Method for supporting amino acids on a resin for solid-phase synthesis

Abstract

A problem addressed by the present invention is to provide a method for efficiently producing a high-purity peptide compound at a high yield. It was discovered that an amino acid can be supported efficiently by a resin for solid-phase synthesis by bringing an amino acid solution including a specific solvent into contact with a resin for solid-phase synthesis swollen by a specific solvent, thereby solving the problem.

Description

[Technical Field]

[0001] The present invention relates to a method for supporting a starting compound onto a solid-phase synthesis resin in the production of peptide compounds by solid-phase synthesis, and to a method for producing peptide compounds using this method. [Background technology]

[0002] Peptides are molecules composed of many linked amino acids, and naturally occurring peptides (natural peptides) exhibit a variety of physiological activities. To obtain natural peptides as reference samples for research purposes, two methods are possible: isolation from nature and chemical synthesis. For obtaining samples on a gram scale, such as for experimental research, isolating naturally occurring substances in trace amounts is extremely inefficient. On the other hand, chemical synthesis is a more attractive method compared to isolation from nature, as it allows for the synthesis of the desired peptide by sequentially linking amino acids to achieve the desired sequence. However, amino acids may contain functional groups other than amino and carboxyl groups that can undergo unintended structural transformations through arbitrary chemical reactions, making the establishment of efficient synthesis methods for obtaining peptides with the desired sequence essential. Furthermore, when applying physiologically active peptides to pharmaceuticals, even more advanced chemical synthesis techniques are essential from the perspective of both the quantity and quality of compound supply. Among such chemical synthesis techniques, advances in solid-phase synthesis, in particular, are considered to have greatly contributed to the elucidation of the physiological activities of peptides (Non-Patent Literature 1).

[0003] In recent years, it has become known that non-natural peptides, particularly medium-sized molecules with molecular weights of around 500-2000, whose structures have been artificially designed, can effectively act on tough targets such as protein-protein interaction inhibitors. Furthermore, medium-sized molecules are attracting attention as a new modality that can act as modulators for target proteins that were previously considered unsuitable as drug targets. Research into artificially designing peptide structures to search for non-natural peptides with desired functions is actively being conducted (Non-Patent Literature 2).

[0004] With the aim of developing peptides as pharmaceuticals, it has been found that metabolic stability and membrane permeability can be improved by cyclizing peptides or by using non-natural amino acids as the amino acids contained in the peptides (Non-Patent Documents 3, 4).

[0005] Among cyclic peptides containing non-natural amino acids, cyclic peptides containing N-substituted amino acids in particular have become known to exhibit excellent metabolic stability and membrane permeability, as well as drug-like properties (Patent Document 1).

[0006] Macrocyclic peptides containing unnatural amino acids have also been suggested to be useful as inhibitors of protein-protein interactions (Non-Patent Document 5), and the conditions for cyclic peptides containing unnatural amino acids to be drug-like molecules have been clarified (Patent Documents 2 and 3).

[0007] Peptide synthesis is (i) A step to obtain an activated ester by activating the carboxyl group of an amino acid that has a protecting group on its amino group and an unprotected carboxyl group with a condensing agent or the like (activation step), (ii) A step of reacting the amino acid with a peptide whose N-terminus is unprotected to obtain a peptide in which the amino acid has been extended (extension step), and (iii) A step of removing the protecting group from the N-terminus of the extended peptide (deprotection step), This is achieved by repeating the process to link multiple amino acids with amide bonds and extend them into the desired sequence. More specific methods for peptide synthesis include liquid-phase and solid-phase methods (Non-Patent Literature 5).

[0008] Of these, the solid-phase method uses a resin for solid-phase synthesis in which linker atomic groups are bonded to a polymer resin. The solid-phase method is (a) A step of supporting amino acid carboxyl groups protected by amino groups onto linker atomic groups contained in a solid-phase synthesis resin (supporting step), (b) A step of deprotecting the protecting group of the N-terminal amino group (deprotection step), (c) A step to activate the carboxyl group of the elongated amino acid (activation step), (d) A step of extending the amino acid (extension step), (e) A step of repeating steps (b) to (d) the required number of times until a peptide chain of the desired sequence is obtained, and (f) A step of cleaving the target peptide from the solid-phase synthesis resin (de-resinization step). This includes. In the extension process, N-terminally protected amino acids are commonly used, primarily those in which the N-terminal amino group is protected with an Fmoc group or a Boc group (Non-Patent Documents 6, 7).

[0009] Solid-phase synthesis resins are roughly classified by linker atomic groups, and solid-phase synthesis resins containing linker atomic groups including trityl groups and benzyl groups are widely used. Specific examples of such resins include CTC resin, Wang resin, SASRIN resin, or Rink Amide resin. These resins each have different linker atomic groups, and due to the differences in the linker atomic groups, the reaction conditions for the resin removal process are different. The resin removal process is mainly carried out under acidic conditions. However, CTC resin, which can be de-resinized with weak acid, contains a trityl group in the linker atomic group, and peptide residues are supported on the resin through this group. On the other hand, Wang resin, which requires strong acid for resin removal, contains a benzyl group in the linker atomic group, and peptide residues are supported on the resin through this group. Thus, depending on the chemical properties of the target peptide, the resin used for solid-phase synthesis can be selected (Non-Patent Document 8).

[0010] When producing a peptide containing an N-methyl amino acid in the sequence, due to the steric hindrance of the N-methyl group, the condensation reaction is slow, and problems such as a decrease in the yield of the target product due to racemization at the α-position of the amino acid residue have been issues. In particular, many problems have been reported, such as the amide bond between the N-methyl amino acid residue and the adjacent amino acid residue being prone to cleavage reaction under acidic conditions, and the desorption reaction of the amino acid residue due to diketopiperazine formation being likely to occur. It is widely recognized that the synthesis of peptides containing N-methyl amino acids is more difficult than the synthesis of peptides derived only from natural amino acids (Non-Patent Document 9).

[0011] It is known that aspartic acid derivatives can be supported on solid-phase synthesis resins (Patent Document 4). On the other hand, it is known that non-natural amino acids containing aspartic acid derivatives may decompose in a solution state (Non-Patent Document 10).

[0012] In addition, amino acids having a carboxyl group in the side chain, such as aspartic acid and glutamic acid, are known to be likely to cause an amide transfer reaction in which the carboxyl group in the side chain transfers to the nitrogen atom in the main chain amide bond in the peptide residue depending on the solvent used in the peptide production process (Non-Patent Documents 10 and 11).

[0013] When synthesizing a peptide that is unstable under acidic conditions in this way, CTC resin that enables a deprotection reaction with a weak acid is useful (Non-Patent Document 12).

[0014] On the other hand, in the solid-phase synthesis of peptides using CTC resin, since the peptide can be deprotected from the CTC resin under mild conditions, problems of premature cleavage (also called premature peptide release or premature acidolytic cleavage), in which the amino acid or peptide supported on the CTC resin is inadvertently released, have been reported (Non-Patent Document 13).

[0015] In addition, it is known that the binding site of CTC resin with non-natural amino acids is hydrolyzed in the presence of moisture, and a reaction under non-aqueous conditions is required in the process of loading non-natural amino acids onto CTC resin (Non-Patent Document 14).

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0017] [Non-licensed document 1] J. Am. Chem. Soc., 1963, 85, 2149-2154. [Non-licensed document 2] Future Med. Chem., 2009, 1, 1289-1310. [Non-licensed document 3] Acc. Chem. Res., 2008, 41, 1331-1342.

Non-licensed Document 4

Non-licensed Document 5

Non-licensed Document 6

Non-licensed Document 7

Non-licensed Document 8

Non-licensed literature 9

Non-licensed literature 10

Non-licensed Document 11

[0018] The object of this invention is to provide a method for efficiently producing high-purity peptide compounds in high yield.

[0019] Solid-phase synthesis of peptides containing N-substituted amino acids that are unstable under acidic conditions is considered appropriate to be carried out using a resin that allows for the removal of peptides from the solid-phase synthesis resin under mild reaction conditions, such as CTC resin. The steps of supporting unnatural amino acids on the solid-phase synthesis resin, and extending the peptide chain by condensing unnatural amino acids onto the solid-phase synthesis resin on which peptides containing natural and / or unnatural amino acids are supported, are performed by contacting a solution containing unnatural amino acids with the solid-phase synthesis resin or the peptide linked thereto.

[0020] The preparation of non-natural amino acid solutions may involve not only simply dissolving the non-natural amino acids in a solvent, but also performing operations such as deprotection reactions on the non-natural amino acids before dissolving them in a solvent.

[0021] When preparing a solution by simply dissolving unnatural amino acids in a solvent, if the unnatural amino acids are hydrates or hygroscopic, water will be mixed into the amino acid solution. In this case, the linker atomic groups contained in the solid-phase synthesis resin undergo hydrolysis, causing the resin to decompose and reducing its ability to support amino acids.

[0022] Furthermore, when non-natural amino acids undergo functional group transformations such as deprotection reactions, decomposition can occur because the non-natural amino acids remain in solution during post-transformation processing, such as compound extraction, isolation, solvent removal, or azeotropic dehydration. For example, if the synthesis process involves leaving or heating the non-natural amino acids in solution, by-products may be generated, reducing the yield of the target product and complicating the purification process. For instance, in industrial manufacturing, when handling large quantities of non-natural amino acids with solvents, the non-natural amino acids remain in the solvent for longer periods during post-processing steps such as solvent extraction and during the concentration of the solution to obtain the product. Therefore, in large-scale synthesis, the decomposition of non-natural amino acids can become more pronounced depending on factors such as the storage time in solution, the concentration time, and the handling temperature. In particular, in industrial manufacturing, these operations are prolonged due to the large amounts of reagents and solvents involved, resulting in longer periods in which the non-natural amino acids remain in solution, leading to more pronounced decomposition reactions. Specifically, amino acids that have reactive functional groups in addition to the amino and carboxyl groups of the amino acid main chain, more specifically aspartic acid and glutamic acid with carboxyl groups in their side chains, serine and threonine with hydroxyl groups in their side chains, lysine, glutamine, and asparagine with free amino groups in their side chains, cysteine ​​and methionine with nucleophilic sulfur atoms in their side chains, and tryptophan, tyrosine, and histidine with free NH or OH groups in their side chains, as well as their derivatives, can undergo unintended functional group transformations when stored in solution.

[0023] The present invention aims to provide a method for efficiently producing peptide compounds containing high-purity unnatural amino acid residues in high yield by suppressing the decrease in amino acid loading rate due to the decomposition of solid-phase synthesis resins and suppressing the decomposition of amino acids during the process of loading amino acids onto solid-phase synthesis resins, thereby efficiently loading amino acids onto solid-phase synthesis resins. [Means for solving the problem]

[0024] The inventors, in order to solve the above problems, have found that the decomposition of amino acids is suppressed when they are handled in a specific solvent. Specifically, they have identified a solvent to be used for swelling of the solid-phase synthesis resin and a solvent to be used for the subsequent loading reaction of amino acids onto the solid-phase synthesis resin. Furthermore, they have found a method for carrying out the reaction in which the functional group of an amino acid is converted to another functional group and then loaded onto the solid-phase synthesis resin without removing the solvent used during the functional group conversion. In addition, they have found a drying method for amino acid solutions that can suppress hydrolysis at the binding site between the linker atomic group contained in the solid-phase synthesis resin and the amino acid, and does not require a dehydration operation involving the removal of the solvent. As a result, the decomposition of amino acids can be suppressed and amino acids can be efficiently loaded onto the solid-phase synthesis resin, making it possible to obtain peptide compounds in high yield and high purity more efficiently than with conventional methods.

[0025] In a non-limiting specific embodiment, the present invention includes the following: [1] A method for producing a peptide compound containing at least one N-substituted amino acid, a salt thereof, or a solvate thereof, comprising the step (step 1) of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent to obtain an amino acid supported on the solid-phase synthesis resin, The first solvent and the third solvent are each independently selected from halogenated solvents, and The method wherein the second solvent is an ether-based solvent. [2] A method for producing amino acids supported on a solid-phase synthesis resin, comprising the step of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent, The first solvent and the third solvent are each independently selected from halogenated solvents, and The method wherein the second solvent is an ether-based solvent. [3] The method according to [1] or [2], wherein the solution is a solution containing an amino acid and a second solvent. [4] The method according to [1] or [2], wherein the solution is a solution comprising an amino acid, a second solvent, and a third solvent. [5] The method according to [1], [2], or [4], wherein the first solvent and the third solvent are of the same type. [6] The method according to any one of [1] to [5], wherein the first solvent is selected from the group consisting of DCM, DCE, chloroform, chlorobenzene, and carbon tetrachloride. [7] The method according to any one of [1] to [6], wherein the second solvent is selected from the group consisting of MeTHF, MTBE, CPME, THF, IPE, DME, diethyl ether, and dioxane. [8] The method according to any one of [1] to [2] and [4] to [7], wherein the third solvent is selected from the group consisting of DCM, DCE, chloroform, chlorobenzene, and carbon tetrachloride. [9] The method according to any one of [1] to [2] and [4] to [8], wherein the volume ratio of the second solvent to the third solvent is 1:1 to 1:10.

[10] The method according to any one of [1] to [3] and [5] to [9], wherein the solution containing an amino acid and a second solvent is obtained by an extraction step, which includes using a second solvent, and a subsequent optional dehydration step, which is carried out after the deprotection reaction of the protecting group of the carboxyl group of the amino acid prior to step 1.

[11] The method according to any one of [1] to [2] and [4] to [9], wherein the solution comprising an amino acid, a second solvent, and a third solvent is obtained by adding a third solvent to a solution obtained by an extraction operation including the use of a second solvent, which is carried out after the deprotection reaction of the protecting group of the carboxyl group of the amino acid prior to step 1, and a subsequent optional dehydration operation.

[12] The method according to

[10] or

[11] , wherein the dehydration is carried out by a desiccant.

[13] The method according to

[12] , wherein the desiccant is Na2SO4, MgSO4, or CaCl2.

[14] The method according to any one of

[10] to

[13] , wherein the protecting group of the carboxyl group is removable with an acid.

[15] The method according to any one of

[10] to

[14] , wherein the protecting group of the carboxyl group is t-Bu, trityl, methoxytrityl, or cumyl.

[16] The method according to any one of [1] to

[15] , wherein the solid-phase synthesis resin is CTC resin, Wang resin, SASRIN resin, Trt resin, Mtt resin, or Mmt resin.

[17] The method according to

[16] , wherein the resin for solid-phase synthesis is a CTC resin.

[18] The method according to any one of [1] to

[17] , wherein the amino acid is a non-natural amino acid.

[19] The method according to

[18] , wherein the non-natural amino acid is a non-natural N-substituted amino acid.

[20] The method according to

[18] or

[19] , wherein a non-natural amino acid is supported on a solid-phase synthesis resin by a carboxyl group bonded to the carbon atom at the β position or the carbon atom at the γ position of the amino group.

[21] The method according to any one of

[18] to

[20] , wherein the non-natural amino acid contains an aminocarbonyl group.

[22] The unnatural amino acid supported on the solid-phase synthesis resin by a carboxyl group bonded to the β-carbon or γ-carbon of the amino group is aminocarbonylated aspartic acid, aminocarbonylated glutamic acid, or 2-aminobutanoic acid, or N-substituted derivatives thereof. The method according to

[20] or

[21] , wherein aminocarbonylated aspartic acid is obtained by aminocarbonylating the free carboxyl group of aspartic acid, and aminocarbonylated glutamic acid is obtained by aminocarbonylating the free carboxyl group of glutamic acid.

[23] The method according to any one of [1] and [3] to

[22] , wherein at least one N-substituted amino acid contained in the peptide compound is a non-natural N-substituted amino acid.

[24] The method according to any one of [1] and [3] to

[23] , wherein the peptide compound comprises two or more N-substituted amino acids.

[25] The method according to any one of [1] and [3] to

[24] , wherein 30% or more of the total number of amino acids constituting the peptide compound are N-substituted amino acids.

[26] A method for producing a cyclic peptide compound, a salt thereof, or a solvate thereof, comprising the following steps: A step of obtaining a peptide compound containing at least one N-substituted amino acid, a salt thereof, or a solvate thereof, according to the method described in any one of items [1] and [3] to

[25] , A step to remove the resin for solid-phase synthesis, and A step of cyclizing the C-terminal group and the N-terminal group of the peptide compound, its salt, or solvate thereof to form a cyclic portion. [Effects of the Invention]

[0026] According to the present invention, which uses a specific solvent when swelling the solid-phase synthesis resin and when supporting amino acids on the solid-phase synthesis resin, amino acids can be supported on the solid-phase synthesis resin with a high support rate and high yield. Furthermore, since the amino acid solution used in the reaction to support amino acids on the resin can be prepared without concentration or heating, the time that the amino acids are stored in the solution can be shortened, the decomposition of amino acids can be suppressed, and amino acids can be supported on the solid-phase synthesis resin at a high rate. In addition, by applying a specific operation to the post-treatment of the deprotection step preceding the support step, including the use of the solvent and drying agent used in the support step, the amino acid solution used in the support step can be obtained without isolating and purifying the deprotected amino acids, and amino acids can be supported on the solid-phase synthesis resin at a high rate. Furthermore, since operations such as azeotropic dehydration and heat drying are not performed prior to the preparation of the amino acid solution, even in industrial-scale synthesis, amino acids are not stored in the solution for a long time, and amino acids can be efficiently supported on the resin. The present invention is applicable to the production of peptide compounds containing any type and number of amino acids, and can be a useful method for producing peptide compounds in high yield and high purity. [Modes for carrying out the invention]

[0027] (abbreviation) The abbreviations used in this invention are listed below. Asp: Aspartic acid CTC Resin: 2-Chlorotrityl Chloride Resin CPME: Cyclopentyl methyl ether DCE: 1,2-Dichloroethane DCM: Dichloromethane DIPEA: Diisopropylethylamine DME: 1,2-dimethoxyethane DMF: N,N-dimethylformamide Fmoc: 9-Fluorenylmethyloxycarbonyl group HMDS: Hexamethyldisilazane IPE: Diisopropyl ether Me: Methyl group MeAsp: N-methylaspartic acid MeTHF: 2-methyltetrahydrofuran MTBE: t-butyl methyl ether pip: piperidinyl group pyrro: pyrrolidinyl group TFA: Trifluoroacetic acid THF: Tetrahydrofuran TMSOTf: Trimethylsilyl trifluoromethanesulfonate

[0028] (Definition of functional groups, etc.) Examples of "halogen atoms" as used herein include F, Cl, Br, or I.

[0029] In this specification, "alkyl" refers to a monovalent group derived from an aliphatic hydrocarbon by removing one arbitrary hydrogen atom, and does not contain heteroatoms (atoms other than carbon and hydrogen atoms) or unsaturated carbon-carbon bonds in its skeleton, but has a subset of a hydrocarbyl or hydrocarbon group structure containing hydrogen and carbon atoms. Alkyls include not only linear but also branched chains. Specifically, alkyls include groups with 1 to 20 carbon atoms (C1-C20). 20 , hereinafter referred to as “C p -C q" means an alkyl group with p to q carbon atoms, preferably C1-C 10 Alkyl, more preferably C1-C6 alkyl, is a possible example. Specifically, examples of alkyl include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, isobutyl(2-methylpropyl), n-pentyl, s-pentyl(1-methylbutyl), t-pentyl(1,1-dimethylpropyl), neopentyl(2,2-dimethylpropyl), isopentyl(3-methylbutyl), 3-pentyl(1-ethylpropyl), 1,2-dimethylpropyl, 2-methylbutyl, n-hexyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, and the like.

[0030] In this specification, "alkenyl" means at least one double bond (two adjacent SPs) 2 It is a monovalent group having carbon atoms. Depending on the arrangement of the double bond and substitutions (if present), the geometric form of the double bond can be entgegen (E) or thusanmen (Z), cis or trans configuration. Alkenyls include not only linear but also branched chains. Preferably, the alkenyl is C2-C 10 Examples include alkenyls, more preferably C2-C6 alkenyls, specifically vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl (including cis and trans), 3-butenyl, pentenyl, 3-methyl-2-butenyl, and hexenyl.

[0031] In this specification, "alkynyl" refers to a monovalent group having at least one triple bond (two adjacent SP carbon atoms). Alkynnyls include not only linear but also branched chains. Preferably, the alkynyl is C2-C 10Examples include alkynyls, more preferably C2-C6 alkynyls, specifically, ethinyl, 1-propynyl, propargyl, 3-butynyl, pentynyl, hexynyl, 3-phenyl-2-propynyl, 3-(2'-fluorophenyl)-2-propynyl, 2-hydroxy-2-propynyl, 3-(3-fluorophenyl)-2-propynyl, and 3-methyl-(5-phenyl)-4-pentynyl.

[0032] In this specification, "cycloalkyl" means a saturated or partially saturated cyclic monovalent aliphatic hydrocarbon group, including monocyclic, bicyclocyclic, and spirocyclic groups. Preferred cycloalkyls are C3-C8 cycloalkyls, specifically, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo[2.2.1]heptyl, and spiro[3.3]heptyl.

[0033] In this specification, "aryl" means a monovalent aromatic hydrocarbon ring, preferably C6-C 10 Examples of aryl compounds include phenyl and naphthyl (e.g., 1-naphthyl, 2-naphthyl).

[0034] In this specification, "heterocyclyl" means a non-aromatic, cyclic, monovalent group containing one to five heteroatoms in addition to carbon atoms. Heterocyclyls may have double and / or triple bonds in the ring, carbon atoms in the ring may be oxidized to form carbonyls, and may be monocyclic or fused rings. The number of atoms constituting the ring is preferably 4 to 10 (4-10 membered heterocyclyl), more preferably 4 to 7 (4-7 membered heterocyclyl). Examples of heterocyclyls include, for example, azetidinil, oxyranil, oxetanil, azetidinil, dihydrofuryl, tetrahydrofuryl, dihydropyranil, tetrahydropyranil, tetrahydropyridyl, tetrahydropyrimidyl, morpholinil, thiomorpholinil, pyrrolidinil, piperidinil, piperazinil, pyrazolidinil, imidazolinil, imidazolidinil, oxazolidinil, isoxazolidinil, thiazolidinil, isothiazolidinil Examples include yl, 1,2-thiadinane, thiadiazolidinyl, azetidinyl, oxazolidone, benzodioxanil, benzoxazolyl, dioxolanil, dioxanil, tetrahydropyrrolo[1,2-c]imidazole, thietanil, 3,6-diazabicyclo[3.1.1]heptanil, 2,5-diazabicyclo[2.2.1]heptanil, 3-oxa-8-azabicyclo[3.2.1]octanil, sultam, and 2-oxaspiro[3.3]heptyl.

[0035] In this specification, "protected heterocyclyl" means a group in which one or more functional groups, such as an amino group, contained in the "heterocyclyl" as defined above are protected by any protecting group, preferably a protected 4- to 7-membered heterocyclyl. Specific examples of protecting groups include Boc, Fmoc, Cbz, Troc, and Alloc, and specific examples of protected heterocyclyls include Boc-protected azetidine.

[0036] In this specification, "heterocycloalkylidene" means a divalent group whose free valence is part of a double bond, obtained by removing two hydrogen atoms from one carbon atom of the "heterocyclyl" as defined above. Preferred heterocycloalkylides are 4 to 7-membered heterocycloalkylides, specifically, for example, tetrahydropyran-4-ylidene and azetidine-3-ylidene.

[0037] In this specification, "protected heterocycloalkylidene" means a group in which one or more functional groups, for example, an amino group, contained in the "heterocycloalkylidene" as defined above is protected with any protecting group, preferably a protected 4- to 7-membered heterocycloalkylidene. Specific examples of protecting groups include Boc, Fmoc, Cbz, Troc, and Alloc, and specific examples of protected heterocyclines include Boc-protected azetidine-3-ylidene.

[0038] In this specification, "heteroaryl" means an aromatic, cyclic, monovalent group containing one to five heteroatoms in addition to a carbon atom. The ring may be a monoring or a fused ring with other rings, and may be partially saturated. The number of atoms constituting the ring is preferably 5 to 10 (5 to 10-membered heteroaryl), and more preferably 5 to 7 (5 to 7-membered heteroaryl). Examples of heteroaryl compounds include, for instance, furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, benzothienyl, benzothiadiazolyl, benzothiazolyl, benzoxazolyl, benzoxadiazolyl, benzimidazolyl, indolyl, isoindolyl, indazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, benzodioxolyl, indolidinyl, and imidazopyridyl.

[0039] As used herein, "alkoxy" means an oxy group to which the "alkyl" as defined above is bonded, and preferably C1-C6 alkoxy. Specific examples of alkoxy include, for example, methoxy, ethoxy, 1-propoxy, 2-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, pentyloxy, 3-methylbutoxy, and the like.

[0040] As used herein, "alkenyloxy" means an oxy group to which the "alkenyl" as defined above is bonded, and preferably C2-C6 alkenyloxy. Specific examples of alkenyloxy include, for example, vinyloxy, allyloxy, 1-propenyloxy, 2-propenyloxy, 1-butenyloxy, 2-butenyloxy (including cis and trans), 3-butenyloxy, pentyloxy, hexyloxy, and the like.

[0041] As used herein, "cycloalkoxy" means an oxy group to which the "cycloalkyl" as defined above is bonded, and preferably C3-C8 cycloalkoxy. Specific examples of cycloalkoxy include, for example, cyclopropoxy, cyclobutoxy, cyclopentyloxy, and the like.

[0042] ​​​​​​​In this specification, "amino" means -NH2 in the narrow sense and -NRR' in the broad sense, where R and R' are independently selected from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, or heteroaryl, or R and R' together with the nitrogen atom to which they are bonded to form a ring. Preferred aminos include -NH2, monoC1-C6 alkylaminos, diC1-C6 alkylaminos, and 4- to 8-membered cyclic aminos.

[0044] In this specification, "monoalkylamino" means a group of "amino" as defined above, in which R is hydrogen and R' is "alkyl" as defined above, and preferably monoC1-C6 alkylaminos. Specifically, examples of monoalkylaminos include methylamino, ethylamino, n-propylamino, i-propylamino, n-butylamino, s-butylamino, and t-butylamino.

[0045] In this specification, "dialkylamino" means a group of "amino" as defined above, in which R and R' are independently "alkyl" as defined above, and preferably includes diC1-C6 alkylaminos. Specifically, examples of dialkylaminos include dimethylamino and diethylamino.

[0046] In this specification, "cyclic amino" means, among the "amino" as defined above, groups R and R' that, together with the nitrogen atom to which they are bonded, form a ring, and preferably, 4- to 8-membered cyclic aminos. Specific examples of cyclic aminos include, for example, 1-azetidyl, 1-pyrrolidyl, 1-piperidyl, 1-piperazyl, 4-morpholinyl, 3-oxazolidyl, 1,1-dioxidethiomorpholinyl-4-yl, and 3-oxa-8-azabicyclo[3.2.1]octan-8-yl.

[0047] In this specification, "protected amino" means an amino group protected with any protecting group. Specific examples of protected aminos include aminos protected with protecting groups such as Boc, Fmoc, Cbz, Troc, and Alloc.

[0048] In this specification, "aminocarbonyl" means a carbonyl group to which the above-defined "amino" is attached, and preferably includes -CONH2, monoC1-C6 alkylaminocarbonyl, diC1-C6 alkylaminocarbonyl, and 4- to 8-membered cyclic aminocarbonyl. Specifically, examples of aminocarbonyls include -CONH2, dimethylaminocarbonyl, 1-azetidinylcarbonyl, 1-pyrrolidinylcarbonyl, 1-piperidinylcarbonyl, 1-piperazinylcarbonyl, 4-morpholinylcarbonyl, 3-oxazolidinylcarbonyl, 1,1-dioxidethiomorpholinyl-4-ylcarbonyl, and 3-oxa-8-azabicyclo[3.2.1]octane-8-ylcarbonyl.

[0049] In this specification, "alkenyloxycarbonyl" means a carbonyl group to which the "alkenyloxy" defined above is attached, and preferably includes C2-C6 alkenyloxycarbonyl. Specific examples of alkenyloxycarbonyl include vinyloxycarbonyl, allyloxycarbonyl, 1-propenyloxycarbonyl, 2-propenyloxycarbonyl, 1-butenyloxycarbonyl, 2-butenyloxycarbonyl (including cis and trans forms), 3-butenyloxycarbonyl, pentenyloxycarbonyl, and hexenyloxycarbonyl.

[0050] In this specification, "alkylsulfonyl" means a sulfonyl group to which the "alkyl" defined above is attached, and preferably C1-C6 alkylsulfonyls are mentioned. Specific examples of alkylsulfonyls include methylsulfonyl.

[0051] In this specification, "hydroxyalkyl" means a group in which one or more hydrogen atoms of the "alkyl" defined above are substituted with hydroxyl groups, and C1-C6 hydroxyalkyl is preferred. Specific examples of hydroxyalkyl include hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-hydroxy-2-methylpropyl, and 5-hydroxypentyl.

[0052] In this specification, "haloalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with halogens, with C1-C6 haloalkyls being preferred and C1-C6 fluoroalkyls being more preferred. Specific examples of haloalkyls include difluoromethyl, trifluoromethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 3,3-difluoropropyl, 4,4-difluorobutyl, and 5,5-difluoropentyl.

[0053] In this specification, "cyanoalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with cyano, and C1-C6 cyanoalkyls are preferred. Specific examples of cyanoalkyls include cyanomethyl and 2-cyanoethyl.

[0054] In this specification, "aminoalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "amino" as defined above, and C1-C6 aminoalkyls are preferred. Specific examples of aminoalkyls include 1-piperidylmethyl, 2-(1-piperidyl)ethyl, 3-(1-piperidyl)propyl, and 4-aminobutyl.

[0055] In this specification, "carboxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with carboxyl, and C2-C6 carboxyalkyls are preferred. Specific examples of carboxyalkyls include carboxymethyl.

[0056] In this specification, "alkenyloxycarbonylalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "alkenyloxycarbonyl" as defined above, with C2-C6 alkenyloxycarbonyl C1-C6 alkyl being preferred, and C2-C6 alkenyloxycarbonyl C1-C2 alkyl being more preferred. Specific examples of alkenyloxycarbonylalkyls include allyloxycarbonylmethyl and 2-(allyloxycarbonyl)ethyl.

[0057] In this specification, "alkoxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "alkoxy" as defined above, with C1-C6 alkoxyC1-C6 alkyl being preferred and C1-C6 alkoxyC1-C2 alkyl being more preferred. Specific examples of alkoxyalkyls include methoxymethyl, ethoxymethyl, 1-propoxymethyl, 2-propoxymethyl, n-butoxymethyl, i-butoxymethyl, s-butoxymethyl, t-butoxymethyl, pentyloxymethyl, 3-methylbutoxymethyl, 1-methoxyethyl, 2-methoxyethyl, and 2-ethoxyethyl.

[0058] In this specification, "cycloalkylalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "cycloalkyl" as defined above, with C3-C8 cycloalkylC1-C6 alkyl being preferred and C3-C6 cycloalkylC1-C2 alkyl being more preferred. Specific examples of cycloalkylalkyl include cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, and cyclohexylmethyl.

[0059] In this specification, "cycloalkoxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "cycloalkoxy" as defined above, with C3-C8 cycloalkoxy C1-C6 alkyl being preferred and C3-C6 cycloalkoxy C1-C2 alkyl being more preferred. Specific examples of cycloalkoxyalkyls include cyclopropoxymethyl and cyclobutoxymethyl.

[0060] In this specification, "heterocyclylalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "heterocyclyl" as defined above, and 4- to 7-membered heterocyclyl C1-C6 alkyl is preferred, and 4- to 7-membered heterocyclyl C1-C2 alkyl is more preferred. Specific examples of heterocyclylalkyls include 2-(tetrahydro-2H-pyran-4-yl)ethyl and 2-(azetidine-3-yl)ethyl.

[0061] In this specification, "alkylsulfonylalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with "alkylsulfonyl" as defined above, with C1-C6 alkylsulfonyl C1-C6 alkyl being preferred, and C1-C6 alkylsulfonyl C1-C2 alkyl being more preferred. Specific examples of alkylsulfonylalkyl include methylsulfonylmethyl and 2-(methylsulfonyl)ethyl.

[0062] In this specification, "aminocarbonylalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with "aminocarbonyl" as defined above, with aminocarbonyl C1-C6 alkyl being preferred and aminocarbonyl C1-C4 alkyl being more preferred. Specific examples of aminocarbonylalkyls include methylaminocarbonylmethyl, dimethylaminocarbonylmethyl, t-butylaminocarbonylmethyl, 1-azetidinylcarbonylmethyl, 1-pyrrolidinylcarbonylmethyl, 1-piperidinylcarbonylmethyl, 4-morpholinylcarbonylmethyl, 2-(methylaminocarbonyl)ethyl, 2-(dimethylaminocarbonyl)ethyl, 2-(1-azetidinylcarbonyl)ethyl, 2-(1-pyrrolidinylcarbonyl)ethyl, 2-(4-morpholinylcarbonyl)ethyl, 3-(dimethylaminocarbonyl)propyl, and 4-(dimethylaminocarbonyl)butyl.

[0063] In this specification, "aryloxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "aryloxy" as defined above, C6-C 10 Aryloxy C1-C6 alkyl is preferred, C6-C 10 Aryloxy C1-C2 alkyl groups are more preferred. Specific examples of aryloxy alkyl groups include phenoxymethyl and 2-phenoxyethyl.

[0064] In this specification, "aralkyl (arylalkyl)" means a group in which at least one hydrogen atom of the "alkyl" as defined above is substituted with the "aryl" as defined above, C7-C 14 Aralkyl is preferred, C7-C 10 Aralkyl is more preferable. Specific examples of aralkyl include benzyl, phenethyl, and 3-phenylpropyl.

[0065] In this specification, "aralkoxy" means an oxy group to which the "aralkyl" defined above is bonded, C7-C 14 Allalcoxy is preferred, C7-C10 Aralcoxy is more preferred. Specific examples of aralcoxy include benzyloxy, phenethyloxy, and 3-phenylpropoxy.

[0066] In this specification, "aralcoxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "aralcoxy" as defined above, C7-C 14 Aralcoxyl C1-C6 alkyl is preferred, C7-C 14 Aralcoxy C1-C2 alkyl groups are more preferred. Specific examples of aralcoxyalkyl groups include benzyloxymethyl and 1-(benzyloxy)ethyl.

[0067] In this specification, "heteroarylalkyl" means a group in which at least one hydrogen atom of the "alkyl" as defined above is substituted with the "heteroaryl" as defined above, and 5-10 membered heteroaryl C1-C6 alkyl is preferred, and 5-10 membered heteroaryl C1-C2 alkyl is more preferred. Specific examples of heteroarylalkyls include 3-thienylmethyl, 4-thiazolylmethyl, 2-pyridylmethyl, 3-pyridylmethyl, 4-pyridylmethyl, 2-(2-pyridyl)ethyl, 2-(3-pyridyl)ethyl, 2-(4-pyridyl)ethyl, 2-(6-quinolyl)ethyl, 2-(7-quinolyl)ethyl, 2-(6-indolyl)ethyl, 2-(5-indolyl)ethyl, and 2-(5-benzofuranyl)ethyl.

[0068] In this specification, "heteroarylalkoxy" means an oxy group to which a "heteroarylalkyl" as defined above is bonded, and 5-10 membered heteroaryl C1-C6 alkoxys are preferred, and 5-10 membered heteroaryl C1-C2 alkoxys are more preferred. Specific examples of heteroarylalkoxys include 3-thienylmethoxy and 3-pyridylmethoxy.

[0069] In this specification, "heteroarylalkoxyalkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "heteroarylalkoxy" as defined above, and 5-10 membered heteroaryl C1-C6 alkoxy C1-C6 alkyl is preferred, and 5-10 membered heteroaryl C1-C2 alkoxy C1-C2 alkyl is more preferred. Specific examples of heteroarylalkoxyalkyls include, for example, 3-pyridylmethoxymethyl.

[0070] In this specification, "heterocycloalkylidene alkyl" means a group in which one or more hydrogens of the "alkyl" as defined above are substituted with the "heterocycloalkylidene" as defined above, and 4- to 7-membered heterocycloalkylidene C1-C6 alkyl is preferred, and 4- to 7-membered heterocycloalkylidene C1-C2 alkyl is more preferred. Specific examples of heteroarylalkoxyalkyls include tetrahydro-4H-pyran-4-ylidenemethyl and azetidine-3-ylidenemethyl.

[0071] In this specification, "alkoxyalkenyl" means a group in which one or more hydrogens of the "alkenyl" as defined above are substituted with the "alkoxy" as defined above, and C1-C6 alkoxyC2-C6 alkenyls are preferred. Specific examples of alkoxyalkenyls include (E)-4-methoxybuto-2-en-1-yl.

[0072] In this specification, "aminocarbonyl alkenyl" means a group in which one or more hydrogens of the "alkenyl" as defined above are substituted with the "aminocarbonyl" as defined above, and aminocarbonyl C2-C6 alkenyls are preferred. Specific examples of aminocarbonyl alkenyls include (E)-3-(dimethylaminocarbonylcarbonyl)-propa-2-en-1-yl.

[0073] In this specification, "haloalkoxy" means a group in which one or more hydrogens of the "alkoxy" as defined above are substituted with a halogen, and C1-C6 haloalkoxy is preferred. Specific examples of haloalkoxy include difluoromethoxy, trifluoromethoxy, 2,2-difluoroethoxy, and 2,2,2-trifluoroethoxy.

[0074] In this specification, "alkylene" means a divalent group derived by removing one arbitrary hydrogen atom from the aforementioned "alkyl," and C4-C8 alkylenes are preferred. Specific examples of alkylenes include -CH2-, -(CH2)2-, -(CH2)3-, -CH(CH3)CH2-, -C(CH3)2CH2-, -CH2CH(CH3)CH2-, -CH2C(CH3)2-, -CH2CH2CH(CH3)-, -(CH2)5-, -(CH2)6-, -(CH2)7-, and -(CH2)8-.

[0075] In this specification, "alicyclic ring" means a non-aromatic hydrocarbon ring. An alicyclic ring may have unsaturated bonds within the ring, or it may be a polycyclic ring having two or more rings. The carbon atoms constituting the ring may also be oxidized to form carbonyls. Preferred alicyclic rings are 3 to 8-membered alicyclic rings, specifically, for example, cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, cycloheptane rings, cyclooctane rings, and bicyclo[2.2.1]heptane rings.

[0076] As used herein, "saturated heterocycle" means a non-aromatic heterocycle containing 1 to 5 heteroatoms in addition to carbon atoms, and not containing double and / or triple bonds in the ring. A saturated heterocycle may be a monocycle or may form a fused ring with another ring, such as an aromatic ring like a benzene ring. When saturated heterocycles form fused rings, the saturated heterocycles are preferably 4- to 7-membered saturated heterocycles, specifically including, for example, azetidine rings, oxetane rings, tetrahydrofuran rings, tetrahydropyran rings, morpholine rings, thiomorpholine rings, pyrrolidine rings, 4-oxopyrrolidine rings, piperidine rings, 4-oxopiperidine rings, piperazine rings, pyrazolidine rings, imidazolidine rings, oxazolizidine rings, isoxazolidine rings, thiazolidinedine rings, isothiazolidine rings, thiadiazolidinedine rings, sazolidone rings, dioxolane rings, thiethane rings, octahydroindole rings, indoline rings, and the like.

[0077] In this specification, "peptide chain" means a peptide chain in which one, two, three, four, or more natural amino acids and / or non-natural amino acids are linked by amide bonds and / or ester bonds. Preferably, the peptide chain is a peptide chain containing one to four amino acid residues, and more preferably a peptide chain consisting of one to four amino acid residues.

[0078] In this specification, "amino group protecting groups" include carbamate-type protecting groups, amide-type protecting groups, arylsulfonamide-type protecting groups, alkylamine-type protecting groups, imide-type protecting groups, and specifically, examples include Fmoc group, Boc group, Alloc group, Cbz group, Teoc group, trifluoroacetyl group, benzenesulfonyl group, tosyl group, nosyl group, dinitronosyl group, t-Bu group, trityl group, cumyl group, benzylidene group, 4-methoxybenzylidene group, and diphenylmethylidene group.

[0079] In this specification, "carboxyl group protecting group" includes alkyl ester type protecting groups, benzyl ester type protecting groups, and substituted alkyl ester type protecting groups. Specific examples of carboxyl group protecting groups include methyl group, ethyl group, t-Bu group, benzyl group, trityl group, cumyl group, methoxytrityl group, 2-(trimethylsilyl)ethyl group, 2,2,2-trichloroethyl group, and allyl group.

[0080] In this specification, "hydroxyl protecting group" refers to alkyl ether type protecting groups, aralkyl ether type protecting groups, silyl ether type protecting groups, carbonate ester type protecting groups, and the like. Specifically, examples of hydroxyl protecting groups include methoxymethyl group, benzyloxymethyl group, tetrahydropyranyl group, tert-butyl group, allyl group, 2,2,2-trichloroethyl group, benzyl group, 4-methoxybenzyl group, trimethylsilyl group, triethylsilyl group, triisopropylsilyl group, t-butyldimethylsilyl group, t-butyldiphenylsilyl group, methoxycarbonyl group, 9-fluorenylmethoxycarbonyl group, and 2,2,2-trichloroethoxycarbonyl group.

[0081] In this specification, “may be substituted” means that a group may be substituted with any substituent.

[0082] In this specification, “may be protected” means that a group may be protected by any protecting group.

[0083] In this specification, “one or more” means one or more numbers. When “one or more” is used in a context relating to substituents of a group, the term means a number from one up to the maximum number of substituents permitted by that group. Specifically, “one or more” could be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and / or greater numbers.

[0084] The compounds of the present invention may be salts thereof, preferably chemically or pharmaceutically acceptable salts thereof. Furthermore, the compounds of the present invention or their salts may be solvates thereof, preferably chemically or pharmaceutically acceptable solvates thereof. Examples of salts of the compounds of the present invention include hydrochloride salts; hydrobromide salts; hydroiodide salts; phosphate salts; phosphonate salts; sulfate salts; sulfonates such as methanesulfonate and p-toluenesulfonate; carboxylate salts such as acetate, citrate, malate, tartrate, succinate, and salicylate salts; or alkali metal salts such as sodium salts and potassium salts; alkaline earth metal salts such as magnesium salts and calcium salts; and ammonium salts such as ammonium salts, alkylammonium salts, dialkylammonium salts, trialkylammonium salts, and tetraalkylammonium salts. These salts are produced, for example, by contacting the compound with an acid or base that can be used in the manufacture of pharmaceuticals. In the present invention, a solvate of a compound refers to the phenomenon in which solute molecules strongly attract solvent molecules in a solution, forming a molecular aggregate; if the solvent is water, it is called a hydrate. The solvates of the compounds of the present invention are preferably hydrates, and specifically, such hydrates include 1-10 hydrates, preferably 1-5 hydrates, and more preferably 1-3 hydrates. The solvates of the compounds of the present invention include not only solvates with a single solvent such as water, alcohol (e.g., methanol, ethanol, 1-propanol, 2-propanol, etc.), and dimethylformamide, but also solvates with multiple solvents.

[0085] In this specification, "amino acids" include natural amino acids and non-natural amino acids. In this specification, "natural amino acids" refer to Gly, Ala, Ser, Thr, Val, Leu, Ile, Phe, Tyr, Trp, His, Glu, Asp, Gln, Asn, Cys, Met, Lys, Arg, and Pro. Non-natural amino acids are not particularly limited, but examples include β-amino acids, γ-amino acids, D-type amino acids, N-substituted amino acids, α,α-disubstituted amino acids, amino acids with side chains different from those of natural amino acids, and hydroxycarboxylic acids. Any stereochemistry is permitted for amino acids in this specification. There are no particular restrictions on the selection of amino acid side chains, but in addition to hydrogen atoms, they can be freely selected from, for example, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, aralkyl groups, and cycloalkyl groups, and one or two non-adjacent methylene groups among these groups may be substituted with oxygen atoms, carbonyl groups (-CO-), or sulfonyl groups (-SO2-). Each of these groups may be substituted, and these substituents are not limited; for example, one or more substituents may be freely selected independently from any group containing halogen atoms, oxygen atoms, sulfur atoms, nitrogen atoms, boron atoms, silicon atoms, or phosphorus atoms. Examples include substituted alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, aralkyl groups, and cycloalkyl groups. In one non-limiting embodiment, the amino acids in this specification may be compounds having both a carboxyl group and an amino group within the same molecule (even in this case, imino acids such as proline and hydroxyproline are also included as amino acids).

[0086] The amino group in the main chain of an amino acid may be unsubstituted (NH2 group) or substituted (i.e., an -NHR group: R represents an alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, or cycloalkyl group which may have substituents, and one or two non-adjacent methylene groups in these groups may be substituted with an oxygen atom, a carbonyl group (-CO-), or a sulfonyl group (-SO2-), and the carbon chain bonded to the N atom and the carbon atom at the α position may form a ring, as in proline). The substituent of R is selected in the same way as the substituents in the amino acid side chain described above. When the main chain amino group is substituted, R is included in the "side chain of an amino acid" as used herein. Amino acids in which such main chain amino groups are substituted are referred to as "N-substituted amino acids" as used herein. Examples of "N-substituted amino acids" as used herein are preferably N-alkyl amino acids, N-C1-C6 alkyl amino acids, N-C1-C4 alkyl amino acids, and N-methyl amino acids, but are not limited to these.

[0087] In this specification, "side chain of an amino acid" refers to the group of atoms bonded to the carbon atom to which the amino group and carboxyl group are bonded (α-carbon) in the case of α-amino acids. For example, the methyl group of Ala is a side chain of an amino acid. In the case of β-amino acids, the group of atoms bonded to the α-carbon and / or β-carbon becomes the side chain of the amino acid, and in the case of γ-amino acids, the group of atoms bonded to the α-carbon, β-carbon, and / or γ-carbon can become the side chain of the amino acid.

[0088] In this specification, "amino acid backbone" means the chain portion consisting of an amino group, an α-carbon, and a carboxyl group in the case of α-amino acids, the chain portion consisting of an amino group, a β-carbon, an α-carbon, and a carboxyl group in the case of β-amino acids, and the chain portion consisting of an amino group, a γ-carbon, a β-carbon, an α-carbon, and a carboxyl group in the case of γ-amino acids.

[0089] In this specification, "peptide back chain," "peptide compound back chain," and "cyclic peptide compound back chain" refer to a structure formed by the linking of multiple "amino acid back chains" via amide bonds.

[0090] The "amino acids" that constitute the peptide compounds in this specification include all of their corresponding isotopes. An isotope of an "amino acid" is one in which at least one atom is substituted with an atom that has the same atomic number (number of protons) but a different mass number (sum of the number of protons and neutrons). Examples of isotopes contained in the "amino acids" that constitute the peptide compounds of the present invention include hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, and chlorine atoms, respectively. 2 H, 3 H, 13 C, 14 C, 15 N, 17 O, 18 O, 31 P, 32 P, 35 S, 18 F, 36 Includes Cl, etc.

[0091] Examples of substituents containing halogen atoms in this specification include alkyl groups, cycloalkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, and aralkyl groups having halogens as substituents, and more specifically, examples include fluoroalkyl groups, difluoroalkyl groups, and trifluoroalkyl groups.

[0092] Substituents containing an oxygen atom include groups such as hydroxy(-OH), oxy(-OR), carbonyl(-C=OR), carboxy(-CO2H), oxycarbonyl(-C=O-OR), carbonyloxy(-OC=OR), thiocarbonyl(-C=O-SR), carbonylthio(-SC=OR), aminocarbonyl(-C=O-NHR), carbonylamino(-NH-C=OR), oxycarbonylamino(-NH-C=O-OR), sulfonylamino(-NH-SO2-R), aminosulfonyl(-SO2-NHR), sulfamoylamino(-NH-SO2-NHR), thiocarboxyl(-C(=O)-SH), and carboxylcarbonyl(-C(=O)-CO2H).

[0093] Examples of oxy (-OR) compounds include alkoxy, cycloalkoxy, alkenyloxy, alkynyloxy, aryloxy, heteroaryloxy, and aralkyloxy compounds. C1-C4 alkoxy and C1-C2 alkoxy compounds are preferred, with methoxy or ethoxy compounds being particularly preferred.

[0094] Examples of carbonyl (-C=OR) include formyl (-C=OH), alkylcarbonyl, cycloalkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, arylcarbonyl, heteroarylcarbonyl, and aralkylcarbonyl.

[0095] Examples of oxycarbonyl (-C=O-OR) include alkyloxycarbonyl, cycloalkyloxycarbonyl, alkenyloxycarbonyl, alkynyloxycarbonyl, aryloxycarbonyl, heteroaryloxycarbonyl, and aralkyloxycarbonyl.

[0096] Examples of carbonyloxy (-OC=OR) include alkylcarbonyloxy, cycloalkylcarbonyloxy, alkenylcarbonyloxy, alkynylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy, and aralkylcarbonyloxy.

[0097] Examples of thiocarbonyl (-C=O-SR) include alkylthiocarbonyl, cycloalkylthiocarbonyl, alkenylthiocarbonyl, alkynylthiocarbonyl, arylthiocarbonyl, heteroarylthiocarbonyl, and aralkylthiocarbonyl.

[0098] Examples of carbonylthio (-SC=OR) include alkylcarbonylthio, cycloalkylcarbonylthio, alkenylcarbonylthio, alkynylcarbonylthio, arylcarbonylthio, heteroarylcarbonylthio, and aralkylcarbonylthio.

[0099] Examples of aminocarbonyl (-C=O-NHR) groups include alkylaminocarbonyls (e.g., C1-C6 or C1-C4 alkylaminocarbonyls, particularly ethylaminocarbonyl and methylaminocarbonyl), cycloalkylaminocarbonyls, alkenylaminocarbonyls, alkynylaminocarbonyls, arylaminocarbonyls, heteroarylaminocarbonyls, and aralkylaminocarbonyls. In addition to these, groups in which the H atom bonded to the N atom in the -C=O-NHR group is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl groups are also included.

[0100] Examples of carbonylamino (-NH-C=OR) groups include alkylcarbonylamino, cycloalkylcarbonylamino, alkenylcarbonylamino, alkynylcarbonylamino, arylcarbonylamino, heteroarylcarbonylamino, and aralkylcarbonylamino. In addition to these, groups in which the H atom bonded to the N atom in the -NH-C=OR group is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl groups are also included.

[0101] Examples of oxycarbonylamino (-NH-C=O-OR) groups include alkoxycarbonylamino, cycloalkoxycarbonylamino, alkenyloxycarbonylamino, alkynyloxycarbonylamino, aryloxycarbonylamino, heteroaryloxycarbonylamino, and aralkyloxycarbonylamino. In addition to these, groups in which the H atom bonded to the N atom in the -NH-C=O-OR group is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl groups are also included.

[0102] Examples of sulfonylamino (-NH-SO2-R) groups include alkylsulfonylamino, cycloalkylsulfonylamino, alkenylsulfonylamino, alkynylsulfonylamino, arylsulfonylamino, heteroarylsulfonylamino, and aralkylsulfonylamino. In addition to these, groups in which the H atom bonded to the N atom in -NH-SO2-R is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl groups are also included.

[0103] Examples of aminosulfonyl (-SO2-NHR) groups include alkylaminosulfonyl, cycloalkylaminosulfonyl, alkenylaminosulfonyl, alkynylaminosulfonyl, arylaminosulfonyl, heteroarylaminosulfonyl, and aralkylaminosulfonyl. In addition to these, groups in which the H atom bonded to the N atom in -SO2-NHR is further substituted with alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, or aralkyl groups are also included.

[0104] Examples of sulfamoylamino (-NH-SO2-NHR) include alkyl sulfamoylamino, cycloalkyl sulfamoylamino, alkenyl sulfamoylamino, alkynyl sulfamoylamino, aryl sulfamoylamino, heteroaryl sulfamoylamino, and aralkyl sulfamoylamino. Furthermore, the two H atoms bonded to the N atom in -NH-SO2-NHR may be substituted with substituents independently selected from the group consisting of alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl, and these two substituents may form a ring.

[0105] Substituents containing a sulfur atom include groups such as thiol (-SH), thio (-SR), sulfinyl (-S=OR), sulfonyl (-SO2-R), and sulfo (-SO3H).

[0106] Examples of thio(-SR) are selected from alkylthio, cycloalkylthio, alkenylthio, alkynylthio, arylthio, heteroarylthio, and aralkylthio.

[0107] Examples of sulfonyl (-SO2-R) compounds include alkylsulfonyl, cycloalkylsulfonyl, alkenylsulfonyl, alkynylsulfonyl, arylsulfonyl, heteroarylsulfonyl, and aralkylsulfonyl compounds.

[0108] Substituents containing an N atom include azide (-N3, also called "azide group"), cyano (-CN), primary amino (-NH2), secondary amino (-NH-R; also called monosubstituted amino), tertiary amino (-NR(R'); also called disubstituted amino), amidino (-C(=NH)-NH2), substituted amidino (-C(=NR)-NR'R"), guanidino (-NH-C(=NH)-NH2), substituted guanidino (-NR-C(=NR''')-NR'R"), aminocarbonylamino (-NR-CO-NR'R"), pyridyl, piperidino, morpholino, and azetidinyl groups.

[0109] Examples of secondary amino acids (-NH-R; monosubstituted amino acids) include alkylaminos, cycloalkylaminos, alkenylaminos, alkynylaminos, arylaminos, heteroarylaminos, and aralkylaminos.

[0110] Examples of tertiary aminos (-NR(R'); disubstituted aminos) include, for example, alkyl (aralkyl)aminos, and amino groups having any two substituents independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl groups, where any two substituents may form a ring. Specifically, dialkylaminos, particularly C1-C6 dialkylaminos, C1-C4 dialkylaminos, dimethylaminos, and diethylaminos are examples. In this specification, "C p -C q A "dialkylamino group" is an amino group with a carbon atom. p -C q This refers to a group in which two alkyl groups are substituted, and both C p -C q The alkyl groups may be the same or different.

[0111] Examples of substituted amidinos (-C(=NR)-NR'R") include groups in which the three substituents R, R', and R'' on the N atom are independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl groups, such as alkyl(aralkyl)(aryl)amidinos.

[0112] Examples of substituted guanidinos (-NR-C(=NR''')-NR'R") include groups where R, R', R'', and R''' are independently selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl groups, or groups in which these groups form a ring.

[0113] Examples of aminocarbonylamino (-NR-CO-NR'R") include groups where R, R', and R'' are independently selected from a hydrogen atom, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and aralkyl groups, or groups that form a ring.

[0114] In this specification, the "amino acid residues" that constitute a peptide compound may be simply referred to as "amino acids."

[0115] In this specification, "linear peptide compounds" are not particularly limited as long as they are compounds formed by linking natural amino acids and / or non-natural amino acids by amide or ester bonds and do not have a cyclic portion. The total number of natural or non-natural amino acids constituting a linear peptide compound can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30, with preferred ranges being 6-20, 7-19, 7-18, 7-17, 7-16, 7-15, 8-14, or 9-13.

[0116] In this specification, "cyclic peptide compound" is a compound formed by linking natural amino acids and / or non-natural amino acids by amide or ester bonds, and is not particularly limited as long as it has a cyclic portion. The total number of natural or non-natural amino acids constituting a cyclic peptide compound can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, or 30, with preferred ranges being 6-20, 7-19, 7-18, 7-17, 7-16, 7-15, 8-14, or 9-13.

[0117] In this specification, the "cyclic portion" of a peptide compound means the ring portion formed by the linking of two or more amino acid residues. In this specification, the "linear portion" used to refer to a substructure of a cyclic peptide compound means a portion that is not included in the main chain structure of the cyclic portion and has at least one amide bond and / or ester bond on its chain.

[0118] The number of amino acids constituting the cyclic portion of a cyclic peptide compound in this specification is not limited, but examples include 2 or more, 3 or more, 4 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 30 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16. Considering the balance between membrane permeability and metabolic stability, the number of amino acids constituting the cyclic portion is preferably 2 to 30, 2 to 15, or 5 to 15, more preferably 5 to 14, 7 to 14, or 8 to 14, even more preferably 8 to 13, 9 to 13, 8 to 12, 8 to 11, or 9 to 12, and particularly preferably 9 to 11.

[0119] In one embodiment, the number of amino acids (units) in the linear portion is preferably 0 to 8, more preferably 0 to 5, and more preferably 0 to 3. In one non-limiting embodiment, the "linear portion" as used herein may include natural amino acids and non-natural amino acids (including chemically modified or reconstructed amino acids).

[0120] In one embodiment, the molecular weight of the cyclic peptide compound in this specification may be 500 to 2000.

[0121] In this specification, “peptide compounds” may include pharmaceutically acceptable salts thereof or solvates thereof.

[0122] In this specification, "side chain" is used in the context of the side chain of an amino acid or the side chain of the cyclic portion of a cyclic peptide compound, and refers to the portion not included in the main chain structure.

[0123] In this specification, "number of amino acids" refers to the number of amino acid residues (amino acid units) that make up a peptide compound, and means the number of amino acid units that are produced when the amide bonds, ester bonds, and cyclization bonds linking the amino acids are cleaved.

[0124] In this specification, "amino acid breakdown" includes any structural transformation in which the original amino acid structure is not maintained.

[0125] In this specification, “peptide degradation” includes any structural transformation in which the original peptide structure is not preserved, including the transfer of functional groups in the main chain or side chains.

[0126] In this specification, "decomposition of solid-phase synthesis resins" includes not only physical decomposition in which the solid resin changes to a state in which it no longer maintains its original shape, but also changes in which it loses some or no ability to support amino acids or peptides.

[0127] In this specification, "support rate" refers to the reaction conversion rate, calculated based on the amount of amino acids used as starting materials, which represent the amount of amino acids that could be supported on the solid-phase synthesis resin in the support reaction.

[0128] In this specification, "reaction conversion rate" refers to the proportion of amino acids in a solution that are converted to a state supported on a solid-phase synthesis resin, and can be calculated from the amino acid concentrations in the reaction solution before and after the start and completion of the amino acid support reaction on the solid-phase synthesis resin. Specifically, the reaction conversion rate can be calculated using the following formula, using the measurement conditions described in the examples. Reaction conversion rate (%) = {(Area of ​​amino acids before the start of the loading reaction) - (Area of ​​amino acids after loading is complete)} x 100 / Area of ​​amino acids before the start of the loading reaction

[0129] In this specification, the meaning of the terms “and / or” includes any combination of “and” and “or” as appropriate. Specifically, for example, “A, B, and / or C” includes the following seven variations: (i) A, (ii) B, (iii) C, (iv) A and B, (v) A and C, (vi) B and C, (vii) A, B, and C.

[0130] In one embodiment, the present invention relates to a method for producing peptide compounds, salts thereof, or solvates thereof, comprising the step (Step 1) of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent, to obtain an amino acid supported on the solid-phase synthesis resin. In this method, the first solvent and the third solvent are each independently selected from halogenated solvents. The second solvent is an ether solvent.

[0131] In one embodiment, the present invention relates to a method for producing amino acids supported on a solid-phase synthesis resin, comprising the step of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent. In this method, the first solvent and the third solvent are each independently selected from halogenated solvents, and the second solvent is an ether solvent.

[0132] In solid-phase synthesis, to efficiently support amino acids on a solid-phase synthesis resin, it is common practice to swell the solid-phase synthesis resin with a solvent prior to the amino acid loading reaction. In the present invention, the solid-phase synthesis resin is swelled using a solvent containing a first solvent selected from halogenated solvents. Specifically, the first solvent can be DCM, DCE, chloroform, chlorobenzene, carbon tetrachloride, etc., with DCM being preferred among these. Furthermore, if the first solvent contains another solvent in addition to the halogenated solvent, any solvent, such as MeTHF, MTBE, CPME, THF, IPE, DME, diethyl ether, or dioxane, may be included in addition to the halogenated solvent. MeTHF, MTBE, and CPME are preferred solvents to be included in addition to the halogenated solvent. These solvents are preferably dehydrated solvents to suppress the decomposition of the solid-phase synthesis resin. The dehydrated solvent may be a commercially available dehydrated solvent that can be purchased from a commercial supplier, or a solvent that has been dehydrated in advance by any method. The swelling of the solid-phase synthesis resin can be carried out by adding a solvent containing the first solvent to a container such as a column containing the resin, and maintaining that state at any temperature, for example, room temperature, for any time, for example, 5 minutes to 24 hours, during which the container may be shaken. Once the swelling of the resin is complete, it is preferable to discharge the solvent from the container by filtration or the like.

[0133] In one embodiment, once the solid-phase synthesis resin has swollen sufficiently, amino acids can be supported on the solid-phase synthesis resin by contacting the solid-phase synthesis resin with a solution containing amino acids and a second solvent. The support of amino acids on the solid-phase synthesis resin is usually carried out by linking the carboxyl groups of the amino acids to the linker atomic groups contained in the resin. The second solvent is an ether-based solvent such as MeTHF, MTBE, CPME, THF, IPE, DME, diethyl ether, or dioxane, with MeTHF, MTBE, and CPME being preferred. Furthermore, it is preferable that the solution does not contain any solvents other than the second solvent. Contact of the solid-phase synthesis resin with the solution containing amino acids and the second solvent can be carried out, for example, by adding the solution containing amino acids and the second solvent to a container such as a column containing the resin, and maintaining the state at an arbitrary temperature, such as room temperature, for an arbitrary time, such as 10 minutes to 24 hours, during which the container may be shaken. The concentration of amino acids in the solution is not particularly limited, but a range of 0.01 mol / L to 2.0 mol / L is preferred. Furthermore, if an acid is generated by the support reaction between the linker group and the amino acids, a base such as DIPEA can be added to the solution to capture the acid.

[0134] In another embodiment, once the solid-phase synthesis resin has swollen sufficiently, the solid-phase synthesis resin can be contacted with a solution containing amino acids and a mixed solvent of a second solvent and a third solvent to support the amino acids on the solid-phase synthesis resin. The second solvent is an ether-based solvent such as MeTHF, MTBE, CPME, THF, IPE, DME, diethyl ether, or dioxane, of which MeTHF, MTBE, and CPME are preferred. The third solvent is a halogen-based solvent such as DCM, DCE, chloroform, chlorobenzene, or carbon tetrachloride, of which DCM is preferred. The mixing ratio of the second and third solvents is not particularly limited, but it is preferable that the volume ratio is in the range of 1:1 to 1:10, and specifically, examples include second solvent:third solvent = 1:1, 1:2, 1:5, 1:10, etc. Furthermore, preferred combinations of the second and third solvents include MeTHF and DCM, MTBE and DCM, CPME and DCM, MeTHF and DCE, THF and DCM, and IPE and DCM. Preferably, the solution does not contain any solvents other than the second and third solvents. Contact of the solid-phase synthesis resin with the solution containing the amino acid and the mixed solvent of the second and third solvents is performed, for example, by adding the solution containing the amino acid and the second or third solvent to a container such as a column containing the resin, then adding the third or second solvent, or by adding the solution containing the amino acid and the mixed solvent of the second and third solvents, and maintaining the state at any temperature, for example room temperature, for any time, for example, 10 minutes to 24 hours, during which the container may be shaken. The concentration of amino acid in the solution is not particularly limited, but a range of 0.01 mol / L to 2.0 mol / L is preferably exemplified. Furthermore, if an acid is produced by the support reaction between the linker group and the amino acid, a base such as DIPEA can be added to the solution to capture the acid.

[0135] The present invention, which uses a specific solvent for swelling of a solid-phase synthesis resin and subsequent loading of amino acids onto the resin, makes it possible to link amino acids to the resin with very high loading rates or reaction conversion rates, for example, 90% or more, 91% or more, 92% or more, 93% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, 99% or more, or about 100%.

[0136] The "solid-phase synthesis resin" used in the present invention is not particularly limited as long as it can be used for the synthesis of peptide compounds by the solid-phase method. Specific examples of such solid-phase synthesis resins include those that can be removed under acidic conditions, such as CTC resin, Wang resin, SASRIN resin, trityl chloride resin (Trt resin), 4-methyltrityl chloride resin (Mtt resin), and 4-methoxytrityl chloride resin (Mmt). The resin can be appropriately selected according to the functional group of the amino acid used. For example, when using a carboxyl group (main chain carboxyl group, or side chain carboxyl group represented by Asp or Glu) or a hydroxyl group on an aromatic ring (phenolic hydroxyl group represented by Tyr) as the functional group of the amino acid, it is preferable to use trityl chloride resin (Trt resin) or 2-chlorotrityl chloride resin (CTC resin) as the resin. When using an aliphatic hydroxyl group (such as Ser or Thr, which are aliphatic alcoholic hydroxyl groups) as the functional group on the amino acid side, it is preferable to use trityl chloride resin (Trt resin), 2-chlorotrityl chloride resin (CTC resin), or 4-methyltrityl chloride resin (Mtt resin) as the resin. In this specification, resin may be referred to as "resin."

[0137] The type of polymer constituting the resin is not particularly limited. In the case of a resin composed of polystyrene, either 100-200 mesh or 200-400 mesh may be used. The crosslinking ratio is also not particularly limited, but 1% DVB (divinylbenzene) crosslinking is preferred. Examples of polymers constituting the resin include TentaGel® or ChemMatrix®.

[0138] In one embodiment, the amino acid supported on the solid-phase synthesis resin in the present invention may be either a natural or unnatural amino acid. When the amino acid supported on the solid-phase synthesis resin is an unnatural amino acid, it is preferable that the amino acid is an unnatural N-substituted amino acid. Unnatural amino acids can include aminocarbonyl groups such as monoC1-C6 alkylaminocarbonyl, diC1-C6 alkylaminocarbonyl, and 4- to 8-membered cyclic aminocarbonyl. Examples of such aminocarbonyl groups include dimethylaminocarbonyl, 1-azetidinylcarbonyl, 1-pyrrolidinylcarbonyl, 1-piperidinylcarbonyl, 1-piperazinylcarbonyl, 4-morpholinylcarbonyl, 3-oxazolidinylcarbonyl, 1,1-dioxidethiomorpholinyl-4-ylcarbonyl, and 3-oxa-8-azabicyclo[3.2.1]octane-8-ylcarbonyl, and it is preferable that these groups are present in the side chain. Furthermore, it is preferable that the amino acids supported on the solid-phase synthesis resin have their amino groups protected by a protecting group.

[0139] Amino acids are supported on solid-phase synthesis resins via carboxyl groups bonded to the α, β, or γ carbon atoms of the amino group. An example of an amino acid supported on a solid-phase synthesis resin via a carboxyl group bonded to the β carbon atom of the amino group is aspartic acid or its derivatives. Specifically, the case where aspartic acid is supported on a solid-phase synthesis resin via a carboxyl group present in its side chain corresponds to the case where it is supported on a solid-phase synthesis resin via a carboxyl group bonded to the β carbon atom of the amino group. Similarly, an example of an amino acid supported on a solid-phase synthesis resin via a carboxyl group bonded to the γ carbon atom of the amino group is glutamic acid or its derivatives. Specifically, the case where glutamic acid is supported on a solid-phase synthesis resin via a carboxyl group present in its side chain corresponds to the case where it is supported on a solid-phase synthesis resin via a carboxyl group bonded to the γ carbon atom of the amino group. Other natural amino acid residues and their N-substituted amino acid residues are typically supported on solid-phase synthesis resins via a carboxyl group bonded to the α-carbon atom of the amino group.

[0140] In one embodiment, the unnatural amino acid supported on the solid-phase synthesis resin by a carboxyl group bonded to the carbon atom at the β position of the amino group is aminocarbonylated aspartic acid, 2-aminobutanoic acid, or N-substituted derivatives thereof. Here, aminocarbonylated aspartic acid is obtained by aminocarbonylating (-CONRR') the free carboxyl (-COOH) group bonded to the carbon atom at the α position of the amino group of aspartic acid. Examples of aminocarbonylated aspartic acid include dialkylaminocarbonylated aspartic acid such as dimethylaminocarbonyl, in other words aspartic acid in which R and R' are independently alkyl groups, aspartic acid aminocarbonylated with the N atom of a saturated heterocycle containing an N atom (e.g., azetidine ring, morpholine ring, pyrrolidine ring, piperidine ring, azepane ring, etc.), in other words aspartic acid in which R and R' together with the N atom to which they are bonded to form a saturated heterocycle, and these can also be N-substituted compounds such as N-methyl and N-ethyl alkyl compounds.

[0141] In one embodiment, the unnatural amino acid supported on a solid-phase synthesis resin by a carboxyl group bonded to the carbon atom at the γ position of the amino group is aminocarbonylated glutamic acid or an N-substituted derivative thereof. Here, aminocarbonylated glutamic acid is obtained by aminocarbonylating (-CONRR') the free carboxyl (-COOH) group of glutamic acid. Specifically, as aminocarbonylated glutamic acid, dialkylaminocarbonylated glutamic acid such as dimethylaminocarbonyl, in other words, where R and R' are independently alkyl groups. Glutamic acid , glutamic acid that is aminocarbonylated with the N atom of a saturated heterocycle containing an N atom (e.g., azetidine ring, morpholine ring, pyrrolidine ring, piperidine ring, azepane ring, etc.), in other words, the R and R' atoms together with the N atom to which they are bonded to form a saturated heterocycle. Glutamic acid These include N-substituted compounds such as N-methyl and N-ethyl derivatives, as well as N-alkyl derivatives.

[0142] In one embodiment, it is preferable that the first solvent used for swelling the solid-phase synthesis resin and the third solvent used for supporting amino acids onto the resin are of the same type. That is, when a mixed solvent of the second and third solvents is used in the reaction to support amino acids onto the solid-phase synthesis resin, the third solvent can be of the same type as the solvent used for swelling the solid-phase synthesis resin. When the first and third solvents are of the same type, DCM is preferred as the solvent.

[0143] In one embodiment, the solution containing the amino acid and the second solvent may be a solution obtained by an extraction operation involving the use of the second solvent, followed by an optional dehydration operation, which is carried out after the deprotection reaction of the protecting group of the carboxyl group of the amino acid prior to step 1.

[0144] In another embodiment, the solution comprising an amino acid, a second solvent, and a third solvent may be a solution obtained by adding a third solvent to a solution obtained by an extraction operation involving the use of a second solvent, followed by an optional dehydration operation, which is carried out after the deprotection reaction of the carboxyl group protecting the amino acid prior to step 1.

[0145] When amino acids to be supported on a solid-phase synthesis resin are provided as amino acids in which the carboxyl group or both the amino group and the carboxyl group are protected by protecting groups, it is necessary to deprotect the carboxyl group prior to the support reaction on the resin in preparation for linking with the linker atomic group of the resin. In the present invention, by subjecting the product amino acid to an extraction operation including the use of a second solvent after the deprotection reaction, a "solution containing amino acids and a second solvent" to be used in the support reaction on the solid-phase synthesis resin can be obtained without isolating or purifying the amino acids. Alternatively, by adding a third solvent to the "solution containing amino acids and a second solvent" obtained in this way, a "solution containing amino acids, a second solvent, and a third solvent" to be used in the support reaction on the solid-phase synthesis resin can be obtained. A dehydration operation may be performed after the extraction operation, and it is preferable to use a drying agent such as Na2SO4, MgSO4, or CaCl2. When deprotected amino acids are isolated and purified, operations such as solvent removal or azeotropic dehydration are required, and as a result the amino acids are left in solution for a long time, decomposition of the amino acids is likely to occur. This tendency is even more pronounced in large-scale synthesis where the amount of solvent and reagents increases. By using the above method of the present invention, which does not involve the isolation and purification of deprotected amino acids, such problems can be avoided, and the subsequent support reaction can be effectively carried out. For the removal of the protecting group of the carboxyl group, known methods, such as the method described in "Greene's, "Protective Groups in Organic Synthesis" (5th edition, John Wiley & Sons 2014)," can be used. Furthermore, before and after the extraction operation, which involves the use of a second solvent after the deprotection reaction, any operations commonly used in the art, such as reaction termination, back extraction to transfer the target product to an aqueous layer, or washing of the organic layer and aqueous layer, may be included. When back extraction is performed, a solution containing amino acids and a second solvent can be obtained by adding an acid (e.g., phosphoric acid) and a second solvent to the aqueous layer from which the organic layer has been removed after back extraction and extracting the product.

[0146] When the carboxyl group of an amino acid is protected by a protecting group, it is preferable that the protecting group be removable by acid. Specific examples of such protecting groups include t-Bu, trityl, methoxytrityl, or cumyl. Acids that can remove such protecting groups can be those described under acidic conditions in "Greene's, 'Protective Groups in Organic Synthesis' (5th edition, John Wiley & Sons 2014)" or those described in WO2020 / 111238.

[0147] In one embodiment, the present invention further comprises the step of extending one or more arbitrary amino acids onto an amino acid supported on a solid-phase synthesis resin. This step makes it possible to obtain a peptide compound having a desired amino acid sequence. Methods known in the art can be used for this step, such as the methods described in WO2013 / 100132, WO2018 / 225851, WO2018 / 225864, or the methods described in the Solid-Phase Synthesis Handbook published by Merck KGaA on May 1, 2002.

[0148] In one embodiment, the "peptide compound" of the present invention produced by a solid-phase method is a linear peptide compound that, in addition to the above-mentioned condition of the total number of natural and non-natural amino acids, contains at least one, preferably at least two, N-substituted amino acid residues (specifically 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, preferably 5, 6, or 7, with preferred ranges being 2-30, 3-30, 6-20, 7-19, 7-18, 7-17, 7-16, 7-15, 8-14, 9-13), and contains at least one unsubstituted amino acid residue. Examples of the proportion of N-substituted amino acids contained in such a peptide compound include 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, and 80% or more of the total number of amino acids constituting the peptide compound. The N-substituted amino acid residue in this invention may be a non-natural N-substituted amino acid residue other than proline.

[0149] In one embodiment, the present invention also relates to a method for producing a cyclic peptide compound, further comprising the steps of obtaining a linear peptide compound, a salt thereof, or a solvate thereof produced by a solid-phase method, removing a resin for solid-phase synthesis, and cyclizing the C-terminal and N-terminal groups of the peptide compound to form a cyclic portion.

[0150] The steps of removing the peptide compound from the solid-phase synthesis resin and cyclizing the C-terminal and N-terminal groups of the peptide compound to form a cyclic portion can both be performed using methods known in the art. For example, the methods described in WO2013 / 100132, WO2018 / 225851, and WO2018 / 225864, or the methods described in the Solid-Phase Synthesis Handbook published by Merck KGaA on May 1, 2002, can be applied.

[0151] In one embodiment, the number of N-substituted amino acids contained in the cyclic portion of a cyclic peptide compound is preferably 2 or more or 3 or more, more preferably 4 or more, 5 or more or 6 or more, even more preferably 7 or more, particularly preferably 8 or more, and preferably 20 or less, 15 or less, 14 or less, 13 or less, 12 or less, 10 or less, and 9 or less. Examples of the number of N-substituted amino acids contained in a cyclic peptide compound as used herein include 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, and 80% or more of the number of amino acids constituting the cyclic portion.

[0152] The compounds of the present invention, their salts, or solvates thereof include all stereoisomers of the target compound obtained through the above-described reaction steps (e.g., enantiomers, diastereomers (including cis and trans geometric isomers), racemates of the isomers, and other mixtures). For example, the compounds of the present invention may have one or more chiral centers, and the present invention includes racemic mixtures, diastereomer mixtures, and enantiomers of such compounds.

[0153] When the compound according to the present invention is obtained as a free compound, it can be converted to a salt or a hydrate or solvate thereof, which may be formed by the compound, according to conventional methods.

[0154] Furthermore, if the compound according to the present invention is obtained as a salt, hydrate, or solvate of the compound, the compound can be converted to its free form according to conventional methods.

[0155] Furthermore, all prior art documents cited herein are incorporated herein by reference. [Examples]

[0156] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto. All starting materials and reagents were obtained from commercial suppliers or synthesized using known methods.

[0157] [Quantitative method] The method for evaluating the loading rate onto the solid-phase synthesis resin was calculated based on the reaction conversion rate shown below. Specifically, the reaction conversion rate in the loading reaction was calculated by comparing the amount of amino acids in the reaction solution before the loading reaction started with the amount of amino acids in the reaction solution after the loading reaction was completed, and using the decrease in amount. The amount of amino acids was calculated by measuring the amino acid concentration in the reaction solution using the method shown below. Specifically, the solution after loading was filtered, 5 μL of the filtrate was diluted with 1 mL of acetonitrile, and then 1 μL of this diluted solution was used for HPLC measurement. When an aspartic acid derivative was used as the amino acid, it was calculated according to the following formula.

[0158] Reaction conversion rate (%) = {(Area of ​​aspartic acid derivative before the start of the loading reaction) - (Area of ​​aspartic acid derivative after the completion of loading)} x 100 / Area of ​​aspartic acid derivative before the start of the loading reaction

[0159] The yield in the loading reaction was calculated using either the Fmoc quantitative method or by measuring the weight of the recovered amino acids after deresination treatment of the resin following the loading reaction (isolation method).

[0160] The Fmoc quantification method involves removing the Fmoc group from Fmoc amino acids supported for solid-phase synthesis and calculating the amount of Fmoc from the absorbance of the freed dibenzoflubene. The procedure for the Fmoc quantification method is as follows.

[0161] Approximately 15 mg of dry resin was accurately weighed out, and a 20% piperidine DMF solution was added to make a total volume of 100 mL. The mixture was shaken for at least 30 minutes, and approximately 1 mL of the solution was measured using a spectrophotometer.

[0162] The yield using the Fmoc quantitative method was calculated according to the following formula. Loading rate = ((Absorption value at a wavelength of 289.8 nm) / 6089) x 100000 / (Weight of dry resin measured) Yield (Fmoc quantitative method) = (Total weight of dry resin) x (Loading rate) x (Molecular weight of supported amino acid) x 100 / (Weight of supported amino acid)

[0163] Isolation procedure: A solid-phase synthesis resin on which amino acids were supported was swollen with DMF. The amino acids supported on the solid-phase synthesis resin were removed by mixing a DCM solution containing TFA with the solid-phase synthesis resin. The solid-phase synthesis resin and the solution were separated, and the solvent of the solution was removed by distillation to measure the weight of the amino acids supported on the solid-phase synthesis resin. The isolation yield of the amino acids supported on the solid-phase synthesis resin was calculated based on the weight of the amino acids used in the loading process and the weight of the amino acids recovered in the above procedure.

[0164] Amino acid isolation yield: This was calculated by subtracting the residual amount of solvent (DCM, TFA, or DMF, etc.) used in the reaction and isolation operations from the dry weight of the obtained amino acids. The residual solvent was measured under NMR conditions 1 or 2 and calculated using the method described below.

[0165] DCM residue: After accurately weighing 5 mg of the cleaved amino acid and dissolving it in 700 μL of DMSO-d6 to prepare the sample, 11H-NMR was measured. Using the aromatic ring region derived from the Fmoc group (δ: 7.90-7.29, 8H, m) as a reference, the amount of residual solvent contained in the amino acid was calculated using the following formula based on the integral ratio of the DCM (δ: 5.76, 2H, s).

[0166] Weight % of residual DCM relative to amino acids = ((84.93 (DCM molecular weight)) x (integral ratio of DCM when the integral value of the aromatic ring region of the amino acid is set to 1)) x 100 / ((84.93 (DCM molecular weight)) x (integral ratio of DCM when the integral value of the aromatic ring region of the amino acid is set to 1) + (molecular weight of the amino acid))

[0167] DMF residue: After accurately weighing 5 mg of the cleaved amino acid and dissolving it in 700 μL of DMSO-d6 to prepare the sample, 1 ¹H-NMR was measured, and the amount of residual solvent contained in the amino acid was calculated using the following formula based on the integral ratio of DMF (δ:7.95, 1H, s) with the aromatic ring region derived from the Fmoc group (δ:7.90-7.29, 8H, m) as the reference.

[0168] Weight % of residual DMF relative to amino acids = ((73.09 (DMF molecular weight)) x (integral ratio of DMF when the integral value of the aromatic ring region of the amino acid is set to 1)) x 100 / ((73.09 (DMF molecular weight)) x (integral ratio of DMF when the integral value of the aromatic ring region of the amino acid is set to 1) + (molecular weight of amino acid))

[0169] TFA residue: After accurately weighing 5 mg of cleaved amino acids and 5 mg of internal standard material and dissolving them in 700 μL of DMSO-d6 to prepare the sample, 19 1F-NMR was measured using an internal standard (δ: -76.0, 6F, s) as the reference, and the amount of residual solvent contained in the amino acids was calculated from the integral ratio of TFA (δ: -89.4, 3F, s) using the following formula.

[0170] Weight % of residual TFA in amino acids = ((Weight of internal standard) x (114.02 (Molecular weight of TFA)) x (6 (Number of fluorine atoms in internal standard)) x (Integral value of TFA) x 100) / ((Weight of amino acid) x (258.12 (Molecular weight of internal standard)) x (3 (Number of fluorine atoms in TFA)) x (Integral value of internal standard))

[0171] [Measurement method] The measurement conditions using HPLC are shown below.

[0172] [High-performance liquid chromatography conditions 1] Equipment: Waters Acquity UPLC / H-class, Acquity QDa Column: Ascentis Express C18 (2.1 mm I.D. x 50 mm) Mobile phase: Water containing 0.05% trifluoroacetic acid (A) and acetonitrile containing 0.05% trifluoroacetic acid (B) Elution method: Stepwise solvent gradient elution from 5% B to 100% B (4.0 min), followed by retention at 100% B (0.5 min). Flow rate: 1.0 mL / min Column temperature: 35°C

[0173] [High-performance liquid chromatography conditions 2] Equipment: Waters Acquity UPLC / H-class Column: Capcell Core Adme (3.0 mm I.D. x 150 mm) Mobile phase: Water containing 0.05% trifluoroacetic acid (A) and acetonitrile containing 0.05% trifluoroacetic acid (B) Elution method: Stepwise solvent gradient elution from 30% B to 70% B (20.0 min), followed by retention at 100% B (2.0 min). Flow rate: 0.3 mL / min Column temperature: 30°C

[0174] [Conditions for high-performance liquid chromatography 3] Equipment: Waters Acquity UPLC / H-class Column: CSH Fluoro-phenyl (2.1 mm I.D. x 150 mm) Mobile phase: Water containing 0.1% formic acid (A) and acetonitrile containing 0.1% formic acid (B) Elution method: Stepwise solvent gradient elution with retention at 5% B, 100% B (15.0 min), 100% B (3.0 min), 5% B (0.01 min), and 5% B (2 min). Flow rate: 0.3 mL / min Column temperature: 35°C

[0175] [HPLC retention time of amino acids] [Table 1] n / a: Not available

[0176] The measurement conditions using NMR are shown below.

[0177] [NMR Condition 1] 1 ¹H-NMR spectra were measured using a JEOL 500MHz Royal HFX probe. The chemical shift of Me4Si, used as an internal standard, was set to 0 ppm, and the deuterium lock signal from the sample solvent was referenced. The chemical shift of the analyte signal is expressed in ppm. The abbreviations for signal splitting are s = singlet and m = multiplet. The integral value of the signal was calculated based on the ratio of the signal area intensities of each signal.

[0178] [NMR Condition 2] 19F-NMR spectra were measured using a JEOL 500MHz Royal HFX probe. The chemical shift of 3,5-bis(trifluoromethyl)-benzoic acid (GC purity 99.3%), used as an internal standard, was set to -76 ppm, and the chemical shift of the analyte's signal was expressed in ppm. Signal splitting was abbreviated as s = singlet. The integral value of the signal was calculated based on the ratio of the signal area intensities of each signal.

[0179] [Example of a description of a support reaction on a solid-phase synthetic resin] In this specification, when a polymer or resin is bonded to a compound, the polymer or resin portion may be indicated by a circle (○). Furthermore, to clearly indicate the reaction site of the resin portion, the chemical structure of the reaction site may be shown connected to the circle. For example, in the structure Fmoc-MeAsp(O-CTC)-pip shown below, the 2-chlorotrityl group of the resin (CTC resin) is bonded to the side-chain carboxyl group of Asp via an ester bond. Note that "pip" refers to a piperidinyl group, and in the above structure, the C-terminal carboxyl group forms an amide bond with piperidine. TIFF0007885139000002.tif38170

[0180] 2-Chlorotritylchloride resin (1.00~1.37 mmol / g, 100-200 mesh, 1% DVB) was purchased from Sunresin New Materials Co., Ltd. (Xi'an, China). Fmoc-MeAsp(O-tBu)-OH was purchased from New England Chemicals (New York, USA), GL Biochem (Shanghai, China), ChemBioBank (Shanghai, China), and SINO High Goal Chemical Technology Co., Ltd. (Shanghai, China). Among the reaction solvents used in the solid-phase synthesis reaction, dehydrated grade dichloromethane, methanol, t-butyl methyl ether, and cyclopentyl methyl ether were purchased from Fujifilm Wako Pure Chemical Industries. Piperidine and diisopropylethylamine were purchased from Watanabe Chemical. Dehydrated grade N,N-dimethylformamide was purchased from Fujifilm Wako Pure Chemical Industries, Junsei Chemical Co., Ltd., or Mitsubishi Gas Chemical Company, Inc. 2-methyltetrahydrofuran was purchased from Fujifilm Wako Pure Chemical Industries and Watanabe Chemical.

[0181] A constant-temperature shaker (EYELA, MMS-1 model) was used during solid-phase synthesis. The solid-phase synthetic resin was dried using a vacuum pump at 25°C and a temperature of 5 torr or less for at least 12 hours. A constant weight was defined as the resin weight when the weight change between two consecutive weight measurements was within 1% of the resin's total weight.

[0182] Example 1: Reaction to support Fmoc-MeAsp(OH)-pip on CTC resin TIFF0007885139000003.tif38170

[0183] Example 1-1-1: CTC resin was swollen with DCM and the loading reaction was carried out in MeTHF. 146.9 mg (0.196 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a MeTHF solution (1.2 mL) of Fmoc-MeAsp(OH)-pip (50.87 mg, 0.117 mmol) and DIPEA (56 μL, 0.321 mmol) was added to the CTC resin and shaken at room temperature for 23 hours. The reaction conversion rate was 90%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (180.0 mg). The yield by the Fmoc quantification method was 97%.

[0184] Example 1-1-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:1. 1.36 mmol / g CTC resin (286.4 mg, 0.389 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared amino acid solution, consisting of Fmoc-MeAsp(OH)-pip (100.2 mg, 0.229 mmol), DIPEA (114 μL, 0.641 mmol), MeTHF (1.2 mL), and DCM (1.2 mL), was added to the CTC resin and shaken at room temperature for 21 hours. The reaction conversion rate was 99%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (363.5 mg). The yield by the Fmoc quantification method was 100%.

[0185] Example 1-1-3: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. 1.36 mmol / g CTC resin (145.77 mg, 0.198 mmol) was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared amino acid solution, consisting of Fmoc-MeAsp(OH)-pip (50.66 mg, 0.116 mmol), DIPEA (56 μL, 0.321 mmol), MeTHF (0.4 mL), and DCM (0.8 mL), was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (181.1 mg). The yield by the Fmoc quantification method was 96%.

[0186] Example 1-1-3-2: A complete experiment from the deprotection reaction to the loading step of Fmoc-MeAsp(O-tBu)-pip. The CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. TIFF0007885139000004.tif81170

[0187] Fmoc-MeAsp(O-tBu)-pip (8.012 g, 16.24 mmol) was dissolved in MeTHF (40.0 mL). HMDS (4.1 mL, 19.5 mmol) was added to the solution at 0°C, followed by dropwise addition of TMSOTf (3.2 mL, 17.9 mmol). The reaction solution was heated to 25°C and stirred for 2 hours. 5% sodium carbonate aqueous solution (80 mL) was added to the reaction solution at 0°C, and the mixture was heated to 25°C and stirred for 1 hour. Back-extraction was performed using MTBE (40 mL), and the aqueous layer was washed with MTBE (80 mL). MeTHF (40 mL) was added to the aqueous layer, followed by phosphoric acid (5.6 mL, 81 mmol). After draining the aqueous layer, the organic layer was washed three times with 15% sodium chloride aqueous solution (40 mL). MgSO4 (6.01 g, 0.75 w / w) was added to the obtained MeTHF solution and stirred for 30 minutes. The MgSO4 was filtered off and the mixture was washed with MeTHF (16 mL). Of the 38.7114 g of the obtained Fmoc-MeAsp(OH)-pip MeTHF solution, 37.2225 g was used to proceed to the next step.

[0188] 17.18 g of 1.00 mmol / g CTC resin was placed in a solid-phase synthesis column, and 172 mL of DCM was added and shaken for 30 minutes to swell the CTC resin. After filtration, 10 mL of MeTHF was added to the CTC resin in a MeTHF solution (containing 36 mL of MeTHF) containing the Fmoc-MeAsp(OH)-pip (6.24 g, 14.30 mmol) obtained above, followed by 6.70 mL of DIPEA (38.5 mmol) and 92 mL of DCM. The mixture was shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 137.4 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (92 mL) and four times with methanol (172 mL). The CTC resin was dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (23.1879 g). The yield by the Fmoc quantification method was 97%. The obtained Fmoc-MeAsp(O-CTC)-pip (1.0099 g) was placed in a solid-phase synthesis column, DMF (8 mL) was added, and the mixture was shaken for 30 minutes. After filtration, the CTC resin was washed four times with DCM (8 mL). 1% TFA-DCM solution (8 mL) was added and the mixture was shaken for 1 minute to cleave amino acids from the resin. After filtration, the filtrate was set aside. 1% TFA-DCM solution was added to the resin again and shaken for 1 minute. After filtration, the filtrate was collected (this procedure was repeated three times). The CTC resin was then washed twice more with DCM (8 mL). All filtrates and washings were mixed and concentrated under reduced pressure. The concentrated residue was dried using a vacuum pump to obtain 485.4 mg of Fmoc-MeAsp(OH)-pip. The isolation yield was 91%.

[0189] Example 1-1-3-3: Continuous experiment from deprotection reaction to loading step of Fmoc-MeAsp(O-tBu)-pip. DCM was used as the extraction solvent after the deprotection reaction. CTC resin was swollen with DCM, and the loading reaction was carried out with DCM. Fmoc-MeAsp(O-tBu)-pip (8.00 g, 16.24 mmol) was dissolved in MeTHF (40.0 mL). HMDS (4.1 mL, 19.5 mmol) was added to the solution at 0°C, followed by dropwise addition of TMSOTf (3.2 mL, 17.9 mmol). The reaction solution was heated to 25°C and stirred for 2 hours. 5% sodium carbonate aqueous solution (80 mL) was added dropwise to the reaction solution at 0°C, and the mixture was heated to 25°C and stirred for 1 hour. Back-extraction was performed using MTBE (40 mL), and the aqueous layer was washed with MTBE (80 mL). DCM (40 mL) was added to the aqueous layer, followed by phosphoric acid (5.6 mL, 81 mmol). After draining the aqueous layer, the organic layer was washed three times with 15% sodium chloride aqueous solution (40 mL). MgSO4 (4.99 g, 0.63 w / w) was added to the obtained DCM solution and stirred for 30 minutes. The MgSO4 was filtered off and the mixture was washed with DCM (16 mL). Of the 42.6802 g of the obtained Fmoc-MeAsp(OH)-pip DCM solution (containing 27.6 mL of DCM), 41.1315 g was used to proceed to the next step.

[0190] 17.19 g, 23.37 mmol of CTC resin with a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (137 mL) and shaking for 30 minutes. After filtration, the CTC resin was mixed with a DCM solution containing the Fmoc-MeAsp(OH)-pip (5.98 g, 13.74 mmol) obtained above, DIPEA (6.70 mL, 38.5 mmol), and DCM (96 mL), and shaken at room temperature for 3 hours. The reaction conversion rate was 99.8%. After filtration, the CTC resin was mixed with a DMF solution (DMF:methanol:DIPEA = 85:10:5 (total 137.4 mL)) and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (172 mL) and four times with methanol (172 mL). The CTC resin was dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (24.1879 g). The yield by the Fmoc quantification method was 89%. The obtained Fmoc-MeAsp(O-CTC)-pip (2.0023 g) was placed in a solid-phase synthesis column, DMF (16 mL) was added, and the mixture was shaken for 30 minutes. After filtration, the CTC resin was washed four times with DCM (16 mL). 1% TFA-DCM solution (8 mL) was added and the mixture was shaken for 1 minute to cleave amino acids from the resin. After filtration, the filtrate was set aside. 1% TFA-DCM solution was added to the resin again and shaken for 1 minute. After filtration, the filtrate was collected (this procedure was repeated four times). The CTC resin was further washed twice with DCM (16 mL). All filtrates and washing solutions were mixed and concentrated under reduced pressure. The concentrated residue was dried using a vacuum pump to obtain 967.9 mg of Fmoc-MeAsp(OH)-pip. The yield by isolation method was 80%.

[0191] Example 1-1-3-4: Continuous experiment from deprotection reaction to loading step of Fmoc-MeAsp(O-tBu)-pip. In the deprotection step, the loading reaction was carried out without removing water with a desiccant. The CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. Fmoc-MeAsp(O-tBu)-pip (13.19 g, 26.8 mmol) was dissolved in MeTHF (56.0 mL). HMDS (5.7 mL, 27.3 mmol) was added to the solution at 0°C, followed by dropwise addition of TMSOTf (4.5 mL, 25.0 mmol). The reaction solution was heated to 25°C and stirred for 1 hour and 30 minutes. 5% sodium carbonate aqueous solution (132 mL) was added to the reaction solution at 0°C, and the mixture was heated to 25°C and stirred for 2 hours. Back-extraction was performed using MTBE (66 mL), and the aqueous layer was washed with MTBE (132 mL). MeTHF (66 mL) was added to the aqueous layer, followed by phosphoric acid (9.2 mL, 134 mmol). After draining the aqueous layer, the organic layer was washed twice with 15% sodium chloride aqueous solution (66 mL). Of the 76.72 g of the obtained Fmoc-MeAsp(OH)-pip MeTHF solution (containing 76.1 mL of MeTHF), 39.37 g was used to proceed to the next step.

[0192] 17.2 g, 23.39 mmol of CTC resin with a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (137 mL) and shaking for 30 minutes. After filtration, MeTHF (7.0 mL) was added to the CTC resin along with MeTHF solution (39.0 mL) containing the above-prepared Fmoc-MeAsp(OH)-pip (6.00 g, 13.74 mmol), followed by DIPEA (6.70 ml, 38.5 mmol) and DCM (92 mL). The mixture was shaken at room temperature for 2 hours. The reaction conversion rate was 99.7%. After filtration, the CTC resin was added to a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 137.4 mL)) and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (172 mL) and four times with methanol (172 mL). The CTC resin was dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (21.88 g). The yield by the Fmoc quantification method was 94%. The obtained Fmoc-MeAsp(O-CTC)-pip (0.9996 g) was placed in a solid-phase synthesis column, DMF (8 mL) was added, and the mixture was shaken for 30 minutes. After filtration, the CTC resin was washed four times with DCM (8 mL). 1% TFA-DCM solution (8 mL) was added and the mixture was shaken for 1 minute to cleave amino acids from the resin. After filtration, the filtrate was set aside. 1% TFA-DCM solution was added to the resin again and shaken for 1 minute. After filtration, the filtrate was collected (this procedure was repeated three times). The CTC resin was then washed twice with DCM (8 mL). All filtrates and washings were mixed and concentrated under reduced pressure. The concentrated residue was dried using a vacuum pump to obtain 449.4 mg of Fmoc-MeAsp(OH)-pip. The isolation yield was 91%.

[0193] Example 1-1-4: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:10. 1.36 mmol / g CTC resin (145.39 mg, 0.198 mmol) was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. An amino acid solution prepared separately by mixing Fmoc-MeAsp(OH)-pip (50.48 mg, 0.116 mmol), DIPEA (56 μL, 0.321 mmol), MeTHF (0.1 mL), and DCM (1.0 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (178.1 mg). The yield by the Fmoc quantification method was 85%.

[0194] Example 1-2-1: CTC resin was swollen with DCM and the loading reaction was carried out in MTBE. 1.36 mmol / g CTC resin (287.1 mg, 0.390 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, MTBE solution (2.3 mL) of Fmoc-MeAsp(OH)-pip (100.7 mg, 0.231 mmol) and DIPEA (114 μL, 0.641 mmol) was added to the CTC resin and shaken at room temperature for 15 hours. The reaction conversion rate was 76%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (363.7 mg). The yield by the Fmoc quantification method was 79%.

[0195] Example 1-2-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:1. 1.36 mmol / g CTC resin (286.6 mg, 0.390 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared amino acid solution, consisting of Fmoc-MeAsp(OH)-pip (100.1 mg, 0.229 mmol), DIPEA (114 μL, 0.641 mmol), MTBE (1.2 mL), and DCM (1.2 mL), was added to the CTC resin and shaken at room temperature for 17 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (355.9 mg). The yield by the Fmoc quantification method was 90%.

[0196] Example 1-2-3: CTC resin was swollen with DCM and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:2. 148.38 mg (0.202 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. An amino acid solution prepared separately by mixing Fmoc-MeAsp(OH)-pip (51.71 mg, 0.118 mmol), DIPEA (56 μL, 0.321 mmol), MTBE solution (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (186.2 mg). The yield by the Fmoc quantification method was 73%.

[0197] Example 1-2-4: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:10. 143.72 mg (0.195 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. An amino acid solution prepared separately, consisting of Fmoc-MeAsp(OH)-pip (50.24 mg, 0.115 mmol), DIPEA (56 μL, 0.321 mmol), MTBE (0.1 mL), and DCM (1.0 mL), was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (174.9 mg). The yield by the Fmoc quantification method was 88%.

[0198] Example 1-3-1: CTC resin was swollen with DCM and the loading reaction was carried out with CPME. 1.36 mmol / g CTC resin (286.8 mg, 0.390 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, CPME solution (2.3 mL) of Fmoc-MeAsp(OH)-pip (100.0 mg, 0.229 mmol) and DIPEA (114 μL, 0.641 mmol) was added to the CTC resin and shaken at room temperature for 17 hours. The reaction conversion rate was 39%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (353.2 mg). The yield by the Fmoc quantification method was 72%.

[0199] Example 1-3-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:1. 1.36 mmol / g CTC resin (287.1 mg, 0.390 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pip (100.6 mg, 0.230 mmol), DIPEA (112 μL, 0.641 mmol), CPME (1.15 mL), and DCM (1.15 mL) was added to the CTC resin and shaken at room temperature for 3 hours. The reaction conversion rate was 99%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (366.8 mg). The yield by the Fmoc quantification method was 77%.

[0200] Example 1-3-3: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:2. 144.00 mg (0.196 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pip (50.23 mg, 0.115 mmol), DIPEA (56 μL, 0.321 mmol), CPME (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (182.0 mg). The yield by the Fmoc quantification method was 79%.

[0201] Example 1-3-4: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:10. 144.45 mg (0.196 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pip (50.07 mg, 0.115 mmol), DIPEA (56 μL, 0.321 mmol), CPME (0.1 mL), and DCM (1.0 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (175.7 mg). The yield by the Fmoc quantification method was 84%.

[0202] Example 1-4-1: CTC resin was swollen with DCM, and the loading reaction was carried out in DCM. 1.36 mmol / g CTC resin (287.1 mg, 0.390 mmol) was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a DCM solution (2.3 mL) of Fmoc-MeAsp(OH)-pip (99.83 mg, 0.229 mmol) and DIPEA (114 μL, 0.641 mmol) was added to the CTC resin and shaken at room temperature for 3 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (375.2 mg). The yield by the Fmoc quantification method was 97%.

[0203] Example 1-5-1: CTC resin was swollen with MeTHF, and the loading reaction was carried out in MeTHF. 146.9 mg (0.200 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and MeTHF (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a MeTHF solution (1.2 mL) of Fmoc-MeAsp(OH)-pip (50.56 mg, 0.116 mmol) and DIPEA (56 μL, 0.321 mmol) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 33%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.5 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (180.0 mg). The yield by Fmoc quantification method was 49%.

[0204] Example 1-6-1: CTC resin was swollen with CPME and the loading reaction was carried out in CPME. 1.36 mmol / g CTC resin (286.0 mg, 0.389 mmol) was placed in a solid-phase synthesis column, and CPME (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, CPME solution (2.3 mL) of Fmoc-MeAsp(OH)-pip (99.6 mg, 0.228 mmol) and DIPEA (114 μL, 0.641 mmol) was added to the CTC resin and shaken at room temperature for 23 hours. The reaction conversion rate was 67%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (2.9 mL) and four times with methanol (2.9 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pip (349.8 mg). The yield by the Fmoc quantification method was 51%.

[0205] Example 2: Reaction to support Fmoc-Asp(OH)-pip on CTC resin TIFF0007885139000005.tif38170

[0206] Example 2-1-1: CTC resin was swollen with DCM and the loading reaction was carried out with MeTHF. 148.56 mg (0.202 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a MeTHF solution (1.2 mL) of Fmoc-Asp(OH)-pip (50.33 mg, 0.119 mmol) and DIPEA (58 μL, 0.331 mmol) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 92%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (194.1 mg). The yield by the Fmoc quantification method was 84%.

[0207] Example 2-1-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:1. 147.7 mg (0.201 mmol) of CTC resin with a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (2.3 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.07 mg, 0.119 mmol), DIPEA (58 μL, 0.331 mmol), MeTHF (1.2 mL), and DCM (1.2 mL) was added to the CTC resin and shaken at room temperature for 17 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. The CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL), and then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (190.9 mg). The yield by the Fmoc quantification method was 96%.

[0208] Example 2-1-3: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. 147.62 mg (0.201 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.34 mg, 0.119 mmol), DIPEA (58 μL, 0.331 mmol), MeTHF (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (184.7 mg). The yield obtained by the Fmoc quantification method was quantitative.

[0209] Example 2-2-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:1. 148.84 mg (0.202 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.83 mg, 0.120 mmol), DIPEA (58 μL, 0.331 mmol), MTBE (0.6 mL), and DCM (0.6 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (193.1 mg). The yield by the Fmoc quantification method was 86%.

[0210] Example 2-2-2: CTC resin was swollen with DCM, and the loading reaction was carried out with a mixed solvent of MTBE:DCM = 1:2. 147.61 mg (0.201 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.04 mg, 0.118 mmol), DIPEA (58 μL, 0.331 mmol), MTBE (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (186.8 mg). The yield by the Fmoc quantification method was 86%.

[0211] Example 2-3-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:1. 147.63 mg (0.201 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.12 mg, 0.119 mmol), DIPEA (58 μL, 0.331 mmol), CPME (0.6 mL), and DCM (0.6 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (188.7 mg). The yield by the Fmoc quantification method was 85%.

[0212] Example 2-3-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:2. 148.03 mg (0.201 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-Asp(OH)-pip (50.28 mg, 0.119 mmol), DIPEA (58 μL, 0.331 mmol), CPME (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 6 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL), then dried using a CTC resin vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (189.1 mg). The yield by the Fmoc quantification method was 89%.

[0213] Example 2-3-2-2: Continuous experiment from deprotection reaction to loading of Fmoc-Asp(O-tBu)-pip. CTC resin was swollen with DCM and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:2. TIFF0007885139000006.tif81170

[0214] Fmoc-Asp(O-tBu)-pip (9.19 g, 19.2 mmol) was dissolved in MeTHF (46.0 mL). After adding HMDS (4.8 mL, 23.0 mmol) to the solution at 0 °C, TMSOTf (3.8 mL, 21.2 mmol) was added dropwise. After warming the reaction solution to 25 °C, it was stirred for 1 hour. At 0 °C, 5% aqueous sodium carbonate solution (92 mL) was added to the reaction solution, and after warming to 25 °C, it was stirred for 1 hour. Back extraction was performed using MTBE (46 mL), and then the aqueous layer was washed with MTBE (92 mL). After adding CPME (46 mL) to the aqueous layer, phosphoric acid (4.6 mL, 96 mmol) was added. After discharging the aqueous layer, the organic layer was washed twice with 15% aqueous sodium chloride solution (40 mL). Na2SO4 (6.84 g, 0.75 w / w) was added to the obtained CPME solution and stirred for 30 minutes. Na2SO4 was filtered off and washed with CPME (20 mL). Of the obtained 55.2828 g of CPME solution of Fmoc-Asp(OH)-pip, 52.2534 g was used for the next step.

[0215] 18.00 g of 1.00 mmol / g CTC resin (18.00 mmol) was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (180 mL) and shaking for 30 minutes. After filtration, the CTC resin was mixed with CPME solution (48 mL) containing the Fmoc-Asp(OH)-pip (6.08 g, 14.40 mmol) obtained above, DIPEA (7.02 mL, 40.0 mmol), and DCM (96 mL), and shaken at room temperature for 23 hours. The reaction conversion rate was 98%. After filtration, the CTC resin was mixed with DMF solution (DMF:methanol:DIPEA = 85:10:5 (total 144 mL)) and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (180 mL) and four times with methanol (180 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (25.0996 g). The yield by the Fmoc quantification method was 92%. The obtained Fmoc-Asp(O-CTC)-pip (0.9993 g) was placed in a solid-phase synthesis column, DMF (8 mL) was added, and the mixture was shaken for 30 minutes. After filtration, the mixture was washed four times with DCM (8 mL). 1% TFA / DCM solution (8 mL) was added and the mixture was shaken for 1 minute to cleave amino acids from the resin. After filtration, the filtrate was set aside. 1% TFA-DCM solution (8 mL) was added to the resin again and shaken for 1 minute. After filtration, the filtrate was collected (this procedure was repeated four times). The resin was then washed twice with DCM (8 mL). All filtrates and washings were mixed and concentrated under reduced pressure. The concentrated residue was dried using a vacuum pump to obtain 322 mg of Fmoc-Asp(OH)-pip. The yield by isolation method was 86%.

[0216] Example 2-4-1: CTC resin was swollen with DCM, and the loading reaction was carried out in DCM. 1.36 mmol / g of CTC resin (144.9 mg, 0.200 mmol) was placed in a column for solid-phase synthesis, and DCM (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a DCM solution (2.3 mL) of Fmoc-Asp(OH)-pip (50.42 mg, 0.117 mmol) and DIPEA (58 μL, 0.331 mmol) was added to the CTC resin and shaken at room temperature for 3 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF: methanol: DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed 4 times with DMF (1.5 mL) and 4 times with methanol (1.5 mL), and then the CTC resin was dried with a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (183.7 mg). The yield by the Fmoc quantification method was 94%.

[0217] Example 2-5-1: CTC resin was swollen with MeTHF, and the loading reaction was carried out in MeTHF. 1.36 mmol / g of CTC resin (147.8 mg, 0.200 mmol) was placed in a column for solid-phase synthesis, and MeTHF (1.2 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, a MeTHF solution (1.2 mL) of Fmoc-Asp(OH)-pip (49.94 mg, 0.117 mmol) and DIPEA (58 μL, 0.331 mmol) was added to the CTC resin and shaken at room temperature for 25 hours. The reaction conversion rate was 59%. After filtration, a DMF mixed solution (DMF: methanol: DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed 4 times with DMF (1.5 mL) and 4 times with methanol (1.5 mL), and then the CTC resin was dried with a vacuum pump to obtain Fmoc-Asp(O-CTC)-pip (173.4 mg). The yield by the Fmoc quantification method was 56%.

[0218] Example 3: Reaction to support Fmoc-MeAsp(OH)-pyrro on CTC resin TIFF0007885139000007.tif37170

[0219] Example 3-1-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:1. 152.5 mg (0.207 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and 1.5 mL of DCM was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.53 mg, 0.120 mmol), DIPEA (60 μL, 0.343 mmol), MeTHF (0.6 mL), and DCM (0.6 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (157.9 mg). The yield by the Fmoc quantification method was 78%.

[0220] Example 3-1-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. 151.9 mg (0.207 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.5 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.58 mg, 0.120 mmol), DIPEA (60 μL, 0.343 mmol), MeTHF (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (210.5 mg). The yield by the Fmoc quantification method was 91%.

[0221] Example 3-2-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:1. 152.5 mg (0.207 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and 1.5 mL of DCM was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.42 mg, 0.119 mmol), DIPEA (60 μL, 0.343 mmol), MTBE (0.6 mL), and DCM (0.6 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (193.9 mg). The yield by the Fmoc quantification method was 91%.

[0222] Example 3-2-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:2. 152.1 mg (0.207 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.5 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.63 mg, 0.120 mmol), DIPEA (60 μL, 0.343 mmol), MTBE (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (198.5 mg). The yield by Fmoc quantification method was 87%.

[0223] Example 3-3-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:1. 152.4 mg (0.207 mmol) of 1.36 mmol / g CTC resin was placed in a solid-phase synthesis column, and DCM (1.5 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.61 mg, 0.120 mmol), DIPEA (60 μL, 0.343 mmol), CPME (0.6 mL), and DCM (0.6 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (158.0 mg). The yield by the Fmoc quantification method was 70%.

[0224] Example 3-3-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:2. 152.6 mg (0.207 mmol) of CTC resin at a concentration of 1.36 mmol / g was placed in a solid-phase synthesis column, and DCM (1.5 mL) was added and shaken for 30 minutes to swell the CTC resin. The DCM was filtered out. A separately prepared mixture of Fmoc-MeAsp(OH)-pyrro (50.51 mg, 0.120 mmol), DIPEA (60 μL, 0.343 mmol), CPME (0.4 mL), and DCM (0.8 mL) was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixture (DMF:methanol:DIPEA = 85:10:5 (total 1.2 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.5 mL) and four times with methanol (1.5 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-pyrro (196.4 mg). The yield by the Fmoc quantification method was 85%.

[0225] Example 4: Reaction to support Fmoc-MeAsp(OH)-NMe2 on CTC resin. TIFF0007885139000008.tif37170

[0226] Example 4-1-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:1. 1.36 mmol / g CTC resin (164.02 mg, 0.223 mmol) was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (1.3 mL) and shaking for 30 minutes. After filtration, an amino acid solution prepared by dissolving Fmoc-MeAsp(OH)-NMe2 (50.84 mg, 0.133 mmol) in a mixed solvent of MeTHF (0.65 mL) and DCM (0.65 mL) and adding DIPEA (64 μL, 0.366 mmol) was added to the CTC resin, and the mixture was shaken at room temperature for 16 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.3 mL)) was added to the CTC resin, and the mixture was shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.6 mL) and four times with methanol (1.6 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (205.0 mg). The yield by the Fmoc quantification method was 94%.

[0227] Example 4-1-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MeTHF:DCM = 1:2. 1.36 mmol / g CTC resin (163.54 mg, 0.222 mmol) was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (1.3 mL) and shaking for 30 minutes. After filtration, an amino acid solution containing Fmoc-MeAsp(OH)-NMe2 (50.17 mg, 0.132 mmol) dissolved in MeTHF (0.44 mL) and DCM (0.88 mL), with DIPEA (58 μL, 0.331 mmol) added, was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.6 mL) and four times with methanol (1.6 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (213.5 mg). The yield by the Fmoc quantification method was 82%.

[0228] Example 4-2-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:1. 1.36 mmol / g CTC resin (163.09 mg, 0.221 mmol) was placed in a solid-phase synthesis column, and DCM (1.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, an amino acid solution prepared by dissolving Fmoc-MeAsp(OH)-NMe2 (50.49 mg, 0.132 mmol) in a mixed solvent of MTBE (0.65 mL) and DCM (0.65 mL), followed by the addition of DIPEA (64 μL, 0.366 mmol), was added to the CTC resin, and the mixture was shaken at room temperature for 16 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 2.3 mL)) was added to the CTC resin, and the mixture was shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.6 mL) and four times with methanol (1.6 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (207.3 mg). The yield by the Fmoc quantification method was 89%.

[0229] Example 4-2-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of MTBE:DCM = 1:2. 1.36 mmol / g of CTC resin (163.51 mg, 0.222 mmol) was placed in a column for solid-phase synthesis, and DCM (1.3 mL) was added and shaken for 30 minutes to swell the CTC resin. After filtration, an amino acid solution prepared by dissolving Fmoc-MeAsp(OH)-NMe2 (50.71 mg, 0.128 mmol) in MTBE (0.4 mL) and DCM (0.8 mL) and adding DIPEA (58 μL, 0.331 mmol) was added to the CTC resin, and the mixture was shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF: methanol: DIPEA = 85: 10: 5 (total 1.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed 4 times with DMF (1.6 mL) and 4 times with methanol (1.6 mL), and then the CTC resin was dried with a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (209.7 mg). The yield by the Fmoc quantification method was 95%.

[0230] Example 4-3-1: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:1. 1.36 mmol / g CTC resin (162.71 mg, 0.221 mmol) was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (1.3 mL) and shaking for 30 minutes. After filtration, an amino acid solution containing Fmoc-MeAsp(OH)-NMe2 (49.84 mg, 0.130 mmol), CPME (0.65 mL), and DCM (0.65 mL), with DIPEA (64 μL, 0.366 mmol) added, was added to the CTC resin, and the mixture was shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.3 mL)) was added to the CTC resin, and the mixture was shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.6 mL) and four times with methanol (1.6 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (204.1 mg). The yield by the Fmoc quantification method was 85%.

[0231] Example 4-3-2: CTC resin was swollen with DCM, and the loading reaction was carried out in a mixed solvent of CPME:DCM = 1:2. 1.36 mmol / g CTC resin (163.32 mg, 0.222 mmol) was placed in a solid-phase synthesis column, and the CTC resin was swollen by adding DCM (1.3 mL) and shaking for 30 minutes. After filtration, an amino acid solution containing Fmoc-MeAsp(OH)-NMe2 (50.19 mg, 0.131 mmol) dissolved in a mixed solvent of CPME (0.44 mL) and DCM (0.88 mL), with DIPEA (62 μL, 0.3 mmol) added, was added to the CTC resin and shaken at room temperature for 18 hours. The reaction conversion rate was 100%. After filtration, a DMF mixed solution (DMF:methanol:DIPEA = 85:10:5 (total 1.3 mL)) was added to the CTC resin and shaken at room temperature for 2 hours. After filtration, the CTC resin was washed four times with DMF (1.6 mL) and four times with methanol (1.6 mL). The CTC resin was then dried using a vacuum pump to obtain Fmoc-MeAsp(O-CTC)-NMe2 (214.3 mg). The yield by the Fmoc quantification method was 89%. [Industrial applicability]

[0232] This invention is useful for producing peptide compounds containing at least one N-substituted amino acid using a solid-phase method.

Claims

1. A method for producing a peptide compound containing at least one N-substituted amino acid, a salt thereof, or a solvate thereof, comprising the step (step 1) of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent to obtain an amino acid supported on the solid-phase synthesis resin, wherein The first solvent and the third solvent are each independently selected from halogenated solvents, and The second solvent is an ether-based solvent. The amino acids are unnatural amino acids, The method wherein a non-natural amino acid is supported on a solid-phase synthesis resin via a carboxyl group bonded to the carbon atom at the β-position or γ-position of the amino group.

2. A method for producing amino acids supported on a solid-phase synthesis resin, comprising the step of contacting a solid-phase synthesis resin swollen in a solvent containing a first solvent with (i) a solution containing an amino acid and a second solvent, or (ii) a solution containing an amino acid, a second solvent, and a third solvent, The first solvent and the third solvent are each independently selected from halogenated solvents, and The second solvent is an ether-based solvent. The amino acids are unnatural amino acids, The method wherein a non-natural amino acid is supported on a solid-phase synthesis resin via a carboxyl group bonded to the carbon atom at the β-position or γ-position of the amino group.

3. The method according to claim 1 or 2, wherein the solution is a solution comprising an amino acid and a second solvent.

4. The method according to claim 1 or 2, wherein the solution is a solution comprising an amino acid, a second solvent, and a third solvent.

5. The method according to claim 1, 2, or 4, wherein the first solvent and the third solvent are of the same type.

6. The method according to any one of claims 1 to 2 and 4 to 5, wherein the volume ratio of the second solvent to the third solvent is 1:1 to 1:

10.

7. The method according to any one of claims 1 to 3 and 5 to 6, wherein the solution comprising an amino acid and a second solvent is a solution obtained by an extraction operation including the use of a second solvent, which is carried out after the deprotection reaction of the protecting group of the carboxyl group of the amino acid prior to step 1, and a subsequent optional dehydration operation.

8. The method according to any one of claims 1 to 2 and 4 to 6, wherein the solution comprising an amino acid, a second solvent, and a third solvent is obtained by adding a third solvent to a solution obtained by an extraction operation including the use of a second solvent, and an optional dehydration operation, which is carried out after the deprotection reaction of the protecting group of the carboxyl group of the amino acid prior to step 1.

9. The method according to claim 7 or 8, wherein the dehydration operation is carried out by a desiccant.

10. The method according to any one of claims 7 to 9, wherein the protecting group of the carboxyl group is removable with an acid.

11. The method according to any one of claims 1 to 10, wherein the solid-phase synthesis resin is CTC resin, Wang resin, SASRIN resin, Trt resin, Mtt resin, or Mmt resin.

12. The method according to any one of claims 1 and 3 to 11, wherein the peptide compound comprises two or more N-substituted amino acids.

13. A method for producing cyclic peptide compounds, salts thereof, or solvates thereof, comprising the following steps: A step of obtaining a peptide compound comprising at least one N-substituted amino acid, a salt thereof, or a solvate thereof, according to the method of any one of claims 1 and 3 to 12. A step to remove the resin for solid-phase synthesis, and A step of cyclizing the C-terminal group and the N-terminal group of the peptide compound, its salt, or solvate thereof to form a cyclic portion.

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