PGI2 receptor agonist compound, pharmaceutical composition, and use

Abstract

The present application relates to the technical field of chemical medicines, and provides a PGI2 receptor agonist compound as represented by general formula I or a pharmaceutically acceptable salt, stable isotope derivative, isomer and mixture thereof. In the formula, R1 and R2 are each independently selected from H, C1-C3 alkyl, or a halogen atom; Z is selected from CR7 or an N atom, wherein R7 is selected from H or C1-C3 alkyl, a halogen atom or halogenated C1-C3 alkyl; R3 is selected from C1-C3 alkyl and C3-C6 monocyclic cycloalkyl; R4 is selected from H, C1-C3 alkoxy, or 3-6 membered heteroalicyclyl; R5 represents OH, OR6, or NHSO2R6, wherein R6 represents C1-4alkyl or C1-4 alkyl substituted with a halogen; and [Symbol 1] represents a single bond or a double bond. The compound has good affinity to a PGI2 receptor, and exhibits minimal adverse effects, thereby avoiding the current defects of PGI2 analogs and selexipag.

Description

PGI2 receptor agonist compounds, pharmaceutical compositions and applications

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application CN202311824286.0, filed on December 27, 2023, and Chinese patent application CN202410701014.X, filed on May 31, 2024. This application cites the full text of the above-mentioned Chinese patent applications. Technical Field

[0003] The present application belongs to the field of chemical medicine technology, and specifically relates to a PGI2 receptor agonist compound, a pharmaceutical composition and an application thereof. Background Art

[0004] Pulmonary arterial hypertension (PAH) is a disease characterized by vasospasm, intimal hyperplasia, and remodeling of the pulmonary arterioles. This proliferation and remodeling leads to a progressive increase in pulmonary vascular resistance, ultimately causing right heart failure and ultimately death. PAH is ranked the third most common cardiovascular disease, second only to hypertension and coronary heart disease in prevalence. It has become a serious public health concern threatening human health and well-being, and is included in the World Health Organization's global monitoring of major chronic diseases.

[0005] PGI2 is a substance produced in vivo from arachidonic acid via prostaglandin H2 (PGH2). PGI2 deficiency can cause pulmonary hypertension. Currently, marketed PGI2 receptor agonists include epoprostenol, beraprost, and iloprost, all of which are PGI2 analogs. However, due to PGI2's very short biological half-life and poor target selectivity, it is difficult to separate the intended effect from other effects, making adverse reactions more likely. Selexipag is currently the only PGI2 receptor agonist that does not have a PGI2 backbone but exhibits excellent selectivity for the PGI2 receptor and demonstrated efficacy. It has been approved for marketing in multiple countries for the treatment of adult pulmonary arterial hypertension. Its specific therapeutic effect is stronger and longer-lasting than other drugs with similar mechanisms, but its high price undoubtedly imposes a significant financial burden on patients with pulmonary arterial hypertension who require long-term treatment. In addition, although selexipag has relatively good specificity, it still has obvious adverse reactions, such as headache, facial flushing, nausea, vomiting, etc. For patients who need long-term medication, the cumulative damage caused by the drug to the body will reduce their health level and quality of life to varying degrees. Technical issues

[0006] In response to the above problems, the present application provides a PGI2 receptor agonist compound, pharmaceutical composition and application. The compound has good affinity for PGI2 receptors and very low adverse reactions, avoiding the shortcomings of current PGI2 analogs and selexipag. Technical Solutions

[0007] In order to achieve the above application objectives, this application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a PGI2 receptor agonist compound represented by general formula I or a pharmaceutically acceptable salt, stable isotope derivative, isomer, and mixture thereof,

[0009] In Formula I, R1 and R2 are independently selected from H, C1-C3 alkyl or halogen atom;

[0010] Z is selected from CR7 or N atom, wherein R7 is selected from H or C1-C3 alkyl, halogen atom or halogenated C1-C3 alkyl;

[0011] R3 is selected from C2-C4 alkyl, C 3- C6 monocyclic cycloalkyl;

[0012] R4 is selected from H, C1-C3 alkoxy or 3-6 membered heteroalicyclic group;

[0013] R5 represents OH, OR6 or NHSO2R6, wherein R6 represents C 1-4 Alkyl or halogen-substituted C 1-4 Alkyl; carbonyl forms acid, ester or sulfonamide with R5;

[0014] Indicates a single bond or a double bond.

[0015] One embodiment of the present application relates to the above-mentioned compound of formula I or its pharmaceutically acceptable salts, stable isotope derivatives, isomers and mixtures thereof, wherein Z is an N atom; or Z is CR7, and R7 is selected from H or CH3.

[0016] In one embodiment, Represents a double bond, R4 is H, and accordingly, its structural formula is shown in Formula II:

[0017] In formula II, R1 and R2 are independently selected from H, methyl or F; Z is a nitrogen atom, or Z is CR7, and R7 is selected from H or CH3, more preferably an H atom; R3 is selected from isopropyl, ethyl or cyclopropane, more preferably isopropyl; R5 is selected from OH or NHSO2R6, and R6 is selected from C 1-4 Alkyl or halogen-substituted C 1-4Alkyl, R6 is more preferably methyl.

[0018] One embodiment of the present application relates to the above-mentioned compound of formula I or its pharmaceutically acceptable salts, stable isotope derivatives, isomers and mixtures thereof, wherein Represents a single bond, and its structural formula is shown in Formula III:

[0019] In formula III, R4 is selected from H, C1-C3 alkoxy or 3-6 membered heteroalicyclic group, preferably R4 is H, methoxy, ethoxy, More preferably, R4 is H, methoxy or ethoxy.

[0020] One embodiment of the present application relates to the above-mentioned compound of formula I or formula III or its pharmaceutically acceptable salts, stable isotope derivatives, isomers and mixtures thereof, wherein R1 and R2 are independently selected from H, methyl or F; R3 is selected from isopropyl, ethyl or cyclopropane, preferably R3 is isopropyl; R5 is preferably OH or NHSO2CH3.

[0021] One embodiment of the present application relates to a compound represented by the above-mentioned general formula I, wherein the compound is selected from but not limited to:

[0022] or in the form of prodrugs, stable isotope derivatives, pharmaceutically acceptable salts, isomers and mixtures thereof of the above structural formula.

[0023] The second aspect of the present application relates to a pharmaceutical composition comprising a pharmaceutically acceptable carrier, an excipient, and the above-mentioned compound or its pharmaceutically acceptable salt, prodrug, stable isotope derivative, isomer and mixture thereof as an active ingredient.

[0024] The pharmaceutical composition can be in any dosage form, optionally, conventional dosage forms such as tablets, granules, capsules, powders or injections.

[0025] Another aspect of the present application relates to the use of the above-mentioned compound or its pharmaceutically acceptable salts, stable isotope derivatives, isomers and mixtures thereof, as well as the above-mentioned pharmaceutical composition in the preparation of drugs for treating pulmonary arterial hypertension. Beneficial effects

[0026] The PGI2 receptor agonist compound described herein does not have a PGI2 skeleton and exhibits strong selectivity and affinity for the PGI2 receptor, demonstrating superior target selectivity compared to PGI2 analogs. Experimental studies have demonstrated that the compound is more effective in vivo than selexipag and less toxic than selexipag. Therefore, the compound may offer a promising and clinically valuable therapeutic for pulmonary arterial hypertension. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a graph showing the effects of oral administration of the compound in the example and ACT-333679 on pulmonary artery systolic pressure (*** indicates P≤0.001 compared with the model group, ** indicates P≤0.01 compared with the model group). Modes for Carrying Out the Invention

[0028] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0029] the term

[0030] In the method for preparing the compound of the present application, "eq" means equivalent in chemistry. This concept is very critical in stoichiometry and chemical reactions, especially when it comes to the molar ratio of substances. For example, if 0.3 mol (1 eq) of A is used in a reaction, and the amount of B used is 6 times that of A, that is, 6 eq, then the amount of B used is 1.8 mol. This method of expression helps to make it more convenient and accurate when calculating the molar ratio of substances in chemical reactions. The "eq" of this application is calculated in terms of molar ratio.

[0031] The notation “C x-y " represents the range of carbon atoms, where x and y are both integers, for example, C 3- The 6-cycloalkyl group represents a cycloalkyl group having 3 to 6 carbon atoms.

[0032] "Alkyl" refers to a saturated, straight-chain or branched hydrocarbon group having a certain number of carbon atoms, for example, 1 to 6 carbon atoms or 1 to 4 carbon atoms. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, and 2-ethylbutyl.

[0033] The heteroalicyclic group represents a monocyclic or condensed ring containing one or more heteroatoms such as N, O or S. Typically, it is a 3-8 membered heterocyclic group containing one or more heteroatoms such as N, O or S, preferably a 3-6 membered heterocyclic group containing one or more heteroatoms such as N, O or S, such as propylene oxide, butylene oxide, piperazino, morpholino, piperidino and their derivatives.

[0034] For example, a morpholino group refers to a group having the following chemical structure: Piperidino refers to a group having the following chemical structure:

[0035] "Halogen" refers to fluorine, chlorine, bromine or iodine.

[0036] As defined herein, "isomers" refer to compounds that have the same molecular formula but differ in the nature or sequence of bonding of their atoms or in the arrangement of their atoms in space. Isomers that differ in the arrangement of their atoms in space are termed "stereoisomers." Stereoisomers include optical isomers, geometric isomers, and conformational isomers.

[0037] The compounds of the present invention may exist as optical isomers. Depending on the configuration of the substituents around the chiral carbon atom, these optical isomers are "R" or "S" configurations. Optical isomers include enantiomers and diastereomers. Methods for preparing and separating optical isomers are known in the art.

[0038] The compounds of the present invention may also exist as geometric isomers. The present invention contemplates various geometric isomers and mixtures thereof resulting from the distribution of substituents around carbon-carbon double bonds, carbon-nitrogen double bonds, cycloalkyl groups, or heterocyclic groups. Substituents around carbon-carbon double bonds or carbon-nitrogen bonds are designated as Z or E configurations, and substituents around cycloalkyl groups or heterocyclic rings are designated as cis or trans configurations.

[0039] "Isotopes" include all isotopes of atoms present in the compounds of the present invention. Isotopes include those atoms having the same atomic number but different mass numbers. Examples of isotopes suitable for incorporation into the compounds of the present invention are hydrogen, carbon, nitrogen, oxygen, fluorine, and chlorine, for example, but not limited to, 2 H. 3 H. 13 C. 14 C. 15 N. 18 O. 17 O. 35 S. 18 F and 36 Cl. Isotope-labeled compounds of the present application can generally be prepared by conventional techniques known to those skilled in the art or by methods similar to those described in the accompanying Examples using appropriate isotope-labeled reagents in place of non-isotope-labeled reagents. Such compounds have various potential uses, for example as standards and reagents in determining biological activity. In the case of stable isotopes, such compounds have the potential to advantageously alter biological, pharmacological, or pharmacokinetic properties.

[0040] "Prodrug" means that the compound of the present application can be given in the form of a prodrug. Prodrug refers to a derivative of the bioactive compound of the present application that is converted under physiological conditions in vivo, for example, by oxidation, reduction, hydrolysis, etc. (each of which utilizes an enzyme or is carried out without enzyme participation). Examples of prodrugs are compounds wherein the amino group in the compound of the present application is acylated, alkylated, or phosphorylated, such as methylacylamino, alanylamino, pivaloyloxymethylamino, or wherein the hydroxyl group is acylated, alkylated, phosphorylated, or converted into a borate, such as acetoxy, fumaryloxy, alanyloxy, or wherein the carboxyl group is esterified or amidated. These compounds can be prepared by the compound of the present application according to known methods.

[0041] "Pharmaceutically acceptable salts" or "pharmaceutically acceptable salts" refer to salts made from pharmaceutically acceptable bases or acids, including inorganic bases or acids and organic bases or acids. In the case where the compounds of the present application contain one or more acidic or basic groups, the present application also includes their corresponding pharmaceutically acceptable salts. Therefore, the compounds of the present application containing acidic groups can exist in salt form and can be used according to the present application, for example, as alkali metal salts, alkaline earth metal salts or as ammonium salts, exemplified by sodium salts, potassium salts, calcium salts, magnesium salts or salts with ammonia or organic amines, such as ethylamine, ethanolamine, triethanolamine or amino acids. The compounds of the present application containing basic groups can exist in salt form and can be used according to the present application in the form of addition salts thereof with inorganic or organic acids. The example of suitable acid comprises hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, nitric acid, methanesulfonic acid, p-methyl benzenesulfonic acid, naphthalenedisulfonic acid, oxalic acid, acetic acid, tartaric acid, lactic acid, salicylic acid, benzoic acid, formic acid, propionic acid, pivalic acid, malonic acid, succinic acid, pimelic acid, fumaric acid, maleic acid, malic acid, sulfamic acid, phenylpropionic acid, gluconic acid, ascorbic acid, isonicotinic acid, citric acid, adipic acid and other acid well known by persons skilled in the art.If the compound of the application contains acidic and basic groups in molecule simultaneously, the application also comprises inner salt or betaine except mentioned salt form.Each salt can obtain by conventional method well known by persons skilled in the art, for example, by making these and organic or inorganic acid or alkali contact or by with other salt anion exchange or cation exchange in solvent or dispersant.

[0042] A "pharmaceutical composition" refers to a composition comprising one or more compounds described herein, or pharmaceutically acceptable salts, prodrugs, stable isotopic derivatives, isomers, and mixtures thereof, as well as other components, such as pharmaceutically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration to an organism, facilitating absorption of the active ingredient and thereby exerting its biological activity.

[0043] Therefore, when referring to "a compound," "a compound of the present application," or "a compound described herein," all forms of the compound, such as pharmaceutically acceptable salts, prodrugs, stable isotope derivatives, isomers, and mixtures thereof, are included in this application.

[0044] The present application also provides a method for preparing the compound. The preparation of the compound described in the general formula (I) of the present application can be accomplished by the following illustrative methods and examples, but these methods and examples should not be considered in any way to limit the scope of the present application. The compounds described in this application can also be synthesized by synthetic techniques known to those skilled in the art, or a combination of methods known in the art and the methods described in this application. The product obtained from each step of the reaction is obtained using separation techniques known in the art, including but not limited to extraction, filtration, distillation, crystallization, chromatographic separation, etc. The starting materials and chemical reagents required for the synthesis can be synthesized or purchased according to conventional literature.

[0045] Reference Example 1

[0046] Preparation of 6-isopropylamino-3-ethoxy-ethyl hexanoate (denoted as SM1), the preparation route is as follows:

[0047] Preparation of SM1-B: SM1-A (4-isopropylamino-1-n-butanol, 200 g, 1 eq), Boc anhydride (349.3 g, 1.05 eq), and tetrahydrofuran (1200 ml) were added to the reaction flask in sequence, reacted at room temperature for 2 to 2.5 h, and concentrated to obtain 353 g of compound SM1-B.

[0048] Preparation of SM1-C: Compound SM1-B (300 g, 1 eq) and dichloromethane (1500 ml) were added to the reaction flask in sequence, cooled in an ice bath, and Dess-Martin reagent (660 g, 1.2 eq) was added in batches. The reaction was kept warm for 2 to 3 hours. The reaction solution was washed with saturated sodium bicarbonate solution and saturated sodium chloride aqueous solution in sequence. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 172 g of compound SM1-C.

[0049] Preparation of SM1-D: Triethyl phosphoacetate (199 g, 1.2 eq) and tetrahydrofuran (1300 ml) were added to the reaction flask in sequence, cooled in an ice bath, and sodium hydride (35.6 g, 1.2 eq) was added in batches, stirred for 1 to 2 h, and compound SM1-C (170 g, 1 eq) was added in batches at 0 to 5 ° C. The temperature was raised to room temperature and reacted for 2 to 3 h. Water was added dropwise to the reaction solution to quench it, and then ethyl acetate was added for extraction. The organic phase was washed with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate. It was concentrated to dryness, and the concentrate was purified by silica gel column chromatography to obtain 135 g of compound SM1-D.

[0050] Preparation of SM1-E: Compound SM1-D (30 g, 1 eq) and anhydrous ethanol (150 ml) were added to the reaction flask in sequence, cooled in an ice bath, sodium hydride (6 g, 1.5 eq) was added, and the temperature was raised to room temperature for reaction for 2 to 3 hours, then lowered to 0 to 10°C, quenched with 100 ml of water, concentrated to remove most of the ethanol, extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate, concentrated to dryness, and purified by silica gel column chromatography to obtain 26.3 g of compound SM1-E.

[0051] Preparation of SM1: SM1-E (25 g, 1 eq) and dichloromethane were added to a reaction flask, and a hydrochloric acid / ethanol solution (1.1 eq) was added dropwise at room temperature. After the addition was complete, the mixture was concentrated to dryness to obtain 19.4 g of SM1.

[0052] Example 1

[0053] Preparation of 6-{N-[5,6-di(4-methylphenyl)pyrazine]-2-yl-N-isopropylamino}-2-hexenoic acid, the compound is designated as SYN-001, corresponding to the structural formula (1).

[0054] The preparation route is as follows:

[0055] STEP 1: Compound 1A (300 g, 1 eq of 4,4'-dimethylbenzil), 2-aminoacetamide hydrochloride (209 g, 1.5 eq), and methanol (2.0 L) were added to the reaction flask in sequence. The temperature was raised to reflux, and an aqueous sodium hydroxide solution (101 g, 2 eq of sodium hydroxide, 200 ml of purified water) was added dropwise. The mixture was stirred for 4 to 5 hours, cooled to room temperature, and the pH was adjusted to 6 to 7 with hydrochloric acid. The mixture was filtered, and the filter cake was rinsed with methanol (300 ml). The mixture was dried in vacuo to obtain 320 g of compound 1B.

[0056] STEP 2: Add compound 1B (100 g, 1 eq) and phosphorus oxychloride (277.4 g, 5 eq) to the reaction flask in sequence, heat to 100-105°C, maintain stirring for 3-5 hours, and concentrate under reduced pressure to remove residual phosphorus oxychloride. Add 200 mL of toluene and continue concentrating to remove residual phosphorus oxychloride. Add 100 mL of dichloromethane to the reaction mixture and stir to dissolve. Add the reaction solution dropwise to 1000 mL of isopropanol. After addition, stir at 0-5°C for 1-3 hours, filter, and vacuum dry to obtain 90.7 g of compound 1C.

[0057] STEP 3: Compound 1C (100 g, 1 eq) and 4-(isopropylamino)butanol (245 g, 5.5 eq) were added to the reaction flask in sequence, the temperature was raised to 160-170°C, the reaction was kept warm for 20-30 h, and the temperature was lowered to 60-80°C. The reaction solution was poured into water (1.0 L) and extracted with ethyl acetate. The organic phase was washed with saturated aqueous ammonium chloride solution, dried over anhydrous sodium sulfate, and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 74 g of compound 1D.

[0058] STEP 4: Compound 1D (70 g, 1 eq) and dichloromethane (700 ml) were added to the reaction flask in sequence. The mixture was cooled in an ice bath and Dess-Martin reagent (152 g, 2 eq) was added in batches. The mixture was kept warm for 3 to 5 h. The reaction solution was washed with saturated sodium bicarbonate solution and saturated sodium chloride solution in sequence, dried over anhydrous sodium sulfate, and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 21.5 g of compound 1E.

[0059] STEP 5: Triethyl phosphoacetate (9 g, 1.2 eq) and tetrahydrofuran (130 ml) were added to the reaction flask in sequence. The mixture was cooled in an ice bath. Sodium hydride (1.34 g, 1 eq) was added in batches and stirred for 1 h. Compound 1E (13 g, 1 eq) was added in batches at 0-5°C. The temperature was raised to room temperature and the reaction was carried out for 2-3 h. 50 ml of water was added dropwise to the reaction solution to quench the mixture. Ethyl acetate was added for extraction. The organic phase was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 13 g of compound 1F.

[0060] STEP 6: Compound 1F (3 g, 1 eq), tetrahydrofuran (30 ml), and 3 ml of purified water were added to the reaction flask in sequence. Sodium hydroxide (1.05 g, 4 eq) was added, and the temperature was raised to reflux. The reaction was allowed to react for 12 to 15 hours, then cooled to room temperature. 50 ml of water was added, and the pH was adjusted to 5 to 6 with hydrochloric acid. Ethyl acetate was added for extraction. The organic phase was dried over anhydrous sodium sulfate, concentrated to dryness, and purified by silica gel column chromatography to obtain 1.3 g of compound SYN-001. The H NMR spectrum data of compound SYN-001 are as follows:

[0061] 1 H NMR (500MHz, CDCl3): δ: 8.019 (s, 1H), 7.366~7.350 (m, 2H), 7.282 (s, 2H), 7.158~7.057 (m, 5H), 5.925~5.894 (d, 1 H), 4.714~4.688(m,1H), 3.460~3.429(m,2H), 2.371~2.332(m,8H), 1.918~1.857(m, 2H), 1.291~1.277(m, 6H)ppm.

[0062] Example 2

[0063] Preparation of 6-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]-2-hexenoic acid, the compound is designated as SYN-002, corresponding to structural formula (2).

[0064] The preparation route is as follows:

[0065] The preparation method of 6-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]-2-hexenoic acid was the same as that of 6-{N-[5,6-di(4-methylphenyl)pyrazin-2-yl-N-isopropylamino}-2-hexenoic acid (SYN-001) in Example 1, except that benzil was used as the starting material. The H NMR spectrum data of compound SYN-002 are as follows:

[0066] 1 H NMR (500MHz, CDCl3): δ: 8.050 (s, 1H), 7.449 ~ 7.430 (m, 2H), 7.366 ~ 7.347 (m, 2H), 7.285 ~ 7.247 (m, 6H), 7.232 ~ 7.211 (m, 1H), 5.9 20~5.889(m,1H), 4.741~4.715(m,1H), 3.454~3.422(m,2H), 2.354~2.340(m,2H), 1.898~1.867(m,2H), 1.285~1.272(m,6H)ppm.

[0067] Example 3

[0068] Prepare 6-{N-[5,6-di(4-methylphenyl)-1,2,4-triazine]-2-yl-N-isopropylamino}hexanoic acid, the compound is recorded as SYN-003, corresponding to the structural formula (3).

[0069] The preparation route is as follows:

[0070] STEP 1: To a reaction flask, add glacial acetic acid (2.5 L), 4,4'-dimethylbenzil (compound 6A; 500 g, 1 eq), semicarbazide hydrochloride (351 g, 1.5 eq), and purified water (1 L) in sequence, stir well, and heat to 100-110°C. Incubate at this temperature for 2-3 hours, cool to 30-40°C, add purified water, stir at room temperature for 0.5-1.5 hours, filter, add the filter cake to 3 L of ethyl acetate, heat to reflux, stir for 2-3 hours, cool to room temperature, filter, and vacuum dry to obtain 523 g of intermediate 6B.

[0071] STEP 2: Add phosphorus oxychloride (2 L) and intermediate 6B (500 g, 1 eq) to the reaction flask. Heat to 80-85°C and stir to dissolve. Incubate for 1-1.5 hours, then concentrate to remove the phosphorus oxychloride. Add 1 L of toluene and continue concentrating to remove any residual phosphorus oxychloride. Add methyl tert-butyl ether to the concentrate and stir for 1 hour. Filter and vacuum dry to obtain 320 g of intermediate 6C.

[0072] STEP 3: To the reaction flask, add intermediate 6C (100 g, 1 eq) and 4-(isopropylamino)butanol (155.3 g, 3.5 eq) in sequence, raise the temperature to 140-160°C, keep the reaction for 14-20 h, cool to room temperature, pour the reaction solution into water, add ethyl acetate for extraction, wash the organic phase with saturated sodium chloride aqueous solution, dry over anhydrous sodium sulfate, and concentrate to dryness. The concentrate is purified by silica gel column chromatography to obtain 71 g of intermediate 6D.

[0073] STEP 4: Add intermediate 6D (70 g, 1 eq) and dichloromethane (700 ml) to a reaction flask, cool to 0-10°C, add Dess-Martin reagent (152 g, 2 eq) in portions, and maintain at 0-10°C for 3-5 h. Stop the reaction, wash the reaction solution twice with saturated sodium bicarbonate solution, then with saturated sodium chloride solution. Dry the organic phase over anhydrous sodium sulfate and concentrate to dryness. Purify the concentrate by silica gel column chromatography to obtain 41.3 g of intermediate 6E.

[0074] STEP 5: Add triethyl phosphoacetate (27.7 g, 1.2 eq) and tetrahydrofuran (400 ml) to the reaction flask, cool to 0-10°C, add sodium hydride (4.1 g, 1 eq), stir for 1-2 h, add intermediate 6E (40 g, 1 eq) at 0-5°C, warm to room temperature after addition and react for 2-3 h, add 100 ml of water dropwise to the reaction solution to quench the reaction, concentrate to remove most (more than 80%) of tetrahydrofuran, add 200 ml of ethyl acetate to the concentrate for extraction, wash the organic phase with saturated sodium chloride aqueous solution, dry over anhydrous sodium sulfate, and concentrate to dryness. The concentrate is purified by silica gel column chromatography to obtain 21.3 g of intermediate 6F.

[0075] STEP 6: Add 21 g of intermediate 6F, 2.1 g of 10% palladium carbon, and anhydrous ethanol (210 ml) to the reaction flask, replace with hydrogen, and react at room temperature for 5 to 7 hours. Filter to remove the palladium carbon, and concentrate the filtrate to dryness to obtain 20.2 g of intermediate 6G.

[0076] STEP 7: Add intermediate 6G (20 g, 1 eq), tetrahydrofuran (200 ml), purified water (20 ml), and sodium hydroxide (6.9 g, 4 eq) to the reaction flask in sequence, raise the temperature to reflux, react for 2-3 h, concentrate to remove tetrahydrofuran, add purified water (100 ml) and ethyl acetate (100 ml), stir evenly, stand and separate, retain the aqueous phase, add hydrochloric acid to the aqueous phase to adjust the pH to 3-5, add methyl tert-butyl ether for extraction, dry the organic phase over anhydrous sodium sulfate, and concentrate to dryness under reduced pressure to obtain 16.8 g of compound SYN-003. The H NMR spectrum data of compound SYN-003 are as follows:

[0077] 1H NMR (500MHz, CDCl3): δ: 7.455~7.439 (m, 2H), 7.396~7.380 (m, 2H), 7.146~7.129 (m, 4H), 5.137 (m, 1H), 3.599(m,2H), 2.462~2.378(m,8H), 1.795~1.735(m,4H), 1.527~1.454(m,2H), 1.365~1.238(m,6H)ppm.

[0078] Example 4

[0079] Preparation of 3-ethoxy-6-{N-[5,6-di(4-methylphenyl)pyrazine]-2-yl-N-isopropylamino}hexanoic acid, the compound is recorded as SYN-004, and the corresponding structural formula is numbered (4).

[0080] Compound 1F, designated 6-{N-[5,6-di(4-methylphenyl)pyrazin-2-yl-N-isopropylamino}-2-hexenoic acid ethyl ester (prepared using the same method as "Compound 1F" in Example 1) (3 g, 1 eq), and anhydrous ethanol (30 ml) were added to the reaction flask in sequence. The mixture was cooled in an ice bath, and sodium hydride (0.79 g, 3 eq) was added. The reaction was brought to reflux for 12 to 15 hours, then cooled to room temperature. The pH was adjusted to 5 to 6 with hydrochloric acid, and 30 ml of water was added. The mixture was extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 1.2 g of compound SYN-004. The H NMR spectrum data of compound SYN-004 are as follows:

[0081] 1H NMR (500MHz, CDCl3): δ: 8.013 (s, 1H), 7.378~7.366 (m, 2H), 7.350 (s, 1H) ,7.090~7.065(m,5H),4.803~4.776(m,1H),3.814~3.792(m,1H),3.594~ 3.536(m,2H),3.449~3.398(m,2H),2.628~2.461(m,2H),2.348~2.337(m ,6H), 1.802~1.642(m, 4H), 1.281~1.268(m, 6H), 1.212~1.185(t, 3H)ppm.

[0082] Example 5

[0083] Prepare 3-ethoxy-6-{N-[5,6-di(4-methylphenyl)-1,2,4-triazine]-2-yl-N-isopropylamino}hexanoic acid, the compound is recorded as SYN-005, corresponding to the structural formula (5).

[0084] The preparation route is as follows:

[0085] STEP 1: Compound 6C (30 g, 1 eq, prepared by the same method as compound 6C in Example 3, named 5,6-bis(4-methylphenyl)-3-chloro-1,2,4-triazine), SM1 (37.2 g, 1.3 eq, prepared by reference example), potassium carbonate (42 g, 3 eq), and DMF (1.5 L) were added to the reaction flask in sequence. The temperature was raised to 80-85°C, and the reaction was kept warm for 2-3 h. Water was added, and the mixture was extracted with ethyl acetate and concentrated to obtain 43.9 g of compound 7D.

[0086] STEP 2: Compound 7D (10 g, 1 eq), tetrahydrofuran (100 ml), and purified water (10 ml) were added to the reaction flask in sequence. Sodium hydroxide (2.4 g, 3 eq) was added, and the temperature was raised to reflux. The reaction was allowed to proceed for 12-15 h, then the temperature was lowered to room temperature. The pH was adjusted to 5-6 with hydrochloric acid. 100 ml of water was added, and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 4.8 g of compound SYN-005. The H NMR spectrum data of compound SYN-005 are as follows:

[0087] 1H NMR (500MHz, CDCl3): δ: 7.451~7.425(m,2H), 7.381~7.365(m,2H), 7.133~7.117(m,4H), 3.835~3.811(m, 1H), 3.605~3.6 54(m,4H), 2.601~2.573(m,2H), 2.384~2.365(m,7H), 1.699~1.688(m,4H), 1.328~1.315(m,6H), 1.210~1.182(t,3H)ppm.

[0088] Example 6

[0089] Preparation of 3-methoxy-6-{N-[5,6-di(4-methylphenyl)pyrazine]-2-yl-N-isopropylamino}hexanoic acid, the compound is designated as SYN-006, corresponding to the structural formula (6).

[0090] STEP 1: Compound 1F (3 g, 1 eq, see compound 1F in Example 1 for preparation method) and anhydrous methanol (30 ml) were added to the reaction flask in sequence, cooled in an ice bath, sodium hydride (0.79 g, 3 eq) was added, and the reaction temperature was raised to room temperature for 3-5 h. The mixture was quenched with 50 ml of water, and extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 2.1 g of compound 4G.

[0091] STEP 2: Compound 4G (2 g, 1 eq), tetrahydrofuran (30 ml), and 3 ml of purified water were added to the reaction flask in sequence. Sodium hydroxide (0.65 g, 4 eq) was added, and the temperature was raised to reflux. The reaction was allowed to proceed for 12-15 hours. The temperature was then lowered to room temperature, and the pH was adjusted to 5-6 with hydrochloric acid. 30 ml of water was added, and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 0.9 g of compound SYN-006. The H NMR spectrum of compound SYN-006 is as follows:

[0092] 1 H NMR (500MHz, CDCl3): δ: 8.021 (s, 1H), 7.368~7.352 (m, 2H), 7.278~7.258 (m, 2H), 7.091~7.067 (m, 4H), 4.812 (m, 1H), 3.740~ 3.716(m,1H),3.428~3.413(m,5H),2.642~2.487(m,2H), 2.349~2.338(m,6H), 1.784~1.671(m,4H), 1.293~1.269(m,6H)ppm.

[0093] Example 7

[0094] Prepare 6-[N-(5,6-diphenyl-1,2,4-triazine)-2-yl-N-isopropylamino]hexanoic acid, the compound is recorded as SYN-007, corresponding to the structural formula (7).

[0095] The preparation method of 6-[N-(5,6-diphenyl-1,2,4-triazine)-2-yl-N-isopropylamino]hexanoic acid is the same as the preparation method of 6-{N-[5,6-di(4-methylphenyl)-1,2,4-triazine]-2-yl-N-isopropylamino}hexanoic acid (SYN-003) in Example 3, except that the starting material is benzil. The H NMR spectrum data of compound SYN-007 are as follows:

[0096] 1 H NMR (500MHz, CDCl3): δ: 7.510~7.493 (m, 2H), 7.475~7.448 (m, 2H), 7.396~7.364 (m, 1H), 7.317~7.269 (m, 5H), 5.141~ 5.070 (m, 1H), 3.592 (m, 2H), 2.407 ~ 2.362 (m, 2H), 1.779 ~ 1.707 (m, 4H), 1.506 ~ 1.445 (m, 2H), 1.322 ~ 1.308 (m, 6H) ppm.

[0097] Example 8

[0098] Prepare 3-ethoxy-6-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]hexanoic acid, the compound is recorded as SYN-008, corresponding to the structural formula (8).

[0099] Compound 8F (3 g, 1 eq, Compound 8F in Preparation Example 2) and anhydrous ethanol (30 ml) were added sequentially to a reaction flask. The mixture was cooled in an ice bath and sodium hydride (0.84 g, 3 eq) was added. The reaction was brought to reflux for 12-15 hours, then cooled to room temperature. The pH was adjusted to 5-6 with hydrochloric acid. 100 ml of water was added and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 1.2 g of compound SYN-008. The H NMR spectrum of compound SYN-008 is as follows:

[0100] 1H NMR (500MHz, CDCl3): δ: 8.037 (s, 1H), 7.443~7.226 (m, 10H), 4.785 (m, 1H), 3.790 (m, 1H), 3.545~ 3.414(m,4H), 2.585~2.507(m,2H), 1.773~1.661(m,4H), 1.278~1.265(m,6H), 1.175(t,3H)ppm.

[0101] Example 9

[0102] Preparation of 6-{N-[5,6-bis(4-fluorophenyl)pyrazin-2-yl-N-isopropylamino}-2-hexenoic acid, the compound is designated as SYN-013, corresponding to the structural formula (9).

[0103] The preparation route is as follows:

[0104] The preparation method of 6-{N-[5,6-bis(4-fluorophenyl)pyrazine]-2-yl-N-isopropylamino}-2-hexenoic acid is the same as the preparation method of 6-{N-[5,6-bis(4-methylphenyl)pyrazine]-2-yl-N-isopropylamino}-2-hexenoic acid (SYN-001) in Example 1, except that the starting material is 1,2-bis(4-fluorophenyl)ethane-1,2-dione. The H NMR spectrum data of compound SYN-013 are as follows:

[0105] 1 H NMR (500MHz, CDCl3): δ: 8.062 (s, 1H), 7.413 ~ 7.385 (m, 2H), 7.326 ~ 7.298 (m, 2H), 7.143 ~ 7.084 (m, 1H), 6.981 ~ 6.933 (m, 4H), 5.9 19~5.888(d,1H), 4.709~4.683(m,1H), 3.455~3.424(m,2H), 2.361~2.319(m,2H), 1.886~1.840(m,2H), 1.297~1.274(m,6H)ppm.

[0106] Example 10

[0107] Prepare 6-{N-[5,6-bis(4-fluorophenyl)pyrazine]-2-yl-N-isopropylamino}-hexanoic acid, the compound is recorded as SYN-010, corresponding to structural formula (10).

[0108] STEP 1: Compound 12F (6 g, 1 eq, for the preparation method, see Example 9 for compound 12F), 60 ml of anhydrous ethanol, and 0.6 g of 10% wet palladium carbon were added to the reaction flask in sequence, H2 was replaced, and the reaction was carried out at room temperature for 3 to 4 hours. The palladium carbon was removed by filtration, and the filtrate was concentrated to obtain 5.8 g of compound 13G.

[0109] STEP 2: Compound 13G (5 g, 1 eq), tetrahydrofuran (50 ml), and 5 ml of purified water were added to the reaction flask in sequence. Sodium hydroxide (1.3 g, 3 eq) was added, and the temperature was raised to reflux. The reaction was allowed to proceed for 12-15 h, then the temperature was lowered to room temperature. The pH was adjusted to 5-6 with hydrochloric acid. 100 ml of water was added, and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 2.3 g of compound SYN-010. The H NMR spectrum of compound SYN-010 is as follows:

[0110] 1 H NMR (500MHz, CDCl3): δ: 8.125 (s, 1H), 7.423~7.388 (m, 2H), 7.333~7.298 (m, 2H), 7.194~7.100 (m, 4H), 4.768~4.7 35(m,1H), 3.424(m,2H), 2.258~2.220(m,2H), 1.658~1.554(m,4H), 1.425~1.351(m,2H), 1.239~1.164(m,6H)ppm.

[0111] Example 11

[0112] Preparation of 3-morpholino-6-{N-[5,6-di(4-methylphenyl)pyrazine]-2-yl-N-isopropylamino}hexanoic acid, the compound is designated as SYN-017, corresponding to the structural formula (11).

[0113] STEP 1: Compound 1F (3 g, 1 eq, prepared as described in Example 1 for compound 1F) and 6 ml of morpholine were added to a pressure bottle in sequence. The temperature was raised to 100-105°C, and the reaction was carried out for 12-15 h. The mixture was cooled to room temperature, and quenched with aqueous ammonium chloride solution. The mixture was extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 2.1 g of compound 5G.

[0114] STEP 2: Compound 5G (2 g, 1 eq), tetrahydrofuran (30 ml), and 3 ml of purified water were added to the reaction flask in sequence. Sodium hydroxide (0.44 g, 3 eq) was added, and the temperature was raised to reflux. The reaction was allowed to react for 12 to 15 hours, then cooled to room temperature. The pH was adjusted to 5 to 6 with hydrochloric acid. 60 ml of water was added, and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 1.2 g of compound SYN-017. The H NMR spectrum data of compound SYN-017 are as follows:

[0115] 1 H NMR (500MHz, CDCl3): δ: 8.013 (s, 1H), 7.339 ~ 7.323 (m, 2H), 7.282 (m, 2H), 7.086 ~ 7.052 (m, 4H), 4.580 ~ 4.554 (m, 1H), 3.748 (m, 4H), 3.460 ~ 3.4 31(m,2H),2.889~2.869(m,1H), 2.782~2.759(m,2H), 2.555~2.495(m,3 H), 2.387~2.323(m,7H), 1.825~1.605(m,3H), 1.332~1.253(m,7H)ppm.

[0116] Example 12

[0117] Preparation of 3-ethoxy-6-{N-[5,6-di(4-methylphenyl)pyrazin-2-yl-N-isopropylamino}-N-(p-methylsulfonyl)hexanamide, the compound is designated as SYN-044, corresponding to structural formula (12).

[0118] Compound SYN-004 (1 g, 1 eq), dichloromethane (20 ml), methanesulfonamide (300 mg, 1.5 eq), 4-dimethylaminopyridine (DMAP) (308 mg, 1.2 eq), and EDCI (484 mg, 1.2 eq) were added to the reaction flask in sequence. The mixture was refluxed for 2-3 hours, cooled to room temperature, and the reaction solution was washed with purified water. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 650 mg of compound SYN-044. The H NMR spectrum data of compound SYN-044 are as follows:

[0119] 1H NMR (500MHz, CDCl3): δ: 8.013 (s, 1H), 7.292 ~ 7.272 (m, 2H), 7.208 ~ 7.188 (m, 2H), 7.129 ~ 7.066 (m, 4H), 4.769 ~ 4.737 (m, 1H), 3.771 ~ 3.74 1(m,1H),3.493~3.459(m,2H), 3.183(s,3H),2.434~2.290(m,10H), 1.694~1.525(m,4H), 1.246~1.229(m,6H), 1.092~1.057(t,3H)ppm.

[0120] Example 13

[0121] Preparation of 6-{N-[5,6-bis(4-fluorophenyl)pyrazin-2-yl-N-isopropylamino}-N-(p-methylsulfonyl)hexanamide, the compound is designated as SYN-046, corresponding to the structural formula (13).

[0122] Compound SYN-010 (1.1 g, 1 eq), dichloromethane (20 ml), methanesulfonamide (357 mg, 1.5 eq), DMAP (367 mg, 1.2 eq), and EDCI (574 mg, 1.2 eq) were added to the reaction flask in sequence. The mixture was refluxed for 2-3 hours, cooled to room temperature, and the reaction solution was washed with purified water. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 0.6 g of compound SYN-046. The H NMR spectrum data of compound SYN-046 are as follows:

[0123] 1 H NMR (500MHz, CDCl3): δ: 8.131 (s, 1H), 7.428 ~ 7.392 (m, 2H), 7.337 ~ 7.302 (m, 2H), 7.204 ~ 7.106 (m, 4H), 4.765 (m, 1H), 3.424(m,2H),3.229(s,3H),2.322~2.285(m,2H), 1.632~1.596(m,4H), 1.397~1.361(m,2H), 1.246~1.229(m,6H)ppm.

[0124] Example 14

[0125] {N-[5,6-bis(4-methylphenyl)-1,2,4-triazine]-2-yl-N-isopropylamino}-2-hexenoic acid was prepared, and the compound was designated as SYN-018, corresponding to the structural formula (14).

[0126] Compound 6F (5 g, 1 eq, see Example 3 for preparation), tetrahydrofuran (50 ml), and 5 ml of purified water were added to the reaction flask in sequence. Sodium hydroxide (0.87 g, 2 eq) was then added. The temperature was raised to reflux and the reaction was allowed to proceed for 12-15 hours. The temperature was then lowered to room temperature and the pH was adjusted to 5-6 with hydrochloric acid. 100 ml of water was added and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The concentrate was purified by silica gel column chromatography to obtain 3.5 g of compound SYN-018. The H NMR spectrum of compound SYN-018 is as follows:

[0127] 1 H NMR (500MHz, CDCl3): δ: 8.062 (s, 1H), 7.368 ~ 7.351 (m, 2H), 7.283 ~ 7.268 (m, 1H), 7.143 ~ 7.050 (m, 5H), 5.981 ~ 5.899 ( d, 1H), 4.719 ~ 4.690 (m, 1H), 3.453 ~ 3.422 (m, 2H), 2.371 ~ 2.330 (m, 8H), 1.916 ~ 1.855 (m, 2H), 1.293 ~ 1.278 (m, 6H)ppm.

[0128] Experimental example

[0129] 1. Target Selectivity

[0130] Experimental Procedure: Using HEK cells stably expressing the prostacyclin receptor, the functional activities of compounds numbered SYN-001, SYN-002, SYN-003, SYN-004, SYN-005, SYN-006, SYN-007, SYN-008, SYN-010, SYN-013, SYN-017, SYN-044, SYN-046, and SYN-018 against the following eight targets: IP, EP1, EP2, EP3, EP4, DP, FP, and TP, were investigated using the HTRF cAMP and HTRF IP1 assays. Selexipag (available commercially) was used as a comparison. The EC50 (half-effective dose) was used as a metric. EC50 is the dose required to elicit a 50% change in a given biological effect, representing the drug concentration that is effective in 50% of individuals.

[0131] The experimental results are shown in Table 1.

[0132] Table 1 Target selectivity

[0133] These results demonstrate that compounds numbered SYN-001, SYN-002, SYN-003, SYN-004, SYN-005, SYN-006, SYN-007, SYN-008, SYN-010, SYN-013, SYN-017, SYN-044, SYN-046, and SYN-018 exhibit potent agonist activity against IP receptors, comparable to that of selexipag. While SYN-001, SYN-002, and SYN-003 exhibit mild agonist activity against EP1, EP2, EP3, EP4, DP, FP, and TP, the remaining compounds exhibit no agonist activity against receptors other than IP, demonstrating high selectivity.

[0134] Among them, the chemical structural formula (Formula IV) of the active ingredient of Selexipag is shown below.

[0135] Its chemical name is 2-{4-[(5,6-diphenylpyrazin-2-yl)(2-propyl)amino]butoxy}-N-(methylsulfonyl)acetamide. ACT-333679 is a metabolite of selexipag, and its chemical structure is shown below.

[0136] Its chemical name is: 2-(4-((5,6-diphenylpyrazin-2-yl)(isopropyl)amino)butoxy)acetic acid.

[0137] The structures of the compounds in the examples of this application differ from the butoxyacetamide structure in the branched chain of selexipag's active component. The main structure of the branched chain in the examples of this application is hexanoic acid or hexenoic acid, or hexanoic acid sulfonamide. SYN-001, SYN-002, SYN-003, SYN-004, SYN-005, SYN-006, SYN-007, SYN-008, SYN-010, SYN-013, SYN-017, SYN-044, SYN-046, and SYN-018 all exhibit excellent agonist activity against IP receptors. These compounds have promising applications in the preparation of drugs for the treatment of pulmonary artery cancer.

[0138] 2. Drug Efficacy Test in Rats with Pulmonary Hypertension

[0139] Experimental Procedure: Rats were randomly divided into 11 groups, including a normal control group, a model group, a positive control group, and eight test article groups. Except for the normal control group, all other groups received a subcutaneous injection of monocrotaline (40 mg / kg) to establish a model. The normal control group received a subcutaneous injection of sodium chloride. Drug administration began approximately 2 hours after the modeling agent was administered, twice daily, for 19 consecutive days.

[0140] Specifically, the normal control group and the model group were administered orally with 10 wt% DMSO + 90 wt% NaCl at 5 ml / kg; the positive control group was administered orally with ACT-333679 at 3 mg / kg; and the eight test groups were administered orally with compounds numbered SYN-003, SYN-004, SYN-006, SYN-007, SYN-008, SYN-010, SYN-013, and SYN-017 by suspension in 10 wt% DMSO + 90 wt% NaCl. The suspensions were then administered orally at a concentration of 3 mg / kg of the active ingredient in a volume of 5 mL / kg.

[0141] After 19 consecutive days of administration, the mean pulmonary artery pressure of the rats was measured using right cardiac catheterization. The experimental results are shown in Figure 1.

[0142] The results showed that the compounds numbered SYN-003, SYN-004, SYN-006, SYN-007, SYN-008, SYN-010, SYN-013, and SYN-017 all significantly reduced pulmonary artery pressure in rats, among which SYN-004, SYN-007, and SYN-010 had the most significant antihypertensive effects.

[0143] 3. Survival rate test of rats with pulmonary hypertension

[0144] Experimental Procedure: Monocrotaline 40 mg / kg was injected subcutaneously to establish the model. A normal control group received a subcutaneous injection of sodium chloride injection. Dosing began approximately 2 hours after the modeling agent was administered, twice daily, for 45 consecutive days. Compounds SYN-004, SYN-007, and SYN-010 were each suspended in 10 wt% DMSO + 90 wt% NaCl to prepare a suspension, and administered orally at a rate of 1 mg / kg body weight of the active ingredient. Selexipag was also administered orally as a positive control group at a rate of 1 mg / kg body weight of the active ingredient. The normal control and model groups received normal saline by gavage.

[0145] The survival status of the rats was recorded. The experimental results are shown in Table 2.

[0146] Table 2 Effects of SYN-004, SYN-007, and SYN-010 on the survival rate of rats with pulmonary hypertension

[0147] The results showed that Selexipag, SYN-004, SYN-007 and SYN-010 could significantly improve the survival rate of rats with pulmonary hypertension.

[0148] 4. Toxicity Comparison

[0149] Acute toxicity experiment procedure: Rats were randomly divided into groups according to body weight, 10 rats per group, and were given single oral administration of 250, 500, 1000, and 2000 mg / kg of the compounds SYN-003, SYN-004, SYN-005, SYN-007, SYN-010, and Selexipag prepared in the above examples, respectively, at a dosage of 10 ml / kg. The rats were observed for 7 days after administration.

[0150] The experimental results are shown in Table 3.

[0151] Table 3 Acute toxicity of SYN-003, SYN-004, SYN-005, SYN-007 and SYN-010 in rats

[0152] Results showed that the oral lethal dose of Selexipag in rats was approximately 500 mg / kg, and the non-lethal dose was 250 mg / kg. SYN-003, SYN-004, SYN-005, SYN-007, and SYN-010 did not cause mortality at 1000 mg / kg, but did at 2000 mg / kg, indicating that these drugs were less toxic than Selexipag.

[0153] Genotoxicity test procedure: The test articles SYN-004, SYN-007, SYN-010, and ACT-333679 were diluted serially into eight concentrations at a final concentration of 1000 μg / well. A 6-well plate incorporation method was used, with two wells treated in parallel. A negative control (DMSO) and a positive control were also included. Parallel experiments were performed with or without a metabolic activation system (±S9). After 48-72 hours of incubation, the test articles were observed for precipitation and background plaque growth, and the number of revertant colonies in each well was counted. The test results are shown in Tables 4-11.

[0154] Positive result determination

[0155] A result is considered positive if one or both of the following criteria are met:

[0156] 1) In at least one strain, the number of revertant colonies shows a dose-dependent increase with or without metabolic activation, and the number of revertant colonies is 2 times or more that of the negative control group.

[0157] 2) With or without metabolic activation, the number of revertant colonies in one or more dose groups increases significantly and reproducibly, and the number of revertant colonies is 2 times or more that of the negative control group.

[0158] After the test sample is tested with two test strains, as long as one of the test strains is positive, regardless of whether S9 mixed solution is added or not, the test sample can be determined to be a mutagen.

[0159] Negative result judgment

[0160] If the test results show that there is no dose-dependent increase in the number of revertant colonies of each test strain, and the peak value of the number of revertant colonies in each dose group of all strains does not exceed 2 times that of the negative control group, the test article can be determined to be a non-mutagenic agent.

[0161] The results showed that under ±S9 conditions, non-interfering precipitation was observed for TA98 and TA100 strains at final concentrations of ACT-333679 ≥250 μg / well; non-interfering precipitation was only observed at a final concentration of 1000 μg / well for SYN-004, SYN-007, and SYN-010. Under ±S9 conditions, background plaque reduction was observed for TA98 and TA100 strains at final concentrations of ACT-333679 ≥250 μg / well; background plaque reduction was observed at a final concentration of 1000 μg / well for SYN-010; no abnormal background plaque was observed at any concentration of SYN-004 or SYN-007. For strains TA98 and TA100, under ±S9 conditions, the number of revertant mutant colonies in each concentration group of SYN-004, SYN-007, SYN-010, and ACT-333679 did not reach twice that of the negative control group, and there was no concentration-effect relationship, so the test results were considered negative.

[0162] Therefore, SYN-004, SYN-007, SYN-010, and ACT-333679 are not genotoxic.

[0163] Table 4 Results of SYN-004 bacterial reverse mutation 6-well plate initial screening test (TA98 strain)

[0164] Remark:

[0165] Background plaque: T0: normal;

[0166] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0167] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0168] Table 5 Results of SYN-004 bacterial reverse mutation 6-well plate initial screening test (TA100 strain)

[0169] Remark:

[0170] Background plaque: T0: normal;

[0171] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0172] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0173] Table 6 Results of SYN-007 bacterial reverse mutation 6-well plate initial screening test (TA98 strain)

[0174] Remark:

[0175] Background plaque: T0: normal;

[0176] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0177] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0178] Table 7 Results of SYN-007 bacterial reverse mutation 6-well plate initial screening test (TA100 strain)

[0179] Remark:

[0180] Background plaque: T0: normal;

[0181] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0182] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0183] Table 8 Results of SYN-010 bacterial reverse mutation 6-well plate initial screening test (TA98 strain)

[0184] Remark:

[0185] Background plaque: T0: normal, T1: background plaque slightly reduced;

[0186] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0187] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0188] Table 9 Results of SYN-010 bacterial reverse mutation 6-well plate initial screening test (TA100 strain)

[0189] Remark:

[0190] Background plaque: T0: normal, T1: background plaque slightly reduced;

[0191] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0192] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0193] Table 10 Results of ACT-333679 bacterial reverse mutation 6-well plate initial screening test (TA98 strain)

[0194] Remark:

[0195] NA: not counted;

[0196] Background plaque: T0: normal, T1: background plaque slightly reduced, T2: background plaque moderately reduced, T3: background plaque severely reduced, T4: background plaque disappeared;

[0197] Solubility of test / reference substance: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0198] a : The positive drugs when S9 was not added and added were 2-nitrofluorene (0.4 μg / well) and 2-aminoanthracene (0.6 μg / well), respectively;

[0199] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0200] Table 11 Results of ACT-333679 bacterial reverse mutation 6-well plate initial screening test (TA100 strain)

[0201] Remark:

[0202] NA: not counted;

[0203] Background plaque: T0: normal, T1: slightly reduced background plaque, T3: severely reduced background plaque, T4: disappeared background plaque; Solubility of test / control: P0: normal / no precipitation, P1: non-interfering precipitation under the microscope;

[0204] a : The positive drugs without and with S9 were sodium azide (0.4 μg / well) and 2-aminoanthracene (0.6 μg / well), respectively;

[0205] *: The number of reverse mutant colonies in the positive control group was 3 times higher than that in the negative control group.

[0206] In summary, this application synthesized a series of new structural compounds, which have good affinity for PGI2 receptors and very low adverse reactions, and have broad application prospects in the preparation of drugs for the treatment of pulmonary arterial hypertension.

[0207] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A PGI2 receptor agonist compound represented by General Formula I, or a pharmaceutically acceptable salt, stable isotope derivative, isomer, or mixture thereof, In general formula I, R1 and R2 are each independently selected from H, C1-C3 alkyl or a halogen atom; Z is selected from CR7 or an N atom, wherein, R7 is selected from H or C1-C3 alkyl, a halogen atom or a halogenated C1-C3 alkyl; R3 is selected from C2-C4 alkyl, C3-C6 monocyclic cycloalkyl; R4 is selected from H, C1-C3 alkoxy or a 3- to 6-membered heteroalicyclic group; R5 represents OH, OR6 or NHSO2R6, where R6 represents C 1-4 alkyl or C 1-4 alkyl substituted by halogen; represents a single bond or a double bond.

2. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer, or mixture thereof according to claim 1, characterized in that, Z is an N atom; or Z is CR7, wherein R7 is selected from H or CH3.

3. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to claim 2, characterized in that, represents a double bond and R4 is H.

4. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to claim 2, characterized in that, represents a single bond, and R4 is selected from H, C1-C3 alkoxy, or a 3- to 6-membered heteroalicyclic group.

5. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer, and mixture thereof according to claim 4, wherein R4 is selected from H, methoxy, ethoxy, 6. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to any one of claims 2-5, characterized in that, R1 and R2 are each independently selected from H, methyl or F.

7. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to claim 6, characterized in that, R3 is selected from isopropyl, ethyl or cyclopropyl.

8. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to claim 7, characterized in that, R3 is selected from isopropyl.

9. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer, and mixture thereof according to claim 6, wherein, R5 is selected from OH or NHSO2CH3.

10. The PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer or mixture thereof according to claim 1, characterized in that, The PGI2 receptor agonist compound is selected from:

11. A pharmaceutical composition, characterized in that, Comprising a pharmaceutically acceptable carrier, excipient, and the PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer and mixture thereof according to any one of claims 1-10 as an active ingredient.

12. The pharmaceutical composition according to claim 11, wherein The dosage form of the pharmaceutical composition is a pharmaceutically acceptable dosage form.

13. The pharmaceutical composition according to claim 12, wherein, The dosage form includes tablets, granules, capsules, powders or injections.

14. Use of the PGI2 receptor agonist compound or a pharmaceutically acceptable salt, stable isotope derivative, isomer and mixture thereof according to any one of claims 1-10 or the pharmaceutical composition according to any one of claims 11-13 in the preparation of a medicament for treating pulmonary hypertension.

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