WO2025061122A1 - Polyamide salt, preparation method therefor and use thereof - Google Patents

Abstract

Provided are a polyamide salt, a preparation method therefor and a use thereof. Provided are a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound or a salt of a stereoisomer thereof, a preparation method therefor, a use thereof, a pharmaceutical composition comprising a therapeutically effective amount of the salt, and a use thereof in preparation of a medication for preventing and/or treating κ-opioid receptor-mediated related diseases.

Description

A polyamide salt, preparation method and application thereof

This application claims the priority of Chinese Patent Application No. 202311226591X filed on September 22, 2023, the contents of which are incorporated herein by reference in their entirety

Technical Field

The invention belongs to the technical field of drug synthesis, and particularly relates to a polyamide salt and a preparation method and application thereof.

Background Art

Opioid receptors are an important class of G protein-coupled receptors. They are the binding targets of endogenous opioid peptides and opioid drugs. After activation, opioid receptors have a regulatory effect on the immune and endocrine systems of the nervous system. Opioid drugs are currently the strongest and most commonly used central analgesics. The opioid receptors in the central nervous system include μ, δ, and κ receptors.

The κ-opioid receptor (KOR) is composed of 380 amino acids and is expressed in sensory neurons, dorsal root ganglion cells and primary afferent neuron terminals. It is involved in important physiological activities such as pain, neuroendocrine, emotional behavior and cognition.

KOR agonists have good application prospects as drugs in the pharmaceutical industry. For example, CN108290926A discloses a class of phenylpropionamide derivatives that can be used as KOR agonists, and CN101627049A also discloses a class of synthetic peptide amides that can be used as KOR agonists, among which the compound D-Phe-D-Phe-D-Leu-D-Lys-[ω(4-aminopiperidine-4-carboxylic acid)]-OH (development code CR845) has been approved for marketing in Europe and the United States.

Summary of the invention

International patent application PCT/CN2023/083063 describes a tetrahydro-2H-pyran-4-yl (1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl) carbamate compound represented by formula (A) (hereinafter referred to as "Compound A"), the structure of which is shown below. All contents involved in International patent application PCT/CN2023/083063 are added to the present invention by reference.

The inventors found that the free state of compound A is extremely unstable and is not suitable for industrial production and storage. The technical problem to be solved by the present invention is to provide a polyamide salt, a preparation method and application thereof, specifically a salt form of compound A or its stereoisomers, a preparation method and application thereof.

In one aspect, the present invention provides an acid salt of Compound A or a stereoisomer thereof.

In another aspect, the present invention provides a method for preparing an acid salt of Compound A or a stereoisomer thereof.

In another aspect, the present invention provides a pharmaceutical composition comprising a therapeutically effective dose of Compound A or a stereoisomer thereof. Acid salt, and one or more pharmaceutically acceptable carriers, diluents or excipients.

On the other hand, the present invention provides a use of an acid salt of Compound A or its stereoisomer or a pharmaceutical composition comprising the same in the preparation of a drug, wherein the drug is preferably a drug for preventing and/or treating diseases mediated by κ opioid receptors.

The acetate of compound A and the hydrochloride of compound A of the present invention have excellent physical and chemical properties, such as good solubility in a variety of solvents, and high stability in stability tests such as high temperature, illumination, oxidation, and accelerated tests. These characteristics make the acetate of compound A and the hydrochloride of compound A of the present invention have significant advantages in the formulation development and production process, can ensure the effectiveness and consistency of the drug, and improve its feasibility and reliability in clinical applications. These characteristics are of great significance for the stability and effectiveness of the drug in long-term storage, transportation, and actual use.

DETAILED DESCRIPTION

definition

Different terms such as "X is selected from A, B or C", "X is selected from A, B and C", "X is A, B or C", "X is A, B and C" all express the same meaning, that is, X can be any one or more of A, B, C.

"Amino protecting group" refers to a group that is easily removed and introduced on the amino group in order to keep the amino group unchanged when other parts of the molecule are reacted. Non-limiting examples include: (trimethylsilyl)ethoxymethyl, tetrahydropyranyl, tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), methyloxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilylethoxycarbonyl (Teoc), methoxycarbonyl, ethoxycarbonyl, phthaloyl (Pht), p-toluenesulfonyl (Tos), p-nitrobenzenesulfonyl, tert-butylsulfinyl, trifluoroacetyl (Tfa), trityl (Trt), 2,4-dimethoxybenzyl (DMB), acetyl, benzyl, allyl, or p-methoxybenzyl, etc.

"Room temperature" refers to a temperature from 10°C to 40°C. In some embodiments, "room temperature" refers to a temperature from 15°C to 30°C; in other embodiments, "room temperature" refers to a temperature from 18°C to 25°C.

"Optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and the description includes instances where the event or circumstance occurs or does not occur. For example, "cycloalkyl optionally substituted with alkyl" means that alkyl may but need not be present, and the description includes instances where cycloalkyl is substituted with alkyl and instances where cycloalkyl is not substituted with alkyl.

"Pharmaceutical composition" refers to a composition containing one or more compounds of the present invention or their physiologically/pharmaceutically acceptable salts or prodrugs, as well as other components such as physiologically/pharmaceutically acceptable carriers, diluents or excipients. The purpose of a pharmaceutical composition is to facilitate administration to an organism, facilitate the absorption of the active ingredients, and thus exert biological activity.

"Pharmaceutically acceptable salts" refer to salts of the compounds of the present invention, which are safe and effective when used in mammals and have the desired biological activity.

"Amorphous", "amorphous" or "amorphous form" refers to the material formed when the particles (molecules, atoms, ions) of the material are arranged in three-dimensional space without periodicity, characterized by a diffuse X-ray powder diffraction pattern without peaks. Amorphous/form is a special physical form of solid matter, and its locally ordered structural characteristics suggest that it is inextricably linked to crystalline substances.

"Equivalent" or its abbreviation "eq" refers to the equivalent amount of other raw materials required based on the equivalent relationship of chemical reactions, with the basic raw material used in each step as the benchmark (1 equivalent).

Unless otherwise specified, the "%" mentioned herein when describing the content refers to mass percentage.

In the present invention, the mechanism of the "acid radical conversion" process is different from the traditional mechanism of strong acid to weak acid. The "acid radical conversion" of the present invention is mainly achieved by anion exchange resin. The anion exchange resin has the ability to adsorb and exchange anions in the solution. Usually, the anion exchange resin contains a strong alkaline group, and the positively charged groups on it can be adsorbed and combined with the anions in the solution, thereby realizing anion exchange. Under the combined action of electrostatic attraction and concentration gradient diffusion force, the anions on the anion exchange resin are replaced. In the implementation process of the present invention, in the method for "acid radical conversion" of the acetate salt of compound A, the model of the anion exchange resin used is 205*7 acetic acid type resin.

In the context of the present invention, when or whether the words "about" or "approximately" are used, it means within 10%, suitably within 5%, and especially within 1% of a given value or range. Alternatively, for a person skilled in the art, the term "about" or "approximately" means within an acceptable standard error range of the mean. Whenever a number having a value of N is disclosed, any number having a value within N+/-1%, N+/-2%, N+/-3%, N+/-5%, N+/-7%, N+/-8% or N+/-10% will be explicitly disclosed, where "+/-" means plus or minus.

As mentioned above, since compound A is extremely unstable in its free state and easily deteriorates after being released, it is not suitable for industrial production and storage. Therefore, the present invention aims to provide a salt of compound A.

In some embodiments, the acid salt of Compound A of the present invention has good physicochemical properties. In some embodiments, the salt of Compound A of the present invention has good solubility in a variety of solvents. In some embodiments, the salt purity of Compound A of the present invention is high. In some embodiments, the salt stability of Compound A of the present invention is high, for example, the HPLC purity changes little under conditions of high temperature, illumination, oxidation, high humidity, etc. In some embodiments, the salt of Compound A of the present invention can meet the pharmaceutical requirements of production, transportation and storage, and can be adapted to industrial production. In some embodiments, the salt of Compound A of the present invention has one or more of the above-mentioned beneficial effects.

In one aspect, the present invention provides an acid salt of Compound A or a stereoisomer thereof.

In some embodiments, the acid salt is hydrochloride, hydrobromide, sulfate, nitrate, phosphate, formate, acetate, trifluoroacetate, maleate, succinate, mandelate, fumarate, malonate, malate, 2-hydroxypropionate, pyruvate, oxalate, glycolate, salicylate, glucuronate, galacturonate, lactate, citrate, tartrate, aspartate, glutamate, benzoate, citrate, cinnamate, p-toluenesulfonate, benzenesulfonate, methanesulfonate, ethanesulfonate, trifluoromethanesulfonate, or a combination thereof.

In some embodiments, the acid salt is formate, trifluoroacetate, phosphate, citrate, benzoate, lactate, hydrochloride, or acetate, preferably hydrochloride or acetate.

In some embodiments, the acid salt is a hydrochloride salt.

In some embodiments, the acid salt is acetate.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (radical) is 1:0.4 to 1:4, preferably 1:0.4 to 0.6 (e.g. 1:0.5), 1:0.8 to 1.2 (e.g. 1:1), 1:1.4 to 1.6 (e.g. 1:1.5), 1:1.8 to 2.2 (e.g. 1:2), 1:2.4 to 2.6 (e.g. 1:2.5) or 1:2.8 to 3.2 (e.g. 1:3), preferably 1:0.8 to 1.2 (e.g. 1:1), 1:1.8 to 2.2 (e.g. 1:2) or 1:2.8 to 3.2 (e.g. 1:3).

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 1:4; preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 3; more preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 2.5; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 2; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 1.5; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5 to 1. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:0.5.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1 to 1:4; preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1 to 3; more preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1 to 2.5; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1 to 2; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1 to 1.5. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5 to 1:4; preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5 to 3; more preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5 to 2.5; further preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5 to 2. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:2 to 1:4; preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:2 to 3; more preferably, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:2 to 2.5. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:2.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1 to 2. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.1 to 1.9. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.2 to 1.9. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.3 to 1.8. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.4 to 1.7. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.1. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1: 1.2. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.3. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.4. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.5. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.6. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.7. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.8. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:1.9. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acid (root) is 1:2.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the formic acid molecule is 1:0.8-1.2, 1:1.8-2.2 or 1:2.8-3.2, preferably 1:1.8-1.2, for example about 1:1.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the trifluoroacetic acid molecule is 1:0.8-1.2, 1:1.8-2.2 or 1:2.8-3.2, preferably 1:1.8-2.2, for example about 1:2.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:0.8-1.2, 1:1.8-2.2 or 1:2.8-3.2, preferably 1:1-2, 1:0.8-1.2, for example, about 1:2, 1:1.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the hydrogen chloride molecule is 1:0.8-1.2, 1:1.8-2.2 or 1:2.8-3.2, preferably 1:1.8-2.2, for example about 1:2.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the hydrogen chloride molecule is 1:0.5-2; preferably, the molar ratio of the compound of formula A or its stereoisomer to the hydrogen chloride molecule is 1:1-2. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the hydrogen chloride molecule is 1:2.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:0.5-2; preferably, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1-2; more preferably, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.4-1.7. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.1. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.2. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.3. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.4. In some specific embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.5. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.6. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.7. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.8. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:1.9. In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the acetic acid molecule is 1:2.

On the other hand, the present invention provides an acetate salt of a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound represented by formula (I) or a stereoisomer thereof.

On the other hand, the present invention provides an acetate salt of a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound represented by formula (I-1) or a stereoisomer thereof.

On the other hand, the present invention provides an acetate salt of a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound represented by formula (I-2) or a stereoisomer thereof.

On the other hand, the present invention provides an acetate salt of a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound represented by formula (I-3) or a stereoisomer thereof.

On the other hand, the present invention provides a tetrahydro-2H-pyran-4-yl (1-(D-phenylalanyl-D-phenylalanyl) represented by formula (I-4) The acetic acid salt of a (4-yl)-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound or a stereoisomer thereof.

On the other hand, the present invention provides a tetrahydro-2H-pyran-4-yl(1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl)carbamate compound represented by formula (II) or the hydrochloride of its stereoisomer.

In some embodiments, the acid salt is a non-solvate or a solvate, wherein the solvent is selected from one or more of water, methanol, ethanol, ethylene glycol, propylene glycol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, glacial acetic acid, acetone, butanone, 3-pentanone, n-hexane, cyclohexane, n-heptane, isopropyl ether, methyl tert-butyl ether, petroleum ether, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, dichloromethane, chloroform, 1,2-dichloroethane, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, acetonitrile, tetrahydrofuran, 1,4-dioxane, 1,2-dioxane, benzene or toluene.

In some embodiments, the acid salt is a non-solvate or a solvate, wherein the solvent is selected from water and methyl acetate.

In some embodiments, the molar ratio of the compound of formula A or its stereoisomer to the solvent is 1:0.4 to 1:4, preferably 1:0.4 to 0.6 (e.g. 1:0.5), 1:0.8 to 1.2 (e.g. 1:1), 1:1.4 to 1.6 (e.g. 1:1.5), 1:1.8 to 2.2 (e.g. 1:2), 1:2.4 to 2.6 (e.g. 1:2.5) or 1:2.8 to 3.2 (e.g. 1:3); more preferably 1:0.8 to 1.2 (e.g. 1:1), 1:1.8 to 2.2 (e.g. 1:2) or 1:2.8 to 3.2 (e.g. 1:3); further preferably 1:1, 1:2 or 1:3.

In some embodiments, the acid salt is a non-solvate.

In some embodiments, the acid salt is anhydrous.

In some embodiments, the acid salt is crystalline or amorphous.

On the other hand, the present invention also relates to a method for preparing the acid salt of the compound represented by formula A or its stereoisomer.

In some embodiments, the method for preparing the acid salt of compound A comprises the step of subjecting compound A to a salt-forming reaction with an acid.

In some specific embodiments, the method for preparing the formate salt of Compound A comprises contacting Compound A with formic acid to undergo a salt-forming reaction to obtain the formate salt of Compound A.

In some specific embodiments, the method for preparing the hydrochloride of Compound A comprises contacting Compound A with hydrochloric acid to produce a salt-forming reaction to obtain the hydrochloride of Compound A.

In some specific embodiments, the method for preparing the trifluoroacetate salt of compound A comprises contacting compound A with trifluoroacetic acid to undergo a salt-forming reaction to obtain the trifluoroacetate salt of compound A.

In some specific embodiments, the method for preparing the acetate salt of Compound A comprises contacting Compound A with acetic acid to produce a salt-forming reaction to obtain the acetate salt of Compound A.

In some embodiments, the method for preparing the acid salt of compound A comprises contacting compound A protected by an amino protecting group with an acid (eg, a strong acid), and then reacting compound A after removing the amino protecting group under acidic conditions with the acid to form a salt.

In some embodiments, the method for preparing the acid salt of compound A comprises contacting the compound represented by formula (A) or its stereoisomer protected by an amino protecting group (such as Boc) with an acid X to remove the amino protecting group (such as Boc) and then reacting with the acid X to form a salt to obtain the acid X salt of the compound represented by formula (A) or its stereoisomer, wherein the acid X has the property of being able to remove the amino protecting group (such as Boc).

In some embodiments, the acid X includes but is not limited to hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, or ethanesulfonic acid.

In some specific embodiments, the method for preparing the formate salt of compound A comprises contacting the compound of formula (A) or its stereoisomer protected by an amino protecting group (such as Boc) with formic acid to remove the amino protecting group (such as Boc) and then reacting with formic acid to form a salt to obtain the formate salt of the compound of formula (A) or its stereoisomer.

In some specific embodiments, the method for preparing the hydrochloride of compound A comprises contacting the compound represented by formula (A) or its stereoisomer protected by an amino protecting group (such as Boc) with hydrochloric acid to remove the amino protecting group (such as Boc) and then reacting with hydrochloric acid to form a salt to obtain the hydrochloride of the compound represented by formula (A) or its stereoisomer.

In some specific embodiments, the method for preparing the trifluoroacetate salt of compound A comprises contacting the compound represented by formula (A) or its stereoisomer protected by an amino protecting group (such as Boc) with trifluoroacetic acid to remove the amino protecting group (such as Boc) and then reacting with trifluoroacetic acid to form a salt to obtain the trifluoroacetate salt of the compound represented by formula (A) or its stereoisomer.

The aforementioned compound represented by formula (A) or its stereoisomer protected by an amino protecting group refers to the introduction of an easily removable group on the amino group of the compound represented by formula (A) or its stereoisomer, so that the amino group remains unchanged when reacting at other positions. Non-limiting examples of such amino protecting groups include: (trimethylsilyl)ethoxymethyl, tetrahydropyranyl, tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz), methoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilylethoxycarbonyl (Teoc), methoxycarbonyl, ethoxycarbonyl, phthaloyl (Pht), p-toluenesulfonyl (Tos), p-nitrobenzenesulfonyl, tert-butylsulfinyl, trifluoroacetyl (Tfa), trityl (Trt), 2,4-dimethoxybenzyl (DMB), acetyl, benzyl, allyl, or p-methoxybenzyl, etc.

In some embodiments, the method for preparing the acid salt of Compound A adopts an acid radical conversion method, that is, converting one acid salt of Compound A into another acid salt.

In some embodiments, the acid conversion method comprises converting a strong acid salt of Compound A into a weak acid salt.

In some embodiments, the method for preparing the acid salt of compound A or its stereoisomer comprises contacting the Y acid salt of the compound represented by formula A or its stereoisomer with Z acid to perform acid radical conversion to generate the Z acid salt of the compound represented by formula A or its stereoisomer; wherein the Y acid is an acid stronger than the Z acid.

In some embodiments, the method for preparing the acetate salt of compound A or its stereoisomer comprises contacting the Y acid salt of the compound shown in formula A or its stereoisomer with acetic acid, performing acid radical conversion, and generating the acetate salt of the compound shown in formula A or its stereoisomer, wherein the Y acid is an acid with stronger acidity than acetic acid. The Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid and formic acid; preferably, the Y acid is one or more of hydrochloric acid, trifluoroacetic acid or formic acid.

In some embodiments, the hydrochloride salt of Compound A is contacted with acetic acid to produce the acetate salt of Compound A.

In some embodiments, the trifluoroacetate salt of Compound A is contacted with acetic acid to produce the acetate salt of Compound A.

In some embodiments, the formate salt of Compound A is contacted with acetic acid to produce the acetate salt of Compound A.

In some embodiments, the acid radical conversion method comprises eluting the Y salt of compound A through high performance liquid chromatography with an eluent containing acetic acid, concentrating and drying to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the Y salt of compound A with an alkali free treatment and then adding acetic acid to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the Y salt of compound A with an acetic acid type ion exchange resin to obtain the acetate of compound A. Wherein, the Y acid is an acid with stronger acidity than acetic acid. The Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid.

In some embodiments, the acid radical conversion method comprises eluting the trifluoroacetate of compound A through high performance liquid chromatography with an eluent containing acetic acid, concentrating, and drying to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the trifluoroacetate of compound A with alkali free treatment and then adding acetic acid dropwise to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the trifluoroacetate of compound A with an acetate type ion exchange resin to obtain the acetate of compound A.

In some embodiments, the acid radical conversion method comprises eluting the formate of compound A through high performance liquid chromatography with an eluent containing acetic acid, concentrating, and drying to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the formate of compound A with alkali free treatment and then adding acetic acid dropwise to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the formate of compound A with an acetate type ion exchange resin to obtain the acetate of compound A.

In some embodiments, the acid radical conversion method comprises eluting the hydrochloride of compound A through high performance liquid chromatography with an eluent containing acetic acid, concentrating, and drying to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the hydrochloride of compound A with an alkali free treatment and then adding acetic acid dropwise to obtain the acetate of compound A. In some embodiments, the acid radical conversion method comprises treating the hydrochloride of compound A with an acetate type ion exchange resin to obtain the acetate of compound A. Salt.

In some embodiments, the method for preparing the acetate salt of compound A or its stereoisomer comprises: adding a Y acid salt of compound A or its stereoisomer and 205*7 acetate-type ion exchange resin to water, stirring to ensure that the acid radical is completely converted, filtering, and freeze-drying the resulting filtrate at a temperature of (-45°C)-(20-25°C) for 60-75 hours to obtain the acetate salt of compound A or its stereoisomer; the Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid.

In some embodiments, the method for preparing the acetate salt of compound A or its stereoisomer shown in formula (I-2) comprises: adding compound A or its stereoisomer Y acid salt and 205×7 acetate type ion exchange resin to water, stirring to ensure that the acid radical is completely converted, filtering, and freeze-drying the obtained filtrate at a temperature of (-45°C)-(25°C) for 70 to 75 hours to obtain the acetate salt of compound A or its stereoisomer shown in formula (I-2); preferably, the freezing temperature is (-45°C) )-(25°C), the freezing time is 70-73h; more preferably, the freezing temperature is (-45°C)-(25°C), and the freezing time is 71-73h; further preferably, the freezing temperature is (-45°C)-(25°C), and the freezing time is 72h; the Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid. In some embodiments, the method for preparing the acetate of compound A or its stereoisomer shown in formula (I-3) comprises: adding Y acid salt of compound A or its stereoisomer and 205×7 acetate type ion exchange resin to water, stirring to ensure complete conversion of acid radicals, filtering, and freeze-drying the obtained filtrate at a temperature of (-45°C)-(20°C) for 67-70 hours to obtain the acetate of compound A or its stereoisomer shown in formula (I-3); preferably, the freezing temperature is (-45°C)-(25°C), and the freezing time is 68-70 hours; more preferably, the freezing temperature is (-45°C)-(25°C), and the freezing time is 69 hours; the Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid.

In some embodiments, the method for preparing the acetate salt of compound A or its stereoisomer shown in formula (I-4) comprises: adding Y acid salt of compound A or its stereoisomer and 205×7 acetate type ion exchange resin to water, stirring to ensure complete conversion of acid radicals, filtering, and freeze-drying the obtained filtrate at a temperature of (-45°C)-(20°C) for 63 to 66 hours to obtain the acetate salt of compound A or its stereoisomer shown in formula (I-4); preferably, the freezing temperature is (-45°C)-(20°C), and the freezing time is 64 to 66 hours; more preferably, the freezing temperature is (-45°C)-(20°C), and the freezing time is 65 to 66 hours; the Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid.

The present invention can obtain the acetate of compound A containing different molar ratios of compound A and acetic acid by strictly controlling the freezing temperature and the freeze-drying time; in particular, the acetate of compound A containing the molar ratio of compound A to acetic acid of 1:1 to 2 can be obtained.

This method of using the strong acid salt of compound A to undergo acid radical conversion with a weak acid to obtain the weak acid salt of compound A is also applicable to the preparation of other weak acid salts of compound A, which cannot directly remove the amino protecting group (such as Boc) on compound A.

The present invention further relates to a pharmaceutical composition comprising a therapeutically effective dose of any acid salt as described above, and a or a variety of pharmaceutically acceptable carriers, diluents or excipients.

In some embodiments, the composition comprises a therapeutically effective dose of any acid salt as described above, and a buffer system. In some embodiments, the buffer system is an acetic acid-acetate (e.g., sodium salt) buffer system, a phosphoric acid-phosphate (e.g., sodium salt) buffer system, or a tartaric acid-tartrate (e.g., sodium salt) buffer system. In some embodiments, the buffer system is an acetic acid-sodium acetate buffer system.

The present invention further relates to the use of an acid salt of any of the compounds described above, or a pharmaceutical composition thereof, in preparing a drug.

In some embodiments of the present invention, the drug is a drug for preventing and/or treating diseases mediated by kappa opioid receptors.

In further embodiments of the present invention, the κ opioid receptor-mediated related diseases are selected from one or more of pain, inflammation, pruritus, edema, hyponatremia, hypokalemia, intestinal obstruction, cough and glaucoma, preferably pain.

In further embodiments of the present invention, the pain is selected from one or more of neuropathic pain, truncal pain, visceral pain, cutaneous pain, arthritis pain, kidney stone pain, uterine cramps, dysmenorrhea, endometriosis, indigestion, postoperative pain, post-medical treatment pain, eye pain, otitis pain, breakthrough cancer pain, and pain associated with GI disorders.

Example

Below in conjunction with specific embodiment, further elaborate the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.In addition, should be understood that after reading the content of the present invention's teaching, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

The reagents or instruments used in this application that do not indicate the manufacturer are all conventional products that can be purchased commercially. Specifically, compounds 1-3 were purchased from Nanjing Komer Biopharmaceutical Co., Ltd. Among them, "FA" is formic acid. "TFA" refers to trifluoroacetic acid. "EtOAc" refers to ethyl acetate. "MeOH" refers to methanol. "DMF" refers to N,N-dimethylformamide. "DIPEA" refers to N,N-diisopropylethylamine. "HATU" refers to 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate. "MeCN" refers to acetonitrile. "DCM" refers to dichloromethane.

Example 1 (Formate of Compound A)

1.1 Synthesis of Compound 1-1

4-aminopiperidine-1-carboxylic acid benzyl ester (500 mg, 2.134 mmol, 1 eq.) was dissolved in toluene (5 mL), diphosgene (260 uL, 1.314 mmol, 0.62 eq.) was added, stirred at 90 ° C for 3 h, and then tetrahydropyran-4-ol (205 uL, 2.007 mmol, 0.94 eq.) was added dropwise. The resulting mixture was stirred overnight at 90 ° C under a nitrogen atmosphere, cooled to room temperature, then poured into ice water, and extracted with EtOAc (3x10 mL). The combined organic layer was washed twice with a saturated NaCl aqueous solution (2x15 ml), dried over anhydrous Na ₂ SO ₄ , filtered, and the filtrate was concentrated under reduced pressure to obtain a crude product of compound 1-1. The crude product of compound 1-1 can be directly used in the next step without further purification.

1.2 Synthesis of compound 1-2

Compound 1-1 (433 mg, 1.195 mmol, 1 eq.) and Pd/C (100 mg, w/t, 10%) were added to methanol (10 mL, 246.99 mmol, 206.73 eq.), stirred overnight at room temperature under hydrogen atmosphere, filtered, and the resulting filter cake was washed with MeOH (3 x 10 mL). The filtrate was concentrated under reduced pressure to obtain a crude product of compound 1-2 (448 mg). The crude product of compound 1-2 can be directly used in the next step without further purification.

1.3 Synthesis of Compounds 1-4

Under nitrogen protection at room temperature, compound 1-2 (113 mg, 0.495 mmol, 1.5 eq.) was dissolved in DMF (10 mL), compound 1-3 (248.79 mg, 0.330 mmol, 1 eq.) was added and stirred, and DIPEA (85.30 mg, 0.660 mmol, 2 eq.) and HATU (188.21 mg, 0.495 mmol, 1.5 eq.) were added and stirred overnight. Water was added to quench, and the resulting mixture was extracted with EtOAc (3×20 mL). The combined organic layer was washed with saturated aqueous NaCl solution (3x20 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain a residue. The residue was purified by high performance liquid chromatography to obtain compound 1-4 (104 mg, yield 32.69%, purity 99%). The purification conditions were as follows: mobile phase, MeCN-H2O; elution time: 10 min; elution gradient 10% (MeCN) to 50% (MeCN); detection wavelength: UV 254 nm.

1.4 Synthesis of Compound A Formate

Under nitrogen protection at room temperature, compound 1-4 (104 mg, 0.108 mmol, 1 eq.) and TFA (4 mL) were added to DCM (16 mL), stirred for 3 h, and concentrated under reduced pressure. 25 ml of ice water was added to the residue, and a saturated sodium bicarbonate aqueous solution was added dropwise to adjust the pH value to 7-8, and extracted with EtOAc (3x10 mL). The combined organic phase was washed with a saturated NaCl aqueous solution (3x20 mL), dried over anhydrous Na ₂ SO ₄ , filtered, and the residue was concentrated. After the residue was purified by high performance liquid chromatography, the obtained aqueous phase was placed in a freeze drying oven and lyophilized to obtain the formate salt of compound A (19.7 mg, yield 22.73%, purity 95.0%). The conditions are as follows: mobile phase, MeCN-H ₂ O (0.1% FA), elution time: 10 min; elution gradient 10% (MeCN) to 50% (MeCN); detection wavelength, UV 254 nm. LC-MS (ES, m/z)=764[M+H] ⁺ .

¹ H NMR (400 MHz, D ₂ O)δ8.36(s,1H),7.26(h,J＝6.6Hz,6H),7.13(t,J＝7.1Hz,4H),4.65(s,2H), 4.59–4.47(m,1H),4.26–4.03(m,2H),3.96–3.76(m,4H),3.56(d,J＝10.2Hz, 3H),3.22(q,J＝13.7Hz,1H),3.02–2.75(m,7H),1.86(s,4H),1.60(dt,J＝15 .1,7.7Hz,6H),1.46(d,J＝6.3Hz,3H),1.38–1.11(m,4H),0.91–0.70(m,6H).

Example 2 (Trifluoroacetate salt of compound A)

Compound 1-4 (104 mg, 0.108 mmol, 1 eq.) and TFA (4 mL) were added to DCM (16 mL) at room temperature and in a nitrogen atmosphere and stirred for 3 h. The resulting mixture was concentrated under reduced pressure to obtain a residue. The residue was dispersed in DCM (2 mL), stirred at room temperature for 2 h, and MBTE (6 mL) was added dropwise to precipitate a solid, which was then filtered. The resulting filter cake was placed in a vacuum oven and dried to obtain the trifluoroacetate salt of compound A (87.47 mg, yield 81.64%, purity 98%). LC-MS (ES, m/z) = 764 [M+H] ⁺ .

1H NMR (400MHz, DMSO-d ₆ )δ8.81(d,J＝8.1Hz,1H),8.41(d,J＝8.0Hz,1H),8.12(t,J＝6.1Hz,1H),8.06(s,2H),7.84(d,J＝7.3Hz,2H),7.33–7 .20(m,10H),4.81–4.59(m,3H),4.37(dd,J＝12.0,6.2Hz,1H),4.17(dd,J＝24.9,13.1Hz,1H),4.02(s,1H),3.90–3 .72(m,3H),3.41(t,J＝10.8Hz,4H),3.10(ddd,J＝17.0,12.1,4.2Hz,3H),2.94(dd,J＝14.4,7.9Hz,1H),2.87–2.64 (m,4H),1.90–1.70(m,4H),1.53(ddt,J＝26.5,21.0,10.0Hz,8H),1.36–1.18(m,4H),0.90(dd,J＝16.7,5.9Hz,6H).

Example 3 (Preparation of the hydrochloride salt of compound A)

Compound 1-4 (100 mg, 0.104 mmol, 1 eq.) was added to HCl/ethyl acetate (2 M, 5 mL) at room temperature and under nitrogen atmosphere, and then stirred for 3 h under ice bath conditions to precipitate solids, which were filtered. The resulting filter cake was dried to obtain the hydrochloride of compound A shown in formula (II) (79.1 mg, yield 88.04%, purity 99%). LC-MS (ES, m/z) = 764 [M+H] ⁺ .

¹ H NMR (400MHz, DMSO-d6) δ9.07(t,J＝6.7Hz,1H),8.54(d,J＝7.9Hz,1H),8.14(d,J＝10.8Hz,6H),7.41(d,J＝7.5Hz,2H),7.32–7. 19(m,8H),4.76–4.58(m,3H),4.42–4.29(m,1H),4.17(t,J＝16.2Hz,1H),4.03(d,J＝6.8Hz,1H),3.81(t,J＝12.4Hz,3H),3.54 (s,1H),3.42(dd,J＝6.7,3.0Hz,1H),3.22(dd,J＝14.4,4.6Hz,1H),3.18–3.05(m,2H),2.96(dd,J＝14.2,7.6Hz,1H),2.90–2. 81(m,1H),2.75(q,J＝9.6,8.3Hz,2H),1.88–1.64(m,5H),1.53(dp,J＝30.6,7.3Hz,8H),1.37–1.14(m,4H),1.03–0.70(m,6H).

The method for determining the number of HCl in the hydrochloride of compound A is as follows:

Take 0.3g of the hydrochloride of compound A obtained by the above experimental steps, add 20ml of water to dissolve, add 3-5 drops of potassium chromate indicator and shake well. Slowly add silver nitrate titration solution (0.05mol/L), shaking while adding. When the solution changes from yellow to light brick red, it is the titration end point. A total of 14.70ml of silver nitrate titration solution is used. Each 1ml of silver nitrate titration solution (0.05mol/L) is equivalent to 1.772mg of Cl. The final mass percentage of hydrochloric acid is 8.8%; nCompound _A : _nHCl = (100-8.8)/763.46: 8.8/36.5 = 0.1195: 0.2411 = 1: 2.02≈1:2.

Example 4 (Preparation of Acetate Salt of Compound A)

At room temperature and nitrogen atmosphere, the trifluoroacetate of compound A obtained in Example 2 (75 mg, 0.077 mmol, 1 eq.) and 205×7 acetate type ion exchange resin (211 mg, 0.77 mmol, 10 eq.) were added to purified water (5 mL), stirred for 5 h and filtered. The obtained aqueous phase was placed in a freeze drying oven for freeze drying, and freeze dried for 72 h at a freezing temperature of -45-25°C to obtain the acetate of compound A shown in formula (I-2) (54.6 mg, yield 83.61%, purity 99%). LC-MS (ES, m/z) = 764 [M+H] ⁺ .

¹ HNMR (400MHz, CD ₃ OD)δ7.25(ddd,J＝32.5,17.2,7.3Hz,10H),4.87–4.74(m,2H),4.65(dd,J＝9.0,5 .2Hz,1H),4.45–4.27(m,2H),4.01(d,J＝13.9Hz,1H),3.93–3.83(m,2H),3.73–3 .51(m,4H),3.29–3.11(m,2H),3.03–2.81(m,5H),2.67(dd,J＝13.7,8.3Hz,1H), 1.93(s,7H),1.81–1.53(m,9H),1.52–1.28(m,4H),0.97(dd,J＝14.5,6.0Hz,6H).

Example 5 (Preparation of Acetate Salt of Compound A)

At room temperature and nitrogen atmosphere, the hydrochloride of compound A shown in formula (II) obtained by the method described in Example 3 (8.0 g, 9.56 mmol, 1 eq.) and 205×7 acetate type ion exchange resin (26.21 g, 95.6 mmol, 10 eq.) were added to purified water (40 mL), stirred for 10 h and then filtered. The obtained aqueous phase was placed in a freeze drying oven for freeze drying at a freezing temperature of -45-20°C for 66 h to obtain the acetate of compound A shown in formula (I-4) (6.92 mg, yield 83.57%, purity 99%). LC-MS (ES, m/z) = 764 [M+H] ⁺ .

¹ H NMR (400MHz, CD ₃ OD)δ7.39–7.28(m,10H),7.23(t,J＝7.3Hz,1H),4.84–4.70(m,3H),4.47–4.27(m,2H),4.18(dd,J＝9.0 ,4.8Hz,1H),4.03–3.85(m,3H),3.69(d,J＝6.1Hz,1H),3.55(t,J＝10.3Hz,2H),3.42–3.31(m,2H),3.2 5(dd,J＝14.5,5.3Hz,2H),3.11–2.92(m,5H),2.92–2.75(m,1H),1.93(d,J＝13.7Hz,4H),1.69(dtd,J＝ 33.5,18.3,16.2,7.8Hz,10H),1.50(d,J＝8.9Hz,2H),1.47–1.33(m,2H),0.98(dd,J＝15.8,6.0Hz,6H).

Example 6 (Preparation of Acetate Salt of Compound A)

At room temperature and nitrogen atmosphere, the hydrochloride of compound A shown in formula (II) (8.0 g, 9.56 mmol, 1 eq.) obtained by the method described in Example 3 and 205×7 acetate type ion exchange resin (26.21 g, 95.6 mmol, 10 eq.) were added to purified water (40 mL), stirred for 10 h and then filtered. The obtained aqueous phase was placed in a freeze drying oven for freeze drying at a freezing temperature of -45-20°C for 69 h to obtain the acetate of compound A shown in formula (I-3) (6.78 g, yield 83.09%, purity 99%). LC-MS (ES, m/z) = 764 [M+H] ⁺ .

¹ H NMR (400MHz, CD ₃ OD)δ7.41–7.15(m,10H),4.89–4.62(m,5H),4.48–4.26(m,2H),4.15–3.86(m,4H),3.69(d,J＝11.1Hz,1H),3.55(t,J＝10.3Hz,2H),3.33(s,1 H),3.25(td,J＝15.0,5.2Hz,3H),3.02–2.77(m,5H),2.10–1.85(m,4H),1.82–1.55(m,9H),1.52–1.30(m,4H),0.98(dd,J＝14.7,6.2Hz,6H).

Example 7 (Preparation of Acetate Salt of Compound A)

At room temperature and nitrogen atmosphere, the hydrochloride of compound A represented by formula (II) obtained by the method described in Example 3 (8.0 g, 9.56 mmol, 1 eq.) and 205×7 acetate type ion exchange resin (26.21 g, 95.6 mmol, 10 eq.) were added to water (40 mL), stirred for 10 h and then filtered. Acetic acid (1.74 g, 28.68 mmol, 3 eq.) was added to the filtrate, stirred evenly, and the obtained aqueous phase was placed in a freeze drying oven for freeze drying, and freeze dried for 69 h at a freezing temperature of -45-20°C to obtain the acetate of compound A represented by formula (I-5) (7.21 g, yield 85.94%, purity 99%).

The acetate salt (5.0 g) of compound A represented by formula (I-5) was freeze-dried at 20°C for 36 hours to obtain the acetate salt (4.75 g, yield 97.74%, purity 99%) of compound A represented by formula (I-3).

The acetate salt (3.0 g) of compound A represented by formula (I-3) was freeze-dried at 25°C for 36 hours to obtain the acetate salt (2.89 g, yield 98.97%, purity 99%) of compound A represented by formula (I-6).

Example 8 (Preparation of Acetate Salt of Compound A)

The acetate salt (5.0 g) of compound A represented by formula (I-3) obtained by the method described in Example 6 was freeze-dried at a freezing temperature of 20°C for 36 hours to obtain the acetate salt (4.88 g, yield 97.99%, purity 99%) of compound A represented by formula (I-7).

The acetate salt (3.0 g) of compound A represented by formula (I-7) was freeze-dried at a freezing temperature of 25°C for 36 hours to obtain the acetate salt (2.92 g, yield 98.98%, purity 99%) of compound A represented by formula (I-8).

Example 7 Method for determining the number of acetic acid in the acetate salt of compound A

The detection conditions of high performance liquid chromatography (HPLC) are as follows:

Filler: octadecylsilane bonded silica gel; mobile phase A: phosphoric acid solution (V _{phosphoric acid} : V _water = 0.7 ml: 1000 ml; pH value adjusted to 3.0 with sodium hydroxide solution (0.42%)); mobile phase B: methanol; column temperature: 35°C; detection wavelength: 210 nm; flow rate: 1.2 ml/min; injection volume: 10 μl; elution gradient is as follows:

Preparation of the sample solution to be tested: Take the acetate salt of compound A represented by formula (I-2), formula (I-4) and formula (I-3) in Example 4, Example 5 and Example 6 respectively, dissolve them by ultrasonication with a diluent (V _{mobile phase A} :V _{mobile phase B} = 95:5) and dilute them into a sample solution to be tested (1 mg/ml).

Preparation of reference solution: dissolve glacial acetic acid in diluent (Vmobile _{phase A} : Vmobile _{phase B} = 95:5) and dilute to obtain reference solution (1 mg/ml).

Inject the reference solution (10 μl) and each sample solution (10 μl) into the liquid chromatograph and record the chromatogram. According to the calculation formula: as well as The percentage of acetic acid in the sample to be tested is obtained; wherein _Rf is the correction factor obtained from the reference solution; A _sample is the main peak area of the sample to be tested; V _supply is the volume of the sample solution to be tested (ml); m _supply is the weight of the sample to be tested (mg). Then according to the calculation formula: n _{compound A} : n _CH3COOH = (100-acetic acid content)/763.46: acetic acid content/60.05, the molar ratio of compound A to acetic acid in the sample to be tested is obtained.

The test results are as follows:

Physical and chemical properties research

The inventors further studied the physical and chemical properties of the salt forms of the corresponding compounds. The preparation and characterization of the specific salt forms disclosed in this application do not limit the scope of protection of the present invention. A person of ordinary skill in the art can obtain more salt forms of the compounds of the present invention by conventional salt-forming methods based on the content of this disclosure, and these salt forms are all solutions protected by the present invention.

1. Physicochemical properties of compound A salt

1.1 Experimental Purpose

The physicochemical properties of the salt form of compound A were investigated.

1.2 Experimental methods

1.2.1 pH determination

Take an appropriate amount of sample, weigh it accurately, dissolve it in water and dilute it to make a solution containing approximately 10 mg per 1 ml, and determine it according to the law (Chinese Pharmacopoeia 2020 Edition Part 4 General Rules 0631).

1.2.2 Specific rotation determination

Take an appropriate amount of sample, weigh it accurately, add methanol to dissolve and dilute it to make a solution containing about 10 mg per 1 ml, and measure it according to the law (measurement temperature 25°C, the rest is in accordance with the general rules of Part IV of the Chinese Pharmacopoeia 2020 edition 0621).

1.2.3 Moisture determination

Take a sample and determine it according to the moisture determination method (Method 0832, General Rules of Part 4 of the Chinese Pharmacopoeia 2020 Edition).

1.2.4 Determination of acetic acid content

Take an appropriate amount of sample (acetate), weigh accurately, add diluent [mobile phase A (General Rule 0872)-methanol (95:5)] to dissolve and quantitatively dilute to make a solution containing about 1 mg per 1 ml as the test solution. Determine according to the method for determining acetic acid in synthetic peptides (General Rule 0872 of the Fourth Part of the Chinese Pharmacopoeia 2020 Edition).

1.3 Experimental Results

The results are shown in the following table:

Table 1.3 Physicochemical properties of compound A salt

Note: “/” means not detected.

2. Solubility test of compound A salt

2.1 Experimental Purpose

The solubility of the salt form of compound A in various solvents was investigated.

2.2 Experimental methods

Weigh the sample and grind it into fine powder. Place it in a certain volume of solvent at 25℃±2℃ and shake it vigorously for 30 seconds every 5 minutes. Observe the dissolution within 30 minutes. If there are no visible solute particles or droplets, it is considered to be completely dissolved.

2.3 Experimental results:

The results are shown in the following table:

Table 2.3 Solubility of different salt forms of compound A

Note: "Soluble" means that 1g (ml) of solute can be dissolved in 1 to less than 10ml of solvent; "Slightly soluble" means that 1g (ml) of solute can be dissolved in 1 to less than 10ml of solvent.
"Almost insoluble or insoluble" means that 1 g (ml) of the solute cannot be completely dissolved in 10000 ml of the solvent.

From the above data, it can be seen that the acetate of compound A and the hydrochloride of compound A represented by formula (II) are easily soluble in water, methanol, and ethanol, while compound A is almost insoluble in water and slightly soluble in methanol and ethanol.

Considering that the acetate of compound A shown in formula (I-2), the acetate of compound A shown in formula (I-3), the acetate of compound A shown in formula (I-4), the acetate of compound A shown in formula (I-5), the acetate of compound A shown in formula (I-6), the acetate of compound A shown in formula (I-7), and the acetate of compound A shown in formula (I-8) all show the same or similar stability in stability tests such as high temperature, light, oxidation, and accelerated tests, only one of the acetates is selected as a representative for testing in the following stability tests.

3. Stability test under high temperature and light conditions

Compound A, the hydrochloride of compound A represented by formula (II), and the acetate of compound A represented by formula (I-4) are respectively placed under the following experimental conditions:

(1) High temperature conditions: open, temperature is 40°C;

(2) Lighting conditions: Cool white fluorescent lamp and near ultraviolet lamp are present at the same time, open, room temperature, illumination is 5000lx±500lx, near The UV lamp intensity is 90 μW/cm ² ;

Compound A, the hydrochloride of compound A represented by formula (II), and the acetate of compound A represented by formula (I-4) were placed under each of the above test conditions for 30 days, and samples were taken on the 5th day, the 10th day, and the 30th day, and the percentage of compound A, the maximum single impurity, and the total impurities were detected by high performance liquid chromatography (HPLC).

The detection conditions of HPLC are as follows:

The detection conditions of high performance liquid chromatography (HPLC) are as follows: filler: octadecylsilane bonded silica gel; mobile phase A: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 90:10; mobile phase B: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 30:70; column temperature: 40°C; detection wavelength: 210 nm; flow rate: 1.0 ml/min; injection volume: 10 μl; elution gradient is as shown in Table 3.1;

Table 3.1 Elution gradient

The stability test results are shown in Table 3.2 below;

Table 3.2 Stability test data under high temperature and light conditions

As shown in Table 3.2, under the conditions of (high temperature 40°C, 30 days) and (light exposure for 30 days), the acetate of compound A shown in formula (I-4) and the hydrochloride of compound A shown in formula (II) have better stability than compound A. Especially under the condition of 30 days of light exposure, the maximum single impurity content of compound A is 30 times that of the acetate of compound A shown in formula (I-4) and 18 times that of the hydrochloride of compound A shown in formula (II); the total impurity content of compound A is 8.8 times that of the acetate of compound A shown in formula (I-4) and 3 times that of the hydrochloride of compound A shown in formula (II).

4. Stability test under accelerated conditions

Compound A, the hydrochloride of compound A shown in formula (II), and the acetate of compound A shown in formula (I-2) were ultrasonically dissolved with methanol solution (20%) and diluted to a solution with a concentration of 0.5 mg/ml. The obtained solution of compound A (0.5 mg/ml), the solution of the hydrochloride of compound A shown in formula (II) (0.5 mg/ml), and the solution of the acetate of compound A shown in formula (I-2) (0.5 mg/ml) were placed in simulated commercial packaging (the packaging material was a medicinal low-density polyethylene bag) and subjected to an accelerated test for 6 months at a temperature of 25°C ± 2°C and a relative humidity of 60% ± 5% RH. Samples were taken at the first month, the second month, the third month, and the sixth month, and the percentage of compound A, the maximum single impurity, and the total impurity was detected by high performance liquid chromatography (HPLC).

The detection conditions of HPLC are as follows:

The detection conditions of high performance liquid chromatography (HPLC) are as follows: filler: octadecylsilane bonded silica gel; mobile phase A: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 90:10; mobile phase B: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 30:70; column temperature: 40°C; detection wavelength: 210 nm; flow rate: 1.0 ml/min; injection volume: 10 μl; elution gradient is as shown in Table 4.1;

Table 4.1 Elution gradient

The results of the accelerated test are shown in Table 4.2 below;

Table 4.2 Stability test data under accelerated conditions

Table 4.2 shows that in the 6-month accelerated experiment at a temperature of 25°C ± 2°C and a relative humidity of 60% ± 5% RH, the acetate of compound A represented by formula (I-2) and the hydrochloride of compound A represented by formula (II) showed better stability than compound A. At 2 months of the accelerated experiment, the maximum single impurity content of compound A was 38.9 times that of the acetate of compound A represented by formula (I-2) and 58.3 times that of the hydrochloride of compound A represented by formula (II); the total impurity content of compound A was 14.4 times that of the acetate of compound A represented by formula (I-2) and 27.6 times that of the hydrochloride of compound A represented by formula (II).

5. Stability test under oxidative conditions

To a measuring bottle (20 ml) containing compound A (10 mg), the hydrochloride of compound A shown in formula (II) (10 mg), and the acetate of compound A shown in formula (I-3) (10 mg), a hydrogen peroxide solution (10%, 2 ml) was added, and the mixture was placed at room temperature for 2 hours, and then a methanol solution (20%) was added for ultrasonic dissolution and diluted to the scale, and the mixture was shaken to obtain the test solutions of compound A, the hydrochloride of compound A shown in formula (II), and the acetate of compound A shown in formula (I-3), respectively. A blank control solution containing no oxidant hydrogen peroxide solution was set. The percentage of compound A, the maximum single impurity, and the total impurity in each test solution was detected by high performance liquid chromatography (HPLC).

The detection conditions of HPLC are as follows:

The detection conditions of high performance liquid chromatography (HPLC) are as follows: filler: octadecylsilane bonded silica gel; mobile phase A: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 90:10; mobile phase B: potassium dihydrogen phosphate aqueous solution (0.02 mol/L, containing 0.1% triethylamine, pH adjusted to 3.0 with phosphoric acid) and acetonitrile, wherein V _{potassium dihydrogen phosphate solution} : V _acetonitrile = 30:70; column temperature: 40°C; detection wavelength: 210 nm; flow rate: 1.0 ml/min; injection volume: 10 μl; elution gradient is as shown in Table 5.1;

Table 5.1 Elution gradient

The results of the stability test under oxidative conditions are shown in Table 5.2 below;

Table 5.2 Stability test data under oxidative conditions

It can be seen from Table 5.2 that under the oxidative conditions of hydrogen peroxide, the stability of the acetate of compound A shown in formula (I-3) and the hydrochloride of compound A shown in formula (II) are better than that of compound A. The maximum single impurity and total impurity contents of compound A are significantly higher than those of the acetate of compound A shown in formula (I-3) and the hydrochloride of compound A shown in formula (II).

Although the present invention has been described in detail above, those skilled in the art will appreciate that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention, and these modifications and changes are also encompassed within the scope of the present invention.

Claims (21)

A tetrahydro-2H-pyran-4-yl (1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl) carbamate compound represented by formula (A) or an acid salt of a stereoisomer thereof
The acid salt according to claim 1, characterized in that the acid salt is hydrochloride, hydrobromide, sulfate, nitrate, phosphate, formate, acetate, trifluoroacetate, maleate, succinate, mandelate, fumarate, malonate, malate, 2-hydroxypropionate, pyruvate, oxalate, glycolate, salicylate, glucuronate, galacturonate, lactate, citrate, tartrate, aspartate, glutamate, benzoate, citrate, cinnamate, p-toluenesulfonate, benzenesulfonate, methanesulfonate, ethanesulfonate, trifluoromethanesulfonate or a combination thereof. The acid salt according to claim 1 or 2, characterized in that the acid salt is formate, trifluoroacetate, phosphate, citrate, benzoate, lactate, hydrochloride or acetate, preferably hydrochloride or acetate. The acid salt according to any one of claims 1 to 3, characterized in that the acid salt is a hydrochloride. The acid salt according to any one of claims 1 to 3, characterized in that the acid salt is acetate. The acid salt according to any one of claims 1 to 5, characterized in that the molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:0.4 to 1:4, preferably 1:0.4 to 0.6, 1:0.8 to 1.2, 1:1.4 to 1.6, 1:1.8 to 2.2, 1:2.4 to 2.6 or 1:2.8 to 3.2, preferably 1:0.8 to 1.2, 1:1.8 to 2.2 or 1:2.8 to 3.2, preferably 1:1, 1:2 or 1:3. The acid salt according to any one of claims 1 to 6, characterized in that the molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1 to 2. The acid salt according to any one of claims 1 to 7, characterized in that The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.1; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.2; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.3; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.4; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.5; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.6; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.7; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.8; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:1.9; or The molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:2. The acid salt according to any one of claims 1 to 8, characterized in that the molar ratio of the compound of formula (A) or its stereoisomer to the acid radical is 1:2. A tetrahydro-2H-pyran-4-yl (1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl) carbamate compound represented by formula (I) or an acetate of a stereoisomer thereof
A tetrahydro-2H-pyran-4-yl (1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidin-4-yl) carbamate compound represented by formula (II) or the hydrochloride of its stereoisomer
A method for preparing an acid salt of a compound represented by formula (A) or a stereoisomer thereof, characterized in that the method comprises contacting the compound represented by formula (A) or a stereoisomer thereof protected by an amino protecting group (such as Boc) with an acid X to obtain an acid X salt of the compound represented by formula (A) or a stereoisomer thereof; wherein the acid X is capable of removing the amino protecting group (such as Boc). The method for preparing an acid salt of a compound represented by formula (A) or a stereoisomer thereof according to claim 12, characterized in that the acid X includes but is not limited to one or more of hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, formic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, or ethanesulfonic acid. A method for preparing the hydrochloride of a compound represented by formula (A) or its stereoisomer, characterized in that the method comprises contacting the compound represented by formula (A) or its stereoisomer protected by an amino protecting group (such as Boc) with hydrochloric acid to obtain the hydrochloride of the compound represented by formula (A) or its stereoisomer. A method for preparing an acid salt of a compound represented by formula (A) or its stereoisomer, characterized in that a Y acid salt of the compound represented by formula (A) or its stereoisomer is contacted with a Z acid to perform acid radical conversion to generate a Z acid salt of the compound represented by formula (A) or its stereoisomer; wherein the Y acid is an acid stronger than the Z acid. A method for preparing the acetate of a compound represented by formula (A) or its stereoisomer, characterized in that the Y acid salt of the compound represented by formula (A) or its stereoisomer is contacted with acetic acid to perform acid radical conversion to generate the acetate of the compound represented by formula (A) or its stereoisomer, wherein the Y acid is an acid stronger than acetic acid. The method for preparing the acetate of the compound represented by formula (A) or its stereoisomer according to claim 16, characterized in that the Y acid includes but is not limited to trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, trifluoroacetic acid, phosphoric acid or formic acid; preferably, the Y acid is hydrochloric acid, trifluoroacetic acid or formic acid. The method for preparing the acetate of the compound represented by formula (A) or its stereoisomer according to claim 16 or 17, characterized in that: contacting the compound represented by formula (A) or the hydrochloride of its stereoisomer with acetic acid to generate the acetate of compound A; or contacting the trifluoroacetate of the compound represented by formula (A) or its stereoisomer with acetic acid to generate the acetate of compound A; or The compound represented by formula (A) or its stereoisomer formate salt is contacted with acetic acid to produce the acetate salt of compound A. A pharmaceutical composition comprising a therapeutically effective dose of the acid salt according to any one of claims 1 to 11, and one or more pharmaceutically acceptable carriers, diluents or excipients. The composition according to claim 19, comprising a therapeutically effective dose of the acid salt of any one of claims 1 to 11, and an acetic acid-acetate buffer system, a phosphate-phosphate buffer system or a tartaric acid-tartrate buffer system. A use of the acid salt according to any one of claims 1 to 11, or the pharmaceutical composition according to claims 19 to 20 in the preparation of a medicament, wherein the medicament is preferably a medicament for preventing and/or treating diseases mediated by kappa opioid receptors, preferably, the diseases mediated by kappa opioid receptors are selected from one or more of pain, inflammation, pruritus, edema, hyponatremia, hypokalemia, intestinal obstruction, cough and glaucoma, preferably pain; preferably, the pain is selected from one or more of neuropathic pain, trunk pain, visceral pain, skin pain, arthritis pain, kidney stone pain, uterine cramps, dysmenorrhea, endometriosis, dyspepsia, postoperative pain, post-medical treatment pain, eye pain, otitis pain, explosive cancer pain and pain associated with GI disorders.