Method for producing amide bond-containing compound

Abstract

The purpose of the present invention is to provide a method for producing an amide bond-containing compound with which an active acid raw material having an aromatic heterocycle to which a carbonyl group is bonded can be easily removed. This method for producing an amide bond-containing compound includes, in a reaction via a liquid phase method, step A for synthesizing an amide bond-containing compound by reacting a reactive amine raw material with a compound (an active acid raw material) obtained by esterifying, acid-halogenating, or acid-anhydridizing a carboxylic acid having an aromatic heterocycle to which a carbonyl group is bonded; step B for mixing a specific inducing agent and a monoamine compound with a reaction mixture obtained in step A to thereby react the active acid raw material and the inducing agent; and step C for washing the reaction mixture obtained in step B with a basic and / or acidic aqueous solution.

Description

[Technical field]

[0001] The present invention relates to a method for producing an amide bond-containing compound by a liquid phase method. [Background technology]

[0002] The extension of a compound by an amide bond reaction is carried out by a solid phase method or a liquid phase method. In the solid phase method, the extension of the compound is repeatedly carried out by an amide bond reaction in a state where the end of the compound is bound to a solid support, and the compound is cleaved from the support at the stage where the target compound is obtained. Therefore, it is possible to easily select unreacted active esters and the like by washing. However, the solid phase method requires a large excess of raw materials due to its low reactivity, and it is difficult to scale up. In contrast, the liquid phase method is highly reactive and easy to scale up, making it an industrially useful production method. On the other hand, in the liquid phase method, after the extension of the compound by the amide bond reaction is completed, an isolation operation such as crystallization is required to remove the remaining active esters and by-products. Therefore, there was a problem that the production process became complicated and the production took a very long time. Therefore, there has been a demand for a method for producing an amide bond-containing compound by a liquid phase method that can remove the remaining active ester and by-products without an isolation procedure.

[0003] Patent Document 1 describes a method for the synthesis of peptides in solution in which an excess of an activated carboxyl component is used to acylate an amino component, followed by removal of the remaining activated carboxyl functionality using a scavenger such as benzyl β-alaninate p-toluenesulfonate salt and aqueous extraction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-55396 A Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, a scavenger is a compound having a group that reacts with an active ester, such as an amino group or a sulfanyl group, and an acidic or basic group, such as a sulfo group or a carboxy group, as a water-soluble group. By using such a scavenger, it is possible to decompose the active ester and remove the decomposition product by washing with water. However, it has been found that an active ester having an aromatic heterocycle to which a carbonyl group is bonded is more likely to be emulsified by the scavenger than other active esters, and therefore the decomposition product is not easily removed. An object of the present invention is to provide a method capable of easily removing an activated acid raw material (such as an activated ester, an acid halide, or an acid anhydride) having an aromatic heterocycle bonded to a carbonyl group in the production of an amide bond-containing compound. [Means for solving the problem]

[0006] The present invention, which has solved the above problems, is as follows. [1] In a liquid phase amide bond formation reaction, Formula (1); [ka] [wherein n is an integer of 1 or more and 50 or less, Pro is a protecting group for the C-terminus, and Ra is an amino acid residue. When n is 2 or more, multiple Ra may be the same or different.], Formula (2) or Formula (3); [ka] [In the formula, m represents an integer of 1 or 2, Rb represents an amino acid residue, and when m is 2, the two Rb's may be the same or different. At least one of Rb's is an amino acid residue represented by formula (4). Q represents an N-terminal protecting group, Ar 1 and Ar 2each independently represents an aromatic heterocycle which may have a substituent other than a carboxyl group or an amino group. 2 If you have two Ar 2 may be the same or different. * represents a bond.] is reacted with a compound which has been converted into an active ester, an acid halide, or an acid anhydride to obtain a compound represented by the formula (5) or the formula (6); [ka] [In the formula, Ra, Rb, Ar 1 wherein Pro, Q, n, and m are the same as defined above; The reaction mixture containing the amide bond-containing compound represented by formula (5) or formula (6) obtained in step A is treated with a compound represented by formula (7); [ka] [In the formula, A represents an amino group or a sulfanyl group, B represents -SO3M, -CO2M, -PO3M2, or a dialkylamino group, and R 1 represents an alkylene group having 1 to 4 carbon atoms; M represents a hydrogen atom or an alkali metal atom, and when a plurality of M's are present, they may be the same or different. mixing a monoamine compound having no acidic group or a salt of an acidic group; A step B of reacting a compound obtained by converting the compound represented by formula (2) or (3) into an active ester, an acid halide, or an acid anhydride with the compound represented by formula (7); and A method for producing an amide bond-containing compound, comprising the step C of washing the reaction mixture obtained in the step B with a basic and / or acidic aqueous solution. [2] The method according to [1], wherein the monoamine compound having no acidic group or a salt of an acidic group is triethylamine, tributylamine, N,N-diisopropylethylamine, or N-methylmorpholine. [3] R in the above formula (7) 1wherein R is an alkylene group having 2 to 3 carbon atoms. [4] The method according to any one of [1] to [3], wherein B in the formula (7) is -SO3M, -CO2M, or -PO3M2 [M is the same as defined above]. [5] The method according to any one of [1] to [4], wherein the compound represented by formula (7) is taurine. [6] The method according to any one of [1] to [5], wherein the basic aqueous solution is an aqueous solution of a carbonate or a hydrogencarbonate. [7] The method according to [6], wherein the carbonate or hydrogen carbonate is a lithium salt, a sodium salt, or a potassium salt. [8] The method according to any one of [1] to [7], wherein the acidic aqueous solution is an aqueous solution of an organic acid. [9] The method according to [8], wherein the organic acid is citric acid.

[10] The method according to any one of [1] to [9], wherein the amide bond-containing compound represented by the formula (5) or (6) is a pyrrole-imidazole (poly)amide compound.

[11] A method for producing an amide bond-containing compound represented by the formula (5) by the production method according to any one of [1] to

[10] , and without isolating the obtained amide bond-containing compound represented by the formula (5), deprotecting the N-terminus, and subsequently carrying out the steps A, B, and C to elongate the amide bond-containing compound. Effect of the Invention

[0007] According to the present invention, in the production of an amide bond-containing compound, an activated acid raw material such as an activated ester having an aromatic heterocycle bonded to a carbonyl group can be easily removed, and the target amide bond-containing compound can be obtained in high yield. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The method for producing an amide bond-containing compound of the present invention is an amide bond-forming reaction by a liquid phase method, and includes the following steps A to C. [Step A] An amide bond-containing compound is synthesized by reacting a C-terminal protected amino acid or an amide bond-containing compound (1) (hereinafter, sometimes referred to as a reactive amine raw material) with a compound obtained by converting a carboxylic acid having an aromatic heterocycle to which a carbonyl group is bonded into an active ester, an acid halide, or an acid anhydride (hereinafter, sometimes referred to as an activated acid raw material); [Step B] A step of mixing a specific derivatizing agent (sometimes referred to as a scavenger) and a monoamine compound with the reaction mixture containing the amide bond-containing compound obtained in Step A, and reacting the activated acid raw material remaining in the reaction of Step A with the derivatizing agent; [Step C] The reaction mixture obtained in step B is washed with a basic and / or acidic aqueous solution. The activated acid raw material has a problem that the reaction product with the derivatizing agent (scavenger) tends to become an emulsion because the aromatic heterocycle is bonded to a carbonyl group. By using a specific derivatizing agent (scavenger), the excess activated acid raw material can be removed without causing the emulsion problem.

[0009] <Process A> <<Reactive amine raw material>> The reactive amine starting material used in step A is represented by formula (1). [ka] [In the formula, n represents an integer of 1 to 50, Pro represents a protecting group at the C-terminus, and Ra represents an amino acid residue. When n is 2 or more, multiple Ra may be the same or different.]

[0010] Examples of the amino acid residue represented by Ra include a hydrocarbon group having -NH- and -C(=O)-, an aromatic heterocycle, and the like. The hydrocarbon group may be bonded with a substituent other than a carboxy group and an amino group. In this specification, the term "substituent other than a carboxy group and an amino group" means a free (unsubstituted and unprotected) amino group and a substituent other than a carboxy group, and a carboxy group having a substituent (including a carboxy group protected by a protecting group) and an amino group having a substituent (including an amino group protected by a protecting group) are included in the substituent.

[0011] Examples of amino acid residues represented by Ra include α-amino acid residues such as glycine residue, alanine residue, valine residue, leucine residue, isoleucine residue, proline residue, phenylalanine residue, methionine residue, tryptophan residue, aspartic acid residue, glutamic acid residue, lysine residue, arginine residue, histidine residue, asparagine residue, glutamine residue, serine residue, threonine residue, cysteine ​​residue, and tyrosine residue; β-amino acid residues such as β-alanine residue; and aliphatic amino acid residues such as γ-amino acid residues, such as γ-amino acid residue and α,γ-diaminobutyric acid residue.

[0012] When the α-amino acid residue has a reactive functional group (e.g., hydroxyl group, thiol group, carboxy group, amino group, guanidino group, etc.) in the side chain, the reactive functional group is preferably protected by a protecting group. In addition, the amino group of a γ-amino acid having an amino group such as α,γ-diaminobutyric acid is also preferably protected by a protecting group. As the protecting group for protecting these reactive functional groups, those that are not deprotected under acidic conditions for deprotecting the N-terminal amino group (Q described later) are preferred. For example, examples of the protecting group for the hydroxyl group include benzyl (Bzl), 4-methylbenzyl (4-MeBzl), 4-methoxybenzyl (4-MeOBzl), etc., examples of the protecting group for the thiol group include benzyl (Bzl), 4-methylbenzyl (4-MeBzl), 4-methoxybenzyl (4-MeOBzl), t-butyl (tBu), etc., and examples of the protecting group for the carboxy group include benzyloxy (OBzl), cyclohexyloxy (O-cH Examples of the protecting group for the amino group include 2,4,6-trimethylbenzenesulfonyl (Mts), benzyloxycarbonyl (Z), nitro (NO2), p-toluenesulfonyl (Tos), benzyloxymethyl (BOM), 2,4-dinitrophenyl (Dnp), p-chlorobenzyloxycarbonyl (Cl-Z), and the like. Examples of the protecting group for the guanidino group include 2,2,5,7,8-pentamethylchroman-6-sulfonyl group (Pmc group), 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl group (Pbf group), and the like.

[0013] Further, the amino acid residue represented by Ra may be an aromatic heterocycle-containing amino acid residue represented by the following formula (4-1) (hereinafter, sometimes referred to as aromatic heterocycle-containing amino acid residue (4-1)). It is preferable that at least one Ra of the reactive amine raw material of formula (1) is an aromatic heterocycle-containing amino acid residue (4-1).

[0014] [ka] [In the formula, Ar 3represents an aromatic heterocycle which may have a substituent other than a carboxy group or an amino group. * represents a bond.] When compound (1) has two or more aromatic heterocycle-containing amino acid residues (4-1), a plurality of Ar 3 may be the same or different. As will be described later, Ar 3 The explanation of Ar will be explained later. 1 and Ar 2 It is referred to as a common content in the explanation of Ar 1 , Ar 2 , Ar 3 In cases where the explanation differs between the two, supplementary explanations will be provided below.

[0015] Ar 1 ~Ar 3 Examples of the heteroatom contained in the aromatic heterocycle represented by the formula include a nitrogen atom, an oxygen atom, and a sulfur atom. The number of aromatic rings contained in the aromatic heterocycle is not particularly limited, and may be a single ring or a condensed ring having two or more aromatic rings. The number of carbon atoms in the aromatic heterocycle is preferably 2 to 10, more preferably 2 to 8, and even more preferably 2 to 5. Examples of the aromatic heterocycle include furan, thiophene, pyrrole, pyrazole, oxazole, thiazole, imidazole, pyridine, pyridazine, pyrimidine, pyrazine, purine, indole, isoindole, benzimidazole, quinoline, benzofuran, isobenzofuran, benzothiophene, indazole, benzoxazole, and benzothiazole, and thiophene, pyrrole, imidazole, thiazole, and indole are preferred. Ar 1 In the case of thiophene, pyrrole, imidazole, and thiazole are most preferred, and Ar 2 , Ar 3 Of these, pyrrole and imidazole are most preferred.

[0016] Ar 1 ~Ar 3Examples of the substituent that the aromatic heterocycle represented by the formula (I) may have include an amino group having a substituent, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and an aralkyloxy group having 7 to 12 carbon atoms, and a halogen atom, a hydrocarbon group, etc. are preferred. Examples of the amino group having a substituent include an amino group substituted with one or more selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 10 carbon atoms, such as a methylamino group, an ethylamino group, a dimethylamino group, an ethylmethylamino group, a phenylamino group, a methylphenylamino group, and a diphenylamino group.

[0017] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable. The hydrocarbon group includes an alkyl group and an aromatic hydrocarbon group. The alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a (1-ethyl)propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and the like. The aromatic hydrocarbon group includes a phenyl group, a naphthyl group, and the like. Ar 3 The hydrocarbon group which the aromatic heterocycle represented by the following formula (I) may have as a substituent is more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0018] Examples of the alkoxy group include a methoxy group, an ethoxy group, a butoxy group, and a 2-methoxyethoxy group, and an alkoxy group having 1 to 6 carbon atoms is preferable. Examples of the aryloxy group include a phenoxy group and a naphthoxy group. Examples of the aralkyloxy group include a benzyloxy group and a 1-phenethyloxy group.

[0019] Ar 1 ~Ar 3 As the aromatic heterocycle which may have a substituent and is represented by the following formulae (A1-1) to (A1-5), groups represented by the following formulae (A1-1) to (A1-5) are preferred.

[0020] [ka] [In the formula, *1 represents a bond to -CO-. *2 represents Ar 2 Or Ar 3 In the case of -NH-, it indicates a bond with Ar 1 R represents a hydrogen atom or a halogen atom (preferably a chlorine atom). 10 represents an alkyl group having 1 to 3 carbon atoms, and preferably represents a methyl group. 10 represents a halogen atom, and preferably represents a chlorine atom.] Ar 1 Among them, the formula (A1-1), the formula (A1-2), the formula (A1-3) and the formula (A1-4) are most preferable, and Ar 2 Or Ar 3 Of these, formula (A1-1) and formula (A1-2) are most preferable.

[0021] As Ra, β-amino acid residues such as β-alanine residues; γ-amino acid residues such as γ-aminobutyric acid residues and α,γ-diaminobutyric acid residues; and aromatic heterocycle-containing amino acid residues (4-1) are preferred. It is preferred that at least one Ra of the reactive amine raw material of formula (1) is an aromatic heterocycle-containing amino acid residue (4-1).

[0022] The C-terminal protecting group represented by Pro may be a protecting group for a carboxyl group used in general liquid phase synthesis, and among the protecting groups described in Protective Groups in Organic Chemistry (4th Edition, published by Wiley-Interscience) pp. 533-646 by Theodora W. Greene and Peter G.M.Wuts, those that are not deprotected under acidic conditions for deprotecting the N-terminal amino group are preferred. Examples of -C(=O)-Pro include ester-based protecting groups such as methyl ester, ethyl ester, benzyl ester, 4-nitrobenzyl ester, and 4-methoxybenzyl ester; amide-based protecting groups such as amide, N,N-dimethylamide, N,N-(3-dimethylamino)propylamide, pyrrolidinylamide, piperidinylamide, and o-nitroanilide.

[0023] For example, n may be 1 to 30, 1 to 10, or 1 to 5.

[0024] The reactive amine raw material can be produced by deprotecting a compound represented by formula (1x) (hereinafter, sometimes referred to as an amine raw material). [ka] [In the formula, Q represents a protecting group for an amino group and is the same as Q in formula (2) described later. Ra, n, and Pro are the same as those described above.]

[0025] The deprotection can be carried out by a known method, for example, under acidic conditions using hydrochloric acid, sulfonic acid, or the like.

[0026] <<Active acid raw material>> The activated acid raw material is a compound obtained by converting a compound represented by formula (2) or formula (3) (carboxylic acid compound) into an active ester, an acid halide, or an acid anhydride. [ka] [In the formula, m represents an integer of 1 or 2, Rb represents an amino acid residue, and when m is 2, the two Rb's may be the same or different. At least one of Rb's is an amino acid residue represented by formula (4). Q represents an N-terminal protecting group, Ar 1 and Ar 2 each independently represents an aromatic heterocycle which may have a substituent other than a carboxyl group or an amino group. 2 If you have two Ar 2 may be the same or different. * indicates a bond.]

[0027] The activated acid raw materials obtained from the carboxylic acid compounds represented by formula (2) and formula (3) are highly reactive and are useful for synthesizing an amide bond-containing compound by combining with a reactive amine compound. However, the activated acid raw materials have a high affinity for aromatic heterocycles (Ar 1 , Ar 2 ) is bonded to a carbonyl group, and even if it remains after the formation of the amide bond-containing compound, it is relatively stable and cannot be easily decomposed and removed. Therefore, the remaining active oxygen source is removed using a derivatizing agent (a scavenger), but the aromatic heterocycle (Ar 1 , Ar 2 When an activated acid raw material in which a carbonyl group is bonded to a derivatizing agent (a scavenger) is used to decompose and remove the activated acid raw material, the problem of emulsion formation is easily caused. According to the present invention, the use of a specific derivatizing agent (a scavenger) makes it possible to overcome the problem of emulsion formation.

[0028] The amino acid residue represented by Rb is the same as that represented by Ra in the above formula (1), and Ar 1 and Ar 2 The explanation is given below with reference to Ar in the above formula (4-1). 3 The same content is repeated. When m is 2, it is preferable that one Rb is an amino acid residue represented by formula (4) (hereinafter, sometimes referred to as aromatic heterocycle-containing amino acid residue (4)), and the other Rb is an aromatic heterocycle-containing amino acid residue (4) or an aliphatic amino acid residue (preferably a β amino acid residue or a γ amino acid residue).

[0029] The N-terminal protecting group represented by Q is preferably an amino protecting group removable under acidic conditions, for example, the protecting groups removable under acidic conditions described in Protective Groups in Organic Chemistry by Theodora W. Greene and Peter G.M.Wuts (4th Edition, published by Wiley-Interscience), pp. 696-926, and more preferably a protecting group removable with sulfonic acid. Examples of Q include carbamate-type protecting groups such as methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, tert-butoxycarbonyl (Boc), allyloxycarbonyl, benzyloxycarbonyl, phenoxycarbonyl, and 9-fluorenylmethoxycarbonyl (Fmoc); acyl-type protecting groups such as formyl, acetyl, trichloroacetyl, trifluoroacetyl, benzoyl, and p-nitrobenzoyl; alkoxymethyl-type protecting groups such as methoxymethyl (MOM), benzyloxymethyl, and pivaloyloxy; and phenylmethyl-type protecting groups such as triphenylmethyl, di(p-methoxyphenyl)methyl, and (p-methoxyphenyl)diphenylmethyl. From the viewpoint of ease of deprotection, carbamate-type protecting groups are preferred, and Boc and Fmoc are particularly preferred.

[0030] The active esterification is, for example, a method of converting the OH group of the formula (2) or the formula (3) into -OR X Group (R X represents a nitrogen atom-containing heterocyclic group such as a triazolidinone ring group, a triazole ring group, a succinimide ring group, or a dimethoxytriazyl ring group; a halogenated aryl group; a carboxylate group; a sulfonate group; an acyl group; or the like, and these groups may have a substituent. RX is preferably a group represented by the following formula:

[0031] [ka] [In the formula, R X1 represents an alkyl group having 1 to 5 carbon atoms. * represents a bond.]

[0032] The active esterification can be carried out by reacting a carboxylic acid compound represented by formula (2) or formula (3) with an activating agent such as 1-hydroxybenzotriazole (HOBt), 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (HOOBt), 1-hydroxy-7-azabenzotriazole (HOAt), N-hydroxysuccinimide (HOSu), ethyl cyano(hydroxyimino)acetate (Oxyma), or pentafluorophenol (HOPFP) in the presence of a known condensing agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC).

[0033] The amount of the activating reagent is, for example, 1.00 mol or more, preferably 1.05 mol or more, more preferably 1.10 mol or more, and for example, 1.5 mol or less, preferably 1.4 mol or less, more preferably 1.3 mol or less, relative to 1.00 mol of the carboxylic acid compound. The amount of the condensing agent is, for example, 1.00 mol or more, preferably 1.05 mol or more, more preferably 1.10 mol or more, and for example, 1.5 mol or less, preferably 1.4 mol or less, more preferably 1.3 mol or less, relative to 1.00 mol of the carboxylic acid compound.

[0034] A solvent can be appropriately used in the active esterification reaction. After the active esterification reaction, it is preferable to remove the condensing agent by washing with an aqueous solution or water. The active ester obtained by the active esterification reaction may be concentrated before use, if necessary.

[0035] Examples of the acid halide obtained by the acid halogenation reaction include acid fluorides, acid chlorides, acid bromides, and acid iodides, and acid chlorides are preferred. The acid halogenation reaction can be carried out using an electrophilic halogenating agent such as thionyl chloride, oxalyl chloride, phosphoryl chloride, sulfuryl chloride, phosphorus trichloride, and phosphorus pentachloride, preferably thionyl chloride and sulfuryl chloride. The acid bromation reaction can be carried out, for example, using phosphorus tribromide.

[0036] The acid anhydride obtained by the acid anhydridation reaction may be a dehydration condensate (symmetric acid anhydride) of two molecules of the carboxylic acid compound represented by formula (2) or formula (3), or a condensate of the carboxylic acid compound represented by formula (2) or formula (3) with another acid or its ester (such as a carbonate ester).

[0037] The activated acid raw material is preferably an activated ester obtained by an activated esterification reaction of a carboxylic acid compound represented by formula (2) or formula (3). In addition, the activated acid raw material of the carboxylic acid represented by formula (2) is preferable in that it can be used as a new reactive amine raw material in step A (i.e., in that the amide bond-containing compound can be elongated by forming an amide bond-containing compound together with a reactive amine raw material and performing steps B and C, and then removing the protecting group Q from the obtained amide bond-containing compound under acidic conditions (particularly, sulfonic acid conditions, etc.). On the other hand, the activated acid raw material of the carboxylic acid represented by the formula (3) is preferable in that it can be used as a capping agent for terminating the elongation of the amide bond-containing compound.

[0038] The amount of the activated acid raw material used is, for example, 0.8 mol or more, preferably 0.9 mol or more, more preferably 1.0 mol or more, and even more preferably 1.1 mol or more, per mol of the reactive amine raw material. The amount of the activated acid raw material used is, for example, 1.5 mol or less, preferably 1.4 mol or less, and more preferably 1.3 mol or less, per mol of the reactive amine raw material.

[0039] <<base>> The reaction between the reactive amine source and the activated acid source is preferably carried out in the presence of a base in order to accelerate the reaction.

[0040] Examples of the base include tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tridodecylamine, N-dodecyldimethylamine, N-hexyldibutylamine, N,N-diisopropylbutylamine, N,N-diisopropylethylamine, N,N-dimethylethylamine, N,N-dicyclohexylmethylamine, N,N-dimethylbenzylamine, N-methylpyrrolidine, N,N-dimethyl-4-aminopyridine, quinuclidine, N-methylmorpholine, 1,4-diazabicyclo[2,2,2]octane, and 1,8-diazabicyclo[5,4,0]-7-undecene, and preferably triethylamine, tributylamine, N,N-diisopropylethylamine, or N-methylmorpholine. These bases may be used alone or in combination of two or more kinds, and when they are mixed, there is no limitation on the mixing ratio.

[0041] The amount of the base used is, for example, 0.5 mol or more, preferably 1.0 mol or more, more preferably 2 mol or more, and for example, 30 mol or less, preferably 20 mol or less, more preferably 10 mol or less, per mol of the activated acid raw material.

[0042] <<Solvent>> The reaction between the reactive amine raw material and the activated acid raw material is preferably carried out in the presence of a solvent (reaction solvent).

[0043] The reaction solvent can be used without any particular limitation as long as it does not adversely affect the reaction, and examples of the reaction solvent that can be used include ether solvents such as diethyl ether, cyclopentyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, etc.; halogenated hydrocarbon solvents such as methylene chloride, dichloroethane, etc.; nitrogen-containing solvents such as acetonitrile, dimethylformamide, dimethylacetamide, etc.; alcohol solvents such as methanol, ethanol, etc.; aromatic solvents such as benzene, toluene, xylene, pyridine, etc.; dimethyl sulfoxide; water, etc. The reaction solvent may be used alone or in combination of two or more kinds. The amount of the reaction solvent used is, for example, about 0.1 to 20 times by mass relative to 1 part by mass of the activated acid raw material.

[0044] The reaction solvent can be used as a reaction solvent in other reactions described in the present specification (e.g., the deprotection reaction of the protecting group Q, the reaction in step B, etc.), and the same reaction solvent may be used in the other reactions and the reaction in step A.

[0045] <Process B> In the step A, an amide bond-containing compound represented by formula (5) or (6) is synthesized.

[0046] [ka] [In the formula, Ra, Rb, Ar 1 , Pro, Q, n, and m are the same as above.] In step B, a specific derivatizing agent and a monoamine compound are mixed into the reaction mixture containing the amide bond-containing compound and the unreacted active acid raw material, and the remaining active acid raw material is reacted with the derivatizing agent. The use of the specific derivatizing agent can prevent the reaction solution containing the reaction product of the active acid raw material and the derivatizing agent from becoming an emulsion.

[0047] The amount of the unreacted activated acid raw material in the reaction mixture is, for example, 0.0005 mol or more, preferably 0.005 mol or more, more preferably 0.01 mol or more, and for example, 1.0 mol or less, preferably 0.5 mol or less, more preferably 0.3 mol or less, relative to 1 mol of the amide bond-containing compound.

[0048] <<Derivatizing agent (scavenging agent)>> The specific derivatizing agent can be specifically represented by formula (7).

[0049] [ka] [In the formula, A represents an amino group (-NH2) or a sulfanyl group (-SH), B represents -SO3M, -CO2M, -PO3M2, or a dialkylamino group, and R 1 represents an alkylene group having 1 to 4 carbon atoms. M represents a hydrogen atom or an alkali metal atom, and when there are multiple M's, they may be the same or different.] The dialkylamino group is a di-C group such as a dimethylamino group, a diethylamino group, or a dipropylamino group. 1-4 Alkylamino groups are also included. 1-4 " means "having 1 to 4 carbon atoms." The above M includes lithium, sodium, potassium, etc., with sodium and potassium being preferred, and sodium being more preferred. R 1 The number of carbon atoms can be determined from the viewpoint of the reactivity and water solubility of the derivatizing agent (scavenger). The number of carbon atoms is preferably 2 to 3. A and B are R 1 It is preferable that the alkylene group is bonded to both ends (α-position and ω-position) of the alkylene group. B is preferably -SO3M, -CO2M, or -PO3M2.

[0050] Examples of the derivatizing agent include aliphatic amino acids such as glycine, alanine, β-alanine, and γ-aminobutyric acid or their sodium salts; mercaptocarboxylic acids such as thioglycolic acid, 2-mercaptopropionic acid, and 3-mercaptopropionic acid or their sodium salts; aminosulfonic acids such as aminomethanesulfonic acid, aminoethanesulfonic acid (e.g., taurine), and aminopropanesulfonic acid or their sodium salts; mercaptosulfonic acids such as mercaptomethanesulfonic acid, 2-mercaptoethanesulfonic acid, and 3-mercaptopropanesulfonic acid or their sodium salts; diamines such as N,N-dimethylethanediamine and N,N-dimethylpropanediamine. As the derivatizing agent, from the viewpoint of achieving a better yield, aliphatic amino acids, aminosulfonic acids, and mercaptosulfonic acids are preferred, aminosulfonic acids and mercaptosulfonic acids are more preferred, and taurine is the most preferred.

[0051] The amount of the derivatizing agent used is, for example, 0.1 mol or more, preferably 0.5 mol or more, more preferably 1 mol or more, and for example, 10 mol or less, preferably 7 mol or less, more preferably 5 mol or less, relative to 1 mol of the activated acid raw material used in step A. The amount of the derivatizing agent used is, for example, 1 mol or more, preferably 5 mol or more, more preferably 10 mol or more, and for example, 100 mol or less, preferably 50 mol or less, more preferably 30 mol or less, relative to 1 mol of the activated acid raw material remaining after the reaction in step A.

[0052] The derivatizing agent reacts with the activated acid raw material in the presence of a monoamine compound. The monoamine compound is distinguished from the derivatizing agent in that it does not have an acidic group or a salt of an acidic group, and specifically includes compounds similar to the tertiary amines exemplified as the base in step A. Preferred monoamine compounds include triethylamine, tributylamine, N,N-diisopropylethylamine, and N-methylmorpholine. The amount of the monoamine compound used is, for example, 0.1 mol or more, preferably 0.5 mol or more, more preferably 0.7 mol or more, and for example, 10 mol or less, preferably 2 mol or less, more preferably 1.5 mol or less, relative to 1 mol of the derivatizing agent. The amount (residual amount) of the unreacted activated acid raw material after the treatment with the derivatizing agent is, for example, 0.05 mol or less, preferably 0.01 mol or less, more preferably 0.001 mol or less, relative to 1 mol of the amide bond-containing compound. Note that the amount of the activated acid raw material does not need to be 0 mol, and may be, for example, 0.000001 mol or more.

[0053] <Process C> In step C, the reaction mixture obtained in step B is washed with a basic aqueous solution and / or an acidic aqueous solution. Examples of the acidic aqueous solution include aqueous solutions of inorganic acids such as hydrochloric acid, sulfuric acid, sodium hydrogen sulfate, potassium hydrogen sulfate, phosphoric acid, sodium hydrogen phosphate, and potassium hydrogen phosphate, and aqueous solutions of organic acids (carboxylic acids) such as formic acid, acetic acid, and citric acid. As the acidic aqueous solution, an aqueous solution of an organic acid is preferred, and an aqueous solution of citric acid is more preferred.

[0054] Examples of the basic aqueous solution include an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, an aqueous solution of a carbonate or a hydrogen carbonate, and the like, and an aqueous solution of a carbonate or a hydrogen carbonate is preferred. Examples of the carbonate and the hydrogen carbonate include a lithium salt, a sodium salt, or a potassium salt, and the like, and the sodium salt is preferred.

[0055] The acid concentration of the acidic aqueous solution and the salt concentration of the basic aqueous solution are, for example, 1 mass % or more, preferably 3 mass % or more, and for example, 20 mass % or less, preferably 10 mass % or less. When B in the formula (7) of the derivatizing agent is -SO3M, -CO2M, or -PO3M2, it is preferable to first wash with a basic aqueous solution, and then wash with an acidic aqueous solution as necessary. The washing with the basic aqueous solution is, for example, one or more times, preferably two or more times. The washing with the basic aqueous solution is, for example, five or less times, preferably four or less times, more preferably three or less times. The washing with the acidic aqueous solution that is then performed is, for example, one or more times, for example, three or less times, preferably two or less times.

[0056] On the other hand, when B in the formula (7) of the derivatizing agent is a dialkylamino group, it is preferable to first wash with an acidic aqueous solution, and then wash with a basic aqueous solution as necessary. The washing with the acidic aqueous solution is, for example, one or more times, preferably two or more times. The washing with the acidic aqueous solution is, for example, five or less times, preferably four or less times, more preferably three or less times. The washing with the basic aqueous solution that is then performed is, for example, one or more times, for example, three or less times, preferably two or less times.

[0057] After washing with the basic aqueous solution or the acidic aqueous solution, the mixture is separated into an organic layer (preferably a layer containing the organic solvent used in step A) and an aqueous layer (liquid-liquid separation). The target product is distributed to the organic layer side, and the decomposition product of the activated acid raw material is distributed to the aqueous layer side, so that the activated acid raw material can be removed. The organic layer after washing with the basic aqueous solution or the acidic aqueous solution may be washed with water and separated as necessary. The organic layer may also be dried with a drying agent such as sodium sulfate. The product may be further purified by known techniques such as solvent distillation, crystallization, recrystallization, and column chromatography. However, when the N-terminal protecting group Q is removed from the product (amide bond-containing compound) and the product is used as a reactive amine raw material in step A (i.e., when the amide bond-containing compound is elongated), it is simpler and more preferable not to perform purification such as crystallization, recrystallization, and column chromatography.

[0058] The emulsion problem can also be solved by distilling off the organic solvent contained in the reaction mixture after washing with a basic aqueous solution or an acidic aqueous solution, precipitating the target product (amide bond-containing compound) in the remaining aqueous solvent, and subjecting it to solid-liquid separation (filtration, centrifugation, etc.). The target product recovered by solid-liquid separation may be further purified by known techniques such as crystallization, recrystallization, and column chromatography, but when the N-terminal protecting group Q is removed from the product (amide bond-containing compound) and the product is used as a reactive amine raw material in step A (i.e., when the amide bond-containing compound is elongated), it is simpler and more preferable not to perform purification such as crystallization, recrystallization, and column chromatography. When solving the problems of emulsions by utilizing this solid-liquid separation, compounds other than the compound represented by the above formula (7) (for example, the derivatizing agent used in the Comparative Example described later) can also be used as the derivatizing agent (scavenger) as long as the compound has a group that reacts with an active ester, such as an amino group or a sulfanyl group, and an acidic group, such as a sulfo group or a carboxy group, or a basic group, such as a dialkylamino group, as a water-soluble group.

[0059] The yield of the target product (amide bond-containing compound) obtained in step C is, for example, 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, particularly preferably 85 mol% or more, and for example, 100 mol% or less, or 99 mol% or less.

[0060] The purity of the target product (amide bond-containing compound) obtained in step C is, for example, 70% or more, preferably 75% or more, more preferably 80% or more, even more preferably 85% or more, and particularly preferably 90% or more, and is, for example, 100% or less, or 98% or less.

[0061] The target product (amide bond-containing compound) purified in step C can be used as a raw material for further reactions. For example, after removing the amino-protecting group Q at the N-terminus, it may be returned to step A as a reactive amine raw material, and then steps B and C may be carried out to elongate the amide bond-containing compound. In this case, the value of n in formula (1) is increased by one. The target product (amide bond-containing compound) may be used as a raw material to carry out an elongation reaction of the amide bond-containing compound by a known method different from steps A to C. When the target product (amide bond-containing compound) purified in step C is used as a raw material for further reactions, it is preferable not to carry out an isolation treatment such as crystallization, recrystallization, or column chromatography in step C. By using the reaction product (amide bond-containing compound) as a raw material for the next step without carrying out an isolation treatment, the efficiency of the entire process can be improved.

[0062] The method for producing an amide bond-containing compound of the present invention and the obtained amide bond-containing compound are useful for producing pyrrole imidazole (poly)amide (PIPA). PIPA refers to an amide bond-containing compound whose main constituent units are pyrrole and imidazole, and compounds such as those represented by the following formulae (101), (102), and (103) are known. PIPA is a gene expression control compound that binds in a sequence-specific manner to the minor groove of double-stranded DNA to inhibit the transcription of a target gene. Since PIPA is resistant to nucleases and has nuclear membrane permeability, it is expected to be used in diagnostic applications for identifying DNA sequences and as a molecular probe, and also as a transcription control agent that inhibits the binding interaction between a transcription factor and double-stranded DNA.

[0063] [ka]

[0064] This application claims the benefit of priority based on Japanese Patent Application No. 2020-058966, filed on March 27, 2020. The entire contents of the specification of Japanese Patent Application No. 2020-058966, filed on March 27, 2020, are incorporated by reference into this application. EXAMPLES

[0065] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples, and can be modified as long as it satisfies the spirit of the invention, and all such modifications are included in the technical scope of the present invention. In the following, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0066] 1. Measurement method The HPLC conditions were as follows. Measuring equipment: Agilent 1220 Infinity Column: YMC Meteoric Core C18 (150 x 4.6 mm) Flow rate: 1.5ml / ml Detection wavelength: 210nm Injection volume: 10μl Mobile phase A: 0.1 wt% phosphoric acid aqueous solution Mobile phase B: Acetonitrile Gradient conditions (mobile phase B concentration, time): 15% (0 min) → 80% (8 to 15 min) → 15% (15.1 to 20 min)

[0067] The HPLC purity of the product was calculated from the measurement results under the above-mentioned HPLC conditions using the following formula: HPLC purity (%area) = product peak area / total peak area x 100 However, the total peak area was calculated by excluding the peaks from the blank analysis from the measurement results.

[0068] The amount of the remaining active ester was calculated from the measurement results under the above-mentioned HPLC conditions by the following formula: Amount of remaining active ester (%area) = Peak area of ​​target compound / Total peak area × 100 However, the total peak area was calculated by excluding the peaks from the blank analysis from the measurement results.

[0069] The amount of the product obtained was calculated from the amount of the synthesized compound and the HPLC purity of the product described above. The calculation formula is as follows. Amount of product obtained = amount of synthesized compound × HPLC purity (%) / 100

[0070] 2. Symbols The symbols used in the Examples section have the following meanings. Boc: t-butoxycarbonyl group Bzl, Bn: benzyl group Py: N-methylpyrrole ring Im: N-methylimidazole ring HOOBt: 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine HOBt: 1-hydroxybenzotriazole HOAt: 1-hydroxy-7-azabenzotriazole Oxyma pure: Ethyl cyanoglycosylate-2-oxime DMF: Dimethylformamide

[0071] The active ester and amine raw materials used in the examples are as follows. 3. Active esters Synthesis Example 1 [Production of Boc-Py-OOBt (C-1)]

[0072] [ka]

[0073] To Boc-Py-OH (10.0 g, 41.6 mmol), dichloromethane (125 mL), HOOBt (8.2 g, 50.0 mmol), and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (hereinafter referred to as EDC hydrochloride) (9.6 g, 50.0 mmol) were added and stirred at room temperature for 1.5 hours. Next, EDC was removed by washing with H2O (200 mL x 3). The obtained organic layer was dried using sodium sulfate, filtered, and evaporated under reduced pressure at 40 ° C to obtain 16.6 g of concentrate. Next, 50.0 g of ethyl acetate was added, heated to 70 ° C, and then cooled to 5 ° C with stirring. After 1 hour, the precipitate was collected by filtration and dried in vacuum at 50 ° C to obtain compound (C-1) (14.1 g, 36.6 mmol, yield 87.8%).

[0074] Synthesis Examples 2-10 Active esters (C-2), (C-3), (C-4), (C-5), (C-6), (C-7), (C-8), (C-9), and (C-10) were produced in the same manner as in Synthesis Example 1, except that carboxylic acid compounds (B-1), (B-2), (B-3), (B-4), (B-5), (B-6), and (B-7) were combined with activators shown in Table 1. The results are shown in Table 1.

[0075] [Table 1]

[0076] [ka]

[0077] 4. Amine raw materials Synthesis Example 11 [Preparation of Boc-Py-ONBn (A-1)]

[0078] [ka]

[0079] Boc-Py-OH (10.0 g, 41.5 mmol) was added with DMF (100 mL), H2O (17 mL), and Cs2CO3 (7.2 g, 22.0 mmol) and stirred at 40 ° C for 30 minutes. 4-Nitrobenzyl bromide (10.2 g, 47.3 mmol) was then added and stirred for 29 hours. Next, the reaction solution was added to H2O (50 mL) in an ice bath and stirred for 30 minutes. The resulting precipitate was collected by filtration and dried in vacuum at 50 ° C to obtain the target compound (A-1) (11.3 g, 30.3 mmol, yield 73.0%).

[0080] Synthesis Example 12 [Production of H-Im-ONBn HCl salt (A-2)]

[0081] [ka]

[0082] To Boc-Im-OH (10.0 g, 41.5 mmol), DMF (100 mL), H2O (17 mL), and Cs2CO3 (7.2 g, 22.0 mmol) were added and stirred at 40 °C for 30 minutes. Then, 4-nitrobenzyl bromide (10.2 g, 47.3 mmol) was added and stirred for 29 hours. Next, the reaction solution was added to H2O (500 mL) in an ice bath, and then stirred for 30 minutes. The resulting precipitate was filtered and dried in vacuum at 50 °C to obtain Boc-Im-ONBn (11.3 g, 30.3 mmol, yield 73.0%).

[0083] Next, the Boc-Im-ONBn (11.3 g, 30.0 mmol) obtained above was added to 14% HCl / dioxane (117.2 g, 450 mmol) and stirred at room temperature for 22 hours. Next, hexane (112.9 g) was added dropwise at room temperature and mixed. After stirring for another hour in an ice bath, the precipitate was filtered and dried in vacuum at 40°C to obtain the target compound (A-2) (9.6 g, 30.0 mmol, 100% yield).

[0084] 5. Amide synthesis Comparative Example 1 [Production of Boc-Py-Py-ONBn (D-1)]

[0085] [ka]

[0086] Dichloromethane (0.8 mL) was added to Boc-Py-ONBn (A-1) (0.10 g, 0.27 mmol) to dissolve it, and then methanesulfonic acid (hereinafter referred to as MsOH) (0.09 g, 0.95 mmol) was added dropwise at 20°C and mixed. After 30 minutes, triethylamine (0.15 g, 1.49 mmol) was added dropwise in an ice bath and the temperature was raised to 20°C. Next, Boc-Py-OOBt (C-1) (0.12 g, 0.32 mmol) was added and stirred at 40°C for 1 hour. Next, the mixture was washed with 5% aqueous sodium bicarbonate solution (1 mL x 3), 5% aqueous citric acid solution (1 mL x 1), and HO (1 mL x 1), dried over sodium sulfate, filtered, and the resulting solution was distilled under reduced pressure at 30°C to obtain 0.14 g of a concentrated product of the target product (D-1) (yield: 76.9%, HPLC purity: 71.4%, remaining active ester: 25.5%). [Production of Boc-Py-Py-Py-ONBn (D-2)]

[0087] [ka]

[0088] After adding dichloromethane (0.8 mL) to Boc-Py-Py-ONBn (D-1) (0.14 g) to dissolve it, MsOH (0.12 g, 1.28 mmol) was added dropwise at 20 ° C. and mixed. After 30 minutes, triethylamine (0.18 g, 1.81 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, Boc-Py-OOBt (C-1) (0.12 g, 0.32 mmol) was added and stirred at 40 ° C. for 16.5 hours. Next, the mixture was washed with a 5% aqueous solution of sodium hydrogen carbonate (1 mL x 3), a 5% aqueous solution of citric acid (1 mL x 1), and H2O (1 mL x 1), dried over sodium sulfate, and filtered. The resulting solution was then distilled under reduced pressure at 30°C to obtain 0.17 g of a concentrated product of the target product (D-2) (yield from compound (A-1): 17.1%, HPLC purity: 16.7%, remaining active ester: 42.0%).

[0089] Example 1 [Production of Boc-Py-Py-ONBn (D-1)]

[0090] [ka]

[0091] After adding dichloromethane (0.8 mL) to Boc-Py-ONBn (A-1) (0.10 g, 0.27 mmol) to dissolve it, MsOH (0.10 g, 1.03 mmol) was added dropwise at 20 ° C and mixed. After 60 minutes, triethylamine (0.16 g, 1.57 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, Boc-Py-OOBt (C-1) (0.12 g, 0.32 mmol) was added and stirred at 40 ° C for 1 hour. Next, triethylamine (0.08 g, 0.80 mmol) and taurine (0.10 g, 0.80 mmol) were added and stirred overnight at 40 ° C. Then, it was washed with 5% sodium bicarbonate aqueous solution (1 mL × 3), 5% citric acid aqueous solution (1 mL × 1), and H2O (1 mL × 1). The organic layer after washing was dried over sodium sulfate and filtered, and the resulting solution was distilled under reduced pressure at 30° C. to obtain 0.14 g of the concentrated target product (D-1) (yield: 96.8%, HPLC purity: 91.4%, residual active ester: 0.1%). [Production of Boc-Py-Py-Py-ONBn (D-2)]

[0092] [ka]

[0093] After adding dichloromethane (0.8 mL) to Boc-Py-Py-ONBn (D-1) (0.14 g) to dissolve it, MsOH (0.12 g, 1.24 mmol) was added dropwise at 20 ° C and mixed. After 30 minutes, triethylamine (0.18 g, 1.81 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, Boc-Py-OOBt (C-1) (0.12 g, 0.32 mmol) was added and stirred at 40 ° C for 1 hour. Next, triethylamine (0.13 g, 1.33 mmol) and taurine (0.17 g, 1.33 mmol) were added and stirred overnight at 40 ° C. Then, it was washed with 5% sodium bicarbonate aqueous solution (3 mL x 3), 5% citric acid aqueous solution (3 mL x 1), and H2O (3 mL x 1). The organic layer after washing was dried over sodium sulfate and filtered, and the resulting solution was distilled under reduced pressure at 30° C. to obtain 0.15 g of the concentrated target product (D-2) (yield from compound (A-1) 73.1%, HPLC purity 79.5%, remaining active ester: 0.8%).

[0094] The yield and quality results of Boc-Py-Py-ONBn (D-1) and Boc-Py-Py-Py-ONBn (D-2) prepared in Comparative Example 1 and Example 1 are shown in Table 2.

[0095] [ka]

[0096] [Table 2]

[0097] Example 2 [Production of Boc-Py-Py-ONBn (D-1)]

[0098] [ka]

[0099] After adding dichloromethane (0.8 mL) to Boc-Py-ONBn (A-1) (0.10 g, 0.27 mmol) to dissolve it, MsOH (0.08 g, 0.88 mmol) was added dropwise at 20 ° C. and mixed. After 30 minutes, triethylamine (0.14 g, 1.41 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, Boc-Py-OOBt (C-1) (0.12 g, 0.32 mmol) was added and stirred at 40 ° C. for 2 hours. Next, triethylamine (0.08 g, 0.80 mmol) and sodium 3-mercaptopropanesulfonate (0.14 g, 0.80 mmol) were added and stirred at 40 ° C. overnight. Subsequently, washing was performed with 5% aqueous sodium bicarbonate solution (1 mL x 3), 5% aqueous citric acid solution (1 mL x 1), and H2O (1 mL x 1). The liquid separation during washing was good. The organic layer after washing was dried using sodium sulfate, filtered, and the obtained solution was distilled under reduced pressure at 30°C to obtain 0.16 g of the concentrated target product (D-1) (HPLC purity: 86.9%, remaining active ester: 0.2%).

[0100] Examples 3 to 6, Comparative Examples 2 and 3

[0101] [ka]

[0102] The same procedure was followed as in Example 2, except that the derivatizing agents shown in Table 3 were used. The results are shown in Table 3 together with those of Comparative Example 1, Example 1, and Example 2.

[0103] [Table 3]

[0104] Examples 7 to 13

[0105] [ka]

[0106] The same procedure was followed as in Example 2, except that the active esters and derivatizing agents shown in Table 4 were used. The results are shown in Table 4.

[0107] [Table 4]

[0108] Example 14 [Preparation of Boc-Py-Im-ONBn (D-6)]

[0109] [ka] Pyridine (120mL) and diisopropylethylamine (hereinafter referred to as DIPEA, 15.5g, 120mmol) were added to compound (A-2) (12.5g, 40.0mmol). Next, active ester (C-10) (13.1g, 36.0mmol) was added, and the mixture was stirred at 40°C overnight. Next, DIPEA (15.5g, 120mmol) and taurine (15.0g, 120mmol) were added, and the mixture was stirred at room temperature overnight. Next, pyridine was removed by distillation under reduced pressure at 30°C, and dichloromethane (200mL) and H2O (200mL) were added for washing. Next, washing was performed with 5% sodium carbonate aqueous solution (200mL x 3), 5% KHSO4 aqueous solution (200mL x 2), and 20% NaCl aqueous solution (200mL x 1). The liquid separation during washing was good. The washed organic layer was dried over sodium sulfate and filtered, and the resulting solution was distilled under reduced pressure at 30°C to obtain 16.5 g of a concentrated product of the target product (D-6) (HPLC purity: 95.4%, residual active ester: not detected).

[0110] Example 15

[0111] [ka]

[0112] After adding dichloromethane (0.8 mL) to Boc-Py-ONBn (A-1) (0.10 g, 0.27 mmol) and dissolving it, MsOH (0.09 g, 0.97 mmol) was added dropwise at 20 ° C. and mixed. After 30 minutes, triethylamine (0.15 g, 1.51 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, active ester (C-3) (0.10 g, 0.32 mmol) was added and stirred at 40 ° C. for 1 hour. Next, triethylamine (0.08 g, 0.80 mmol) and taurine (0.10 g, 0.80 mmol) were added and stirred overnight at 40 ° C. Then, 5% sodium bicarbonate aqueous solution (12 mL) was added, and dichloromethane was removed by distillation under reduced pressure at 30 ° C. to obtain a slurry liquid. The obtained slurry was heated to 50°C and aged for 1 hour, then cooled to 20°C, filtered, and dried at 30°C to obtain 0.10 g of the target product (D-7) (HPLC purity: 80.9%, residual active ester: 0.9%).

[0113] Example 16

[0114] [ka]

[0115] After adding dichloromethane (0.8 mL) to Boc-Py-ONBn (A-1) (0.10 g, 0.27 mmol) and dissolving it, MsOH (0.09 g, 0.96 mmol) was added dropwise at 20 ° C. and mixed. After 30 minutes, triethylamine (0.15 g, 1.50 mmol) was added dropwise in an ice bath and the temperature was raised to 20 ° C. Then, active ester (C-4) (0.11 g, 0.32 mmol) was added and stirred at 40 ° C. for 1 hour. Next, triethylamine (0.08 g, 0.80 mmol), taurine (0.10 g, 0.80 mmol), and DMF (0.5 mL) were added and stirred at 40 ° C. for 2.5 hours. Then, 5% sodium bicarbonate aqueous solution (12 mL) and DMF (1 mL) were added, and dichloromethane was removed by distillation under reduced pressure at 30 ° C. to obtain a slurry liquid. The obtained slurry was heated to 50°C and aged for 1 hour, then cooled to 20°C, filtered, and dried at 35°C to obtain 0.12 g of the target product (D-8) (HPLC purity: 87.2%, residual active ester: not detected).

Claims

1. In the liquid phase amide bond formation reaction, Formula (1); 【Chemistry 1】 [wherein n is an integer of 1 or more and 30 or less, Pro is a protecting group for the C-terminus, the protecting group for the C-terminus being an ester-based protecting group or an amide-based protecting group, and Ra is a β-amino acid residue, a γ-amino acid residue, or an aromatic heterocycle-containing amino acid residue represented by formula (4-1). When n is 2 or more, multiple Ra's may be the same or different. Ar 3 is an aromatic heterocycle which may have a substituent other than a carboxy group and an amino group. * represents a bond.], Formula (2) or Formula (3); 【Chemistry 2】 [In the formula, m represents an integer of 1 or 2, Rb represents an amino acid residue, and when m is 2, the two Rb's may be the same or different. At least one of Rb's is an amino acid residue represented by formula (4). Q represents an N-terminal protecting group, and the N-terminal protecting group is a carbamate type protecting group, an acyl type protecting group, an alkoxymethyl type protecting group, or a phenylmethyl type protecting group, and Ar 1 and Ar 2 each independently represents an aromatic heterocycle which may have a substituent other than a carboxy group and an amino group, and the aromatic heterocycle is thiophene, pyrrole, imidazole, thiazole, or indole. 2 When two Ar 2 may be the same or different. * represents a bond.] is reacted with a compound which has been converted into an active ester, an acid halide, or an acid anhydride to obtain a compound represented by the formula (5) or (6); 【Chemistry 3】 [In the formula, Ra, Rb, Ar 1 wherein Pro, Q, n, and m are the same as defined above; The reaction mixture containing the amide bond-containing compound represented by formula (5) or formula (6) obtained in step A is treated with a compound represented by formula (7); 【Chemistry 4】 [In the formula, A represents an amino group or a sulfanyl group, and B represents -SO 3 M, or -CO 2 M indicates R 1 represents an alkylene group having 2 to 3 carbon atoms; M represents a hydrogen atom or an alkali metal atom, and when a plurality of M's are present, they may be the same or different. mixing a monoamine compound having no acidic group or a salt of an acidic group; A step B of reacting a compound obtained by converting the compound represented by formula (2) or (3) into an active ester, an acid halide, or an acid anhydride with the compound represented by formula (7); and A method for producing an amide bond-containing compound, comprising the step of washing the reaction mixture obtained in the step B with a basic and / or acidic aqueous solution in a step C.

2. 2. The method according to claim 1, wherein the monoamine compound having no acidic group or no salt of an acidic group is triethylamine, tributylamine, N,N-diisopropylethylamine, or N-methylmorpholine.

3. The method according to claim 1 or 2, wherein the compound represented by formula (7) is taurine.

4. The method according to any one of claims 1 to 3, wherein the basic aqueous solution is an aqueous solution of a carbonate or a hydrogencarbonate.

5. The method according to claim 4, wherein the carbonate or hydrogen carbonate is a lithium salt, a sodium salt, or a potassium salt.

6. The method according to any one of claims 1 to 5, wherein the acidic aqueous solution is an aqueous solution of an organic acid.

7. The method according to claim 6, wherein the organic acid is citric acid.

8. The method according to any one of claims 1 to 7, wherein the amide bond-containing compound represented by the formula (5) or (6) is a pyrrole-imidazole (poly)amide compound.

9. A method for producing an amide bond-containing compound represented by formula (5) by the production method according to any one of claims 1 to 8, and deprotecting the N-terminus of the obtained amide bond-containing compound represented by formula (5) without isolating it, and then carrying out the steps A, B, and C to elongate the amide bond-containing compound.

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