Arginine derivative

Abstract

To provide a guanidyl-protected arginines which, when used in a liquid-phase peptide synthesis reaction, render satisfactory liquid-liquid separation possible, and a peptide synthesis method in which the guanidyl-protected arginines are used.SOLUTION: The present invention relates to an arginine derivative represented by formula (1), (2), or (3) or a salt thereof. (In the formulae, R1 and R2 are the same or different and each represent a hydrogen atom or a C1-C4 alkyl group; A represents a hydrogen atom or an amino-protecting group; and n represents an integer of 1-6 (with the proviso that the case where n is 3; R1 and R2 are each a hydrogen atom or a methyl group; and R3 to R8 are Boc groups is excluded).)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an arginine derivative or a salt thereof. [Background technology]

[0002] When synthesizing peptides, functional groups other than the extension points of the raw amino acids must be protected in advance to prevent side reactions, decomposition, etc. caused by those functional groups. Even when arginines are used as raw materials, the guanidyl groups are protected in advance, and after the condensation reaction between the α-amino group and the carboxyl group of another amino acid, the protecting groups are removed as necessary.

[0003] As a means for protecting the guanidyl group of arginines in liquid-phase peptide synthesis, (1) protection by a nitro group, (2) protection by a 2,4,6-trimethylphenylsulfonyl (TMS) group, and (3) protection by protonation with a strong acid (e.g., hydrochloric acid) have been known in the past (Patent Document 1). In addition, various protecting groups for arginines have been developed, and the most commonly used protecting groups at present include p-toluenesulfonyl (Tos), 2,2,5,7,8-pentamethylchroman-6-sulfonyl (Pmc), and 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl (Pbf). However, for reasons such as the fact that protective means other than proton protection require strict conditions for deprotection and affect other parts of the structure, for arginines, the guanidyl group has been protonated in the peptide elongation reaction and used in peptide synthesis reactions without using a specific protecting group (Patent Documents 2 to 5). In recent years, indolesulfonyl has been developed as a new means for protecting guanidyl groups (Patent Document 6). However, this compound is difficult to obtain and cannot be widely and generally used.

[0004] Meanwhile, in recent years, a support for liquid-phase peptide synthesis (Tag) has been reported for liquid-phase peptide synthesis (Patent Documents 7 to 22). This support is a highly hydrophobic compound, and therefore by binding highly hydrophilic amino acids, peptides, amino acid amides, or peptide amides (hereinafter sometimes referred to as amino acids, etc.) to this support, the solubility in an organic solvent can be greatly improved. Therefore, when a peptide elongation reaction is carried out in a state where amino acids, etc. are bound to this support, the amino acids, etc. bound to the support are dissolved in the organic layer, and unnecessary components, such as the surplus raw amino acids used in the peptide elongation reaction, their decomposition products, and compounds produced as by-products when the protecting groups of the raw amino acids are deprotected, are dissolved in the aqueous layer, thereby providing the advantage that the amino acids, etc. bound to the support can be easily purified by liquid-liquid separation. In this specification, "amino acid amide" refers to a structure in which the C-terminal carboxyl group (-COOH) of an amino acid becomes an amide group (-CONH2), and "peptide amide" refers to a structure in which the C-terminal carboxyl group of a peptide becomes an amide group. Furthermore, in this specification, the term "liquid-liquid separation" refers to the above-mentioned process, i.e., a process in which amino acids bound to a carrier are dissolved in an organic layer, and unnecessary components, such as surplus raw amino acids used in the peptide elongation reaction, their decomposition products, and compounds produced as by-products when the protecting groups of the raw amino acids are deprotected, are dissolved in an aqueous layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 61-36299 [Patent Document 2] Special Publication No. 2003-500416 [Patent Document 3] Special Publication No. 2004-516330 [Patent Document 4] Japanese Patent Application Publication No. 4-211096 [Patent Document 5] Japanese Patent Application Publication No. 5-170795 [Patent Document 6] JP 2014-193872 A [Patent Document 7] Patent No. 5113118 [Patent Document 8] Patent No. 4500854 [Patent Document 9] Patent No. 5929756 [Patent Document 10] Patent No. 6092513 [Patent Document 11] Patent No. 5768712 [Patent Document 12] Patent No. 5803674 [Patent Document 13] Patent No. 6116782 [Patent Document 14] Patent No. 6201076 [Patent Document 15] Patent No. 6283774 [Patent Document 16] Patent No. 6283775 [Patent Document 17] Patent No. 6322350 [Patent Document 18] Patent No. 6393857 [Patent Document 19] Patent No. 6531235 [Patent Document 20] International Publication No. 2019 / 009317 [Patent Document 21] International Publication No. 2020 / 175472 [Patent Document 22] International Publication No. 2020 / 175473 [Patent Document 23] Patent No. 6703668 [Patent Document 24] Patent No. 6713983 [Patent Document 25] International Publication No. 2021 / 132545 [Non-patent literature]

[0006] [Non-Patent Document 1] Molecules 2021, 26, 3497-3505. Summary of the Invention [Problem to be solved by the invention]

[0007] However, in liquid-phase peptide synthesis carried out in an organic solvent using a support for liquid-phase peptide synthesis, when a compound in which the guanidyl group of arginines is protonated is subjected to a peptide elongation reaction, liquid-liquid separation of the resulting arginines bound to the support for liquid-phase peptide synthesis may not be possible. In addition, when liquid-liquid separation is carried out under acidic conditions to solve this problem, it has become clear that a problem occurs in which the protecting groups of amino acids and the protecting groups of carboxyl groups are removed. Therefore, an object of the present invention is to provide a guanidyl group-protected arginine which enables good liquid-liquid separation after binding to a support for liquid-phase peptide synthesis when a compound having a guanidyl group is used in a liquid-phase peptide synthesis reaction, and a peptide synthesis method using the same. [Means for solving the problem]

[0008] Therefore, the present inventors have investigated various means for protecting the guanidyl group of arginines used in liquid-phase peptide synthesis, and have unexpectedly found that when the guanidyl group of arginines is protected with a Boc group, liquid-liquid separation after binding to a liquid-phase peptide carrier is excellent, and the Boc protecting group can be removed under mild conditions, thereby completing the present invention.

[0009] That is, the present invention provides the following inventions [1] to [7]. [1] An arginine derivative or a salt thereof represented by the following formula (1), (2) or (3):

[0010] [ka]

[0011] (In the formula, R1 and R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A represents a hydrogen atom or an amino-protecting group; R 3 and R 4 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; R 5 and R 6 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; R 7 and R 8 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; n represents an integer of 1 to 6 (provided that n is 3 and R 1 and R 2 is a hydrogen atom or a methyl group, and R 3 ~R 8 is a Boc group) [2] The arginine derivative or a salt thereof according to [1], wherein n in the formula (1), (2) or (3) is 4. [3] The arginine derivative or a salt thereof according to [1] or [2], wherein in the formula (1), (2) or (3), A is a hydrogen atom, an Fmoc group, or a Cbz group. [4] In formula (1), (2) or (3), R 1 and R 2 The arginine derivative or a salt thereof according to any one of [1] to [3], wherein [5] The arginine derivative or a salt thereof according to any one of [1] to [4], wherein in the formula (1), (2) or (3), A is an Fmoc group. [6] In formula (1), (2) or (3), R 3 ~R 8 The arginine derivative or a salt thereof according to any one of [1] to [5], wherein [7] A liquid phase peptide synthesis method, which uses the arginine derivative or a salt thereof according to any one of [1] to [6]. Effect of the Invention

[0012] When liquid-phase peptide synthesis is carried out using the arginine derivative of the present invention or a salt thereof, liquid-liquid separation between the compound in which the arginine derivative of the present invention is bound to a support for liquid-phase peptide synthesis and other unnecessary components is excellent, and deprotection of the guanidyl group of the arginine derivative can be carried out under mild conditions. Therefore, peptides having arginine residues can be efficiently produced by the liquid phase method. [Brief description of the drawings]

[0013] [Figure 1] This is a photograph of the liquid surface after shaking the separatory funnel and then leaving it to stand at room temperature for 25 minutes in the liquid-liquid separation in the step of Example (3-d) *1. [Diagram 2] This is a photograph of the liquid surface after shaking the separatory funnel and leaving it at room temperature for 25 minutes in the liquid-liquid separation process in Comparative Example (1-d) *2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The arginine derivative or salt thereof of the present invention is characterized in that one or both of the amino group and the imino group in the guanidino group are protected with a Boc group, and specifically, is an arginine derivative or salt thereof represented by the following formula (1), (2), or (3):

[0015] [ka]

[0016] (In the formula, R 1 and R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A represents a hydrogen atom or an amino-protecting group, R 3 and R 4 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; R 5 and R 6 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; R 7 and R 8 represents a hydrogen atom or a Boc group, one or both of which are Boc groups; n represents an integer of 1 to 6 (provided that n is 3 and R 1 and R 2 is a hydrogen atom or a methyl group, and R 3 ~R 8 is a Boc group)

[0017] In the present invention, the arginines refer to compounds such as arginine and homoarginine which have a guanidinoalkylglycine structure and have an alkyl group or a protecting group on the guanidino group, α-amino group or carboxyl group. Furthermore, the structures represented by the above formulas (1), (2) and (3) are E / Z isomers or imino / amino isomers, and the arginine derivative of the present invention may be a mixture of these isomers.

[0018] R 1 and R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferred, a methyl group and an ethyl group are more preferred, and an ethyl group is even more preferred. R 1 and R 2 More preferably, each of the groups is an ethyl group.

[0019] A represents a hydrogen atom or a protecting group for an amino group. Examples of the protecting group for an amino group include a Boc (tert-butoxycarbonyl) group, an Fmoc (9-fluorenylmethyloxycarbonyl) group, a Cbz (benzyloxycarbonyl) group, a Trt (trityl) group, an Mmt (monomethoxytrityl) group, an ivDde (4,4-dimethyl-2,6-dioxocyclohex-1-ylidene-3-methylbutyl) group, an Ns (2-nitrobenzenesulfonyl) group, a DNs (2,4-dinitrobenzenesulfonyl) group, a Nos (4-nitrobenzenesulfonyl) group, an Alloc (allyloxycarbonyl) group, a Teoc (2-(trimethylsilyl)ethoxycarbonyl) group, a Troc (2,2,2-trichloroethoxycarbonyl) group, a Phth (phthaloyl) group, and an SES ((2-trimethylsilyl)-ethanesulfonyl) group. Among these, A is preferably an amino-protecting group which can be deprotected under conditions different from those of a Boc group, more preferably a hydrogen atom, an Fmoc group or a Cbz group, and most preferably an Fmoc group.

[0020] R 3 and R 4 represents a hydrogen atom or a Boc group, either one or both of which is a Boc group; R 5 and R 6 represents a hydrogen atom or a Boc group, either one or both of which is a Boc group; R 7 and R 8 represents a hydrogen atom or a Boc group, and one or both of them are a Boc group. R 3 ~R 8 From the viewpoints of protecting the guanidino group and improving liquid-liquid separation in peptide synthesis, it is more preferable that both of these groups are Boc groups.

[0021] n represents an integer of 1 to 6. Among these, 3 to 6 is preferable, 3 to 5 is more preferable, and 4 is even more preferable.

[0022] R 1 and R 2is preferably a methyl group or an ethyl group, more preferably an ethyl group; A is preferably a hydrogen atom, an Fmoc group or a Cbz group, more preferably an Fmoc group; R 3 ~R 8 is preferably an integer of 3 to 6, more preferably an integer of 3 to 5, and even more preferably an integer of 4.

[0023] In the compound represented by formula (1), (2) or (3), n is 3, and R 1 and R 2 is a hydrogen atom or a methyl group, and R 3 ~R 8 Compounds in which is a Boc group are excluded.

[0024] In addition, examples of salts of the arginine derivative represented by the above formula include acid addition salts such as hydrochloride, sulfate, nitrate, acetate, phosphate, formate, and oxalate; and metal salts such as sodium salt, potassium salt, and calcium salt.

[0025] The arginine derivative represented by the formula (1), (2) or (3) or a salt thereof can be produced, for example, by reacting an arginine derivative represented by the following formula (4), (5) or (6) or a salt thereof with a Boc-containing agent such as di-tert-butyl dicarbonate or N-tert-butoxycarbonylimidazole. The amount of the Boc-modifying agent added may be 1 equivalent or more relative to the arginine derivative, more preferably 1 to 15 equivalents, and further preferably 1 to 10 equivalents.

[0026] [ka]

[0027] (In the formula, R 1 and R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A represents a hydrogen atom or an amino-protecting group, n represents an integer of 1 to 6 (provided that n is 3 and R1 and R 2 is a hydrogen atom or a methyl group, and R 3 ~R 8 (Except when is a hydrogen atom)

[0028] This Boc-addition reaction is preferably carried out in a solvent in the presence of a base, which may be an organic base such as pyridine, triethylamine, DMAP (4-dimethylaminopyridine), N-methylimidazole, or a mixed organic base thereof, or an inorganic base such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, or sodium hydroxide. The amount of the base added may be 0.1 equivalent or more relative to the arginine derivative, more preferably 0.1 to 30 equivalents, and further preferably 1 to 20 equivalents. The reaction solvent used may be water, THF, 2-MeTHF, 1,4-dioxane, toluene, DMF, acetonitrile, dichloromethane, chloroform, methanol, ethanol, or a mixture thereof. The reaction is preferably carried out at 0° C. to 40° C. for 1 to 24 hours.

[0029] The arginine derivative of the present invention is useful as an arginine raw material in solid-phase or liquid-phase peptide synthesis. When used in liquid-phase peptide synthesis, it provides good liquid-liquid separation and allows the removal reaction of the Boc group under mild conditions. Here, it is preferable to carry out the liquid-phase peptide synthesis reaction using a recently developed support for liquid-phase peptide synthesis.

[0030] As such a liquid phase peptide synthesis method, a normal liquid phase peptide synthesis may be performed except that the arginine derivative of the present invention is used in the arginine condensation step, but a liquid phase peptide production method including the following steps a to c is preferred. The order of steps b and c does not matter, and the order may be step b followed by step c, i.e., after removing the protecting group of the amino group, an organic solvent layer containing the condensate may be obtained, or the order may be step c followed by step b, i.e., after obtaining an organic solvent layer containing the condensate, the protecting group of the amino group may be removed. a. In a solvent containing an organic solvent 1. A reaction of condensing the arginine derivative of the present invention with a support for liquid phase peptide synthesis; or 2. Condensation reaction of the arginine derivative of the present invention with an amino acid, peptide, amino acid amide, or peptide amide bound to a support for liquid phase peptide synthesis. A process of performing any one of the following: b. removing a protecting group (e.g., Fmoc group) from the amino group of the arginine derivative in the reaction solution; c. After adding an aqueous solution to the reaction solution, the solution is separated, 1. A condensation product of the arginine derivative from which the amino-protecting group has been removed and a support for liquid phase peptide synthesis, or 2. A condensation product of the arginine derivative from which the amino-protecting group has been removed and an amino acid, peptide, amino acid amide, or peptide amide bound to a support for liquid phase peptide synthesis. Obtaining an organic solvent layer containing any one of the above.

[0031] Here, a step of adding a quenching agent for amino acid activated ester to the reaction solution after the condensation reaction in step a may be included. The quenching agent for amino acid activated ester is a compound having an amino group in the molecule, and the compounds described in Patent Documents 23 to 25, Non-Patent Document 5, etc. can be used. As the quenching agent, hydroxylamine, amidosulfuric acid, hydroxylamine-O-sulfonic acid, hydroxylamine-O-phosphonic acid, alkylamine having a primary or secondary amine, aromatic amine having a primary or secondary amine, or tertiary amine can be used. Furthermore, since the excess quenching agent can be removed into the water layer by liquid-liquid separation, it is preferable that the quenching agent is water-soluble, and amines having hydrophilic substituents such as hydroxyl, sulfo, sulfate, and phosphate groups are preferable. Furthermore, the number of amino groups in the compound may be one (monovalent) or may be divalent or more. Specific examples include propylamine, methylamine, hexylamine, aniline, toluidine, 2,4,6-trimethylaniline, anisidine, phenetidine, benzylamine, hydroxylamine, 1-methylpiperazine, 4-aminopiperidine, diethylenetriamine, triaminoethylamine, 1-ethylpiperazine, N,N-dimethylethylenediamine, ethylenediamine, piperazine, 2-(2-aminoethoxy)ethanol (AEE), taurine, 2-aminoethylsulfuric acid (AEHS), etc. In addition, NMI (N-methylimidazole), DMAP (dimethylaminopyridine), and trimethylamine can be mentioned.

[0032] The support for liquid phase peptide synthesis used in step a is a support that protects an amino acid, peptide, amino acid amide or peptide amide (amino acid, etc.) and solubilizes the protected amino acid, etc. in an organic solvent. Such a support for liquid phase peptide synthesis includes a compound represented by the following formula (I):

[0033] [ka]

[0034] [In the formula, Ring A represents a C4-20 aromatic ring which may contain a heteroatom and may be polycyclic; R 11 is a hydrogen atom, or when ring A is a benzene ring and Rb is a group represented by the following formula (b), R13 may together with ring A and ring B represent a single bond to form a fluorene ring, or may together with ring A and ring B via an oxygen atom form a xanthene ring; p X's 1 each independently represents a single bond, -O-, -S-, -C(=O)O-, -C(=O)NH-, -NHC(=O)-, or -NR 15 -(R 15 represents a hydrogen atom, an alkyl group, or an aralkyl group; pR 12 each independently represents an aliphatic hydrocarbon group, an aliphatic hydrocarbon group substituted with an aliphatic hydrocarbon group via an oxygen atom, or an organic group represented by formula (a);

[0035] [ka]

[0036] However, R 16 represents a linear or branched alkylene group having 6 to 16 carbon atoms; 3 is an oxygen atom or -C(=O)NR 17 -(R 17 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and A represents either a silyl group or an alkyl group having a silyloxy group bonded thereto; p represents an integer of 1 to 4; Ring A is a set of p X 1 R 12 and optionally have a substituent selected from the group consisting of a halogen atom, a C1-6 alkyl group optionally substituted with a halogen atom, and a C1-6 alkoxy group optionally substituted with a halogen atom; Ra represents a hydrogen atom or an aromatic ring which may be substituted with a halogen atom; Rb is a hydrogen atom, an aromatic ring optionally substituted with a halogen atom, or a group represented by formula (b):

[0037] [ka]

[0038] (In the formula, * indicates a bond position; q represents an integer of 0 to 4; q X's 2 each independently represents a single bond, -O-, -S-, -C(=O)O-, -C(=O)NH-, -NHC(=O)-, or -NR 18 -(R 18 represents a hydrogen atom, an alkyl group, or an aralkyl group; q R 14 each independently represents an aliphatic hydrocarbon group, an aliphatic hydrocarbon group substituted with an aliphatic hydrocarbon group via an oxygen atom, or an organic group represented by formula (a);

[0039] [ka]

[0040] However, R 16 represents a linear or branched alkylene group having 6 to 16 carbon atoms; 3 is an oxygen atom or -C(=O)NR 17 -(R 17 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and A represents either a silyl group or an alkyl group having a silyloxy group bonded thereto; R 13 indicates a hydrogen atom or R 11 may together with ring A and ring B form a single bond to form a fluorene ring, or may together with ring A and ring B form a xanthene ring via an oxygen atom; Ring B is a ring of q X 2 R 14 In addition, it may further have a substituent selected from the group consisting of a halogen atom, a C1-6 alkyl group optionally substituted by a halogen atom, and a C1-6 alkoxy group optionally substituted by a halogen atom; Y is a hydroxyl group, a thiol group, or NHR 20 (R 20 represents a hydrogen atom, an alkyl group or an aralkyl group. ) or a halogen atom. ]

[0041] Ring A in formula (I) represents a C4-20 aromatic ring which may contain a heteroatom and may be monocyclic or polycyclic. Examples of the aromatic ring include a C6-20 aromatic hydrocarbon ring and a C4-10 aromatic heterocycle. Specific examples of the C6-20 aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a tetracene ring, an indane ring, an indene ring, a fluorene ring, a biphenyl ring, and a 1,1'-binaphthalene ring, etc. Among these, a benzene ring, a naphthalene ring, a phenanthrene ring, and a fluorene ring are more preferable. The C4-10 aromatic heterocycle is preferably a 5- to 10-membered aromatic heterocycle containing 1 to 3 heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically includes a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyrazole ring, an indazole ring, an imidazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, etc. Among these, a 5- to 8-membered aromatic heterocycle containing 1 to 3 heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom is preferred, and a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyrazole ring, and an indazole ring are more preferred.

[0042] R 11 represents a hydrogen atom, or when ring A is a benzene ring and Rb is a group represented by the above formula (b), R 13 R may be taken together with ring A to form a single bond to form a fluorene ring together with ring B, or may be taken together with ring A and ring B via an oxygen atom to form a xanthene ring. 11 and R 13 The ring which may be formed by combining with each other is preferably a fluorene ring or a xanthene ring.

[0043] p X's 1 each independently represents a single bond, -O-, -S-, -C(=O)O-, -C(=O)NH-, -NHC(=O)-, or -NR15 -(R 15 represents a hydrogen atom, an alkyl group or an aralkyl group. Here, R 15 is preferably a hydrogen atom, a C1 to 10 alkyl group, or a C7 to 20 aralkyl group. Examples of the alkyl group include linear or branched C1 to 10 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Examples of the aralkyl group include C7 to C16 aralkyl groups, such as a benzyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenylpropyl group, a naphthylmethyl group, and a 1-naphthylethyl group.

[0044] pR 12 each independently represents an aliphatic hydrocarbon group, an aliphatic hydrocarbon group substituted with an aliphatic hydrocarbon group via an oxygen atom, or an organic group represented by formula (a);

[0045] [ka]

[0046] However, R 16 represents a linear or branched alkylene group having 6 to 16 carbon atoms; 3 is an oxygen atom or -C(=O)NR 17 -(R 17 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and A represents either a silyl group or an alkyl group bonded to a silyloxy group. p represents an integer of 1 to 4.

[0047] In this specification, an organic group having an aliphatic hydrocarbon group is a monovalent organic group having an aliphatic hydrocarbon group in its molecular structure. The position of the aliphatic hydrocarbon group in the organic group having an aliphatic hydrocarbon group is not particularly limited, and may be present at a terminal or at another position. The aliphatic hydrocarbon group present in the organic group is a linear, branched or cyclic saturated or unsaturated aliphatic hydrocarbon group, and from the viewpoint of solubility in an organic solvent, an aliphatic hydrocarbon group of C5 or more is preferable, an aliphatic hydrocarbon group of C5 to 50 is more preferable, and an aliphatic hydrocarbon group of C8 to 30 is even more preferable. Specific examples of the aliphatic hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, and an alkynyl group, and in particular, an alkyl group, a cycloalkyl group, and an alkenyl group are preferable, and an alkyl group is even more preferable. Furthermore, a linear or branched alkyl group of C5 to 30, a cycloalkyl group of C3 to 8, and a linear or branched alkenyl group of C5 to 30 are preferable, a linear or branched alkyl group of C5 to 30, and a cycloalkyl group of C3 to 8 are more preferable, a linear or branched alkyl group of C5 to 30 is even more preferable, and a linear or branched alkyl group of C8 to 30 is even more preferable.

[0048] Specific examples of the alkyl group include alkyl groups having 1 to 30 carbon atoms, such as monovalent groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a lauryl group, a tridecyl group, a myristyl group, a cetyl group, a stearyl group, an arachyl group, a behenyl group, a tetracosanyl group, a hexacosanyl group, and an isostearyl group, divalent groups derived therefrom, and groups obtained by excluding hydroxyl groups and the like from various steroid groups. Examples of the branched alkyl group include a 2,3-dihydrophytyl group and a 3,7,11-trimethyldodecyl group. 1 If -NHC(=O)-, then X 1 R 12 Examples of such amides include 2,2,4,8,10,10-hexamethyl-5-dodecanoic acid amide. Examples of the alkenyl group include monovalent groups such as a vinyl group, a 1-propenyl group, an allyl group, an isopropenyl group, a butenyl group, an isobutenyl group, and an oleyl group, and divalent groups derived therefrom. Examples of the alkynyl group include an ethynyl group, a propargyl group, and a 1-propynyl group.

[0049] The above aliphatic hydrocarbon group may be substituted with an aliphatic hydrocarbon group via an oxygen atom. Examples of the aliphatic hydrocarbon group that may be substituted with an aliphatic hydrocarbon group via an oxygen atom include monovalent groups such as linear or branched alkoxy groups having 1 to 20 carbon atoms, alkenyloxy groups having 2 to 20 carbon atoms, and cycloalkyloxy groups having 3 to 6 carbon atoms, and divalent groups derived therefrom. In addition, the aliphatic hydrocarbon group substituted with an aliphatic hydrocarbon group via an oxygen atom may have a repeating structure in which an aliphatic hydrocarbon group is further substituted with an aliphatic hydrocarbon group via an oxygen atom. Specifically, R 12 Examples of the aryloxy group include a 12-docosyloxy-1-dodecyl group, a 3,4,5-tris(octadecyloxy)benzyl group, a 2,2,2-tris(octadecyloxymethyl)ethyl group, and a 3,4,5-tris(octadecyloxy)cyclohexylmethyl group.

[0050] The aliphatic hydrocarbon group includes

[0051] [ka]

[0052] However, R 16 represents a linear or branched alkylene group having 6 to 16 carbon atoms; 3 is an oxygen atom or -C(=O)NR 17 -(R 17 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and A may be substituted with an organic group which is either a silyl group or an alkyl group having a silyloxy group bonded thereto. The silyl group is preferably a silyl group substituted with three groups selected from a linear or branched alkyl group having 1 to 6 carbon atoms and an aryl group which may have a substituent. Here, examples of the aryl group which may have a substituent include a phenyl group and a naphthyl group. A preferred silyl group is a silyl group substituted with three linear or branched alkyl groups having 1 to 6 carbon atoms, and a more preferred silyl group is a silyl group substituted with three linear or branched alkyl groups having 1 to 4 carbon atoms. The three alkyl or aryl groups substituting the silyl group may be the same or different. The alkyl group bonded to a silyloxy group is preferably a linear or branched alkyl group having 1 to 13 carbon atoms bonded to 1 to 3 silyloxy groups each substituted with 3 groups selected from a linear or branched alkyl group having 1 to 6 carbon atoms and an aryl group which may have a substituent. A preferred silyloxy group is a silyloxy group substituted with 3 linear or branched alkyl groups having 1 to 6 carbon atoms, more preferably a silyloxy group substituted with 3 linear or branched alkyl groups having 1 to 4 carbon atoms. The three alkyl or aryl groups substituted on the silyloxy group may be the same or different. The linear or branched alkyl group having 1 to 13 carbon atoms is preferably a branched alkyl group, and more preferably has a quaternary carbon atom.

[0053] p represents an integer of 1 to 4. Here, p is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0054] Ring A is a set of p X 1 R 12 In addition, it may further have a substituent selected from the group consisting of a halogen atom, a C1-6 alkyl group optionally substituted with a halogen atom, and a C1-6 alkoxy group optionally substituted with a halogen atom. Examples of halogen atoms include chlorine, fluorine, bromine, and iodine atoms. Examples of C1-6 alkyl groups which may be substituted with halogen atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, dichloromethyl, trichloromethyl, and trifluoromethyl groups. Examples of C1-6 alkoxy groups which may be substituted with halogen atoms include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, sec-butyloxy, tert-butyloxy, trichloromethoxy, and trifluoromethoxy groups.

[0055] Ra represents a hydrogen atom or an aromatic ring which may be substituted with a halogen atom. Here, examples of the aromatic ring include a C6 to C18 aromatic hydrocarbon ring and a C4 to C10 aromatic heterocycle. Specific examples of the C6-18 aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a tetracene ring, an indane ring, an indene ring, a fluorene ring, a biphenyl ring, etc. Among these, a benzene ring, a naphthalene ring, a phenanthrene ring, and a fluorene ring are more preferable. The C4-10 aromatic heterocycle is preferably a 5- to 10-membered heterocycle containing 1 to 3 heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically includes a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyrazole ring, an indazole ring, an imidazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, etc. Among these, a 5- to 8-membered heterocycle containing 1 to 3 heteroatoms selected from a nitrogen atom, an oxygen atom, and a sulfur atom is preferred, and a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, a pyrazole ring, and an indazole ring are more preferred. The aromatic ring of Ra may be substituted with 1 to 3 halogen atoms.

[0056] Rb represents a hydrogen atom, an aromatic ring which may be substituted with a halogen atom, or a group represented by the above formula (a). In the formula (a), q represents an integer of 0 to 4. q is preferably 0 to 3, more preferably 1 to 3, and further preferably 1 or 2.

[0057] q X's 2 each independently represents a single bond, -O-, -S-, -C(=O)O-, -C(=O)NH-, -NHC(=O)-, or -NR 18 -(R 18 represents a hydrogen atom, an alkyl group or an aralkyl group. Here, R 18 is preferably a hydrogen atom, a C1 to 10 alkyl group, or a C7 to 20 aralkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Examples of the aralkyl group include C7 to C16 aralkyl groups, such as a benzyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenylpropyl group, a naphthylmethyl group, and a 1-naphthylethyl group.

[0058] q R 14 represents independently an aliphatic hydrocarbon group, an aliphatic hydrocarbon group substituted with an aliphatic hydrocarbon group via an oxygen atom, or an organic group represented by formula (a);

[0059] [ka]

[0060] However, R 16 represents a linear or branched alkylene group having 6 to 16 carbon atoms; 3 is an oxygen atom or -C(=O)NR 17 -(R 17represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and A represents either a silyl group or an alkyl group having a silyloxy group bonded thereto. R 14 The organic group represented by the above R 12 The same as the above R 12 The same is preferably used.

[0061] R 13 indicates a hydrogen atom or R 11 may be taken together with ring A to form a single bond to form a fluorene ring together with ring A and ring B, or may be taken together with ring A and ring B via an oxygen atom to form a xanthene ring.

[0062] Ring B is a ring of q X 2 R 14 In addition, it may further have a substituent selected from the group consisting of a halogen atom, a C1-6 alkyl group optionally substituted with a halogen atom, and a C1-6 alkoxy group optionally substituted with a halogen atom. Examples of halogen atoms include chlorine, fluorine, bromine, and iodine atoms. Examples of C1-6 alkyl groups which may be substituted with halogen atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, dichloromethyl, trichloromethyl, and trifluoromethyl groups. Examples of C1-6 alkoxy groups which may be substituted with halogen atoms include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, sec-butyloxy, tert-butyloxy, trichloromethoxy, and trifluoromethoxy groups.

[0063] Y is a hydroxyl group, a thiol group, or NHR 20 (R 20 represents a hydrogen atom, an alkyl group or an aralkyl group. ) or a halogen atom. Here, R 20is preferably a hydrogen atom, a C1 to 10 alkyl group, or a C7 to 20 aralkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Examples of the aralkyl group include C7 to C16 aralkyl groups, such as a benzyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenylpropyl group, a naphthylmethyl group, and a 1-naphthylethyl group.

[0064] Among the compounds of formula (I) above, specific examples of preferred supports for liquid phase peptide synthesis include compounds represented by the following formulas (7), (20) and (21). As one of them, a compound represented by formula (7) can be used (Patent Documents 13 and 14).

[0065] [ka]

[0066] (Wherein, Yb is -CHOR 34 (where R 34 represents a hydrogen atom, a halogenocarbonyl group, an active ester carbonyl group, or an active ester sulfonyl group), -CH2NHR 35 (where R 35 represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or an aralkyl group, a halogenomethyl group, a formyl group, or an oxime group; R 21 , R 22 , R 23 , R 24 and R 25 At least one of the formulas (8)

[0067] [ka]

[0068] and the remainder represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; R 26 represents a linear or branched alkylene group having 6 to 16 carbon atoms; X 3 O or CONR 36 (where R 36 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; A is formula (9), (10), (11), (12), (13), (14), (15), (16), (17), (18), or (19).

[0069] [ka]

[0070] (where R 27 , R 28 , R 29 are the same or different and each represents a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group which may have a substituent; R 30 represents a single bond or a linear or branched alkylene group having 1 to 3 carbon atoms; R 31 , R 32 and R 33 each represents a linear or branched alkylene group having 1 to 3 carbon atoms. (representing a group represented by the formula:

[0071] As a support for liquid phase peptide synthesis, a compound represented by formula (20) can be used (Patent Documents 15, 16, and 19).

[0072] [ka]

[0073] (In the formula, X 4 -OR 51 (where R 51 represents a hydrogen atom, an active ester carbonyl group, or an active ester sulfonyl group), -NHR 35, azide, halogen, isocyanate, X 5 Together with =N-OH or =O, X 4 -OR 51 , -NHR 35 , azide or halogen X 5 represents a hydrogen atom, a linear or branched alkyl or alkenyl group having 1 to 4 carbon atoms, or a cycloalkyl group; X 4 If isocyanate, X 5 represents a linear or branched alkyl or alkenyl group having 1 to 4 carbon atoms, or a cycloalkyl group; R 41 ~R 50 at least one of them represents a group represented by formula (2), and the remainder represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; X 4 -OR 51 , -NHR 35 , azide or halogen, and X 5 is a hydrogen atom, or X 4 and X 5 When these are combined together =O, R 45 and R 46 may be bonded via an oxygen atom to form a xanthene ring)

[0074] As a support for liquid phase peptide synthesis, a compound represented by formula (21) can be used (Patent Documents 17 and 18).

[0075] [ka]

[0076] (In the formula, X 6 represents a hydroxyl group or a halogen atom, R 61 ~R 75 at least one of the groups represented by formula (2) is a group, and the remainder is a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; R 70 and R 71may be bonded via a single bond to form a fluorene ring, or may be bonded via an oxygen atom to form a xanthene ring).

[0077] Steps b and c can be carried out by methods well known to those skilled in the art, with reference to Patent Documents 7 to 25, etc. Instead of step c, a method for separating the peptide bound to the support for liquid phase peptide synthesis can be used in which the peptide bound to the support for liquid phase peptide synthesis and unnecessary components are purified by solidification, utilizing the difference in solubility in a solvent between the peptide bound to the support for liquid phase peptide synthesis and unnecessary components. EXAMPLES

[0078] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Any amino acid not designated as D-form is designated as L-form.

[0079] Example 1 Synthesis of Fmoc-hArg(Et)2(Boc)2-OH

[0080] [ka]

[0081] (Hereinafter, Cbz-Lys-OH, EtNH-C(SO3H)=NEt, Cbz-hArg(Et)2-OH, Cbz-hArg(Et)2(Boc)2-OH, H-hArg(Et)2(Boc)2-OH, Fmoc-OSu, and Fmoc-hArg(Et)2(Boc)2-OH represent the structures in the above reaction scheme. Note that Cbz-hArg(Et)2(Boc)2-OH, H-hArg(Et)2(Boc)2-OH, and Fmoc-hArg(Et)2(Boc)2-OH each represent a mixture of the three isomers in the above reaction scheme.)

[0082] Example (1-a) 2.00g (7.13mmol) of Cbz-Lys-OH was dissolved in a mixture of 7.13mL of water, 7.13mL of acetonitrile, and 1.28mL of 20% aqueous sodium hydroxide solution (20%NaOHaq.), and 2.25g (12.5mmol) of EtNH-C(SO3H)=NEt was added and stirred at room temperature. Then, 301μL of 20%NaOHaq. was added in small portions, and the reaction solution was stirred at room temperature for 22 hours and 30 minutes while maintaining the pH of the reaction solution at 8.0-12.8. 7.13mL of acetonitrile, 18.8mL of ethyl acetate, and 800μL of 6N HClaq. were added, separated, and the organic layer was collected. 14.3mL of acetonitrile and 18.8mL of ethyl acetate were added to the aqueous layer, separated, and the organic layer was collected. Acetonitrile (14.3 mL) and ethyl acetate (18.8 mL) were added to the aqueous layer again, and the organic layer was collected. The organic layers obtained from the three separate separations were mixed and concentrated under reduced pressure. Ethanol (30.0 mL) was added to the residue, and the mixture was concentrated under reduced pressure. Ethanol (30.0 mL) was added to the residue, and the mixture was stirred, after which the precipitated solid was removed by filtration through Celite. The filtrate was concentrated under reduced pressure, and diisopropyl ether was added to the residue, and the mixture was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate:methanol = 1:1.5 → 1:3) to obtain 1.82 g of Cbz-hArg(Et)2-OH. ESIMS (M / z) 379.3 (M+H) +

[0083] Example (1-b) 6.57g (30.1mmol) of di-tert-butyl dicarbonate was dissolved in 30.1mL of 1,4-dioxane. 1.71g (4.52mmol) of Cbz-hArg(Et)2-OH dissolved in 7.53mL of 1,4-dioxane and 15.1mL of 5N NaOH aq. was added dropwise to this solution and stirred at room temperature for 17 hours. 126mL of dichloromethane, 93.0mL of water, and 3.70mL of acetic acid were added and separated. 93.0mL of saturated saline was added to the obtained organic layer and washed. 22.0g of anhydrous sodium sulfate was added to the obtained organic layer, stirred thoroughly, filtered, and the filtrate was concentrated under reduced pressure. 31.0mL of heptane was added to the residue and concentrated under reduced pressure, and 30mL of diisopropyl ether was added to the residue and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (heptane:ethyl acetate=2:1→ethyl acetate:methanol=4:1) to obtain 2.16 g of Cbz-hArg(Et)2(Boc)2-OH. ESIMS (m / z) 579.5 (M+H) + (Mixture of 3 isomers)

[0084] Example (1-c) Cbz-hArg(Et)2(Boc)2-OH 2.09g (3.61mmol) was dissolved in 20.9mL of methanol, 0.139g of 5%Pd / C (wetted with ca. 55% water) was added, and the mixture was stirred at room temperature under a hydrogen atmosphere for 2 hours. The reaction solution was filtered through Celite, and the residue was washed with 20mL of methanol. The filtrate obtained was concentrated under reduced pressure, and then dried under reduced pressure to obtain 1.28g of H-hArg(Et)2(Boc)2-OH. ESIMS (m / z) 445.4(M+H) + (Mixture of 3 isomers)

[0085] Example (1-d) 0.427g (5.08mmol) of sodium bicarbonate and 1.13g (2.54mmol) of H-hArg(Et)2(Boc)2-OH were added to 9.99mL of water, dissolved, and cooled to 5℃. 0.900g (2.67mmol) of Fmoc-OSu dissolved in 9.99mL of 1,4-dioxane was added dropwise to this solution, and the mixture was stirred at 5℃ for 1 hour and 5 minutes. The mixture was heated to room temperature and stirred for 3 hours and 25 minutes. 20.0mL of water, 50.0μL of acetic acid, and 15.0mL of ethyl acetate were added to the reaction solution, the mixture was separated, and the organic layer was collected. 15.0mL of ethyl acetate was added to the obtained aqueous layer, the mixture was separated, the organic layer was collected, and the same separation operation was performed twice more. The organic layers obtained by the four separation operations were mixed, 15.3g of anhydrous sodium sulfate was added, the mixture was thoroughly stirred, and the mixture was filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (heptane:ethyl acetate=1:1→1:2) to obtain 0.261 g of Fmoc-hArg(Et)2(Boc)2-OH. ESIMS (m / z) 667.5 (M+H) + (Mixture of 3 isomers)

[0086] Example 2 Synthesis of Fmoc-D-hArg(Et)2(Boc)2-OH

[0087] [ka]

[0088] (In the following, Cbz-D-Lys-OH, Cbz-D-hArg(Et)2-OH, Cbz-D-hArg(Et)2(Boc)2-OH, HD-hArg(Et)2(Boc)2-OH, and Fmoc-D-hArg(Et)2(Boc)2-OH represent the structures in the reaction scheme. Note that Cbz-D-hArg(Et)2(Boc)2-OH, HD-hArg(Et)2(Boc)2-OH, and Fmoc-D-hArg(Et)2(Boc)2-OH each represent a mixture of the three isomers in the reaction scheme.)

[0089] Example (2-a) In the same manner as in Example (1-a), 4.57 g of Cbz-D-hArg(Et)2-OH was obtained from 4.80 g of Cbz-D-Lys-OH. ESIMS (m / z) 379.3(M+H) +

[0090] Example (2-b) In the same manner as in Example (1-b), 5.23 g of Cbz-D-hArg(Et)2(Boc)2-OH was obtained from 3.93 g of Cbz-D-hArg(Et)2-OH. Ta. ESIMS (m / z) 579.4 (M+H) + (Mixture of 3 isomers)

[0091] Example (2-c) In a manner similar to that of Example (2-c), 3.35 g of HD-hArg(Et)2(Boc)2-OH was obtained from 4.89 g of Cbz-D-hArg(Et)2(Boc)2-OH. ESIMS (m / z) 445.4(M+H) + (Mixture of 3 isomers)

[0092] Example (2-d) In the same manner as in Example (1-d), a crude Fmoc-D-hArg(Et)2(Boc)2-OH was obtained from 3.00 g of HD-hArg(Et)2(Boc)2-OH. The crude was purified by silica gel column chromatography (heptane:ethyl acetate=2:1→1:1→1:2) to obtain 1.90 g of Fmoc-D-hArg(Et)2(Boc)2-OH. ESIMS (m / z) 667.6 (M+H) + (Mixture of 3 isomers)

[0093] Reference example 1 Synthesis of Fmoc-NH(D2-STag)

[0094] [ka]

[0095] (O=(D2-Stag), OH(D2-STag), Fmoc-NH(D2-STag) indicate the structures in the reaction scheme.)

[0096] Reference example (a) 41.4g (47.7mmol) of O=(D2-STag) (manufactured by Sekisui Medical Co., Ltd.) was dissolved in a mixed solution of 228mL of toluene and 36.0mL of methanol, 2.16g (57.2mmol) of sodium borohydride was added, and the mixture was stirred at room temperature for 3 hours. The reaction solution was washed three times with 83.0mL of water. 20.0g of anhydrous sodium sulfate was added to the obtained organic layer, and the mixture was thoroughly stirred and then filtered to obtain a toluene solution containing OH(D2-STag).

[0097] Reference example (b) The toluene solution obtained in the previous step was mixed with 9-fluorenylmethylcarbamate 1 3.7g (57.2mmol) of tetrahydrofuran and 1.80g (14.3mmol) of oxalic acid dihydrate were added and stirred at 80℃ for 3 hours. The reaction solution was cooled to room temperature, and 414mL of methanol:water = 9:1 and 414mL of heptane were added and separated. The obtained organic layer was washed once with 207mL of 5% aqueous sodium carbonate solution (5%Na2CO3aq.) and three times with 414mL of methanol:water = 9:1. The obtained organic layer was concentrated under reduced pressure, and 83.0mL of tetrahydrofuran was added to the residue and concentrated under reduced pressure. The residue was dissolved in 62mL of tetrahydrofuran and added dropwise to 830mL of methanol. The precipitated solid was collected by filtration and dried under reduced pressure to obtain 45.5g of Fmoc-NH(D2-STag). ESIMS (m / z) 1107.9 (M+NH4) +

[0098] Example 3 Synthesis of H-hArg(Et)2(Boc)2-Pro-D-Ala-NH (D2-STag) using Fmoc-hArg(Et)2(Boc)2-OH

[0099] [ka]

[0100] (NH2(D2-STag), HD-Ala-NH(D2-STag), H-Pro-D-Ala-NH(D2-STag), and H-hArg(Et)2(Boc)2-Pro-D-Ala-NH(D2-STag) represent the structures in the reaction scheme. Note that Fmoc-L-hArg(Et)2(Boc)2-OH represents a mixture of the three isomers in the reaction scheme, and the * in the R' structure represents the attachment point.)

[0101] Example (3-a) 2.00 g (1.83 mmol) of Fmoc-NH(D2-STag) was dissolved in 29.3 mL of cyclopentyl methyl ether (CPME), 7.33 mL of N,N-dimethylformamide (DMF), 0.542 g (3.04 mmol) of 3-mercapto-1-propanesulfonic acid sodium salt (MPS) dissolved in 2.55 mL of dimethyl sulfoxide (DMSO), 0.111 g (0.62 mmol) of MPS was added in the solid state, and 0.548 mL (3.67 mmol) of 2,3,4,6,7,8,9,10-Octahydropyrimidol[1,2-a]azepine(DBU) was added, and the mixture was stirred at room temperature for 1 hour and 35 minutes. The mixture was cooled to 8°C, and 0.319mL (1.83mmol) of N,N-diisopropylethylamine (DIPEA), 3.67mL (3.67mmol) of 1N sulfuric acid, 24.2mL of water, and 1.00mL of CPME were added and separated. 4.55mL of DMF and 6.07mL of 50% aqueous dipotassium hydrogen phosphate (50%K2HPO4aq.) were added to the obtained organic layer, and the mixture was washed and separated to obtain a mixture containing NH2(D2-STag).

[0102] Example (3-b) To the resulting mixture, 1.00 mL of CPME, 8.30 mL of DMF, 0.725 g (2.20 mmol) of Fmoc-D-Ala-OH·HO, 1.28 mL (7.33 mmol) of DIPEA, and 0.942 g (2.20 mmol) of COMU were added and stirred at room temperature for 45 minutes. 44.0 μL (0.444 mmol) of 2-(2-Aminoethoxy)ethanol (AEE) was added and stirred at room temperature for 15 minutes. 0.501 g (2.81 mmol) of MPS dissolved in 2.35 mL of DMSO and 0.284 g (1.59 mmol) of solid MPS were added, cooled to 10°C, and 1.43 mL (9.54 mmol) of DBU was added and stirred for 1 hour and 20 minutes. 11.5 mL (11.5 mmol) of 1N sulfuric acid, 20.2 mL of water, and 0.796 mL of CPME were added and separated. 5.10 mL of DMF and 6.80 mL of 50% K2HPO4aq. were added to the obtained organic layer, and the mixture was separated and washed to obtain a mixture containing HD-Ala-NH(D2-STag).

[0103] Example (3-c) To the resulting mixture, 2.20mL of CPME, 8.30mL of DMF, 0.782g (2.20mmol) of Fmoc-Pro-OH·H2O, 1.28mL (7.33mmol) of DIPEA, and 0.942g (2.20mmol) of COMU were added and stirred at room temperature for 50 minutes. 44.0μL (0.444mmol) of AEE was added and stirred at room temperature for 15 minutes. 0.501g (2.81mmol) of MPS dissolved in 2.35mL of DMSO and 0.284g (1.59mmol) of solid MPS were added and cooled to 8℃. 1.43mL (9.54mmol) of DBU was added and stirred for 1 hour and 20 minutes. 11.5mL (11.5mmol) of 1N sulfuric acid, 20.2mL of water, and 0.861mL of CPME were added and separated. To the obtained organic layer, 5.11 mL of DMF and 6.81 mL of 50% K2HPO4 aq. were added, and the mixture was separated and washed to obtain a mixture containing H-Pro-D-Ala-NH(D2-STag).

[0104] Example (3-d) To the resulting mixture, 2.70 mL of CPME, 8.30 mL of DMF, 1.47 g (2.20 mmol) of Fmoc-hArg(Et)2(Boc)2-OH (a mixture of the three isomers shown in the reaction scheme), 1.28 mL (7.33 mmol), and 0.942 g (2.20 mmol) of COMU were added and stirred at room temperature for 50 minutes. 44.0 μL (0.444 mmol) of AEE was added and stirred at room temperature for 15 minutes. 0.501 g (2.81 mmol) of MPS dissolved in 2.35 mL of DMSO and 0.284 g (1.59 mmol) of solid MPS were added, cooled to 8°C, and 1.43 mL (9.54 mmol) of DBU was added and stirred for 1 hour and 50 minutes. 11.5mL (11.5mmol) of 1N sulfuric acid, 20.3mL of water, and 0.950mL of CPME were added and separated.*1 5.12mL of DMF and 6.83mL of 50% K2HPO4aq. were added to the obtained organic layer, and the mixture was separated and washed to obtain a mixture containing H-hArg(Et)2(Boc)2-Pro-D-Ala-NH(D2-STag). ESIMS (m / z) 1463.7 (M+H) + (Mixture of 3 isomers) *1 HPLC purity of the target substance in the organic layer: 76.2%

[0105] HPLC analysis conditions Column: YMC―Pack Pro C18, S―5μm, 12nm, 250mm×4.6mmI.D. Mobile phase A: 500 mM sodium perchlorate aq. Mobile phase B: THF Flow rate: 1.0mL / min Column temperature: 45℃ Detection wavelength: 280nm Gradient conditions: 75%B (0 min) → 90%B (10 min) → 90%B (20 min) → 75%B (21 min) → 75%B (33 min)

[0106] Comparative Example 1 Synthesis of H-hArg(Et)2-Pro-D-Ala-NH (D2-STag) using Fmoc-hArg(Et)2-OH·HCl

[0107] [ka]

[0108] (Fmoc-hArg(Et)2-OH·HCl and H-hArg(Et)2-Pro-D-Ala-NH(D2-STag) are shown in the reaction scheme.)

[0109] Comparative examples (1-a), (1-b), (1-c) In the same manner as in Examples 3-a, 3-b, and 3-c, a mixed solution containing H-Pro-D-Ala-NH(D2-STag) was obtained from 2.00 g (1.83 mmol) of Fmoc-NH(D2-STag).

[0110] Comparative example (1-d) To the resulting mixture, 2.60 mL of CPME, 8.30 mL of DMF, 1.11 g (2.20 mmol) of Fmoc-hArg(Et)2-OH·HCl, 1.28 mL (7.33 mmol) of DIPEA, and 0.942 g (2.20 mmol) of COMU were added and stirred at room temperature for 50 minutes. 44.0 μL (0.444 mmol) of AEE was added and stirred at room temperature for 15 minutes. 0.501 g (2.81 mmol) of MPS dissolved in 2.35 mL of DMSO and 0.284 g (1.59 mmol) of solid MPS were added, cooled to 8 °C, 1.43 mL (9.54 mmol) of DBU was added, and the mixture was stirred for 1 hour and 50 minutes. 11.5 mL (11.5 mmol) of 1N sulfuric acid, 20.3 mL of water, and 0.950 mL of CPME were added and separation was attempted, but an emulsion*2 occurred and separation was not possible. ESIMS (m / z) 1263.5 (M+H) + *2 HPLC purity of the target substance in the emulsion: 10.4% HPLC analysis conditions: same as in Example (3-d)

[0111] The liquid separation state of Example (3-d) *1 and Comparative Example (1-d) *2 is shown in Figures 1 and 2. In Example (3-d) shown in Figure 1, the interface between the organic layer and the aqueous layer was clear, and liquid-liquid separation was good. On the other hand, in Comparative Example (1-d) shown in Figure 2, the entire inside of the separatory funnel became an emulsion, and even when left to stand at room temperature for 25 minutes, the emulsion did not disappear, and separation into the organic layer and the aqueous layer was not possible. The results of Example 3 and Comparative Example 1 are shown in Table 1. In Example 3, in which Fmoc-hArg(Et)2(Boc)2-OH protected with the Boc group of the present invention was used, separation was good, the purity of the target product was high at 76.2%, and the target peptide could be synthesized. On the other hand, in Comparative Example 1, in which Fmoc-hArg(Et)2-OH·HCl, in which only proton protection was performed instead of the Boc group, separation was not possible and the purity of the target product in the emulsion was extremely low at 10.4%.

[0112] [Table 1]

[0113] From the above results, it was found that the use of the Boc-protected arginine derivative of the present invention provides better liquid-liquid separation in a liquid-phase peptide synthesis reaction and allows the production of peptides with higher purity, compared with the use of the proton-protected arginine derivative of the prior art.

Claims

1. An arginine derivative or a salt thereof represented by the following formula (1), (2) or (3): 【Chemistry 1】 (In the formula, R 1 and R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, A represents a hydrogen atom or an amino-protecting group; R 3 and R 4 represents a hydrogen atom or a Boc group, one or both of which are a Boc group; R 5 and R 6 represents a hydrogen atom or a Boc group, one or both of which are a Boc group; R 7 and R 8 represents a hydrogen atom or a Boc group, one or both of which are a Boc group; n represents an integer from 1 to 6 (provided that n is 3 and R 1 and R 2 is a hydrogen atom or a methyl group, and R 3 ~R 8 is a Boc group)

2. The arginine derivative or a salt thereof according to claim 1, wherein n in formula (1), (2) or (3) is 4.

3. 3. The arginine derivative or a salt thereof according to claim 1 or 2, wherein in formula (1), (2) or (3), A is a hydrogen atom, an Fmoc group, or a Cbz group.

4. In formula (1), (2) or (3), R 1 and R 2 The arginine derivative or a salt thereof according to any one of claims 1 to 3, wherein is an ethyl group.

5. The arginine derivative or a salt thereof according to any one of claims 1 to 4, wherein in formula (1), (2) or (3), A is an Fmoc group.

6. In formula (1), (2) or (3), R 3 ~R 8 The arginine derivative or a salt thereof according to any one of claims 1 to 5, wherein

7. A method for liquid phase peptide synthesis, which uses the arginine derivative or a salt thereof according to any one of claims 1 to 6.

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