(chloromethyl)-3-((oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (67 mg, 0.23 mmol) and potassium carbonate (70 mg, 0.51 mmol) were added and reacted at room temperature for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was extracted (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 50 mg of colorless oily liquid 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (yield: 47%). LC-MS: RT = 1.89 min, [M+H] ⁺ = 623.35.

Step G: Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid

2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetane-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (50 mg, 0.08 mmol) was dissolved in tetrahydrofuran/water/methanol (2/1/1, 4 ml), lithium hydroxide (9 mg, 0.24 mmol) was added, and the mixture was reacted at room temperature for 3 hours. After the reaction was completed, the mixture was concentrated. The resulting residue was purified by preparative HPLC to give 13 mg of a white solid 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid (yield: 17%). LC-MS: RT=1.86 min, [M+H] ⁺ =609.28.

Example 3

Synthesis of 2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-imidazo[4,5-b]pyridine-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 2-fluoro-6-((3-fluoropyridin-4-yl)methoxy)nicotinaldehyde

At room temperature, 2,6-difluoronicotinaldehyde (3.7 g, 26.0 mmol) was dissolved in N,N-dimethylformamide (100 ml), potassium carbonate (9.9 g, 70.8 mmol) and (3-fluoropyridin-4-yl)methanol (3 g, 23.6 mmol) were added, and the temperature was raised to 100 degrees Celsius for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, ethyl acetate was extracted (20 ml × 3 times), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/10) to obtain 1.3 g of white solid 2-fluoro-6-((3-fluoropyridin-4-yl)methoxy)nicotinaldehyde (yield: 22%).

Step B: Synthesis of (R)-tert-butyl 4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

At room temperature, 2-fluoro-6-((3-fluoropyridin-4-yl)methoxy)nicotinaldehyde (0.65 g, 2.6 mmol) was dissolved in N,N-dimethylformamide (10 ml), potassium carbonate (1.1 g, 7.8 mmol) and (R)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (0.9 g, 4.26 mmol) were added, and the temperature was raised to 100 °C for 16 hours.

After the reaction was completed, saturated sodium chloride was added to quench the reaction, and the mixture was extracted with ethyl acetate (10 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/10) to give 190 mg of white solid (R)-4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 16%).

Step C: Synthesis of (R)-tert-butyl 4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

(R)-4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (190 mg, 0.43 mmol) was dissolved in methanol (5 ml), and sodium borohydride (34 mg, 0.86 mmol) was slowly added under an ice-water bath, and the reaction was carried out for 0.5 hours. After the reaction was completed, 0.5 ml of water was added to quench, and the reaction was dried. The crude product was purified by column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 180 mg of oily liquid (R)-4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 93%). LC-MS: RT = 1.88 min, [M+H] ⁺ = 449.21

Step D: Synthesis of (R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester

At room temperature, (R)-4-(6-((3-fluoropyridin-4-yl)methoxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (180 mg, 0.4 mmol) was dissolved in dichloromethane (3 ml), and p-toluenesulfonic acid (35 mg, 0.2 mmol) was added and reacted for 3 hours. After the reaction was completed, water was added to quench, and ethyl acetate was extracted (3 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 120 mg of colorless oily liquid (R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester (yield: 91%). LC-MS: RT = 1.82 min, [M+H] + = 431.33

Step E: Synthesis of (R)-2-((3-fluoropyridin-4-yl)methoxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine

At room temperature, (R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester (120 mg, 0.36 mmol) was dissolved in dioxane (2 ml), and hydrogen chloride dioxane solution (2 ml) was added under ice-water bath, and reacted at room temperature for 0.5 hours. After the reaction was completed, the mixture was concentrated to obtain a crude product (R)-2-((3-fluoropyridin-4-yl)methoxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine LC-MS: RT=1.67min, [M+H] ⁺ =331.25.

Step F: Synthesis of 2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester

At room temperature, (R)-2-((3-fluoropyridin-4-yl)methoxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (0.36 mmol) was dissolved in N,N-dimethylformamide (4 ml), and (S)-2-(chloromethyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (146 mg, 0.43 mmol) and potassium carbonate (149 mg, 1.08 mmol) were added and reacted at room temperature for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was extracted (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 90 mg of colorless oily liquid 2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 43%). LC-MS: RT = 1.89 min, [M+H] ⁺ = 623.35.

Step G: Synthesis of 2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine methyl)-1-(((S)-oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (90 mg, 0.14 mmol) was dissolved in tetrahydrofuran/water/methanol (2/1/1, 4 ml), and lithium hydroxide monohydrate (16 mg, 0.42 mmol) was added and reacted at room temperature for 3 hours. After the reaction was completed, it was concentrated. The resulting residue was purified by preparative HPLC to give 10.9 mg of a white solid 2-(((R)-2-((3-fluoropyridin-4-yl)methoxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 14%). LC-MS: RT = 1.84 min, [M+H] ⁺ = 575.27.

Example 4

Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid

The specific synthetic route is as follows:

Step A: (S)-tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

At room temperature, 6-((4-chloro-2-fluorobenzyl)oxy)-2-fluoronicotinaldehyde (1 g, 3.6 mmol) was dissolved in N,N-dimethylformamide (15 ml), potassium carbonate (1.5 g, 10.8 mmol) and (S)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (0.93 g, 4.3 mmol) were added, and the temperature was raised to 100 °C for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench the reaction, and the mixture was extracted with ethyl acetate (10 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/10) to give 150 mg of white solid (S)-tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate (yield: 8%).

Step B: Synthesis of (S)-tert-butyl 4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

(S)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (150 mg, 0.32 mmol) was dissolved in methanol (5 ml), and sodium borohydride (25 mg, 0.64 mmol) was slowly added under ice-water bath, and the mixture was reacted for 0.5 hour. After the reaction was completed, 0.5 ml of water was added to quench the reaction, and the reaction was dried. The crude product was purified by column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 150 mg of yellow solid (S)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 99%). LC-MS: RT = 1.98 min, [M+H] ⁺ = 482.21.

Step C: Synthesis of (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester

At room temperature, (S)-4-(6-((4-chloro-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (150 mg, 0.32 mmol) was dissolved in dichloromethane (3 ml), p-toluenesulfonic acid (27 mg, 0.16 mmol) was added, and the mixture was reacted for 3 hours. After the reaction was completed, water was added to quench the mixture, and the mixture was extracted with ethyl acetate (3 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 100 mg of yellow oily liquid (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester (yield: 69%). LC-MS: RT = 1.95 min, [M+H] ⁺ = 464.31

Step D: Synthesis of (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine

At room temperature, (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-carboxylic acid tert-butyl ester (100 mg, 0.22 mmol) was dissolved in dioxane (2 ml), and hydrogen chloride dioxane solution (2 ml) was added under ice-water bath, and the mixture was reacted at room temperature for 0.5 hours. After the reaction, the mixture was concentrated to obtain a crude product (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine LC-MS: RT=1.67min, [M+H] ⁺ =364.25.

Step E: Synthesis of 2-(((S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester

At room temperature, (S)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (0.22 mmol) was dissolved in N,N-dimethylformamide (2 ml), and (S)-2-(chloromethyl)-3-((oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (97 mg, 0.33 mmol) and potassium carbonate (91 mg, 0.66 mmol) were added and reacted at room temperature for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was extracted (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 100 mg of colorless oily liquid 2-(((S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (yield: 74%). LC-MS: RT = 1.89 min, [M+H] ⁺ = 623.35.

Step F: Synthesis of 2-(((S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid

2-(((S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetane-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (100 mg, 0.16 mmol) was dissolved in tetrahydrofuran/water/methanol (2/1/1, 4 ml), lithium hydroxide (18 mg, 0.48 mmol) was added, and the mixture was reacted at room temperature for 3 hours. After the reaction was completed, the mixture was concentrated. The resulting residue was purified by preparative HPLC to give 13 mg of a white solid 2-(((S)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-3-(((S)-oxetan-2-yl)methyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid (yield: 17%). LC-MS: RT = 1.86 min, [M+H] ⁺ = 609.28. ¹ H NMR (500MHz, DMSO) δ8.08(d,J＝8.2Hz,1H),7.97(d,J＝8.2Hz,1H),7.52(t,J＝8.2Hz,1H),7.48–7.40(m,2H),7.30(dd,J＝8.2,2.0Hz,1H),6.25(d,J＝7.9Hz,1H),5 .33(s,2H),5.16–5.09(m,1H),4.86(dd,J＝14.8,6.7Hz,1H),4.70(dd,J＝14.7,3.6Hz,1H),4.61(d,J＝12.9Hz,1H),4.53–4. 34(m,3H),4.03(d,J＝13.6Hz,1H),3.95(d,J＝13.4Hz,1H),3.86(d,J＝13.6Hz,1H),3.78–3.73(m,1H),3.67(dd,J＝12.9,6.9Hz,1H),3.23(d,J＝10.5Hz,3 H), 2.83 (d, J = 11.0Hz, 1H), 2.73 (d, J = 9.7Hz, 1H), 2.65 (d, J = 7.9Hz, 1H), 2.46 (s, 1H), 2.37 (t, J = 9.4Hz, 1H), 2.15 (t, J = 10.4Hz, 1H).

Example 5

Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester

At room temperature, (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (70 mg, 0.19 mmol) was dissolved in N,N-dimethylformamide (2 ml), and (S)-2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester (90 mg, 0.29 mmol) and potassium carbonate (80 mg, 0.57 mmol) were added and reacted at room temperature for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was extracted (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 100 mg of colorless oily liquid 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester (yield: 79%). LC-MS: RT = 1.84 min, [M+H] ⁺ = 664.21.

Step B: Synthesis of 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine tert-butyl ester (100 mg, 0.15 mmol) of 1-(((S)-oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate was dissolved in dichloromethane (5 ml), and trifluoroacetic acid (1 ml) was added to react for 1 hour. After the reaction was completed, the reaction was concentrated and the crude product was purified by high-performance liquid chromatography to obtain 30.6 mg of a white solid 2-(((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 34%). LC-MS: RT = 1.68 min, [M+H] ⁺ = 608.31.

Example 6

Synthesis of 2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 3-fluoro-4-(((6-fluoro-5-(formyl)pyridin-2-yl)oxy)methyl)benzonitrile

At room temperature, 3-fluoro-4-(hydroxymethyl)benzonitrile (5.3 g, 35 mmol) was dissolved in N,N-dimethylformamide (30 ml), 2,6-difluoro-3-formylpyridine (5 g, 35 mmol) and potassium carbonate (9.66 g, 70 mmol) were added, and the temperature was raised to 110 degrees Celsius for reaction. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was extracted (30 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/5) to obtain 3 g of white solid synthesis 3-fluoro-4-(((6-fluoro-5-(formyl)pyridin-2-yl)oxy)methyl)benzonitrile (yield: 32%). LC-MS: RT = 1.89 min.

Step B: Synthesis of (R)-tert-butyl 4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

At room temperature, 3-fluoro-4-(((6-fluoro-5-(formyl)pyridin-2-yl)oxy)methyl)benzonitrile (1 g, 3.65 mmol) was dissolved in N,N-dimethylformamide (20 ml), and (R)-tert-butyl 3-(hydroxymethyl)piperazine-1-carboxylate (789 mg, 3.65 mmol) and potassium carbonate (1 g, 7.3 mmol) were added, and the temperature was raised to 110 °C for reaction. After the reaction was completed, saturated sodium chloride was added to quench, and ethyl acetate was used for extraction (30 ml x 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/3) to obtain 1.5 g of white solid (R)-4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 88%). LC-MS: RT = 2.05 min, [M+H] ⁺ = 471.30

Step C: Synthesis of (R)-tert-butyl 4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylate

Under ice bath, (R)-4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(formyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (1.5 g, 3.19 mmol) was dissolved in methanol (20 ml), cooled to zero degrees Celsius, sodium borohydride (240 mg, 6.38 mmol) was added, and the reaction was heated to room temperature. After the reaction was completed, saturated sodium chloride was added to quench, methanol was evaporated off, and ethyl acetate was extracted (30 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain 1.3 g of crude product (R)-4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (yield: 86%). LC-MS: RT＝2.01min,[M+H] ⁺ ＝473.36

Step D: Synthesis of (R)-3-fluoro-4-(((7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -2-yl)oxy)methyl)benzonitrile

At room temperature, (R)-4-(6-((4-cyano-2-fluorobenzyl)oxy)-3-(hydroxymethyl)pyridin-2-yl)-3-(hydroxymethyl)piperazine-1-carboxylic acid tert-butyl ester (1.3 g, 2.75 mmol) was dissolved in dichloromethane (10 ml), p-toluenesulfonic acid (950 mg, 5.51 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was completed, the mixture was concentrated, diluted with ethyl acetate, washed twice with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain 950 mg of a crude product as a light yellow solid (R)-3-fluoro-4-(((7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine LC-MS: RT = 1.65 min, [M+H] ⁺ = 355.25.

Step E: Synthesis of 2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester

At room temperature, (R)-3-fluoro-4-(((7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (S)-2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester (95 mg, 0.28 mmol) and potassium carbonate (78 mg, 0.56 mmol) were added and reacted at room temperature. After the reaction was completed, saturated sodium chloride was added to quench, and the mixture was extracted with ethyl acetate (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The resulting crude product was purified by silica gel column chromatography (eluent: dichloromethane/methanol = 10/1) to obtain 65 mg of colorless oily liquid 2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester (yield: 36%). LC-MS: RT = 2.00 min, [M+H] ⁺ = 655.39.

Step F: Synthesis of 2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine tert-butyl ester (65 mg, 0.10 mmol) was dissolved in dichloromethane (5 ml), and trifluoroacetic acid (1 ml) was added to react for 2 hours. After the reaction, the crude product was concentrated and purified by high-performance liquid chromatography to obtain 18.07 mg of white solid 2-(((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyridino[2,3-e][1,4]oxazepine -9(7H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 30%). LC-MS: RT = 1.79 min, [M+H] ⁺ = 599.36. ¹ H NMR (500 MHz, DMSO-d ₆ ) δ 8.34 (s, 1H), 7.87 (d, J = 9.4 Hz, 2H), 7.77–7.62 (m, 3H), 7.51 (d, J = 8.1 Hz, 1H), 6.37 (d, J = 8.0 Hz, 1H), 5.42 (s, 2H), 5.01 (d, J = 7.0 Hz, 1H), 4.78 (dd, J = 15.4, 7.3 Hz, 1H),4.67–4.57(m,2H),4.51–4.45(m,2H),4.37–4.30(m,1H),4.15(s,1H),3.77(s,2H),3.67(s,2H),2.71(dd,J＝17.7,7.7Hz,2H),2.32(s,2H),1. 70–1.52(m,4H).

Example 7

Synthesis of 2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester

At room temperature, (R)-2-((4-chloro-2-fluorobenzyl)oxy)-7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine (118 mg, 0.32 mmol) was dissolved in N,N-dimethylformamide (5 ml), and methyl 2-((S)-1-chloroethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (100 mg, 0.32 mmol) and potassium carbonate (88 mg, 0.64 mmol) were added and reacted for 16 hours. After the reaction was completed, saturated sodium chloride was added to quench, and the mixture was extracted with ethyl acetate (10 ml × 2 times). The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated. The resulting crude product was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 90 mg of colorless oily liquid 2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 44%). LC-MS: RT = 1.85 min, [M+H] ⁺ = 635.23.

Step B: Synthesis of 2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (90 mg, 0.13 mmol) was dissolved in tetrahydrofuran/water/methanol (2/1/1, 4 ml), and lithium hydroxide monohydrate (17 mg, 0.39 mmol) was added and reacted at room temperature for 3 hours. After the reaction was completed, it was concentrated. The resulting residue was purified by preparative HPLC to give 12.7 mg of a white solid 2-((S)-1-((R)-2-((4-chloro-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 16%). LC-MS: RT = 1.81 min, [M+H] ⁺ = 622.25.

Example 8

Synthesis of 2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester

At room temperature, (R)-3-fluoro-4-(((7,7a,8,9,10,11-hexahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine 2-((S)-1-chloroethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (130 mg, 0.42 mmol) was added to N,N-dimethylformamide (10 ml), and the temperature was raised to 60 degrees Celsius for reaction. After the reaction was completed, saturated sodium chloride was added to quench the reaction, and the mixture was extracted with ethyl acetate (20 ml × 3 times). The organic phases were combined and dried, and the resulting crude product was concentrated and purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 10/1) to give 80 mg of a white solid 2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 30%). LC-MS: RT = 1.86 min, [M+H] ⁺ = 627.34.

Step B: Synthesis of 2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (80 mg, 0.13 mmol) was dissolved in a mixed solvent (6 ml, acetonitrile/water = 5/1), and 1,5,7-triazidobicyclo(4,4,0)dec-5-ene (36 mg, 0.26 mmol) was added and reacted at room temperature. After the reaction was completed, citric acid was added to quench the reaction, and the mixture was extracted with ethyl acetate (10 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, and the concentrated phase was concentrated. The resulting crude product was purified by silica gel column chromatography (eluent: dichloromethane/methanol = 10/1) to obtain 49 mg of a white solid 2-((S)-1-((R)-2-((4-cyano-2-fluorobenzyl)oxy)-7a,8,10,11-tetrahydro-5H-pyrazino[2,1-c]pyrido[2,3-e][1,4]oxazepine -9(7H)-yl)ethyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 58%). LC-MS: RT = 1.78 min, [M+H] ⁺ = 613.41. ¹ H NMR (400 MHz, DMSO-d ₆ )δ8.25(s,1H),7.89(d,J＝10.0Hz,1H),7.79(d,J＝8.4Hz,1H),7.67(dq,J＝15.6,7.7Hz,3H),7.41(t,J＝8.9Hz,1H),6.26(d,J＝7.9Hz,1H),5.49–5.34(m, 2H),5.14(s,1H),4.77(d,J＝13.2Hz,1H),4.66(dd,J＝15.7,5.7Hz,1H),4.57(d,J＝12.9Hz,1H),4.45(dd,J＝7.4,4.3Hz,2 H),4.36(d,J＝13.0Hz,1H),4.16(dt,J＝11.4,5.8Hz,1H),3.83(d,J＝12.7Hz,1H),3.65(d,J＝10.7Hz,2H),3.55(dd,J＝12.7,6.8Hz,2H),3.18-3.11(m,2H) ,2.76(d,J＝10.0Hz,1H),2.62(dd,J＝17.0,8.4Hz,1H),2.35–2.24(m,1H),2.12(t,J＝10.1Hz,1H),1.39(t,J＝8.1Hz,3H).

Comparative Example 1

Synthesis of 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of tert-butyl 4-(3-bromo-2-formylphenyl)piperazine-1-carboxylate

At room temperature, 2-bromo-6-fluorobenzaldehyde (2.0 g, 9.8 mmol) and tert-butyl piperazine-1-carboxylate (2.0 g, 10.8 mmol) were dissolved in N,N-dimethylformamide (15 ml), and triethylamine (3.0 g, 29.4 mmol) was added. The temperature was raised to 110 degrees Celsius to react overnight. After the reaction was complete, it was diluted with ethyl acetate (200 ml), washed with saturated brine (50 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The resulting residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 3.1 g of white solid tert-butyl 4-(3-bromo-2-formylphenyl)piperazine-1-carboxylate (yield: 82.6%). LC-MS: RT = 3.82 min, [M+H] ⁺ = 269.03, 271.02.

Step B: Synthesis of tert-butyl (E)-4-(3-bromo-2-((2-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylate

At room temperature, the compound tert-butyl 4-(3-bromo-2-formylphenyl)piperazine-1-carboxylate (2.0 g, 5.4 mmol) and p-toluenesulfonylhydrazide (1.1 g, 5.7 mmol) were dissolved in ethanol and reacted under reflux for 2 hours. After the reaction was complete, the mixture was concentrated to obtain 3.1 g of pale yellow solid crude product (E)-tert-butyl 4-(3-bromo-2-((2-p-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylate, which was directly used in the next step without further purification.

Step C: Synthesis of tert-butyl 9-bromo-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

Dissolve (E)-tert-butyl 4-(3-bromo-2-((2-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylate (3.1 g, 5.4 mmol) in dry toluene (15 ml) and replace with nitrogen three times. Add 60% sodium hydride (432.2 mg, 10.8 mmol) under nitrogen protection and react overnight under reflux. After the reaction is complete, cool down, add saturated ammonium chloride solution to quench, extract with ethyl acetate (200 ml), wash with 1 mol dilute hydrochloric acid aqueous solution (40 ml × 2 times) and saturated brine (30 ml × 1 time), dry over anhydrous sodium sulfate and concentrate. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 20/1) to obtain 1.5 g of pale yellow solid tert-butyl 9-bromo-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield: 52.6%).

Step D: Synthesis of tert-butyl 9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

Tert-butyl 9-bromo-3,4,10,10a-tetrahydropyrazino[1,2-a]indole-2(1H)-carboxylate (815.0 mg, 2.3 mmol), bis(pinacolato)diboron (876.1 mg, 3.4 mmol), 2-dicyclohexylphospho-2,4,6-triisopropylbiphenyl (43.8 mg, 92.1 μmol) and potassium acetate (677.1 mg, 6.9 mmol) were dissolved in dioxane (10 ml) at room temperature. The mixture was replaced with nitrogen three times. Under the protection of nitrogen, trisdibenzylideneacetone dipalladium (42.1 mg, 46.1 μmol, replaced with nitrogen three times) was added and the temperature was raised to reflux for reaction overnight. After the reaction was complete, the mixture was filtered, diluted with ethyl acetate (150 ml), washed with water (30 ml × 2 times) and saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 20/1) to obtain 681.3 mg of light yellow oily 9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylic acid tert-butyl ester (yield: 68.4%). LC-MS: RT = 3.95 min, [M+H] ⁺ = 401.15.

Step E: Synthesis of tert-butyl 9-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

Under ice bath, compound 9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylic acid tert-butyl ester (681.3 mg, 1.7 mmol) was dissolved in tetrahydrofuran (10 ml), 1 mol sodium hydroxide aqueous solution (5 ml) and 30% hydrogen peroxide (1 ml) were slowly added, and the temperature was slowly raised to room temperature for 3 hours. After the reaction was complete, the temperature was lowered to zero degrees Celsius, the pH was adjusted to 6-7 with 1 mol hydrochloric acid aqueous solution, and extracted with ethyl acetate (30 ml × 3 times), the organic phases were combined, washed with saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 258.2 mg of pale yellow oily tert-butyl 9-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield 52.4%). LC-MS: RT = 1.55 min, [M- ^t Bu] ⁺ = 235.11.

Step F: Synthesis of tert-butyl 9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

At room temperature, tert-butyl 9-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (258.2 mg, 0.9 mmol) and 4-(bromomethyl)-3-fluorobenzonitrile (380.6 mg, 1.7 mmol) were dissolved in N,N-dimethylformamide (3 ml), anhydrous potassium carbonate (494.3 mg, 3.5 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was complete, the mixture was diluted with ethyl acetate (60 ml), washed with saturated brine (20 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 8/1) to obtain 162.2 mg of colorless oily tert-butyl 9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield: 51.1%). LC-MS: RT = 3.18 min, [M- ^t Bu] ⁺ = 368.16

Step G: Synthesis of 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazine[1,2-a]indol-9-yl)oxy)methyl)benzonitrile

At room temperature, tert-butyl 9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (162.2 mg, 383.4 μmol) was dissolved in dichloromethane (2 ml), trifluoroacetic acid (2 ml) was added, and the mixture was reacted at room temperature for 1 hour. After the reaction was complete, the mixture was concentrated to obtain 123.8 mg of a light yellow oily substance, 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazine[1,2-a]indol-9-yl)oxy)methyl)benzonitrile, which was directly used in the next step without further purification.

Step H: Synthesis of methyl 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

At room temperature, 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazin[1,2-a]indol-9-yl)oxy)methyl)benzonitrile (123.8 mg, 383.4 μmol) and (S)-methyl 2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-5-carboxylate (135.1 mg, 459.5 μmol) were dissolved in N,N-dimethylformamide (3 ml), anhydrous potassium carbonate (186.2 mg, 1.3 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was complete, the mixture was diluted with ethyl acetate (60 ml), washed with saturated brine (20 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 1/1 to dichloromethane/methanol = 15/1) to obtain 160.3 mg of pale yellow oily 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 72.1%). LC-MS: RT = 3.84 min, [M+H] ⁺ = 582.53.

Step I: Synthesis of 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

At room temperature, the compound 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (160.3 mg, 275.9 μmol) was dissolved in tetrahydrofuran (3 ml), ethanol (1 ml) and water (1 ml), lithium hydroxide (57.9 mg, 21.4 mmol) was added, and the mixture was reacted at room temperature for 16 hours. After the reaction was completed, the pH was adjusted to 5 with 1 mol/L citric acid aqueous solution, diluted with water (20 ml), extracted with ethyl acetate (25 ml × 3 times), washed with saturated brine (25 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was further purified by semi-preparative HPLC (mobile phase: water containing 0.1% ammonia/acetonitrile = 90/10 to 40/60) to obtain 51.1 mg of white solid 2-((9-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 32.7%). LC-MS: RT = 3.51 min, [M+H] ⁺ = 568.50. ¹ H NMR (400 MHz, CD ₃ OD)δ8.38(d,J＝1.5Hz,1H),8.01(dd,J＝8.4,1.5Hz,1H),7.79–7.68(m,2H),7.65–7.57(m,2H),7.04(t,J＝8.0Hz,1H),6.39(dd,J＝8.3,1.6Hz,1H),6.25(dd ,J＝7.8,3.4Hz,1H),5.29(td,J＝7.2,2.5Hz,1H),5.24(d,J＝2.9Hz,2H),4.78(t,J＝ 2.3Hz,1H),4.68(td,J＝8.0,5.9Hz,1H),4.50(dt,J＝9.0,5.9Hz,1H),4.05(dd,J＝13.8,11.8Hz,1H),3.94(dd,J＝13.7,10.6Hz,1H),3.72–3.60(m,2H),3. 15–2.95(m,2H),2.93–2.75(m,3H),2.55(tt,J＝15.1,5.7Hz,2H),2.46–2.20(m,2H).

Comparative Example 2

Synthesis of 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of tert-butyl 4-(5-bromo-2-formylphenyl)-piperazine-1-carboxylate

At room temperature, 4-bromo-2-fluorobenzaldehyde (2.0 g, 9.8 mmol) and tert-butyl piperazine-1-carboxylate (2.0 g, 10.8 mmol) were dissolved in N,N-dimethylformamide (15 ml), triethylamine (3.0 g, 29.4 mmol) was added, and the mixture was reacted overnight under reflux. After the reaction was complete, the mixture was diluted with ethyl acetate (200 ml), washed with saturated brine (50 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 3.1 g of white solid tert-butyl 4-(5-bromo-2-formylphenyl)-piperazine-1-carboxylate (yield: 82.6%). LC-MS: RT = 3.82 min, [M+H] ⁺ = 269.03, 271.02.

Step B: Synthesis of (E)-tert-butyl 4-(5-bromo-2-((2-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylate

At room temperature, the compound 4-(5-bromo-2-formylphenyl)-piperazine-1-carboxylic acid tert-butyl ester (2.0 g, 5.4 mmol) and p-toluenesulfonyl hydrazide (1.1 g, 5.7 mmol) were dissolved in ethanol (20 ml) and reacted under reflux for 2 hours. After the reaction was complete, the mixture was concentrated to obtain 3.1 g of pale yellow solid crude product (E)-4-(5-bromo-2-((2-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylic acid tert-butyl ester, which was directly used in the next step without further purification.

Step C: Synthesis of tert-butyl 7-bromo-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

At room temperature, tert-butyl (E)-4-(5-bromo-2-((2-toluenesulfonylhydrazono)methyl)phenyl)piperazine-1-carboxylate (3.1 g, 5.4 mmol) was dissolved in dry toluene (15 ml) and replaced with nitrogen three times. Under nitrogen protection, 60% sodium hydride (432.2 mg, 10.8 mmol) was added and the temperature was raised to reflux for reaction overnight. After the reaction was complete, the temperature was lowered, quenched with saturated ammonium chloride solution, diluted with ethyl acetate (200 ml), washed with 1 mol dilute hydrochloric acid aqueous solution (40 ml × 2 times) and saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 20/1) to obtain 1.5 g of pale yellow solid tert-butyl 7-bromo-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield: 52.6%). ¹ H NMR (400 MHz, CDCl ₃ ) δ 6.99-6.92 (m, 1H), 6.81 (dt, J = 7.7, 2.0 Hz, 1H), 6.58 (t, J = 2.1 Hz, 1H), 3.56-3.43 (m, 2H), 3.10-2.64 (m, 6H), 2.55 (ddd, J = 15.4, 8.7, 2.6 Hz, 1H), 1.52 (d, J = 2.7 Hz, 9H).

Step D: Synthesis of tert-butyl 7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

At room temperature, tert-butyl 7-bromo-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (815.0 mg, 2.3 mmol), bis(pinacolato)diboron (876.1 mg, 3.4 mmol), 2-dicyclohexylphospho-2,4,6-triisopropylbiphenyl (43.8 mg, 92.1 μmol) and potassium acetate (677.1 mg, 6.9 mmol) were dissolved in dioxane (10 ml). The atmosphere was replaced with nitrogen three times, and trisdibenzylideneacetone dipalladium (42.1 mg, 46.1 μmol) was added under nitrogen protection. The atmosphere was replaced with nitrogen three times, and the temperature was raised to reflux for reaction overnight. After the reaction was complete, the mixture was filtered, diluted with ethyl acetate (150 ml), washed with water (30 ml × 2 times) and saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 20/1) to obtain 681.3 mg of pale yellow oily tert-butyl 7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield: 68.4%). LC-MS: RT = 3.95 min, [M+H] ⁺ = 401.15.

Step E: Synthesis of tert-butyl 7-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

Under ice bath, compound 7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylic acid tert-butyl ester (681.3 mg, 1.7 mmol) was dissolved in tetrahydrofuran (10 ml), 1 mol sodium hydroxide aqueous solution (5 ml) and 30% hydrogen peroxide (1 ml) were added, and the mixture was slowly returned to room temperature and stirred for 3 hours. After the reaction was complete, the temperature was lowered to zero degrees Celsius, and the pH was adjusted to 6-7 with 1 mol hydrochloric acid aqueous solution, and extracted with ethyl acetate (30 ml × 3 times), the organic phases were combined, washed with saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 258.2 mg of pale yellow oily tert-butyl 7-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield 52.4%). LC-MS: RT = 1.55 min, [M- ^t Bu] ⁺ = 235.11.

Step F: Synthesis of tert-butyl 7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate

At room temperature, tert-butyl 7-hydroxy-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (258.2 mg, 0.9 mmol) and 4-(bromomethyl)-3-fluorobenzonitrile (380.6 mg, 1.7 mmol) were dissolved in N,N-dimethylformamide (3 ml), anhydrous potassium carbonate (494.3 mg, 3.5 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was complete, the mixture was diluted with ethyl acetate (60 ml), washed with saturated brine (20 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 8/1) to obtain 162.2 mg of colorless oily tert-butyl 7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (yield: 51.1%). LC-MS: RT = 3.18 min, [M- ^t Bu] ⁺ = 368.16.

Step G: Synthesis of 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazine[1,2-a]indol-7-yl)oxy)methyl)benzonitrile

At room temperature, tert-butyl 7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indole-2(1H)-carboxylate (162.2 mg, 383.4 μmol) was dissolved in dichloromethane (2 ml), trifluoroacetic acid (2 ml) was added, and the mixture was reacted at room temperature for 1 hour. After the reaction was complete, the mixture was concentrated to obtain 123.8 mg of a light yellow oily substance, 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazine[1,2-a]indol-7-yl)oxy)methyl)benzonitrile, which was directly used in the next step without further purification.

Step H: Synthesis of methyl 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

At room temperature, 3-fluoro-4-(((1,2,3,4,10,10a-hexahydropyrazin[1,2-a]indol-7-yl)oxy)methyl)benzonitrile (123.8 mg, 383.4 μmol) and (S)-methyl 2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-5-carboxylate (135.1 mg, 459.5 μmol) were dissolved in N,N-dimethylformamide (3 ml), anhydrous potassium carbonate (186.2 mg, 1.3 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was complete, the mixture was diluted with ethyl acetate (60 ml), washed with saturated brine (20 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 1/1 to dichloromethane/methanol = 15/1) to obtain 160.3 mg of pale yellow oily 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 72.1%). LC-MS: RT = 3.84 min, [M+H] ⁺ = 582.53.

Step I: Synthesis of 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazino[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

At room temperature, the compound 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (160.3 mg, 275.9 μmol) was dissolved in tetrahydrofuran (3 ml), ethanol (1 ml) and water (1 ml), lithium hydroxide (57.9 mg, 21.4 mmol) was added, and the reaction was carried out at room temperature for 16 hours. After the reaction was completed, the pH was adjusted to 5 with 1 mol/L citric acid aqueous solution, diluted with water (20 ml), extracted with ethyl acetate (25 ml × 3 times), washed with saturated brine (25 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was further purified by semi-preparative HPLC (mobile phase: water containing 0.1% ammonia/acetonitrile = 90/10 to 40/60) to obtain 51.1 mg of white solid 2-((7-((4-cyano-2-fluorobenzyl)oxy)-3,4,10,10a-tetrahydropyrazine[1,2-a]indol-2(1H)-yl)methyl)-1-(((S)-oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 32.7%). LC-MS: RT = 3.51 min, [M+H] ⁺ = 568.50.

Comparative Example 3

Synthesis of (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 5-amino-3,4-dihydroisoquinoline-2-(1H)-carboxylic acid benzyl ester

At room temperature, the compound 1,2,3,4-tetrahydroisoquinoline-5-amino (1.0 g, 6.7 mmol) and sodium bicarbonate (1.1 g, 13.4 mmol) were dissolved in tetrahydrofuran and water (5 ml/5 ml), and benzyl chloroformate (1.4 g, 8.1 mmol) was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 3 hours. After the reaction was complete, the mixture was diluted with ethyl acetate (100 ml), washed with saturated brine (40 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 1/1) to obtain 1.3 g of yellow solid 5-amino-3,4-dihydroisoquinoline-2-(1H)-carboxylic acid benzyl ester (yield 68.4%).

Step B: Synthesis of 5-(3,3-diethoxypropionamido)-3,4-dihydroisoquinoline-2(1H)-carboxylic acid benzyl ester

At room temperature, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (114.2 mg, 379.2 μmol) and 3,3-diethoxypropionic acid (61.4 mg, 379.2 μmol) were dissolved in dry N,N-dimethylformamide (3 ml), and N,N-diisopropylethylamine (98.0 mg, 758.4 μmol) was added. The mixture was reacted for 3 minutes, and 5-amino-3,4-dihydroisoquinoline-2-(1H)-carboxylic acid benzyl ester (107.2 mg, 379.2 μmol) was added. The mixture was reacted for 5 hours at room temperature. After the reaction was complete, the mixture was diluted with ethyl acetate (50 ml), washed with 1 mol hydrochloric acid (15 ml × 2) and saturated brine (15 ml × 1), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 6/1) to obtain 107.2 mg of yellow oily benzyl 5-(3,3-diethoxyamido)-3,4-dihydroisoquinoline-2(1H)-carboxylate (yield 74.7%).

Step C: Synthesis of 2-hydroxy-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester

At room temperature, 5-(3,3-diethoxyamido)-3,4-dihydroisoquinoline-2(1H)-carboxylic acid benzyl ester (627.2 mg, 1.5 mmol) was dissolved in glacial acetic acid (5 ml), and concentrated hydrochloric acid (3 ml) was added dropwise. The reaction was allowed to react at room temperature for 16 hours. After the reaction was complete, ethyl acetate (100 ml) was added for dilution, and the mixture was washed with water (30 ml × 2), saturated sodium bicarbonate aqueous solution (30 ml × 2), saturated brine (30 ml × 1), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 5/1 to petroleum ether/ethyl acetate = 1/1) to obtain 100.1 mg of yellow oily 2-hydroxy-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester (yield 20.3%).

Step D: Synthesis of 2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester

At room temperature, 2-hydroxy-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester (100.0 mg, 0.3 mmol) and 4-cyano-2-fluorobenzyl bromide (96.3 mg, 0.4 mmol) were dissolved in N,N-dimethylformamide (3 ml), potassium carbonate (124.3 mg, 0.9 mmol) was added, and the mixture was reacted at room temperature for 6 hours. After the reaction was complete, the mixture was diluted with ethyl acetate (100 ml), washed with water (30 ml × 2) and saturated brine (30 ml × 1), dried over anhydrous sodium sulfate, and concentrated. The obtained residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 5/1 to petroleum ether/ethyl acetate = 2/1) to obtain 214.2 mg of light yellow oily 2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester (yield 76.2%).

Step E: Synthesis of 3-fluoro-4-(((7,8,9,10-tetrahydro-1,8-phenanthroline-2-yl)oxy)methyl)benzonitrile

At room temperature, 2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-carboxylic acid benzyl ester (214.2 mg, 458.1 μmol) was dissolved in ethyl acetate (6 ml), 10% wet palladium carbon (21.4 mg) was added, and the hydrogen atmosphere was replaced three times. The reaction was allowed to proceed overnight under a hydrogen atmosphere. After the reaction was complete, the mixture was filtered and the filtrate was concentrated. 137.5 mg of light yellow oily 3-fluoro-4-(((7,8,9,10-tetrahydro-1,8-phenanthroline-2-yl)oxy)methyl)benzonitrile was obtained (yield 90.1%).

Step F: Synthesis of (S)-methyl 2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

At room temperature, 3-fluoro-4-(((7,8,9,10-tetrahydro-1,8-phenanthroline-2-yl)oxy)methyl)benzonitrile (141.2 mg, 0.4 mmol) and (S)-methyl 2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (141.4 mg, 0.4 mmol) were dissolved in N,N-dimethylformamide (4 ml), anhydrous potassium carbonate (166.8 mg, 1.2 mmol) was added, and the mixture was reacted at room temperature for 6 hours. The mixture was diluted with ethyl acetate (100 ml), washed with water (30 ml × 2 times) and saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The resulting residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 1/1 to dichloromethane/methanol 15/1) to give 135.1 mg of a light yellow oily substance (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (yield: 54.0%).

Step G: Synthesis of (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

At room temperature, (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid methyl ester (135.0 mg, 228.1 μmol) was dissolved in a mixed solvent of tetrahydrofuran/water/ethanol (3:1:1, 8 ml), and sodium hydroxide (48.0 mg, 1.2 mmol) was added, and the mixture was reacted at room temperature overnight. After the reaction was completed, the pH was adjusted to 3-4 with 1 mol citric acid aqueous solution under ice bath condition, and the mixture was diluted with ethyl acetate (150 ml), washed with water (30 ml × 2 times) and saturated brine (30 ml × 1 time), dried over anhydrous sodium sulfate, and concentrated. The resulting residue was purified by reverse phase HPLC (mobile phase: water/acetonitrile = 90/10 to 40/60) and lyophilized to give 20.1 mg of a white solid (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-9,10-dihydro-1,8-phenanthroline-8(7H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: 15.2%). NMR (400MHz, CD3OD) δ8.32(d,J＝1.6Hz,1H),8.08(d,J＝8.9Hz,1H),7.98(dd,J＝8.5,1.5Hz,1H),7.71(dd,J＝9.9,8.0Hz,2H),7.60–7.53(m,3H),7.07(d,J＝8.3Hz ,1H),6.99(d,J＝8.7Hz,1H),5.66(s,2H),5.25–5.17(m,1H),4.72(dd, J＝15.3,2.7Hz,1H),4.57(dt,J＝8.1,5.9Hz,2H),4.42(dt,J＝9.1,5.9Hz,1H),4.25(d,J＝13.7Hz,1H),4.13(d,J＝13.7Hz,1H),3.83(d,J＝6.7Hz,2H),3.24 –3.22(m,2H),3.01–2.95(m,2H),2.66(t,J＝9.1Hz,1H),2.47(d,J＝9.4Hz,1H).

Comparative Example 4

Synthesis of (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

The specific synthetic route is as follows:

Step A: Synthesis of 1-(tert-butyl)-2-ethyl 1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid

To ethyl 1H-pyrrolo[2,3-b]pyridine-2-carboxylate (2.00 g, 10.5 mmol) in acetonitrile (20 ml) was added di-tert-butyl dicarbonate (2.61 g, 12.1 mmol) and 4-dimethylaminopyridine (128 mg, 1.05 mmol) at room temperature and reacted at room temperature for 1 hour. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with dichloromethane (30 ml x 2 times). The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/4). 2.70 g of 1-(tert-butyl)2-ethyl1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid was obtained as a white solid (yield: 88.5%). LC-MS: RT = 2.14 min, [M+H] ⁺ = 291.15.

Step B: Synthesis of 1-(tert-butyloxycarbonyl)-2-(ethoxycarbonyl)-1H-pyrrolo[2,3-b]pyridine-7-oxide

At 0°C, 85% m-chloroperbenzoic acid (2.33 g, 13.9 mmol) was added to dichloromethane (20 ml) containing 1-(tert-butyl)-2-ethyl 1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid (2.70 g, 9.31 mmol) and reacted at room temperature for 1 hour. After the reaction was completed, sodium sulfite aqueous solution was added to quench, and dichloromethane (30 ml x 2 times) was used for extraction. The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/3. 1.80 g of 1-(tert-butyloxycarbonyl)-2-(ethoxycarbonyl)-1H-pyrrolo[2,3-b]pyridine-7-oxide was obtained as a white solid (yield: 63.3%). LC-MS: RT = 1.98 min, [M+H] ⁺ = 307.23

Step C: Synthesis of 1-(tert-butyl)-2-ethyl-6-bromo-1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid

Hexamethyldisilazane (0.95 g, 5.88 mmol) and benzoyl bromide (2.71 g, 14.7 mmol) were added to toluene (20 ml) containing 1-(tert-butoxycarbonyl)-2-(ethoxycarbonyl)-1H-pyrrolo[2,3-b]pyridine-7-oxide (1.80 g, 5.88 mmol) at room temperature and reacted at room temperature for 2 hours. After the reaction was completed, sodium carbonate solution was added, and the mixture was extracted with ethyl acetate (30 ml x 2 times). The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/5). 840 mg of light yellow solid 1-(tert-butyl)-2-ethyl-6-bromo-1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid was obtained (yield: 40.1%). LC-MS: RT = 2.26 min, [M+H] ⁺ = 369.14.

Step D: Synthesis of ethyl 6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

At room temperature, 1-(tert-butyl)-2-ethyl-6-bromo-1H-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid (840 mg, 2.28 mmol) was dissolved in 10 ml of dichloromethane, and 3 ml of trifluoroacetic acid was added to react for 1 hour. After the reaction was completed, the mixture was extracted with sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain 612 mg of 6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid ethyl ester (yield: 99.6%) as a pale yellow solid. LC-MS: RT = 2.12 min, [M+H] ⁺ = 269.23.

Step E: Synthesis of ethyl 6-bromo-1-(2-((tert-butoxycarbonyl)amino)ethyl)-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

To a solution of ethyl 6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylate (612 mg, 2.28 mmol) in N,N-dimethylformamide (5.0 ml) was added tert-butyl 1,2,3-oxathiazolidine-3-carboxylate-2,2-dioxide (611 mg, 2.74 mmol) and potassium tert-butoxide (384 mg, 3.42 mmol) at room temperature, and the mixture was reacted at room temperature for 2 hours. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with ethyl acetate (30 ml x 2 times). The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/3). 523 mg of 6-bromo-1-(2-((tert-butoxycarbonyl)amino)ethyl)-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid ethyl ester was obtained as a white solid (yield: 55.8%). LC-MS: RT = 2.18 min, [M+H] ⁺ = 412.18.

Step F: Synthesis of ethyl 1-(2-aminoethyl)-6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylate

At room temperature, 6-bromo-1-(2-((tert-butoxycarbonyl)amino)ethyl)-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid ethyl ester (523 mg, 1.27 mmol) was dissolved in 10 ml of dichloromethane, and 3 ml of trifluoroacetic acid was added to react for 30 minutes. After the reaction was completed, the mixture was extracted with sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain 360 mg of 1-(2-aminoethyl)-6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylic acid ethyl ester (yield: 90.9%) as a pale yellow solid. LC-MS: RT = 1.95 min, [M+H] ⁺ = 312.23.

Step G: Synthesis of 2-bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-6(7H)-one

Potassium carbonate (317 mg, 2.30 mmol) was added to methanol (5.0 ml) containing ethyl 1-(2-aminoethyl)-6-bromo-1H-pyrrolo[2,3-b]pyridine-2-carboxylate (360 mg, 1.15 mmol) at room temperature, and the mixture was reacted at room temperature for 2 hours. After the reaction was completed, water was added to quench the mixture, and the mixture was extracted with ethyl acetate (30 ml × 2 times). The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/3. 296 mg of 2-bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine-6(7H)-one was obtained as a light yellow solid. LC-MS: RT = 2.05 min, [M+H] ⁺ = 266.17.

Step H: Synthesis of 2-bromo-6,7,8,9-tetrahydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine

2-Bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine-6(7H)-one (296 mg, 1.11 mmol) was dissolved in 10 ml of methyl tert-butyl ether, and lithium aluminum hydride (84.3 mg, 2.22 mmol) was added at 0°C, and the temperature was raised to 65°C for 1 hour. After the reaction was completed, water was added to quench, and ethyl acetate (30 ml × 2 times) was used for extraction. The organic phases were combined, washed with saturated brine (20 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 1/1) to obtain 160 mg of 2-bromo-6,7,8,9-tetrahydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine as a white solid (yield: 57.3%). LC-MS: RT=1.98min, [M+H] ⁺ =252.13.

Step I: Synthesis of (S)-tert-butyl 2-((2-bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

To a solution of 2-bromo-6,7,8,9-tetrahydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine (160 mg, 0.637 mmol) in N,N-dimethylformamide (5.0 ml) was added (S)-tert-butyl 2-(chloromethyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (225 mg, 0.637 mmol), potassium carbonate (132 mg, 0.955 mmol) and potassium iodide (158 mg, 0.955 mmol) at room temperature, and the mixture was reacted at room temperature for 3 hours. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with ethyl acetate (30 ml x 2 times). The organic phases were combined, washed with saturated brine (30 ml), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 4/1. 182 mg of (S)-2-((2-bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazine-7(6H)-yl)methyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester was obtained (yield: 52.1%). LC-MS: RT = 2.17 min, [M+H] ⁺ = 552.17.

Step J: Synthesis of (S)-tert-butyl 2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate

At room temperature, a mixture containing tert-butyl (S)-2-((2-bromo-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate (70.0 mg, 0.127 mmol), 3-fluoro-4-(hydroxymethyl)benzonitrile (28.7 mg, 0. Cesium carbonate (82.7 mg, 0.254 mmol) and methanesulfonic acid (2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl) (2'-amino-1,1'-biphenyl-2-yl) palladium (II) (10.7 mg, 0.0127 mmol) were added to 1,4-dioxane (5 ml) (191 mmol), and the temperature was raised to 100 degrees Celsius for 3 hours. After the reaction was completed, water was added to quench, and ethyl acetate (30 ml × 3 times) was used for extraction. The organic phases were combined, washed with saturated brine (30 ml × 2 times), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane = 5/1). 47.0 mg of (S)-tert-butyl 2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylate was obtained as a light yellow solid (yield: 59.6%). LC-MS: RT = 2.13 min, [M+H] ⁺ = 623.33.

Step K: Synthesis of (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetan-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid

Dissolve ((S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid tert-butyl ester (47.0 mg, 0.075 mmol) in 4 ml of anhydrous dichloromethane, add 2 ml of trifluoroacetic acid, and react at room temperature for 40 minutes. After the reaction is completed, the reaction solution is poured into 20 ml of sodium bicarbonate solution, and dichloromethane (30 ml × 2 times) is added. ) was extracted, the organic phases were combined, washed with saturated brine (20 ml x 2 times), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluent: methanol/dichloromethane = 10/1) to obtain 22 mg of a white solid (S)-2-((2-((4-cyano-2-fluorobenzyl)oxy)-8,9-dihydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazin-7(6H)-yl)methyl)-1-((oxetane-2-yl)methyl)-1H-benzo[d]imidazole-6-carboxylic acid (yield: ^51.7 %). NMR (400MHz, DMSO) δ12.74(s,1H),8.29(s,1H),7.89(d,J＝9.5Hz,1H),7.85–7.76(m,3H),7.73–7.68(m,2H),6.62(d,J＝8.6Hz,1H),6.14(s,1H),5.51(s,2 H),5.09–5.02(m,1H),4.84–4.77 (m,1H),4.70–4.63(m,1H),4.47–4.42(m,1H),4.38–4.32(m,1H),4.07–4.03(m,2H),3.89–3.81(m,2H),3.09–3.03(m,2H),2.66–2.57(m,2H),2.4 1–2.32(m,2H). LC-MS: RT=1.97min, [M+H] ⁺ =567.25.

Example 9: Measurement of in vitro cAMP signaling activation by compounds in human GLP1R cells

1. Cell culture

A cell line stably expressing human GLP1 R (hGLP1R-U2OS) was used in the experiment. The cells were cultured in a growth medium (complete medium, DMEM + 10% FBS + 500 μg/ml G418 (Promega)) at 37°C in a humidified incubator with 5% CO ₂ .

2. cAMP determination

hGLP1R-U2OS were seeded in 384-well plates at 1.0×10 ⁴ cells/well (5 μl) (cell working solution: DMEM+0.1% BSA+1mM IBMX (Biode Pharmaceuticals)), and placed in a 37°C incubator for 30 min for use. The test compound was diluted stepwise with Stimulation Buffer 1 (1X) in the kit, and the diluted test compound was added to the culture plate at 5 μl/well, and incubated in a 37°C incubator for 30 min. Then, 5 μl/well of cAMP-d2 prepared with Lysis & Detection buffer and 5 μl/well of Anti cAMP-Cryptate working solution were added in sequence, incubated at room temperature for 60 min, and finally detected.

3. Data processing

The ratio of the donor and acceptor emission signals in each well was calculated: HTRF rate = 665 nm signal / 620 nm signal * 104, and then the HTRF rate was converted into a response rate (%). The concentration-response curve of each example compound was created by the four-parameter equation of Y = Bottom + (Top-Bottom) / (1 + 10^((LogIC50-X)*HillSlope)), and the half-maximal (50%) effective concentration ( _EC50 ) was calculated. The results are shown in Table 1.

Table 1: EC ₅₀ of the compounds of the present invention on human GLP-1R

Example compounds _EC50 (nM) 1 2.39 2 1.4 3 24.4 4 25.6 5 6.36 6 1.60 7 13.8 8 4.15 Comparative Example 1 >1000 Comparative Example 2 261.7 Comparative Example 3 269.1 Comparative Example 4 482.7

Conclusion: The compounds of the present invention have obvious agonist activity on human GLP-1R. Among them, the different tricyclic types, the activity of Y and W in the para position is better than that of Y and W in the ortho position, the activity of non-aromatic ring B is better than that of aromatic ring, and the activity of B ring is significantly improved after changing from a 5-membered ring to a 7-membered ring.

The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims (10)

1. A compound of formula (I), or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof:

Wherein:

the A is selected from benzene rings and pyridine rings;

The said Selected from the group consisting of

R ¹ is selected from hydrogen, halogen, cyano, alkyl of C _1-6, alkoxy of C _1-6, haloalkyl of C _1-6;

m is 0, 1,2 or 3;

W is selected from O;

R ² is selected from hydrogen, halogen, cyano, alkyl of C _1-6, haloalkyl of C _1-6, alkoxy of C _1-6;

n is 0, 1,2 or 3;

R ³ is selected from hydrogen, fluoro, hydroxy, cyano, C _1-3 alkyl, OC _1-3 alkyl;

R ⁴ is-C _0-3 alkylene-R ⁹;

R ⁹ is 4 membered heterocyclylalkyl;

Z ¹、Z² and Z ³ are each independently-CR ^Z or N, and each R ^Z is independently H, F, cl or-CH ₃.

2. The compound of claim 1, or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein said 4-membered heterocyclyl is selected from the group consisting of

3. The compound according to claim 1 or 2, or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein the compound is a compound of formula (i)Selected from the group consisting of

4. A compound according to claim 1, or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein a is selected from the group consisting of a benzene ring, a pyridine ring;

r ¹ is selected from cyano, fluoro, chloro;

Selected from the group consisting of

W is-O-;

R ² is hydrogen;

R ³ is hydrogen, methyl;

r ⁴ is oxetan-2-ylmethyl;

z ¹、Z²、Z³ is CH or N.

5. The compound of claim 4, or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein a is selected from the group consisting of a benzene ring, a pyridine ring;

r ¹ is selected from cyano, fluoro, chloro;

Selected from the group consisting of

W is-O-;

R ² is hydrogen;

R ³ is hydrogen, methyl;

r ⁴ is oxetan-2-ylmethyl;

z ¹、Z²、Z³ is CH or N.

6. A compound according to claim 1, or a tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein said compound is selected from the group consisting of the following structures:

7. the compound according to claim 1, or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, wherein said pharmaceutically acceptable salt is prepared from the compound and a pharmaceutically acceptable acid or base.

8. A pharmaceutical composition comprising a compound according to any one of the preceding claims 1-7, or a meso, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers.

9. Use of a compound according to any one of claims 1-7, or a pharmaceutically acceptable salt thereof, in the manufacture of a medicament for the treatment of GLP-1 related diseases.

10. The use according to claim 9, wherein the GLP-1 related disease is selected from diabetes related diseases.