Method for producing bipyridine derivatives, method for producing macrocyclic compounds, method for producing metal complexes containing macrocyclic compounds as ligands, metal complexes, electrodes for air batteries, and air batteries

Abstract

To provide a method for producing a bipyridine derivative, which enables obtaining a high-purity target compound (including an intermediate) without performing purification by column chromatography, provides a high yield, and is industrially advantageous.SOLUTION: A method for producing a bipyridine derivative represented by formula (3) comprises a step of obtaining a metal complex as an intermediate. In the formula, each of R13 to R20 is a hydrogen atom or a substituent; a plurality of R13 to R20 may be the same or different; at least one of six R14 to R16 is a substituent; at least one of two R17 is a hydrogen atom; any two substituents of R13 to R20 may be linked to each other to form a ring; R17 to R20 may contain a pyrrolyl group which may contain a halogen atom or a substituent; and at least one of R14 to R16 may have a halogen atom or a substituent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing bipyridine derivatives, a method for producing macrocyclic compounds, a method for producing metal complexes containing macrocyclic compounds as ligands, a metal complex, an electrode for an air battery, and an air battery. [Background technology]

[0002] Bipyridine derivatives have been developed as ligands for catalytic metal complexes, electron transport materials, luminescent materials, and raw materials for these, and their applications are diverse.

[0003] Patent Document 1 discloses that a metal complex having a metal atom and a ligand represented by the following formula (G-5) is suitably used as an inhibitor of degradation of ion-conducting membranes used in solid polymer electrolyte fuel cells and water electrolysis, as well as an antioxidant in pharmaceuticals, agricultural chemicals, and food products. Here, the ligand represented by the following formula (G-5) is produced by the following reaction scheme.

[0004] [ka]

[0005] Patent Document 1 and Non-Patent Document 1 describe how the ligand represented by formula (G-5) can be obtained by brominating the compound represented by formula (A-34) to obtain the compound represented by formula (C-12), pyrroling this compound to obtain the compound represented by formula (C-16), deprotecting this compound to obtain the compound represented by formula (C-17), and cyclizing this compound, as shown in the scheme above.

[0006] Furthermore, Non-Patent Document 1 states that the compound represented by formula (A-34) can be obtained by the following reaction.

[0007] [ka] [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 5422159 [Non-patent literature]

[0009] [Non-Patent Document 1] Fung Lam, MaoQi Feng, Kin Shing Chan Synthesis of Dinucleating Phenanthroline-Based Ligands, Tetrahedron, 55, (1999), 8377-8384 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] In the above reaction scheme, the compounds represented by formula (A-34), formula (C-12), formula (C-16), and formula (C-17) have low crystallinity, making purification by crystallization difficult even with optimized conditions. Therefore, obtaining high-purity compounds requires purification by column chromatography, resulting in a complex and costly process that is difficult to apply to large-scale production suitable for industrial use. Furthermore, the above reaction scheme also suffers from the problem of low yield of the ligand represented by formula (G-5).

[0011] The present invention has been made in view of the above circumstances, and aims to provide a method for producing a bipyridine derivative that is industrially advantageous, yielding a high-purity target product (including intermediates) without purification by column chromatography, and having a high yield; a method for producing a macrocyclic compound using the bipyridine derivative as a raw material; a method for producing a metal complex containing the macrocyclic compound as a ligand using the macrocyclic compound as a raw material; and a metal complex used in the method for producing the bipyridine derivative. Furthermore, the present invention aims to provide an air-electric electrode and an air battery containing the metal complex.

Means for Solving the Problem

[0012] As a result of intensive studies to solve the above problems, the inventors of the present invention focused on the fact that the intermediates of bipyridine derivatives are polydentate ligands, added metal salts thereto to form metal complexes, and found a method for producing industrially advantageous bipyridine derivatives by passing through these as intermediates, thereby completing the present invention.

[0013] The present invention is as follows [1] to

[11] . [1] A first step of obtaining a metal complex 1 represented by the following formula (2) from a compound represented by the following formula (1), and a second step of obtaining a bipyridine derivative represented by the following formula (3) from the metal complex 1, wherein the second step includes a step of performing either or both of a halogenation reaction and a pyrrolation reaction on the metal complex 1 to obtain a metal complex 2, and a demetallation step of demetallating the metal from the metal complex 2, and the number of halogen atoms contained in the bipyridine derivative is larger than the number of halogen atoms contained in the compound, or the number of pyrrolyl groups which may have substituents contained in the bipyridine derivative is larger than the number of pyrrolyl groups which may have substituents contained in the compound. A method for producing a bipyridine derivative.

[0014]

Chemical formula

[0015] (In the above formula (1), R 4 , 2 , 4 , 4 , 4 , 1 , 3 , 1 , 1 ~R 4 are each independently a hydrogen atom or a substituent, and R 1 ~R 4 may be the same or different from each other, and two R 1 , two R 2 , two R 3 , two R 4 may be the same or different from each other, and any two substituents among R 1 ~R 4 may be bonded to each other to form a ring, and R 1 ~R 4(This may include a halogen atom or a pyrrolyl group which may have a substituent.)

[0016] [ka]

[0017] (In the above formula (2), R 5 ~R 12 Each is independently a hydrogen atom or a substituent, R 5 ~R 12 These two Rs may be the same or different, and 5 , 2 R 6 , 2 R 7 , 2 R 8 , 2 R 9 , 2 R 10 , 2 R 11 , 2 R 12 Each of them may be the same or different, and there are 6 R 6 ~R 8 At least one of them is a substituent, and two R 9 At least one of them is a hydrogen atom, R 5 ~R 12 Any two substituents among them may be bonded to each other to form a ring, R 6 ~R 12 (This may include a halogen atom or a pyrrolyl group which may have substituents, M is a metal belonging to any group from group 4 to group 12 of the fourth period of the periodic table, X is an anionic species, a is an integer from 1 to 3, and b is 0 or greater.)

[0018] [ka]

[0019] (In the above formula (3), R 13 ~R 20 Each is independently a hydrogen atom or a substituent, R 13 ~R 20 These two Rs may be the same or different, and 13 , 2 R 14 , 2 R15 , 2 R 16 , 2 R 17 , 2 R 18 , 2 R 19 , 2 R 20 Each of them may be the same or different, and there are 6 R 14 ~R 16 At least one of them is a substituent, and two R 17 At least one of them is a hydrogen atom, R 13 ~R 20 Any two substituents among them may be bonded to each other to form a ring, R 17 ~R 20 R may contain a halogen atom or a pyrrolyl group which may have a substituent, 14 ~R 16 (At least one of these groups may contain a halogen atom or a pyrrolyl group which may have a substituent.) [2] The method for producing a bipyridine derivative according to [1], wherein the demetallation step is carried out by reacting with an amine represented by the following formula (4).

[0020] [ka]

[0021] (In the above formula (4), R 21 ~R 23 Each of these is independently either a hydrogen atom or a substituent. [3] A method for producing a bipyridine derivative according to [1] or [2], comprising the step of reacting the compound with a metal salt containing the metal represented by M and the anionic species represented by X. [4] A method for producing a bipyridine derivative according to any one of [1] to [3], wherein the second step is a deprotection step after the demetallation step. [5] A method for producing a bipyridine derivative according to any one of [1] to [4], comprising the step of isolating the metal complex 1, the metal complex 2, or the bipyridine derivative by crystallization. A method for producing a macrocyclic compound, comprising cyclizing a bipyridine derivative having two or more pyrrolyl groups which may have substituents, produced by any one of the methods for producing a bipyridine derivative described in [1] to [5], thereby obtaining a macrocyclic compound represented by the following formula (5).

[0022] [ka]

[0023] (In formula (5) above, R 34 ~R 42 Each is independently a hydrogen atom or a substituent, R 34 ~R 42 These two Rs may be the same or different, and 34 , 2 R 35 , 2 R 36 , 2 R 37 , 2 R 38 , 2 R 39 , 2 R 40 , 2 R 41 These may be the same or different, R 34 ~R 42 Any two of the substituents may be bonded to each other to form a ring. A method for producing a metal complex containing a macrocyclic compound as a ligand, comprising reacting the macrocyclic compound produced by the method for producing a macrocyclic compound described in [7] [6] with a metal salt containing a metal belonging to the 4th to 6th period of the periodic table as a ligand.

[0024] [8] A metal complex represented by the following formula (6).

[0025] [ka]

[0026] (In formula (6) above, R 24 R is a substituent, 25 ~R 31 Each is independently a hydrogen atom or a substituent, R 24 ~R 31These two Rs may be the same or different, and 24 , 2 R 25 , 2 R 26 , 2 R 27 , 2 R 28 , 2 R 30 , 2 R 31 Each of them may be the same or different, and there are 6 R 25 ~R 27 At least one of them is a substituent, and two R 28 At least one of them is a hydrogen atom, R 24 ~R 31 Any two substituents may be bonded to each other to form a ring, M is a metal belonging to groups 4 through 12 of the fourth period of the periodic table, X is an anionic species, c is an integer from 1 to 3, and d is 0 or greater. An electrode for an air battery comprising a catalyst layer containing an electrode catalyst containing the metal complex described in [9] [8], a conductive material, and a binder. An air battery comprising an electrode for an air battery as described in

[10] [9] and a negative electrode, wherein the negative electrode comprises a negative electrode active material, and the negative electrode active material comprises one or more selected from the group consisting of zinc, iron, aluminum, magnesium, lithium, hydrogen, and ions thereof.

[11] The air battery according to

[10] , wherein the negative electrode active material comprises one or more selected from the group consisting of magnesium and magnesium ions. [Effects of the Invention]

[0027] According to the present invention, it is possible to obtain a bipyridine derivative with high purity (including intermediates) without purification by column chromatography, and to provide a method for producing a bipyridine derivative with high yield and industrial advantages, a method for producing a macrocyclic compound using the bipyridine derivative as a raw material, a method for producing a metal complex containing the macrocyclic compound as a ligand using the macrocyclic compound as a raw material, and a metal complex used in the method for producing the bipyridine derivative. Furthermore, an air-electric electrode and an air battery containing the metal complex can be provided. [Brief explanation of the drawing]

[0028] [Figure 1] This is a schematic diagram showing an example of an air battery according to this embodiment. [Modes for carrying out the invention]

[0029] ≪Method for producing bipyridine derivatives≫ The method for producing a bipyridine derivative according to this embodiment comprises a first step of obtaining a metal complex 1 represented by the following formula (2) from a compound represented by the following formula (1), and a second step of obtaining a bipyridine derivative represented by the following formula (3) from the metal complex 1. The second step comprises a step of performing either a halogenation reaction or a pyrrole reaction or both on the metal complex 1 to obtain a metal complex 2, and a demetallation step of demetallizing the metal from the metal complex 2.

[0030] The number of halogen atoms contained in the bipyridine derivative is greater than the number of halogen atoms contained in the compound, or the number of optionally substituted pyrrolyl groups contained in the bipyridine derivative is greater than the number of optionally substituted pyrrolyl groups contained in the compound.

[0031] The following describes the compound represented by formula (1), metal complex 1 and metal complex 2 represented by formula (2), and the bipyridine derivative represented by formula (3) in this embodiment. The conditions for the first and second steps will also be described.

[0032] The compounds or metal complexes represented by formulas (1) to (3) above are not included in the macrocyclic compounds described later. The definition of macrocyclic compounds will be described later.

[0033] <Compound represented by formula (1)>

[0034] [ka]

[0035] In equation (1) above, R 1 ~R 4is each independently a hydrogen atom or a substituent, R 1 ~R 4 may be the same or different from each other, and two R 1 , two R 2 , two R 3 , two R 4 may be the same or different from each other, and any two substituents among R 1 ~R 4 may combine with each other to form a ring, and R 1 ~R 4 may contain a halogen atom or a pyrrolyl group which may have a substituent.

[0036] When R 1 ~R 4 is a substituent, the substituent is a hydrocarbyl group and a monovalent group having a hetero element (an element other than carbon and hydrogen), and the hydrocarbyl group is preferred. Examples of the hydrocarbyl group include an alkyl group, an aryl group, and an aralkyl group, and an alkyl group and an aryl group are preferred. Examples of the monovalent group having a hetero atom include a halogen atom, a pyrrolyl group, a hydroxy group, a carbonyl group, a carboxyl group, a carbamoyl group, an amino group, a sulfonic acid group, a nitro group, a phosphonic acid group, a boronic acid group, a boronic acid ester group, a silyl group, an alkoxy group, a heteroaryl group, an aryloxy group, an aralkyloxy group, and a silyloxy group.

[0037] These substituents may or may not have further substituents. Hereinafter, the substituents of the substituents such as R 1 ~R 4 are represented as R 1 ~R 4To distinguish it from substituents such as others, it is denoted as "substituent (1)". In this specification, a substituent having substituent (1) means that one or more hydrogen atoms in the substituent are substituted with a group other than a hydrogen atom (substituent (1)). Examples of substituent (1) include alkyl groups, aryl groups, aralkyl groups, halogen atoms, pyrrolyl groups, hydroxyl groups, carbonyl groups, carboxyl groups, carbamoyl groups, amino groups, sulfonic acid groups, nitro groups, phosphonic acid groups, boronic acid groups, boronic acid ester groups, silyl groups, and alkoxy groups, with alkyl groups, aryl groups, aralkyl groups, halogen atoms, pyrrolyl groups, hydroxyl groups, carbonyl groups, carboxyl groups, amino groups, nitro groups, boronic acid groups, boronic acid ester groups, and alkoxy groups being preferred. Specific examples and preferred forms of these substituents are described later in R 1 ~R 4 Examples of substituents equivalent to those exemplified are shown below. 1 ~R 4 When specifying the number of carbon atoms in such a formula, the number of carbon atoms in substituent (1) is included.

[0038] R 1 ~R 4 Examples of alkyl groups in substituents such as the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, norbonyl, nonyl, decyl, 3,7-dimethyloctyl, dodecyl, pentadecyl, octadecyl, and docosyl groups, with methyl and tert-butyl groups being preferred. The alkyl group may or may not have substituent (1). The number of carbon atoms in the alkyl group is not particularly limited, but from the viewpoint of availability and cost, it is preferably 1 to 20, and more preferably 1 to 8.

[0039] R 1 ~R 4Examples of aryl groups in substituents include phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracenyl, benzophenanthryl, benzoanthracenyl, chrysenyl, pyrenyl, fluoranthenyl, triphenylenyl, benzofluoranthenyl, dibenzoanthracenyl, perilenyl, and hericenyl groups, with phenyl being preferred. The aryl group may or may not have substituent (1). The number of carbon atoms in the aryl group is not particularly limited, but is preferably 6 to 40, and more preferably 6 to 20.

[0040] R 1 ~R 4Examples of aralkyl groups in substituents include benzyl groups, naphthylmethyl groups, and anthracenylmethyl groups. Examples of substituted aralkyl groups include (2-methylphenyl)methyl group, (3-methylphenyl)methyl group, (4-methylphenyl)methyl group, (2,3-dimethylphenyl)methyl group, (2,4-dimethylphenyl)methyl group, (2,5-dimethylphenyl)methyl group, (2,6-dimethylphenyl)methyl group, (3,4-dimethylphenyl)methyl group, (4,6-dimethylphenyl)methyl group, (2,3,4-trimethylphenyl)methyl group, (2,3,5-trimethylphenyl)methyl group, (2,3,6-trimethylphenyl)methyl group, (3,4,5-trimethylphenyl)methyl group, (2,4,6-trimethylphenyl)methyl group, (2, Examples include the 3,4,5-tetramethylphenyl)methyl group, the (2,3,4,6-tetramethylphenyl)methyl group, the (2,3,5,6-tetramethylphenyl)methyl group, the (pentamethylphenyl)methyl group, the (ethylphenyl)methyl group, the (n-propylphenyl)methyl group, the (isopropylphenyl)methyl group, the (n-butylphenyl)methyl group, the (sec-butylphenyl)methyl group, the (tert-butylphenyl)methyl group, the (n-pentylphenyl)methyl group, the (neopentylphenyl)methyl group, the (n-hexylphenyl)methyl group, the (n-octylphenyl)methyl group, the (n-decylphenyl)methyl group, and the (n-decylphenyl)methyl group. The number of carbon atoms in the aralkyl group is not particularly limited, but is preferably 7 to 40, and more preferably 7 to 20.

[0041] R 1 ~R 4 Examples of halogen atoms in substituents include fluorine, chlorine, bromine, and iodine atoms, with chlorine, bromine, and iodine atoms being preferred, and bromine and iodine atoms being more preferred.

[0042] R 1 ~R 4The pyrrolyl group in the substituent is a monovalent group obtained by removing one hydrogen atom from pyrrole. The pyrrolyl group in this embodiment may be a pyrrolyl group having a substituent. The substituent included in the pyrrolyl group is substituent (1) described above.

[0043] In this specification, the pyrrolyl group is not included in the heteroaryl group described later.

[0044] R 1 ~R 4 The silyl group in the substituent may be substituted with a hydrocarbon group. Examples include monosubstituted silyl groups having 1 to 20 carbon atoms, such as methylsilyl, ethylsilyl, and phenylsilyl groups; disubstituted silyl groups having 2 to 20 carbon atoms, such as dimethylsilyl, diethylsilyl, and diphenylsilyl groups; trisubstituted silyl groups having 3 to 20 carbon atoms, such as trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, tri-isobutylsilyl, tert-butyldimethylsilyl, tri-n-pentylsilyl, tri-n-hexylsilyl, tricyclohexylsilyl, and triphenylsilyl groups. Trisubstituted silyl groups having 3 to 20 carbon atoms are preferred.

[0045] R 1 ~R 4Examples of alkoxy groups in substituents such as the methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-dodecyloxy group, n-undecyloxy group, n-dodecyloxy group, tridecyloxy group, tetradecyloxy group, n-pentadecyloxy group, hexadecyloxy group, heptadecyloxy group, octadecyloxy group, nonadecyloxy group, and n-eicosyloxy group are preferred, with methoxy group, ethoxy group, and tert-butoxy group being preferred. The alkoxy group may or may not have substituent (1).

[0046] R 1 ~R 4 A heteroaryl group in substituents is a group in which the carbon atoms constituting the ring of an aryl group are substituted with a heteroatom or a carbonyl group. Heteroaryl groups having 4 to 36 carbon atoms include monovalent groups formed by the direct bonding or indirect bonding via heteroatoms (oxygen, nitrogen, sulfur, etc.) or carbonyl groups (-CO-) of monocyclic heteroaryl groups, fused heteroaryl groups, two or more monocyclic and / or fused heteroaryl groups, and monovalent groups formed by the direct bonding or indirect bonding via heteroatoms (oxygen, nitrogen, sulfur, etc.) or carbonyl groups (-CO-) of one or more monocyclic and / or fused heteroaryl groups and one or more monocyclic and / or fused aryl groups.

[0047] The remaining bonds of the nitrogen atom indirectly attached to the heteroaryl group are bonded to, for example, an alkyl group which may have substituent (1), an aryl group which may have substituent (1), etc. The fused ring included in the heteroaryl group of the fused ring may be a fused ring of two or more heterocycles, or a fused ring of one or more heterocycles and one or more aromatic rings. Specific examples of heteroaryl groups include groups obtained by removing one hydrogen atom from pyridine, pyrazine, pyrimidine, furan, thiophene, thiazole, imidazole, oxazole, benzofuran, benzothiophene, isoquinoline, and quinazoline. Preferably, pyridine, pyrazine, pyrimidine, furan, and thiophene are used, and more preferably, pyridine, furan, and thiophene are used.

[0048] R 1 ~R 4 Examples of aryloxy groups in substituents include phenoxy, naphthoxy, and anthracenoxy groups. Examples of substituted aryloxy groups include 2-methylphenoxy, 3-methylphenoxy, 4-methylphenoxy, 2,3-dimethylphenoxy, 2,4-dimethylphenoxy, 2,5-dimethylphenoxy, 2,6-dimethylphenoxy, 3,4-dimethylphenoxy, 3,5-dimethylphenoxy, 2,3,4-trimethylphenoxy, 2,3,5-trimethylphenoxy, 2,3,6-trimethylphenoxy, 2,4,5-trimethylphenoxy, and 2,4,6-trimethylphenoxy. Examples include hydroxyl groups, 3,4,5-trimethylphenoxyl groups, 2,3,4,5-tetramethylphenoxyl groups, 2,3,4,6-tetramethylphenoxyl groups, 2,3,5,6-tetramethylphenoxyl groups, pentamethylphenoxyl groups, ethylphenoxyl groups, n-propylphenoxyl groups, isopropylphenoxyl groups, n-butylphenoxyl groups, sec-butylphenoxyl groups, tert-butylphenoxyl groups, n-hexylphenoxyl groups, n-octylphenoxyl groups, n-decylphenoxyl groups, and n-tetradecylphenoxyl groups. The number of carbon atoms in the aryloxy group is not particularly limited, but is preferably 6 to 40, and more preferably 6 to 20.

[0049] R 1 ~R 4 Examples of aralkyloxy groups in substituents include benzyloxy group, naphthyl methoxy group, and anthracenyl methoxy group. Examples of substituted aralkyloxy groups include (2-methylphenyl)methoxy group, (3-methylphenyl)methoxy group, (4-methylphenyl)methoxy group, (2,3-dimethylphenyl)methoxy group, (2,4-dimethylphenyl)methoxy group, (2,5-dimethylphenyl)methoxy group, (2,6-dimethylphenyl)methoxy group, (3,4-dimethylphenyl)methoxy group, (3,5-dimethylphenyl)methoxy group, (2,3,4-trimethylphenyl)methoxy group, (2,3,5-trimethylphenyl)methoxy group, (2,3,6-trimethylphenyl)methoxy group, (2,4,5-trimethylphenyl)methoxy group, and (2,4,6-trimethyl Examples include phenyl)methoxy group, (3,4,5-trimethylphenyl)methoxy group, (2,3,4,5-tetramethylphenyl)methoxy group, (2,3,4,6-tetramethylphenyl)methoxy group, (2,3,5,6-tetramethylphenyl)methoxy group, (pentamethylphenyl)methoxy group, (ethylphenyl)methoxy group, (n-propylphenyl)methoxy group, (isopropylphenyl)methoxy group, (n-butylphenyl)methoxy group, (sec-butylphenyl)methoxy group, (tert-butylphenyl)methoxy group, (n-hexylphenyl)methoxy group, (n-octylphenyl)methoxy group, and (n-decylphenyl)methoxy group. Among these, the benzyloxy group is preferred. The number of carbon atoms in the aralkyloxy group is not particularly limited, but is preferably 7 to 40, and more preferably 7 to 20.

[0050] R 1 ~R 4The silyloxy group in the substituent may be substituted with a hydrocarbon group, for example, trimethylsilyloxy group, triethylsilyloxy group, tri-n-butylsilyloxy group, triphenylsilyloxy group, triisopropylsilyloxy group, tert-butyldimethylsilyloxy group, dimethylphenylsilyloxy group, methyldiphenylsilyloxy group, etc., and preferably trimethylsilyloxy group, triphenylsilyloxy group, and triisopropylsilyloxy group.

[0051] R 1 ~R 4 The amino group in the substituent may be substituted with a hydrocarbon group, for example, dimethylamino group, diethylamino group, di-n-propylamino group, diisopropylamino group, di-n-butylamino group, di-sec-butylamino group, di-tert-butylamino group, di-isobutylamino group, tert-butylisopropylamino group, di-n-hexylamino group, di-n-octylamino group, di-n-decylamino group, diphenylamino group, bistrimethylsilylamino group, bis-tert-butyldimethylsilylamino group, pyrrolidinyl group, piperidinyl group, carbazolyl group, dihydroindolyl group, dihydroisoindolyl group, etc.

[0052] R 1 ~R 4 Examples of carbonyl groups in substituents include methoxycarbonyl groups, tert-butoxycarbonyl groups, ethoxycarbonyl groups, and aldehyde groups.

[0053] R 1 ~R 4 Examples of boronic acid ester groups in substituents include pinacol boronic acid ester group, 1,3-propanediol boronic acid ester group, catechol boronic acid ester group, and dimethyl boronic acid ester group.

[0054] R 1 Among the structures mentioned above, the (-OR) in equation (2) below5 ), (-R 6 ), (-R 7 ), (-R 8 ), (-R 9 It is preferable that the phenyl group has ) as a substituent.

[0055] 2 R 1 These may be the same or different, but it is preferable that they be the same.

[0056] 2 R 2 These may be the same or different, but it is preferable that they be the same.

[0057] 2 R 3 These may be the same or different, but it is preferable that they be the same.

[0058] 2 R 4 These may be the same or different, but it is preferable that they be the same.

[0059] R 2 It is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

[0060] R 3 It is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

[0061] R 4 It is more preferable that this is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

[0062] R 1 ~R 4 When has halogen atoms, the number of halogen atoms in the compound represented by formula (1) is preferably 1 to 4, and more preferably 1 to 2. Also, the halogen atoms are R 1 If is a substituent, then as substituent (1), R 1 It is preferable that it be included in R. 1 ~R4 It does not need to have a halogen atom.

[0063] R 1 ~R 4 If the compound has a pyrrolyl group which may have a substituent, the number of pyrrolyl groups which may have a substituent in the compound represented by formula (1) is preferably 1 to 4, and more preferably 1 to 2. In addition, the pyrrolyl group which may have a substituent is R 1 If is a substituent, then as substituent (1), R 1 It is preferable that it be included in R. 1 ~R 4 The pyrrolyl group may or may not have a substituent.

[0064] The aforementioned R 1 ~R 4 Any two of the substituents may be bonded to each other to form a ring.

[0065] Among them, there are two R 4 It is preferable that the two R's bond to each other to form a ring, and the two R's 4 The compounds are preferably phenanthroline derivatives represented by the following formula (7), as they bond to each other to form a ring and condense.

[0066] [ka]

[0067] R a ~R d Each is independently a hydrogen atom or a substituent, R a ~R c Preferably, any two substituents among them do not bond to each other to form a ring, and the R d The two substituents may be bonded to each other to form a ring. a ~R d Examples of substituents when the two substituents do not bond to each other to form a ring are, R 1 ~R 4These are the same as the examples of substituents shown.

[0068] Examples of compounds represented by formula (1) include those represented by the following formulas (A-1) to (A-43). Among them, two R 1 Compounds represented by (A-28) to (A-42), in which is a substituted phenyl group, are preferred, and compounds represented by (A-34) to (A-37) and (A-39) to (A-42) of formula (7) are more preferred. In the chemical formulas described herein, "Me" means a methyl group, "t-Bu" means a tert-butyl group, "Boc" means a tert-butoxycarbonyl group, "Bn" means a benzyl group, "dba" means a dibenzylideneacetone, and "Cy" means a cyclohexyl group.

[0069] [ka]

[0070] [ka]

[0071] <Metal complex 1 represented by formula (2)>

[0072] [ka]

[0073] In equation (2) above, R 5 ~R 12 Each is independently a hydrogen atom or a substituent, R 5 ~R 12 These two Rs may be the same or different, and 5 , 2 R 6 , 2 R 7 , 2 R 8 , 2 R 9 , 2 R 10 , 2 R 11 , 2 R 12 Each of them may be the same or different, and there are 6 R6 ~R 8 At least one of them is a substituent, and two R 9 At least one of them is a hydrogen atom, R 5 ~R 12 Any two substituents among them may be bonded to each other to form a ring, R 6 ~R 12 The compound may contain a halogen atom or a pyrrolyl group which may have a substituent, M is a metal belonging to any group from group 4 to group 12 in the fourth period of the periodic table, X is an anionic species, a is an integer from 1 to 3, and b is 0 or greater.

[0074] In the metal complex 1 represented by formula (2) above, R 5 If R is a substituent, 5 By converting the substituent to hydrogen, -OR 5 It is preferable that the substituent is a protecting group that can convert the moiety to an -OH structure. Specific examples of protecting groups include methyl group, isopropyl group, cyclohexyl group, tert-butyl group, benzyl group, methoxymethyl group, benzyloxymethyl group, methoxyethoxymethyl group, trimethylsilyl group, tert-butyldimethylsilyl group, triisopropylsilyl group, methylcarbonyl group, phenylcarbonyl group, and tert-butoxycarbonyl group. Among these, methyl group, benzyl group, methoxymethyl group, trimethylsilyl group, tert-butyldimethylsilyl group, and tert-butoxycarbonyl group are preferred, with the methyl group being more preferred.

[0075] R 6 ~R 8 Each of these independently represents a hydrogen atom or a substituent, and as a substituent, R in the compound represented by formula (1) above 1 ~R 4 Examples of substituents equivalent to those exemplified are provided.

[0076] R 6It is preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a heteroaryl group having 4 to 36 carbon atoms, or a pyrrolyl group which may have substituents, and more preferably a hydrogen atom, a bromine atom, or a pyrrolyl group which may have substituents.

[0077] R 7 It is preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

[0078] R 8 It is preferable that the substituent is a hydrogen atom.

[0079] R 8 It is preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, a heteroaryl group having 4 to 36 carbon atoms, or a pyrrolyl group which may have substituents, and more preferably a tert-butyl group.

[0080] 6 R 6 ~R 8 At least one of these is a substituent, preferably 2 to 4 substituents, and more preferably 2 or 4 substituents.

[0081] R 9 R represents a hydrogen atom or substituent, and in the compound represented by formula (1) above, R 3 Examples equivalent to those mentioned above are given.

[0082] 2 R 9 At least one of them is a hydrogen atom. There are two R 9 Preferably, each of these is a hydrogen atom.

[0083] R 10 , R 11 , R 12 Each of these independently represents a hydrogen atom or a substituent, and R in the compound represented by formula (1) above. 2 , R 3 , R 4Those equivalent thereto are each exemplified, and the preferred examples are also the same for each.

[0084] The plurality of Rs 5 ~R 12 may each independently be the same or different, and two Rs 5 two Rs 6 two Rs 7 two Rs 8 two Rs 9 two Rs 10 two Rs 11 two Rs 12 are preferably the same.

[0085] R 5 ~R 12 Any two of them may be bonded to each other to form a ring.

[0086] The two Rs 12 are preferably bonded to each other to form a ring in the same manner as the aforementioned Rs 4 and, by bonding the two Rs 12 to each other to form a ring, the metal complex 1 represented by the formula (2) is preferably a phenanthroline derivative.

[0087] R 6 ~R 12 may contain a halogen atom or a pyrrolyl group which may have a substituent. That is, R 6 ~R 12 may be a halogen atom or a pyrrolyl group which may have a substituent, and when R 6 ~R 12 is a substituent, the substituent (1) may also be a halogen atom or a pyrrolyl group which may have a substituent.

[0088] R 6 ~R 12 has a halogen atom, the number of halogen atoms contained in the metal complex 1 represented by the formula (2) is preferably 1 to 4, more preferably 1 to 2. Also, when the metal complex 1 contains a halogen atom, as described above, R 6 or R 8It is preferable that the halogen atom is a halogen atom. The halogen atom is R 6 or R 8 If is a substituent, then as substituent (1), R 6 or R 8 It may be included in R. 6 ~R 12 It does not need to have a halogen atom.

[0089] R 6 ~R 12 If R has a pyrrolyl group which may have a substituent, the number of pyrrolyl groups which may have a substituent in the metal complex 1 represented by formula (2) is preferably 1 to 4, and more preferably 1 to 2. Also, if the metal complex 1 contains a pyrrolyl group which may have a substituent, 6 or R 8 It is preferable that the pyrrolyl group may have a substituent. The pyrrolyl group may have a substituent is R 6 or R 8 If is a substituent, then as substituent (1), R 6 or R 8 It may be included in R. 6 ~R 12 The pyrrolyl group may or may not have a substituent.

[0090] a represents an integer from 1 to 3. That is, a is 1, 2, or 3, and preferably 1.

[0091] M is one of the metals belonging to groups 4 through 12 in the fourth period of the periodic table.

[0092] Examples of M include aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc. Among these metals, cobalt, nickel, copper, and zinc are preferred, and more preferably copper and zinc, as they can form a water-soluble complex ion with the water-soluble amine exemplified as a preferred example in the water-soluble amine represented by formula (4) described later.

[0093] M preferably has a positive charge, more preferably has a positive charge of 1 to 4 valencies, even more preferably has a positive charge of 1 or 2 valencies, and particularly preferably has a positive charge of 2 valencies.

[0094] The metal complex 1 represented by formula (2) is preferably electrically neutral as a whole.

[0095] X represents an anion species, and examples include anions that electrically neutralize the positive charge of M. Specifically, examples include inorganic acid ions such as fluoride ions, chloride ions, bromide ions, iodide ions, sulfide ions, oxide ions, hydroxide ions, hydride ions, sulfite ions, phosphate ions, hexafluorophosphate ions, carbonate ions, sulfate ions, nitrate ions, perchlorate ions, and bicarbonate ions, and organic acid ions such as acetate ions, 2-ethylhexanoate ions, trifluoroacetate ions, thiocyanide ions, methanesulfonate ions, trifluoromethanesulfonate ions, acetylacetonate, tetrafluoroborate ions, tetraphenylborate ions, and stearate ions. Among these, chloride ions, bromide ions, and iodide ions are preferred.

[0096] b is the number of X atoms in the metal complex, representing a number greater than or equal to 0, and can be an integer or a decimal, and represents the number of [X] atoms in the metal complex. b The valence of the partial complex ion, excluding the one specified by b, is determined to be the same as the number obtained by multiplying the valence of X by b. b is usually a number between 0 and 3, preferably 2.

[0097] In the metal complex 1 represented by formula (2) above, [] a The substructure enclosed by the symbols may have a negative charge due to proton detachment, but is preferably neutral.

[0098] The b X elements may consist of multiple types, and in the case of multiple types, the combination is preferably selected from the group consisting of fluoride ions, chloride ions, bromide ions, iodide ions, acetate ions, trifluoromethanesulfonate ions, tetrafluoroborate ions, and perchlorate ions, and more preferably selected from the group consisting of chloride ions and bromide ions.

[0099] Examples of metal complexes 1 represented by formula (2) include those represented by the following formulas (B-1) to (B-32). Among these, examples of metal complexes 1 represented by formula (2) having a halogen atom are those represented by formulas (B-2), (B-23) to (B-25), and examples of metal complexes 1 represented by formula (2) having a pyrrolyl group which may have substituents are those represented by formulas (B-26) to (B-31). Among these, formulas (B-1) to (B-13), (B-17), and (B-22) to (B-32) in which M is zinc are preferred.

[0100] [ka]

[0101] [ka]

[0102] <Metal Complex 2> If metal complex 2 is obtained by performing a halogenation reaction on metal complex 1, then metal complex 2 is R of metal complex 1. 6 ~R 12 One or more of the hydrogen atoms, or R 6 ~R 12 In the case where is a substituent, one or more hydrogen atoms in substituent (1) are substituted with halogen atoms in the metal complex. If metal complex 2 is obtained by performing a pyrrole reaction on metal complex 1, then metal complex 2 is R of metal complex 1. 6 ~R 12 One or more of the halogen atoms, or R 6~R 12 When ~R is a substituent, it is a metal complex in which any one or more of the halogen atoms in the substituent (1) are substituted with a pyrrolyl group which may have a substituent. When the metal complex 2 is obtained by performing a halogenation reaction and a pyrrolation reaction in this order with respect to the metal complex 1, the metal complex 2 is the R of the metal complex 1 6 ~R 12 Any one or more of the hydrogen atoms, or R 6 ~R 12 When ~R is a substituent, it is a metal complex in which any one or more of the hydrogen atoms in the substituent (1) are substituted with a pyrrolyl group which may have a substituent.

[0103] More specifically, the metal complex 2 is a metal complex formed by adding [M] and [X] to a bipyridine derivative represented by the following formula (3). b is a metal complex formed by addition.

[0104] <Bipyridine derivative represented by formula (3)> The bipyridine derivative represented by formula (3) of the present embodiment is a bipyridine derivative (hereinafter also referred to as "demetallated body") obtained by demetallating a metal from the metal complex 2 in the second step or a bipyridine derivative (hereinafter also referred to as "deprotected body") obtained by deprotecting the demetallated body.

[0105]

Chemical formula

[0106] In the above formula (3), R 13 ~R 20 are each independently a hydrogen atom or a substituent, and R 13 ~R 20 may be the same or different from each other, and two Rs 13 two Rs 14 two Rs 15 two Rs 16 two Rs 17 two Rs 18 two Rs 19 two Rs 20 may be the same or different from each other, and six Rs14 ~R 16 At least one of them is a substituent, and two R 17 At least one of them is a hydrogen atom, R 13 ~R 20 Any two substituents among them may be bonded to each other to form a ring, R 17 ~R 20 R may contain a halogen atom or a pyrrolyl group which may have a substituent, 14 ~R 16 At least one of these groups may contain a halogen atom or a pyrrolyl group which may have a substituent.

[0107] R 13 A specific example and preferred form is the metal complex 1 represented by formula (2) above, in which R 5 This is equivalent to the example shown. Note that if the bipyridine derivative represented by formula (3) in this embodiment is the deprotected product, then two R 13 It is a hydrogen atom.

[0108] R 14 , R 15 , R 16 , R 17 Each of these independently represents a hydrogen atom or a substituent, and R 14 , R 15 , R 16 , R 17 A specific example and preferred form is the metal complex 1 represented by formula (2) above, in which R 6 , R 7 , R 8 , R 9 Examples include those shown above.

[0109] 6 R 14 ~R 16 At least one of them is a substituent, and the number of substituents is R 6 ~R 8 Examples of such forms include:

[0110] 2 R 17 At least one of them is a hydrogen atom. There are two R 17 It is preferable that it is a hydrogen atom.

[0111] R 18 , R 19 , R 20 Each of these independently represents a hydrogen atom or a substituent, and specific examples and preferred forms are in the metal complex 1 represented by formula (2) above, where R 10 , R 11 , R 12 Examples include the following:

[0112] Multiple R 13 ~R 20 These may be the same or different, R 13 ~R 20 Any two of these may be joined together to form a ring. 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 A preferred example of whether they are the same or different, and R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 A preferred example of a case where any two of them are joined together to form a ring is as follows: 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 These forms are the same as those in [location].

[0113] R 17 ~R 20 R may contain a halogen atom or a pyrrolyl group which may have a substituent. That is, R 17 ~R 20 R may be a halogen atom or a pyrrolyl group which may have a substituent, 17 ~R 20If (1) is a substituent, the substituent (1) may be a halogen atom or a pyrrolyl group which may have a substituent.

[0114] R 14 ~R 16 At least one of these contains a halogen atom or a pyrrolyl group which may have a substituent. In particular, in formula (3), R 14 , R 16 A bipyridine derivative containing any one of the pyrrolyl groups which may have a halogen atom or substituent is preferred, and two R 14 It is more preferable that the group is a halogen atom or a pyrrolyl group which may have substituents.

[0115] R 14 ~R 20 When has halogen atoms, the number of halogen atoms in the bipyridine derivative represented by formula (3) is preferably 1 to 4, and more preferably 1 to 2. Also, when the bipyridine derivative contains halogen atoms, R 14 or R 16 Preferably, one or more of the halogen atoms are halogen atoms. 14 or R 16 If is a substituent, then as substituent (1), R 14 or R 16 It may be included in that.

[0116] R 14 ~R 20 If the bipyridine derivative has a pyrrolyl group which may have a substituent, the number of pyrrolyl groups which may have a substituent in the bipyridine derivative represented by formula (3) is preferably 1 to 4, and more preferably 1 to 2. Also, if the bipyridine derivative contains a pyrrolyl group which may have a substituent, 14 or R 16 It is preferable that one or more of the pyrrolyl groups may have substituents. The pyrrolyl groups that may have substituents are R 14 or R 16 If is a substituent, then as substituent (1), R 14 or R 16 It may be included in that.

[0117] The bipyridine derivative represented by formula (3) may contain neutral molecules. Examples of such neutral molecules include molecules that solvate to form a solvated salt. Specifically, examples of such neutral molecules include water, methanol, ethanol, n-propanol, isopropyl alcohol, 2-methoxyethanol, 1,1-dimethylethanol, ethylene glycol, N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, acetone, chloroform, acetonitrile, benzonitrile, triethylamine, pyridine, pyrazine, diazabicyclo[2,2,2]octane, 4,4'-bipyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, methyl ethyl ether, methyl-tert-butyl ether, 1,4-dioxane, acetic acid, propionic acid, and 2-ethylhexanoic acid. Preferably, these are water, methanol, dimethyl sulfoxide, chloroform, tetrahydrofuran, and methyl-tert-butyl ether.

[0118] Furthermore, the bipyridine derivative represented by formula (3) may form a salt through an acid-base reaction with an acid. The acid refers to a molecule that reacts with the bipyridine derivative represented by formula (3) to form a salt. Specifically, examples of acids include hydrochloric acid, bromic acid, iodic acid, phosphoric acid, acetic acid, sulfate ions, nitric acid, perchlorate ions, trifluoroacetic acid, trifluoromethanesulfonate ions, tetrafluoroboric acid, hexafluorophosphate, and tetraphenylboric acid. Among these, hydrochloric acid and bromic acid are preferred.

[0119] Examples of bipyridine derivatives represented by formula (3) include metal complexes represented by formulas (B-2), (B-23) to (B-25), and metal complexes represented by formulas (B-26) to (B-31), [M] and [X]. b Examples of structures with detached moieties include bipyridine derivatives represented by the following formulas (C-1) to (C-23). ​​Among these, bipyridine derivatives represented by (C-10) to (C-18) are preferred, and bipyridine derivatives represented by (C-12) to (C-17) are more preferred.

[0120] [ka]

[0121] [ka]

[0122] In one embodiment of the present invention, the number of halogen atoms contained in the bipyridine derivative represented by formula (3) is greater than the number of halogen atoms contained in the compound represented by formula (1). Preferably, the number of halogen atoms contained in the bipyridine derivative represented by formula (3) is 1 to 4 greater than the number of halogen atoms contained in the compound represented by formula (1), and more preferably, it is 1 to 2 greater. In this case, a halogenation reaction is carried out in the second step.

[0123] In one preferred embodiment, the compound represented by formula (1) does not contain halogen atoms, and the bipyridine derivative represented by formula (3) contains one to two halogen atoms. In this case, a halogenation reaction is carried out in the second step.

[0124] In one embodiment of the present invention, the number of optionally substituted pyrrolyl groups in the bipyridine derivative represented by formula (3) is greater than the number of optionally substituted pyrrolyl groups in the compound represented by formula (1). Preferably, the number of optionally substituted pyrrolyl groups in the bipyridine derivative represented by formula (3) is 1 to 4 more than the number of optionally substituted pyrrolyl groups in the compound represented by formula (1), and more preferably 1 to 2 more. In this case, the pyrroleization reaction is carried out in the second step, or the halogenation reaction and the pyrroleization reaction are carried out in this order.

[0125] In one preferred embodiment, the compound represented by formula (1) does not contain a halogen atom and a pyrrolyl group which may have substituents, and the bipyridine derivative represented by formula (3) contains one or two pyrrolyl groups which may have substituents. In this case, the halogenation reaction and the pyrroleation reaction are carried out in this order in the second step.

[0126] Another preferred embodiment is one in which the compound represented by formula (1) contains one to two halogen atoms and does not contain a pyrrolyl group which may have substituents, and the bipyridine derivative represented by formula (3) contains one to two pyrrolyl groups which may have substituents. In this case, a pyrroleization reaction is carried out in the second step.

[0127] <1st process> The first step is to obtain a metal complex 1 represented by formula (2) from a compound represented by formula (1).

[0128] Specifically, the first step includes reacting a metal salt containing the metal represented by M and the anionic species represented by X with the compound represented by formula (1) to obtain a metal complex 1 represented by formula (2) (hereinafter also referred to as the "metal complex formation step").

[0129] The compound represented by formula (1) can be obtained, for example, by reacting a compound represented by formula (1') below, synthesized by general organic synthesis, with an oxidizing agent to oxidize the NH bond in formula (1') and generate a bipyridine skeleton. Specifically, the compound represented by formula (1) can be obtained by reacting a compound represented by formula (1') with an oxidizing agent such as manganese dioxide or benzoquinone in a solvent.

[0130] [ka]

[0131] R in equation (1') above 1’ ~R4’ R in equation (1) above is 1 ~R 4 These are the same as above.

[0132] (Metal complex formation process) There are no particular restrictions on the method used in the metal complex formation process, and any method generally known for forming metal complexes from bipyridine derivatives can be applied. For example, one method involves mixing the compound represented by formula (1) with a metal salt containing the metal represented by M and the anionic species represented by X in a solvent and reacting the mixture.

[0133] In this embodiment, from the viewpoint of the crystallinity of the resulting metal complex, the solvent can be a general-purpose organic solvent, or a solvent that is difficult to concentrate under reduced pressure. Specifically, examples include aromatic hydrocarbon solvents such as benzene, toluene, xylene, and mesitylene; ether solvents such as diethyl ether, 1,2-dimethoxyethane, methyl ethyl ether, methyl-tert-butyl ether, 1,4-dioxane, tetrahydrofuran, 4-methyltetrahydropyran, and 4-tert-butylanisole; alcohol solvents such as methanol, ethanol, n-propanol, isopropyl alcohol, 2-methoxyethanol, 1-butanol, 1,1-dimethylethanol, and ethylene glycol; halogen solvents such as dichloromethane, chloroform, carbon tetrachloride, chlorobenzene, and 1,2-dichlorobenzene; amide solvents such as N,N'-dimethylformamide, N,N'-dimethylacetamide, and N-methyl-2-pyrrolidone; and polar solvents such as dimethyl sulfoxide, acetone, and water. A reaction solvent made by mixing two or more of these solvents may also be used, but it is preferable that the compound represented by formula (1) and the metal salt can be dissolved in it. Among these, ether-based solvents such as methyl-tert-butyl ether, 4-tert-butylanisole, 1,4-dioxane, tetrahydrofuran, and 4-methyltetrahydropyran are preferred.

[0134] The amount of solvent used is not particularly limited, but is usually 1 to 200 parts by mass, preferably 3 to 50 parts by mass, per 1 part by mass of the compound represented by formula (1).

[0135] The metal salt is not particularly limited as long as it is a compound that can dissociate in a solvent to generate metal ions.

[0136] Examples of metal ion species that can form a metal complex with the compound represented by formula (1) used in the first step, and preferred forms, are the same as described in M ​​above.

[0137] Examples of metal salts that can dissolve in a solvent to generate metal ions include metal salts comprising the metal represented by M and the anion species represented by X. Specifically, examples include organic acid ions such as zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc sulfate, zinc perchlorate, zinc acetate, zinc 2-ethylhexanoate, zinc trifluoroacetate, zinc thiocyanate, zinc methanesulfonate, zinc trifluoromethanesulfonate, zinc acetylacetone, zinc tetrafluoroborate, and zinc stearate. Among these, zinc chloride, zinc bromide, zinc iodide, and zinc acetate are preferred.

[0138] This reaction may be carried out by directly adding the metal salt to a solution of the compound represented by formula (1) in a solvent, or by separately preparing a metal salt solution that has been dissolved in the solvent beforehand, and then mixing the metal salt solution with the solution of the compound represented by formula (1).

[0139] The amount of the metal salt added is not particularly limited, and the amount of the metal salt can be adjusted according to the target metal complex. Typically, the amount is 1.0 equivalent to 20 equivalents, and preferably 1.0 equivalent to 5.0 equivalents, relative to the compound represented by formula (1).

[0140] The reaction temperature is typically above the freezing point of the solvent and below the boiling point of the solvent. It is preferably -80 to 100°C, and more preferably -10 to 60°C.

[0141] The reaction time is typically between 1 minute and 1 week, preferably between 5 minutes and 24 hours, and more preferably between 30 minutes and 12 hours. The reaction temperature and reaction time can be appropriately optimized depending on the solvent, the compound represented by formula (1), and the type of metal salt.

[0142] The metal complex 1 represented by formula (2) obtained in the metal complex formation step can be isolated by crystallization.

[0143] The metal complex 1 represented by formula (2) has higher crystallinity than the compound represented by formula (1). Therefore, by appropriately combining operations such as stirring the reaction solution obtained in the metal complex formation step, adding the metal complex as a seed crystal to the reaction solution obtained in the metal complex formation step, partially concentrating the reaction solution obtained in the metal complex formation step, or adding a poor solvent for the metal complex to the reaction solution obtained in the metal complex formation step, the resulting metal complex 1 precipitates as a solid. At this time, by lowering the crystallization temperature compared to the reaction temperature in the metal complex formation step, crystallization can be performed efficiently, and the target product can be extracted in good yield.

[0144] The crystallization temperature should be lower than the reaction temperature and lower the solubility of the metal complex in order to promote the precipitation of the metal complex as a precipitate. Preferably, the temperature is -80 to 60°C, and more preferably -20 to 40°C.

[0145] The method for extracting the metal complex isolated by crystallization is not particularly limited; for example, solid-liquid separation by filtration or centrifugation is used. The resulting solid can be isolated and purified by washing or drying as needed.

[0146] <Second process> The second step involves performing either a halogenation reaction (hereinafter also referred to as the "halogenation step") or a pyrrole reaction (hereinafter also referred to as the "pyrrole step") on the metal complex 1 represented by formula (2) to obtain a metal complex 2, and a demetallation step to remove the metal from the metal complex 2. A deprotection step may also be included after the demetallation step. When the second step is a step in which both a halogenation reaction and a pyrrole reaction are performed to obtain a metal complex 2, it means (i) a step in which a halogenation reaction is performed on the metal complex 1 to obtain a halogenated product of the metal complex 1, and a pyrrole reaction is performed on the halogenated product of the metal complex 1, or (ii) a step in which a pyrrole reaction is performed on the metal complex 1 to obtain a pyrrole product of the metal complex 1, and halogenation is performed on the pyrrole product of the metal complex 1. In particular, (i) a step in which a halogenation reaction is performed on the metal complex 1 to obtain a halogenated product of the metal complex 1, and a pyrrole reaction is performed on the halogenated product of the metal complex 1 is preferred. The following describes the halogenation process, pyrrole process, demetallation process, and deprotection process.

[0147] (Halogenation process) The halogenation step involves reacting a halogenating agent with metal complex 1 or its pyrrole derivative (hereinafter, metal complex 1 and its pyrrole derivative are collectively referred to as "metal complex 1-1, etc.") that has been isolated by crystallization after the metal complexation step, in order to obtain metal complex 2. If the desired portion of metal complex 1 or its pyrrole derivative is already halogenated, the halogenation step is not necessary.

[0148] For reacting metal complex 1-1, etc., with a halogenating agent, methods generally known for reacting bipyridine derivatives with halogenating agents can be applied. There are no particular restrictions, but one example is a method in which the halogenating agent is mixed with the metal complex in a solvent and then reacted.

[0149] The reaction between metal complex 1-1 and the halogenating agent can be carried out in the presence of a suitable solvent. Examples of solvents used in the reaction include halogenated solvents such as dichloromethane, chloroform, and carbon tetrachloride; ether solvents such as tetrahydrofuran and 1,4-dioxane; nitrile solvents such as acetonitrile; ester solvents such as ethyl acetate; amide solvents such as dimethylformamide; and water. A reaction solvent made by mixing two or more of these solvents may also be used, but it is preferable that the metal complex and halogenating agent can be dissolved in the solvent. Among these, halogenated solvents such as dichloromethane, chloroform, and carbon tetrachloride are preferred.

[0150] The amount of solvent used is not particularly limited, but is usually 1 to 200 parts by mass, preferably 3 to 50 parts by mass, per 1 part by mass of metal complex 1-1, etc.

[0151] Examples of halogenating agents used in the halogenation process include halogenating agents that generate free halogens in the reaction system, such as N,N'-bromosuccinimide, N,N'-dibromo-5,5-dimethylhydantoin, and 4-dimethylaminopyridinium bromide perbromide, or bromine (Br2), with bromine being particularly preferred.

[0152] This reaction can be carried out by directly adding the halogenating agent to a solution in which metal complex 1-1, etc., is dissolved in a solvent. Alternatively, a halogenating agent solution pre-dissolved in a solvent can be prepared separately, and this halogenating agent solution can be mixed with the solution in which metal complex 1-1, etc., is dissolved.

[0153] The amount of halogenating agent added is not particularly limited, and the amount of halogenating agent can be adjusted according to its reactivity with metal complex 1-1, etc. Typically, the amount is 1.0 equivalent to 20 equivalents, and preferably 1.0 equivalent to 10 equivalents, relative to metal complex 1-1, etc.

[0154] The reaction temperature is typically above the freezing point of the solvent and below the boiling point of the solvent. It is preferably in the range of -20 to 100°C, and more preferably in the range of 20 to 60°C.

[0155] The reaction time is typically between 1 minute and 1 week, preferably between 5 minutes and 24 hours, and more preferably between 30 minutes and 12 hours. The reaction temperature and reaction time can be appropriately optimized depending on the type of solvent, metal complex 1-1, etc., and halogenating agent.

[0156] Since halogenation reactions are known to generate bromine radicals through photoexcitation of bromine when carried out under light irradiation, potentially yielding byproducts, it is preferable to carry out the reaction in the dark.

[0157] After the reaction is complete, any excess halogenating agent can be quenched by bringing an aqueous solution containing a reducing agent into contact with the solution containing the unreacted halogenating agent. Sodium thiosulfate is an example of a reducing agent. The amount of reducing agent added is 1.0 equivalent to 20 equivalents relative to the amount of halogenating agent added, and preferably 1.0 equivalent to 5.0 equivalents.

[0158] In this aqueous phase, hydrogen bromide generated by the quenching of the halogenating agent and water-soluble impurities are present. By removing the aqueous phase through liquid-liquid separation and recovering only the organic phase, halogenated products such as metal complex 1-1 can be extracted from the organic phase.

[0159] Normally, halogenating agents that generate free bromine, or halogenation reactions using bromine, produce hydrogen bromide as a by-product. When this reaction is carried out with the bipyridine derivative represented by formula (3), the nitrogen atom of the bipyridine derivative is protonated by the by-product hydrogen bromide, thus reducing the electron density of the bipyridine derivative. Since halogenation reactions are electrophilic aromatic substitution reactions, the bipyridine derivative, which becomes electron-deficient due to protonation, becomes less reactive, and the reaction rate slows down.

[0160] On the other hand, when this reaction is carried out with metal complex 1-1, the nitrogen atom in metal complex 1-1 is coordinated to the [M] component in formula (2), and the effect of the decrease in electron density of the bipyridine derivative due to the above-mentioned protonation is small, so halogenation can be carried out efficiently.

[0161] [ka]

[0162] R in equation (8) above 5 ~R 12 , M, X, a, and b are the same as in equation (2) above.

[0163] The metal complex 2 obtained in the halogenation step can be isolated by crystallization.

[0164] By partially concentrating the organic phase of the reaction solution obtained in the halogenation step, adding the poor solvent of the resulting metal complex 2, etc., the generated metal complex 2 precipitates as a solid. At this time, the crystallization temperature is lower than the reaction temperature and is a temperature at which the solubility of metal complex 2 decreases, in order to promote the precipitation of metal complex 2 as a precipitate, and is preferably -80 to 60°C, and more preferably -20 to 40°C.

[0165] The extraction method is not particularly limited; for example, solid-liquid separation by filtration or centrifugation is used. The obtained solid can be isolated and purified by washing or drying as needed.

[0166] (Pyrrole formation process) The pyrrole formation step is a process in which metal complex 1 or a halogenated product of metal complex 1 (hereinafter, metal complex 1 and the halogenated product of metal complex 1 are collectively referred to as "metal complex 1-2, etc.") isolated by crystallization after the metal complex formation step is subjected to a pyrrole formation reaction to obtain metal complex 2.

[0167] For pyrrole reactions, cross-coupling reactions, which are known as carbon-carbon and carbon-heteroatom bond formation reactions using transition metal catalysts, are applicable. These reactions are known as methods for introducing olefins such as aromatics, alkenes, and alkynes as substituents to common organic halogen compounds.

[0168] The R of the metal complex 1 represented by formula (2) above 6 ~R 12 When a halogen atom is present as a substituent on any of the components, or when the halide of metal complex 1 is subjected to a pyrrole reaction, a pyrrolyl group which may have substituents can be introduced by a palladium-catalyzed coupling reaction such as the Suzuki-Miyaura coupling reaction, the Mizoroki-Heck reaction, or the Negishi coupling reaction; a nickel-catalyzed coupling reaction such as the Yamamoto coupling reaction or the Kumada-Tamao coupling reaction; or a copper-catalyzed coupling reaction such as the Ullmann reaction. Preferably, the coupling reaction uses palladium and zinc.

[0169] Among these, coupling reactions using palladium and zinc, such as the Negishi coupling reaction, are preferred, as described in the known literature (Organic Letters, 2004, 6, 3981). In the Negishi coupling reaction, an organic halogen compound and a pyrrole organozinc reagent are mixed in a solvent and reacted, allowing for the direct introduction of a pyrrolyl group, which may have substituents, without protection or deprotection.

[0170] The method for producing the metal complex 2 by the Negishi coupling reaction generally includes a step of preparing a pyrrole organozinc reagent (hereinafter also referred to as the "pyrrole organozinc reagent preparation step") and a step of mixing the prepared pyrrole organozinc reagent with the metal complexes 1-2, etc., in the presence of a suitable solvent and reacting them using a palladium catalyst (hereinafter also referred to as the "pyrrole reaction step").

[0171] (Preparation process for pyrrole organozinc reagent) The pyrrole organozinc reagent preparation process involves adding a base and optionally substituted pyrrole to a suitable solvent to generate pyrrole anion species, and then adding a zinc salt to prepare the pyrrole organozinc reagent.

[0172] The reaction generally proceeds under an inert atmosphere such as argon gas until the conversion is complete, and aproton The process is carried out under conditions of elimination of oxygen or air from the solvent.

[0173] Suitable aprotic solvents include ether-based solvents such as diethyl ether, 1,2-dimethoxyethane, methyl ethyl ether, methyl-tert-butyl ether, 1,4-dioxane, tetrahydrofuran, 4-methyltetrahydropyran, and 4-tert-butylanisole; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, and mesitylene; halogen-based solvents such as dichloromethane, carbon tetrachloride, chlorobenzene, and 1,2-dichlorobenzene; amide-based solvents such as N,N'-dimethylformamide, N,N'-dimethylacetamide, and N-methyl-2-pyrrolidone; and polar solvents such as dimethyl sulfoxide. A reaction solvent made by mixing two or more of these may be used, but it is preferable that the metal complex 1-2 and the pyrrole organozinc reagent can be dissolved in it. Among these, tetrahydrofuran is preferred.

[0174] The amount of solvent used is not particularly limited, but is usually 1 to 200 parts by mass, preferably 3 to 50 parts by mass, per 1 part by mass of metal complex 1-2, etc.

[0175] This reaction is preferably carried out in the substantial absence of a protic solvent such as water. Unless otherwise noted, the solvent is dried to minimize the presence of a protic solvent such as water. The reaction vessel, reactants, and solvent are preferably dried or distilled before use to ensure that water is not present during the reaction.

[0176] The base used to generate the pyrrole anion species is not particularly limited, but examples include metal hydrides such as sodium hydride and potassium hydride, and metal alkoxides such as sodium methoxide and potassium butoxide, with sodium hydride being preferred.

[0177] The amount of base added is not particularly limited and can be adjusted according to the reaction site of the target metal complex 1-2, etc. However, for metal complex 1-2, etc. represented by formula (2), the amount of base added is preferably between 1.0 equivalent and 10 equivalents, and between 2.0 equivalents and 5.0 equivalents.

[0178] The pyrrole, which may be substituted, used in the preparation process of pyrrole organozinc reagents is represented by the following formula (9).

[0179] [ka]

[0180] In equation (9) above, R 32 R is a hydrogen atom or a substituent. 32 If is a substituent, the substituent is later R 32 By converting to hydrogen, -NR 32 It is preferable that the substituent is capable of converting the moiety to an -NH structure, i.e., a protecting group. 32 A specific example of a protecting group in this context is the tert-butoxycarbonyl group.

[0181] R 32 It is preferable that it is a hydrogen atom.

[0182] In the formula, R 33 is a hydrogen atom or "-B(-OY 1 The group is represented as ")2", and is preferably a hydrogen atom.

[0183] Y 1 Y is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. There are two Y 1These elements may be identical or different, and they may be joined together to form a ring.

[0184] R 34 , R 35 Each of these independently represents a hydrogen atom or a substituent. 34 , R 35 If it is a substituent, it is preferably substituent (1).

[0185] R 34 , R 35 It is preferable that it is a hydrogen atom.

[0186] Examples of pyrroles that may be substituted, as represented by formula (9) above, include pyrroles that may be substituted, as represented by the following formulas (E1) to (E10).

[0187] [ka]

[0188] The amount of pyrrole to be added, which may be substituted, is not particularly limited and can be adjusted according to the reaction site of the target metal complex 1-2, etc., preferably between 1.0 equivalent and 40 equivalents, more preferably between 5.0 equivalents and 20 equivalents, and more preferably between 10 equivalents and 20 equivalents, relative to metal complex 1-2, etc.

[0189] The reaction temperature is typically above the freezing point of the solvent and below the boiling point of the solvent. It is preferably between -20 and 100°C, and when a metal hydride is used as the base, it is preferably between -20 and 60°C.

[0190] Zinc salts are compounds that can dissociate in a solvent to produce zinc ions. Specifically, these include zinc chloride, zinc bromide, and zinc iodide, and their hydrates may also be used. Among these, zinc chloride or its hydrate is preferred.

[0191] The amount of zinc salt added is not particularly limited, and the amount of zinc salt can be adjusted according to the target metal complex. For metal complexes 1-2, the amount is preferably between 1.0 and 20 equivalents, and between 2.0 and 8.0 equivalents.

[0192] This reaction can be carried out by directly adding the zinc salt to a solution of pyrrole and base dissolved in a solvent, or by mixing the zinc salt, which has been pre-dissolved in a solvent prepared separately from this reaction, with the solution of pyrrole and base.

[0193] The reaction time is typically in the range of 1 minute to 24 hours, preferably 5 minutes to 1 hour. The reaction temperature and reaction time can be appropriately optimized depending on the type of solvent, base, and zinc salt.

[0194] (Pyrrole reaction process) The pyrrole reaction step involves mixing a solution containing the pyrrole organozinc reagent prepared in the pyrrole organozinc reagent preparation step with metal complex 1-2, etc., in the presence of a suitable solvent and reacting it using a palladium catalyst.

[0195] The reaction generally proceeds under an inert atmosphere such as argon gas until the conversion is complete, and aproton The process is carried out under conditions of elimination of oxygen or air from the solvent.

[0196] Suitable aprotic solvents used in the pyrrole reaction step are the same as those exemplified in the pyrrole organozinc reagent preparation step.

[0197] The amount of solvent used is not particularly limited, but is usually 1 to 200 parts by mass, preferably 3 to 50 parts by mass, per 1 part by mass of metal complex 1-2, etc.

[0198] This reaction is preferably carried out in the substantial absence of a protic solvent such as water. Unless otherwise noted, the solvent is dried to minimize the presence of a protic solvent such as water. The reaction vessel, reactants, and solvent are preferably dried or distilled before use to ensure that water is not present during the reaction.

[0199] Palladium catalysts are preferably complexes in which a ligand is coordinated to palladium.

[0200] While there are no particular limitations on the ligands that can coordinate to transition metals, examples of palladium ligands include phosphorus-based ligands, nitrogen-based ligands, oxygen-based ligands, carbon-based ligands, and anionic ligands.

[0201] The phosphorus ligand is not particularly limited as long as it has a phosphorus atom that can coordinate to a transition metal, but tertiary phosphine ligands are preferred. Specifically, triphenylphosphine, tris(2-methylphenyl)phosphine, tris(2-methoxyphenyl)phosphine, di-tert-butylphenylphosphine, tri-tert-butylphosphine, tricyclohexylphosphine, 1,1'-bis(diphenylphosphino)ferrocene (DPPF), 1,3-bis(diphenylphosphino)propane (DPPP), 1,2-bis(diphenylphosphino)ethane (DPPE), 2,2''-bis(diphenylphosphino)-1,1'-bina Examples include phthyl (BINAP), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos), 2-(dicyclohexylphosphino)-2',4',6'-triisopropylbiphenyl (XPhos), 2-(dicyclohexylphosphino)-2'-methylbiphenyl (MePhos), 2-(dicyclohexylphosphino)-2'-(dimethylamino)biphenyl (DavePhos), and 2-(di-tert-butylphosphino)biphenyl (JohnPhos). Quaternary phosphonium salts may also be used as the phosphine ligand.

[0202] Nitrogen-based ligands are not particularly limited as long as they have a nitrogen atom capable of coordinating to a transition metal, but examples include nitrogen-containing aromatic heterocyclic ligands such as pyridine, dimethylpyridine, bipyridine, terpyridine, quinoline, isoquinoline, acridine, phenanthroline, N,N-dimethyl-4-aminopyridine (DMAP), and porphyrin, and their salts, as well as amine-based ligands such as ammonia, aniline, diisopropylamine, 1,1,1,3,3,3-hexamethyldisilazane (HMDS), triethylamine, triphenylamine, 1,8-diazabicyclo[5.4.0]undeca-7-ene (DBU), and N,N,N',N'-tetramethylethane-1,2-diamine (TMEDA), and their quaternary ammonium salts, and nitrile-based ligands such as acetonitrile and benzonitrile.

[0203] The oxygen-based ligands are not particularly limited as long as they have an oxygen atom capable of coordinating to a transition metal, but examples include ether-based ligands such as dimethyl ether, diethyl ether, tetrahydrofuran, 1,4-dioxane, and dimethoxyethane; alcohol-based ligands such as methanol, ethanol, phenol, and 1,1'-binaphthalene-2,2'-diol; acyl-based ligands such as acetic acid and acetylacetone; and phosphine oxide-based ligands such as phosphate esters, phenylphosphonic acid esters, diphenylphosphinic acid esters, triphenylphosphine oxide, and trimethylphosphine oxide.

[0204] Carbon-based ligands are not particularly limited as long as they have carbon atoms capable of coordinating to transition metals, but examples include ligands containing multiple carbon-carbon bonds such as ethylene, 1-hexene, cyclopentadiene, dibenzylideneacetone (dba), 1,5-cyclooctadiene (COD), and 2-phenylethynylbenzene; isocyanide ligands such as cyanomethyl isocyanides and phenyl isocyanides; carbene ligands such as N-heterocyclic carbenes; and carbon monoxide.

[0205] The anionic ligand is not particularly limited as long as it is coordinately bonded to the transition metal by an anionic group. Specific examples of anionic ligands include oxyanionic ligands such as hydrides, halide ions, cyanide ions, methoxy groups, phenoxy groups, phosphate ions, sulfate ions, nitrate ions, trifluoromethanesulfonates, acetates, and acetylacetonates, as well as carbanionic ligands obtained by removing protons from methane, ethane, ethylene, and benzene.

[0206] Examples of palladium catalysts include palladium complexes such as tetrakis(triphenylphosphine)palladium(O), tris(dibenzylideneacetone)dipalladium(O), palladium(II) acetate, dichlorobistriphenylphosphinepalladium(II), and potassium hexachloropalladate(IV), as well as complexes in which the ligand is coordinated to the palladium complex.

[0207] The palladium catalyst described above may be used as is after being synthesized in advance, or it may be prepared by adding palladium and a ligand to a solvent prepared separately from this reaction. Alternatively, palladium and the ligand may be added directly to the reaction system. A phosphorus-based ligand is preferred as the ligand, and a tertiary phosphine ligand is more preferred. These catalysts may be used individually or in combination of two or more.

[0208] Specific examples of suitable palladium catalysts used in the pyrrole reaction step include those prepared by adding a tertiary phosphine ligand selected from the group consisting of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos), 2-(dicyclohexylphosphino)-2',4',6'-triisopropylbiphenyl (XPhos), and 2-(di-tert-butylphosphino)biphenyl (JohnPhos) to a palladium complex selected from the group consisting of tetrakis(triphenylphosphine)palladium(O) and palladium(II) acetate, or PEPPSI™-iPr. More preferably, it is prepared by adding 2-(di-tert-butylphosphino)biphenyl (JohnPhos) to palladium(II) acetate.

[0209] The amount of palladium catalyst used is not particularly limited, and the amount of R such as the target metal complex 1-2 is used. 6 ~R 12 The amount of palladium catalyst can be adjusted depending on the metal complex having a halogen atom as a substituent on any of the metal complexes, but the catalyst amount is preferable relative to metal complexes 1-2, etc. Specifically, it is preferably 0.001 equivalents or more and 0.5 equivalents or less relative to metal complexes 1-2, etc., and preferably 0.005 equivalents or more and 0.1 equivalents or less.

[0210] This reaction involves a solution containing the pyrrole organozinc reagent prepared in the pyrrole organozinc reagent preparation step and the R of the metal complex 1 represented by formula (2). 6 ~R 12 This can be carried out by mixing a compound having a halogen atom as a substituent on any of the compounds in the presence of a suitable solvent, and then adding the palladium catalyst mentioned above and carrying out the reaction.

[0211] The reaction temperature is typically above the freezing point of the solvent and below the boiling point of the solvent. It is preferably in the range of -20 to 100°C, and more preferably in the range of 0 to 80°C.

[0212] The reaction time is usually from 1 minute to 24 hours, with 5 minutes to 12 hours being preferred. The reaction temperature and reaction time are determined by the solvent, pyrrole organozinc reagent, and the R of the metal complex 1 represented by formula (2) above. 6 ~R 12 The presence of a halogen atom as a substituent in any of the elements, or the type of halide of metal complex 1, and the type of palladium catalyst can be appropriately optimized.

[0213] In equation (2) above, the two R 6 When pyrroleization occurs, it is represented by the following formula (10).

[0214] [ka]

[0215] R in equation (10) 5 ~R 12 The definitions of M, X, a, and b are the same as in equation (2) above, and R 13 ~R 20 The definition of is the same as in equation (3) above, and R 32 ~R 35 The definition of is the same as in equation (9) above. 6 Preferably, it is a halogen atom.

[0216] The metal complex 2 obtained in the pyrroleization process can be isolated by crystallization.

[0217] After the reaction is complete, the resulting metal complex 2 precipitates as a solid by partially concentrating the organic phase containing metal complex 2, adding a poor solvent for metal complex 2, etc. At this time, the crystallization temperature is lower than the reaction temperature and is a temperature at which the solubility of metal complex 2 decreases, in order to promote the precipitation of metal complex 2 as a precipitate, and is preferably in the range of -80 to 60°C, and more preferably in the range of -20 to 40°C.

[0218] The extraction method is not particularly limited; for example, solid-liquid separation by filtration or centrifugation is used. The obtained solid can be isolated and purified by washing or drying as needed.

[0219] Furthermore, isolation of metal complex 2 is not required; in that case, after the reaction is complete, the organic phase containing metal complex 2 can be used in the next step as a solution.

[0220] (Demetallization process) The demetallation step involves adding an acid or base to the metal complex 2 to remove the metal. By performing demetallation, the bipyridine derivative represented by formula (3) can be obtained.

[0221] In the demetallation process, generally known methods for removing metal from metal complexes of bipyridine derivatives can be applied, and there are no particular limitations. As an example, the process involves dissolving metal complex 2 in an organic solvent that can separate the aqueous phase from the organic phase, contacting it with an aqueous solution containing an acid or base, extracting the desorbed metal ions, separating the aqueous phase from the organic phase by liquid-liquid extraction, and recovering the organic phase containing the bipyridine derivative represented by formula (3). The organic phase containing the bipyridine derivative represented by formula (3) obtained in this way may be used in the next step as a solution, or crystals of the bipyridine derivative represented by formula (3) may be grown from the organic phase and the solid material may be recovered.

[0222] The demetallation process involves dissolving the metal complex 2 in an organic solvent that allows for phase separation from the aqueous phase, and then contacting it with an aqueous solution containing an acid or base to remove the metal.

[0223] When an aqueous solution containing an acid is brought into contact with the metal, the detached metal forms a water-soluble metal salt with the acid's anions, which can then be removed by extraction into the aqueous phase.

[0224] When a base-containing aqueous solution is brought into contact with the metal, the detached metal forms a water-soluble metal salt or complex ion with the base anion, which can then be removed by extraction into the aqueous phase. If the detached metal forms a sparingly water-soluble salt with the base anion, the precipitate can be removed by filtration.

[0225] Examples of organic solvents that can be phase-separated from the aqueous phase include ether-based solvents such as diethyl ether, 1,2-dimethoxyethane, methyl ethyl ether, methyl-tert-butyl ether, 1,4-dioxane, tetrahydrofuran, and 4-methyltetrahydropyran; ester-based solvents such as ethyl acetate and butyl acetate; and halogen-based solvents such as dichloromethane, chloroform, carbon tetrachloride, chlorobenzene, and 1,2-dichlorobenzene, with tetrahydrofuran being preferred. The organic solvent that can be phase-separated from the aqueous phase may be a single solvent or a mixture of several solvents.

[0226] The amount of organic solvent that can be phase-separated from the aqueous phase is not particularly limited, but is usually 1 to 200 parts by mass, and preferably 3 to 50 parts by mass, per 1 part by mass of metal complex 2.

[0227] If the phase separation between the organic solvent and the aqueous phase is insufficient and the extraction efficiency is poor, it is preferable to add a salt to the aqueous phase as a phase separation accelerator. Examples of phase separation accelerators include water-soluble inorganic salts such as sodium chloride, potassium chloride, ammonium chloride, sodium bromide, ammonium bromide, sodium acetate, and ammonium acetate, with sodium chloride and ammonium chloride being preferred from the viewpoint of solubility in the aqueous phase and cost.

[0228] Examples of acids used in the demetallation process include hydrogen halides such as hydrogen chloride, hydrogen bromide, and hydrogen iodide; inorganic acids such as perchloric acid, sulfuric acid, fluorosulfonic acid, nitric acid, phosphoric acid, tetrafluoroboric acid, and hexafluorophosphate; sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid; and organic acids such as acetic acid, citric acid, formic acid, gluconic acid, ethylenediaminetetraacetic acid, lactic acid, oxalic acid, tartaric acid, and ascorbic acid.

[0229] The amount of aqueous solution containing the acid is not particularly limited, as long as it is sufficient to demetallate the metal complex 2 and obtain the bipyridine derivative represented by formula (3) above, and may even be in excess.

[0230] Examples of bases used in the demetallation process include amine compounds such as ammonia, methylamine, N,N,N',N'-tetramethylethylenediamine, and water-soluble amines represented by formula (4) described later; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide; quaternary ammonium hydroxides such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; alkali metal bicarbonates such as lithium bicarbonate, sodium bicarbonate, and potassium bicarbonate; and alkali metal salts of organic acids such as sodium citrate, sodium gluconate, sodium ethylenediaminetetraacetate, sodium lactate, sodium oxalate, sodium tartrate, and sodium ascorbate.

[0231] In the demetallation process, it is preferable to use only bases as the acid and base.

[0232] The amount of aqueous solution containing the base is not particularly limited, as long as it is sufficient to demetallate the metal complex 2 and obtain the bipyridine derivative represented by formula (3), and may even be in excess. When using amine compounds, alkali metal hydroxides, or alkaline earth metal hydroxides, using an excess amount relative to the metal complex facilitates aqueous phase extraction by forming a water-soluble complex ion.

[0233] The reaction temperature is typically above the freezing point of the solvent and below the boiling point of the solvent. For example, it is 0 to 100°C, and preferably 10 to 60°C.

[0234] The reaction time is typically between 1 minute and 24 hours, with 5 minutes to 1 hour being preferable. The reaction temperature and reaction time can be appropriately optimized depending on the type of solvent, metal complex 2, acid, and base.

[0235] In this aqueous phase, metal ions separated from metal complex 2 and water-soluble impurities are present. By removing the aqueous phase through liquid-liquid separation and recovering only the organic phase, the bipyridine derivative represented by formula (3) can be extracted from the organic phase.

[0236] (Water-soluble amine) In the demetallation process, it is preferable to use a water-soluble amine represented by the following formula (4) as the base. By using the water-soluble amine, the removed metal ions form a highly water-soluble metal ammine complex, which facilitates aqueous phase extraction of the metal ions.

[0237] [ka]

[0238] In equation (4) above, R 21 ~R 23 Each of these is independently a hydrogen atom or a substituent.

[0239] The substituent is preferably one or more substituents selected from the group consisting of a methyl group, an ethyl group, a hydroxymethyl group, and a hydroxyethyl group. 21 , R 22 , R 23 Each of these is preferably a hydrogen atom. 21 , R 22 , R 23 These may be the same or different, but it is preferable that they be the same.

[0240] The amount of aqueous solution containing the water-soluble amine is not particularly limited, as long as it is sufficient to demetallate the metal complex 2 and obtain the bipyridine derivative represented by formula (3) above; an excess amount is also acceptable. When using an amine compound, alkali metal hydroxide, or alkaline earth metal hydroxide as the base, using an excess amount relative to the metal complex facilitates aqueous phase extraction by forming a water-soluble complex ion.

[0241] Examples of water-soluble amines represented by formula (4) include the water-soluble amines represented by the following formulas (D-1) to (D-19). Among these, the water-soluble amines represented by (D-1), (D-2), and (D-5) are preferred, and the water-soluble amines represented by (D-1) and (D-2) are more preferred.

[0242] [ka]

[0243] The demetallated product obtained in the demetallation process can be isolated by crystallization.

[0244] The organic phase recovered in the demetallation process can be concentrated under reduced pressure, and if necessary, a poor solvent can be added and crystallized to recover it as a solid.

[0245] The crystallization temperature is a temperature at which the solubility of the target substance decreases in order to promote the precipitation of the target substance as a precipitate, and is preferably -80 to 60°C, and more preferably -20 to 40°C.

[0246] The extraction method is not particularly limited; for example, solid-liquid separation by filtration or centrifugation is used. The obtained solid can be isolated and purified by washing or drying as needed.

[0247] Furthermore, the isolation step for the demetallated product is not required; in that case, after the reaction is complete, the organic phase containing the demetallated product can be used in the next step as a solution.

[0248] (Deprotection step) The deprotection step is a step in which, if the demetallated body has a protecting group, the protecting group is deprotected. Specifically, the bipyridine derivative represented by formula (3) obtained by the demetallation step is reacted with a deprotecting agent to obtain the -OR of the bipyridine derivative represented by formula (3). 13 This is a process to obtain a deprotected product by converting the site to an -OH structure and deprotecting it.

[0249] Methods for producing the aforementioned deprotected product can be adapted from known methods for deprotecting general protecting groups of arylhydroxy groups, as described in Japanese Patent Publication No. 5422159 and other known documents (Arch. Pharm. Res. 2008, 31, 305).

[0250] In the above formula (10), NR 32 The site may be deprotected and converted to an NH structure.

[0251] In the above equation (10), R 32 When the protecting group in is a tert-butoxycarbonyl group, methods such as boron tribromide, which are generally known, can be applied as a method for deprotecting the tert-butoxycarbonyl group.

[0252] In the above equation (3), R 13 Preferably, one of the two R 13 It is more preferable that the two R 13 When it is deprotected, it is represented by the following equation (11).

[0253] [ka]

[0254] R in equation (11) 13 ~R 20 The definition of is the same as in equation (3) above. In this case, R 13 This is the protecting group mentioned above.

[0255] The deprotected material obtained in the deprotection process can be isolated by crystallization.

[0256] The organic phase recovered in the deprotection process can be concentrated under reduced pressure, and if necessary, a poor solvent can be added and crystallized to recover it as a solid.

[0257] The crystallization temperature is a temperature at which the solubility of the target substance decreases in order to promote the precipitation of the target substance as a precipitate, and is preferably -80 to 60°C, and more preferably -20 to 40°C.

[0258] The extraction method is not particularly limited; for example, solid-liquid separation by filtration or centrifugation is used. The obtained solid can be isolated and purified by washing or drying as needed.

[0259] <Mechanism of Action> According to the method for producing bipyridine derivatives of this embodiment, the intermediate product extracted during the process from the compound represented by formula (1) to the production of the bipyridine derivative represented by formula (3) can be isolated by crystallization and filtration purification without requiring purification by column chromatography. Therefore, bipyridine derivatives can be produced in high yield. Furthermore, bipyridine derivatives can be produced with high purity by crystallization purification.

[0260] On the other hand, as mentioned above, in the method described in Patent Document 1, it is difficult to isolate the intermediate by crystallization and filtration purification. The reasons for this are thought to be as follows: In the method described in Patent Document 1, when synthesizing the bipyridine derivative represented by formula (3), the intermediate extracted in the intermediate step has low crystallinity. Therefore, even when concentrated in the presence of excess reactants added to the compound represented by formula (1) or solvent-soluble impurities produced as by-products of the reaction, it tends not to solidify and remains in an oily state. Furthermore, even if a poor solvent is added after concentration and recrystallization is attempted, impurities tend to precipitate.

[0261] On the other hand, increasing the amount of good solvent charged to avoid the precipitation of impurities leads to the dissolution of the target product, which has low crystallinity and high solubility, resulting in a decrease in yield. This tendency is particularly pronounced when the reactant charged in excess to the compound represented by formula (1) is itself a good solvent for the bipyridine derivative represented by formula (3). For this reason, it is difficult to recover the target product in high yield by crystallization and filtration, and purification by column chromatography is required.

[0262] In contrast, according to the method for producing bipyridine derivatives of this embodiment, crystallinity can be improved by adding a metal salt in the first step to form metal complex 1 as an intermediate. On the other hand, excess reactants and impurities hardly form metal complexes, so the target product can be selectively metal-complexed. As a result, there is no need to add poor or good solvents in the crystallization step, and the reduction in purity due to impurity precipitation and the reduction in yield due to the dissolution of the target product can be avoided, allowing the target product to be recovered with high purity and high yield.

[0263] Next, metal complex 1, produced in the first step, is isolated. This isolation can typically be achieved by solid-liquid separation through crystallization and filtration. This isolation process removes excess reactants that do not form complexes, as well as solvent-soluble impurities produced as by-products of the reaction, by separating the liquid. Similarly, metal complex 2, produced in the second step, can typically be isolated by solid-liquid separation through crystallization and filtration.

[0264] Next, in the demetallation step, an acid or base is added to the metal complex 2 to demetallate it, thereby obtaining the bipyridine derivative represented by formula (3). Since the metal complex 2 is used as the starting material in the demetallation step, a high-purity bipyridine derivative can be obtained with high purity by carrying out the demetallation step.

[0265] In the method for producing the bipyridine derivative of this embodiment, the selection of metal M is important. In this embodiment, metal M is one of the metals belonging to Group 4 to Group 12 of the fourth period of the periodic table. Such metal M has the characteristic that its valency does not change easily in the method for producing the bipyridine derivative of this embodiment, thus improving the crystallinity of the metal complex and making it easy to remove in the demetallation step. Therefore, it is believed that by simply selecting one of the metals belonging to Group 4 to Group 12 of the fourth period of the periodic table as metal M, a high-purity bipyridine derivative can be obtained with high purity.

[0266] Metal complexes The metal complex of this embodiment is a metal complex represented by the following formula (6).

[0267] [ka]

[0268] In the above formula (6), R 24 R is a substituent, 25 ~R 31 Each is independently a hydrogen atom or a substituent, R 24 ~R 31 These two Rs may be the same or different, and 24 , 2 R 25 , 2 R 26 , 2 R 27 , 2 R 28 , 2 R 30 , 2 R 31 Each of them may be the same or different, and there are 6 R 25 ~R 27At least one of them is a substituent, and two R 28 At least one of them is a hydrogen atom, R 24 ~R 31 Any two of the organic groups may be bonded to each other to form a ring, M is a metal belonging to groups 4 through 12 of the fourth period of the periodic table, X is an anionic species, c is an integer from 1 to 3, and d is 0 or greater.

[0269] The difference between the metal complex 1 represented by formula (2) and the metal complex represented by formula (6) is that in the metal complex 1 represented by formula (2), R 5 While R is a hydrogen atom or substituent, in the metal complex represented by formula (6), 24 The fact that it is a substituent.

[0270] In the metal complex represented by formula (6) above, R 24 By converting the substituents to hydrogen, -OR 24 It is preferable that the substituent can convert the moiety to an -OH structure, i.e., a protecting group. 24 A specific example of a protecting group in is R in formula (2) above. 5 It is similar to that.

[0271] R 25 ~R 27 Each of these is independently a hydrogen atom or a substituent. 25 , R 26 , R 27 Specific examples and preferred forms are R in the metal complex 1 represented by formula (2), respectively. 6 , R 7 , R 8 These are equivalent to those of the 6 R 25 ~R 27 At least one of them is a substituent, R 25 , R 26 , R 27 The preferred configuration of the number of substituents in R is also, respectively, 6 , R 7 , R 8 It is equivalent to those in [the relevant context].

[0272] R28 R represents a hydrogen atom or substituent, and specific examples and preferred forms are R in the metal complex 1 represented by formula (2) above. 9 These are equivalent to those of 2 R 28 At least one of them is a hydrogen atom, R 28 A preferred form of the number of substituents in R 9 It is equivalent to this.

[0273] R 29 ~R 31 Each of these independently represents a hydrogen atom or a substituent. 29 , R 30 , R 31 A specific example and preferred form is R in the metal complex 1 represented by formula (2) above. 10 , R 11 , R 12 It is equivalent to those of the others.

[0274] Multiple R 29 ~R 31 These may be the same or different, R 29 ~R 31 Any two of these may be joined together to form a ring. 29 , R 30 , R 31 Whether they are identical and whether they combine to form a ring, and the preferred form, are also R 10 , R 11 , R 12 It is equivalent to those of the others.

[0275] c represents an integer from 1 to 3. The preferred form of c is the same as a in the metal complex 1 represented by formula (2) above.

[0276] M represents a metal. Specific examples and preferred forms of M are the same as those of M in the metal complex 1 represented by formula (2) above.

[0277] d is the number of X atoms in the metal complex and represents a number greater than or equal to 0. The preferred form of d is the same as b in metal complex 1 represented by formula (2) above.

[0278] The metal complex represented by formula (6) can be produced by performing the operation of the first step using the compound represented by formula (1) as a raw material. When the metal complex represented by formula (6) contains halogen atoms, and the number of halogen atoms in the metal complex represented by formula (6) is greater than the number of halogen atoms in the compound represented by formula (1), the metal complex represented by formula (6) can be produced by performing a halogenation step in addition to the first step. When the metal complex represented by formula (6) contains optionally substituted pyrrolyl groups, and the number of optionally substituted pyrrolyl groups in the metal complex represented by formula (6) is greater than the number of optionally substituted pyrrolyl groups in the compound represented by formula (1), the metal complex represented by formula (6) can be produced by performing a pyrroleization step in addition to the first step, or by performing the halogenation step and the pyrroleization step in that order.

[0279] Examples of metal complexes represented by formula (6) include those represented by the following formulas (F-1) to (F-32). Among these, the halides of the metal complex represented by formula (6) are the metal complexes represented by formulas (F-2), (F-23) to (F-25), and the pyrrole derivatives of the metal complex represented by formula (6) are the metal complexes represented by formulas (F-26) to (F-31). In particular, formulas (F-1) to (F-13), (F-17), and (F-22) to (F-32), where M is zinc, are preferred.

[0280] [ka]

[0281] [ka]

[0282] Method for producing macrocyclic compounds The method for producing a macrocyclic compound of this embodiment is a method for producing a macrocyclic compound represented by the following formula (5) by cyclizing a bipyridine derivative having two or more pyrrolyl groups which may have substituents represented by formula (3), produced by the above-described production method.

[0283] In this specification, "macrocyclic compound" means a compound having five or more aromatic rings, wherein the atoms constituting the ring skeleton of these five or more aromatic rings further form a macrocyclic skeleton with a greater number of ring members (number of atoms constituting the ring skeleton) than the individual aromatic rings. Here, "atoms constituting the ring skeleton" refers, for example, in the case of a pyrrole ring, to four carbon atoms and one nitrogen atom, and the five hydrogen atoms bonded to these carbon and nitrogen atoms are not atoms constituting the ring skeleton.

[0284] In this specification, "aromatic ring" includes heteroaromatic rings in which at least one of the atoms constituting the ring skeleton is a heteroatom (e.g., a nitrogen atom).

[0285] Furthermore, in this specification, "macrocyclic skeleton" refers not to aromatic rings with fewer members than those described above, but to a ring skeleton composed of these aromatic rings with a larger number of members than these aromatic rings.

[0286] In this specification, a ring structure formed by the fusion of two or more aromatic rings, such as a benzotriazole ring, a naphthalene ring, or a phenanthroline ring, is treated as a single aromatic ring. In the case of a phenanthroline ring, 12 carbon atoms and 2 nitrogen atoms form the ring skeleton.

[0287] The method for producing the macrocyclic compound of this embodiment includes a step (hereinafter also referred to as "step 3-1") in which an intramolecular cyclization reaction is carried out by reacting a bipyridine derivative having two or more pyrrolyl groups which may have substituents represented by formula (3) with a compound having an aldehyde group to obtain a precursor of the macrocyclic compound.

[0288] The method for producing the macrocyclic compound of this embodiment further includes a step (hereinafter also referred to as "step 3-2") in which an oxidation reaction is carried out by reacting the precursor of the macrocyclic compound obtained in step 3-1 with an oxidizing agent or the like to obtain the macrocyclic compound.

[0289] The macrocyclic compound represented by formula (5) below in this embodiment will be described below. The manufacturing conditions will also be described.

[0290] [ka]

[0291] In equation (5) above, R 34 ~R 42 Each is independently a hydrogen atom or a substituent, and there are multiple R 34 ~R 42 These may be the same or different, R 34 ~R 42 Any two of the substituents may be bonded to each other to form a ring.

[0292] R 36 , R 37 , R 38 A specific example and preferred form is R in the metal complex 1 represented by formula (2) above. 7 , R 8 , R 9 These substituents are the same as those described earlier.

[0293] 4 R 36 , R 37 The total number of substituents is 0 to 4, preferably 0 to 2, and more preferably 2.

[0294] R 38 R represents a hydrogen atom or substituent, and specific examples and preferred forms are found in the metal complex 1 represented by formula (2) above. 9 This is equivalent to the example given. There are two R 38The number of substituents that can be taken is 0 to 1, and there are 2 R 38 It is preferable that it is a hydrogen atom.

[0295] R 39 , R 40 , R 41 Each of these independently represents a hydrogen atom or a substituent, and specific examples and preferred forms are in the metal complex 1 represented by formula (2) above, where R 10 , R 11 , R 12 These are equivalent to the examples given.

[0296] Multiple R 36 ~R 41 These may be the same or different, R 36 ~R 41 Any two of these may be joined together to form a ring. 36 , R 37 , R 38 , R 39 , R 40 , R 41 A preferred example of whether they are the same or different, and R 36 , R 37 , R 38 , R 39 , R 40 , R 41 A preferred example of a case where any two of them are joined together to form a ring is as follows: 7 , R 8 , R 9 , R 10 , R 11 , R 12 These forms are the same as those in [location].

[0297] R 42 R is a hydrogen atom or a hydrocarbyl group having 1 to 30 carbon atoms, which may be substituted. 42 Examples of hydrocarbyl groups represented by include alkyl groups, aryl groups, and aralkyl groups, with alkyl groups and aryl groups being preferred.

[0298] Examples of alkyl groups, aryl groups, and aralkyl groups are R in formula (1) above. 1 ~R 4 This is the same as the example given earlier.

[0299] R 42 It is preferably a substituted phenyl group, more preferably a phenyl group which may be substituted with a 1-30 carbon atom hydrocarbyl group, and even more preferably a phenyl group which may be substituted with a 1-8 carbon atom alkyl group.

[0300] The macrocyclic compound represented by formula (5) is preferably a compound in which the macrocyclic skeleton is composed of 5 to 12 aromatic rings, and more preferably a compound in which the macrocyclic skeleton is composed of 5 aromatic rings including a phenanthroline ring.

[0301] The macrocyclic compound represented by formula (5) is preferably one having four or more nitrogen atoms as coordinating atoms, preferably one having four to six nitrogen atoms as coordinating atoms, and more preferably one having four nitrogen atoms and two oxygen atoms as coordinating atoms.

[0302] The macrocyclic compound represented by formula (5) has a minimum number of atoms constituting its largest ring skeleton (the number of atoms constituting the inner circumference of the macrocyclic skeleton) which is preferably 9 to 50, more preferably 16 to 33, even more preferably 17 to 32, and particularly preferably 19 to 20.

[0303] Examples of macrocyclic compounds represented by formula (5) include those represented by the following formulas (G-1) to (G-16). Among these, macrocyclic compounds represented by (G-1) to (G-8) are preferred, and macrocyclic compounds represented by (G-5) to (G-6) are more preferred.

[0304] [ka]

[0305] [ka]

[0306] (Step 3-1) Step 3-1 is a step to obtain a precursor of a macrocyclic compound by performing an intramolecular cyclization reaction, such as by reacting a bipyridine derivative having two or more optionally substituted pyrrolyl groups represented by formula (3), obtained by the operation of the deprotection step, with a compound having an aldehyde group. When the bipyridine derivative represented by formula (3) has two or more optionally substituted pyrrolyl groups, the intramolecular cyclization reaction proceeds by a condensation reaction with the compound having an aldehyde group.

[0307] Methods for producing the precursor of the macrocyclic compound described above can be applied to methods known as general pyrrole ring-containing compounds and aldehyde condensation reactions, as described in Japanese Patent No. 5422159 and International Publication No. 2019 / 026883.

[0308] In a bipyridine derivative having two or more pyrrolyl groups which may have substituents represented by formula (3), it is preferable that a precursor of a macrocyclic compound can be obtained by an intramolecular cyclization reaction of a compound having a pyrrolyl group which may have substituents and an aldehyde group. When a precursor of a macrocyclic compound can be obtained by an intramolecular cyclization reaction, the precursor of the macrocyclic compound is represented by the following formula (12).

[0309] [ka]

[0310] R in equation (12) above 15 ~R 20 The definition of is the same as in equation (3) above, and R 34 ~R 42 The definition is the same as in equation (5) above.

[0311] (Step 3-2) Step 3-2 is a step in which an oxidation reaction is carried out by reacting the precursor of the macrocyclic compound represented by formula (12) obtained by the operation of step 3-1 with an oxidizing agent or the like to obtain the macrocyclic compound.

[0312] Methods for producing the aforementioned macrocyclic compound can be adapted to techniques known as general methods for oxidizing the dipyromethine skeleton, as described in Japanese Patent No. 5422159 and International Publication No. 2019 / 026883.

[0313] It is preferable that the dipyromethine skeleton is oxidized in the macrocyclic compound precursor obtained by the operation in step 3-1 by reacting it with an oxidizing agent. When the dipyromethine skeleton is oxidized by an oxidizing agent, it is represented by the following formula (13).

[0314] [ka]

[0315] In the above formula, R in (13) 34 ~R 42 The definition is the same as in equation (5) above.

[0316] ≪Method for producing metal complexes≫ The present embodiment is a method for producing a metal complex containing a macrocyclic compound as a ligand, wherein the macrocyclic compound represented by formula (5), produced by the above-described method, is used as a ligand to react with a metal salt containing a metal belonging to the 4th to 6th periods of the periodic table.

[0317] A metal complex having the macrocyclic compound represented by formula (5) as a ligand will be described.

[0318] The metal complex forms a complex through interaction with the heteroatom in the macrocyclic compound. Furthermore, if there are two metal atoms, they may be bridgingly coordinated.

[0319] Among the metals belonging to the 4th to 6th periods of the periodic table, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, rhodium, palladium, silver, tantalum, tungsten, rhenium, osmium, iridium, platinum, and gold are preferred, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, rhodium, silver, and platinum are more preferred, and manganese, iron, cobalt, nickel, copper, and zinc are particularly preferred.

[0320] Metal complexes may contain neutral molecules or counterions that electrically neutralize the metal complex. Examples of such neutral molecules include molecules that solvate to form a solvated salt. Examples of such neutral molecules include water, methanol, ethanol, n-propanol, isopropyl alcohol, 2-methoxyethanol, 1,1-dimethylethanol, ethylene glycol, N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, acetone, chloroform, acetonitrile, benzonitrile, triethylamine, pyridine, pyrazine, diazabicyclo[2,2,2]octane, 4,4'-bipyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, methyl ethyl ether, 1,4-dioxane, acetic acid, propionic acid, and 2-ethylhexanoic acid. Preferably, examples include water, methanol, ethanol, isopropyl alcohol, ethylene glycol, N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-2-pyrrolidone, chloroform, acetonitrile, benzonitrile, triethylamine, pyridine, pyrazine, diazabicyclo[2,2,2]octane, 4,4'-bipyridine, tetrahydrofuran, dimethoxyethane, 1,4-dioxane, acetic acid, propionic acid, and 2-ethylhexanoic acid.

[0321] Furthermore, regarding counterions, since metals belonging to the 4th to 6th periods of the periodic table have a positive charge, anions that make them electrically neutral are selected. Examples of anions include fluoride ions, chloride ions, bromide ions, iodide ions, sulfide ions, oxide ions, hydroxide ions, hydride ions, sulfite ions, phosphate ions, cyanide ions, acetate ions, 2-ethylhexanoate ions, carbonate ions, sulfate ions, nitrate ions, perchlorate ions, bicarbonate ions, trifluoroacetate ions, thiocyanide ions, trifluoromethanesulfonate ions, acetylacetonate, tetrafluoroborate ions, hexafluorophosphate ions, tetraphenylborate ions, and stearate ions, with chloride ions, bromide ions, phosphate ions, hexafluorophosphate ions, acetate ions, sulfate ions, nitrate ions, perchlorate ions, trifluoromethanesulfonate ions, and tetraphenylborate ions being preferred.

[0322] Furthermore, if multiple counterions are present, they may be identical or different, and a neutral molecule and an ion may coexist.

[0323] The method for producing the metal complex in this embodiment can be adapted to methods known for coordinating metals during the production of general porphyrin derivatives, phthalocyanine derivatives, etc., as described in Japanese Patent Publication No. 5422159 and International Publication No. 2019 / 026883.

[0324] The structure of the compounds obtained in this invention can be confirmed by known methods such as single-crystal X-ray analysis, nuclear magnetic resonance (NMR) spectroscopy, electron spin resonance (ESR) spectroscopy, mass spectrometry (MS), infrared spectroscopy (IR), and ultraviolet-visible absorption spectroscopy.

[0325] Air battery The metal complex represented by formula (6) above can be used as an electrode catalyst for an air battery. An air battery includes an electrode for air batteries (positive electrode), a negative electrode, and an electrolyte. The electrode for air batteries includes a positive electrode current collector and a catalyst layer. The negative electrode includes a negative electrode current collector and a negative electrode active material layer. The catalyst layer includes an electrode catalyst. A metal complex represented by formula (6) can be used as the electrode catalyst.

[0326] Figure 1 is a schematic diagram illustrating one embodiment of the air battery according to this embodiment. The air battery 1 comprises a catalyst layer 11, a positive electrode current collector 12, a negative electrode active material layer 13, a negative electrode current collector 14, an electrolyte 15, and a container (not shown) that houses these.

[0327] The positive electrode current collector 12 is positioned in contact with the catalyst layer 11, and together they constitute the electrode (positive electrode) for the air battery. The negative electrode current collector 14 is positioned in contact with the negative electrode active material layer 13, and together they constitute the negative electrode. A positive electrode terminal (lead wire) 120 is connected to the positive electrode current collector 12, and a negative electrode terminal (lead wire) 140 is connected to the negative electrode current collector 14. The catalyst layer 11 and the negative electrode active material layer 13 are arranged facing each other, and the electrolyte 15 is placed between them so as to be in contact with them. Note that the air battery is not limited to the one shown in Figure 1, and some of its components may be modified as needed. For example, a separator may be provided between the positive and negative electrodes, and an oxygen diffusion film may be provided on the surface of the positive electrode current collector 12 opposite to the catalyst layer 11.

[0328] ≪Electrodes for air batteries≫ The electrode for the air battery is the positive electrode. The electrode for the air battery includes a catalyst layer and a positive electrode current collector. The catalyst layer includes an electrode catalyst containing a metal complex represented by formula (6). Preferably, the catalyst layer further includes a conductive material and a binder. As the conductive material and binder, conductive materials and binders described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320 can be used, and the composition of the catalyst layer (content of electrode catalyst, conductive material, binder, etc.) can also be the same as that described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320. Furthermore, as the positive electrode current collector, positive electrode current collectors described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320 can also be used.

[0329] As a method for manufacturing electrodes for air batteries, a method is applicable in which a catalyst layer prepared by mixing an electrode catalyst containing the metal complex represented by formula (6), a conductive material, and a binder is combined with a positive electrode current collector, as described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320.

[0330] (Negative electrode) The negative electrode includes a negative electrode active material layer containing a negative electrode active material and a negative electrode current collector. The negative electrode active material preferably contains one or more selected from the group consisting of zinc, iron, aluminum, magnesium, lithium, hydrogen, and ions thereof, and more preferably contains one or more selected from the group consisting of magnesium and magnesium ions.

[0331] If the negative electrode active material contains one or more selected from the group consisting of magnesium (elemental magnesium, magnesium compounds) and magnesium ions, then the air battery is a so-called magnesium-air battery.

[0332] As the negative electrode current collector, the negative electrode current collector described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320 can be used.

[0333] As the electrolyte, the electrolytes described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320 can be used.

[0334] Other components of the air battery (container, separator, oxygen diffusion membrane, etc., shape of the air battery, etc.) can be those described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320.

[0335] As a method for manufacturing air batteries, the methods described in Japanese Patent No. 5943194 and Japanese Patent No. 6830320 can be applied. [Examples]

[0336] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

[0337] Below, "TMEDA" is N,N,N',N'-tetramethylethylenediamine, "MTBE" is tert-butylmethyl ether, "THF" is tetrahydrofuran, "OAc" is acetate anion, "DMSO" is dimethyl sulfoxide, "Boc" is tert-butoxycarbonyl group, "dba" is dibenzylideneacetone, "Cy" is cyclohexyl group, "PhCHO" is benzaldehyde, "PhNH + Me2B(C6F5)4 - " means N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate.

[0338] A BRUKER AV NEO 300MHz NMR spectrometer was used for the NMR measurements.

[0339] [Example 1] <Synthesis of metal complex (B-8)> The metal complex (B-8) was synthesized according to the reaction equation shown below.

[0340] [ka]

[0341] After creating a nitrogen gas atmosphere in the reaction vessel, 135 mL of MTBE, 63.80 g (388 mmol) of 4-tert-butylanisole, and 38.69 g (333 mmol) of TMEDA were added dropwise, and the mixture was cooled to 0°C. 212.07 mL (1.6 mol / L, equivalent to 333 mmol of n-butyllithium) of hexane solution was added dropwise, the mixture was heated to 45°C, and stirred for 1.5 hours to obtain the lithiation reaction solution. In another reaction vessel, after creating a nitrogen gas atmosphere, 10.00 g (55.5 mmol) of anhydrous 1,10-phenanthroline was suspended in 113 mL of THF at room temperature. This suspension was added dropwise to the lithiation reaction solution, and the mixture was heated to 65°C and stirred under reflux for 2 hours to obtain the arylation reaction solution. 100.00 g of a 20% by mass aqueous solution of ammonium chloride was added dropwise to the arylation reaction solution, which had been cooled to room temperature. The mixture was stirred for 30 minutes to wash it, and after removing the aqueous phase, the organic phase was concentrated under reduced pressure. After creating a nitrogen gas atmosphere in another reaction vessel, 12.00 g (111 mmol) of p-benzoquinone was dissolved in 113 mL of THF at room temperature. This solution was added dropwise to the concentrated organic phase and stirred at room temperature for 30 minutes to obtain an oxidation reaction solution containing compound (A-34).

[0342] After creating a nitrogen gas atmosphere in another reaction vessel, 11.35 g (83.2 mmol) of zinc chloride was suspended in 113 mL of THF at room temperature. This suspension was added dropwise to the oxidation reaction solution at room temperature. The resulting suspension was cooled to 0°C and stirred for 4 hours. Subsequently, the mixture was filtered at 0°C, washed with THF, and then dried under reduced pressure to obtain metal complex (B-8) in 55% yield. The identification data for the obtained metal complex (B-8) is shown below. Metal complex (B-8) corresponds to metal complex 1 in the present invention.

[0343] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.37(s,18H),3.76(s,6H),6.98(d,J=9.0Hz,2H),7.52(dd,J=9. 0Hz,2.4Hz,2H),7.87(d,J=2.4Hz,2H),8.02(d,J=8.4Hz,2H),8.02(s,2H),8.50(d,J=8.4Hz,2H)

[0344] <Synthesis of metal complex (B-24)> The metal complex (B-24) was synthesized according to the reaction equation shown below.

[0345] [ka]

[0346] After creating a nitrogen atmosphere in the reaction vessel, 8.00 g (12.48 mmol) of metal complex (B-8) was added to 108 mL of chloroform at room temperature and dissolved. 15.96 g (99.85 mol) of bromine was added dropwise while stirring, and the mixture was heated to 45°C and stirred for 6 hours to obtain the bromination reaction solution. In another reaction vessel, after creating a nitrogen atmosphere, 10.39 g (99.85 mmol) of sodium thiosulfate was dissolved in 160 mL of water at room temperature. This aqueous solution was added dropwise to the bromination reaction solution cooled to 0°C, and the mixture was stirred for 1 hour to wash it, after which the aqueous phase was removed. In another reaction vessel, after creating a nitrogen atmosphere, 2.81 g (12.48 mmol) of zinc bromide was dissolved in 151 mL of methanol at room temperature. This solution was added to the organic phase after washing, and the mixture was heated to 75°C to concentrate it. 202 mL of methanol was added, and the mixture was stirred under reflux at 75°C for 1 hour. The mixture was cooled to 0°C, stirred for 1 hour, filtered, washed with methanol, and then dried under reduced pressure to obtain metal complex (B-24) in 88% yield. The identification data for the obtained metal complex (B-24) is shown below. Metal complex (B-24) corresponds to metal complex 2 (halogenated form of metal complex 1) in the present invention.

[0347] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.36(s,18H),3.65(s,6H),7.63(d,J=2.4Hz,2H) ,7.87(s,2H),7.93(d,J=2.4Hz,2H),8.17(d,J=8.1Hz,2H),8.31(d,J=8.1Hz,2H)

[0348] <Synthesis of compound (C-17)> Compound (C-17) was synthesized according to the reaction equation shown below.

[0349] [ka]

[0350] After creating a nitrogen atmosphere in the reaction vessel, 4.39 g (110 mmol) of sodium hydride was added to 106 mL of THF and suspended. This was heated to 40°C, and 32.67 g (487 mmol) of pyrrole was added dropwise over 20 minutes, followed by stirring for 30 minutes to obtain the reaction solution. After creating a nitrogen atmosphere in another reaction vessel, 19.96 g (146 mmol) of zinc chloride was suspended in 137 mL of THF at room temperature. This suspension was added dropwise to the above reaction solution, stirred for 30 minutes, and then cooled to room temperature. 32.50 g (36.6 mmol) of the metal complex (B-24) was added to this. After creating a nitrogen atmosphere in another reaction vessel, 0.082 g (0.37 mmol) of palladium acetate and 0.219 g (0.73 mmol) of 2-(di-tert-butylphosphino)biphenyl were dissolved in 6.5 mL of THF at room temperature to obtain the catalyst solution. After adding this catalyst solution dropwise to the reaction mixture, the temperature was raised to 75°C and stirred under reflux for 6 hours, then cooled to room temperature.

[0351] After creating a nitrogen gas atmosphere in another reaction vessel, 86.23 g of ammonium chloride and 178.15 g of aqueous ammonia solution (28%, 2930 mmol) were dissolved in 217 mL of water at room temperature. This aqueous solution was added dropwise to the above reaction mixture and washed by stirring at room temperature for 30 minutes to remove the aqueous phase. 216 g of 24.8% by mass aqueous ammonium chloride solution was added dropwise to the obtained organic phase and washed by stirring for 15 minutes to remove the aqueous phase.

[0352] 79 mL of DMSO was added to the obtained organic phase, and the temperature was raised to 82°C. THF was removed by vacuum concentration. 6.18 g (30.5 mmol) of 1-dodecanethiol and 7.06 g (28%, 36.6 mmol as sodium methoxide) of a methanol solution of sodium methoxide were added dropwise, and the mixture was stirred at 82°C for 6.5 hours. The reaction mixture was cooled to 40°C, and 58.6 mL of MTBE was added. After creating a nitrogen atmosphere in another reaction vessel, 23.50 g of ammonium chloride and 2.93 g (48.8 mmol) of acetic acid were dissolved in 86.7 mL of water at room temperature. This aqueous solution was added dropwise to the above reaction mixture, and the mixture was washed by stirring at 40°C for 30 minutes to remove the aqueous phase. The obtained organic phase was cooled to 0°C, stirred for 2 hours, and then filtered. The obtained crystals were washed with MTBE and methanol in that order, and the compound (C-17) was obtained in 76% yield by vacuum drying. The identification data for the obtained compound (C-17) is shown below. Note that compounds (C-15) and (C-17) correspond to bipyridine derivatives in the present invention. Compound (C-17) is a deprotected compound.

[0353] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.40(s,18H),6.25(m,2H),6.44(m,2H),6.74(m,2H),7.84(s,2H), 7.89(s,2H),7.92(s,2H),8.35(d,J=8.4Hz,2H),8.46(d,J=8.4Hz,2H),10.61(s,2H),15.88(s,2H)

[0354] <Synthesis of compound (G-5)> Compound (G-5) was synthesized according to the reaction shown below, using the method described in International Publication No. 2019 / 026883. Compound (G-5) corresponds to a macrocyclic compound in this invention.

[0355] [ka]

[0356] <Synthesis of metal complexes using macrocyclic compounds (G-5) as ligands> A metal complex with a macrocyclic compound (G-5) as a ligand was synthesized according to the reaction shown below, using the method described in International Publication No. 2019 / 026883.

[0357] [ka]

[0358] [Comparative Example 1] <Synthesis of compound (A-34)> Compound (A-34) was synthesized according to the reaction equation shown below.

[0359] [ka]

[0360] After creating a nitrogen atmosphere in the reaction vessel, 1.00 g (143 mmol) of metallic lithium was suspended in 10 mL of anhydrous diethyl ether and cooled to 0°C. 15.50 g (63.8 mmol) of 2-bromo-4-(1,1-dimethylethyl)-1-methoxybenzene (synthesized according to Tetrahedron., 1999, 55, 8377.) dissolved in 10 mL of anhydrous diethyl ether was added dropwise, and the mixture was heated and stirred under reflux for 3 hours. This was then cooled to room temperature to obtain the lithiation reaction solution. In another reaction vessel, after creating a nitrogen atmosphere, 1.44 g (7.97 mmol) of anhydrous 1,10-phenanthroline was suspended in 15 mL of anhydrous toluene at room temperature. At room temperature, the lithiation reaction solution was added dropwise, and the mixture was heated to 40°C and stirred under reflux for 48 hours. While cooling to -20°C, 150 mL of water was added dropwise. After returning to room temperature, dichloromethane was added for extraction, and the aqueous phase was removed. 5.00 g (57.0 mmol) of manganese dioxide was added, and the mixture was stirred at room temperature for 8 hours. The resulting suspension was filtered through a funnel packed with Celite. Anhydrous sodium sulfate was added to the filtrate, and after standing, it was filtered again, and the resulting organic phase was concentrated. The residue was purified using a silica gel column with a mixture of ethyl acetate and petroleum ether as the developing solvent, and compound (A-34) was obtained in 64% yield. The identification data for the obtained compound (A-34) is shown below.

[0361] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.38(s,18H),3.83(s,6H),6.97(d,J=8.7Hz,2H),7.42(dd,J=8. 7Hz,2.7Hz,2H),7.80(s,2H),8.05(d,J=2.7Hz,2H),8.08(d,J=8.4Hz,2H),8.22(d,J=8.4Hz,2H)

[0362] <Synthesis of compound (C-12)> Compound (C-12) was synthesized according to the reaction equation shown below.

[0363] [ka]

[0364] After creating a nitrogen gas atmosphere in the reaction vessel, 260.00 g (0.515 mol) of compound (A-34) was dissolved in 15 L of dichloromethane at room temperature. 658.66 g (4.12 mol) of bromine was added dropwise while stirring, and the mixture was heated to 40°C and stirred for 48 hours. At 40°C, an additional 658.66 g (4.12 mol) of bromine was added dropwise, and the mixture was stirred for another 48 hours. The mixture was cooled to 0°C, and 500 mL of 10% sodium thiosulfate aqueous solution was added. The aqueous phase was removed, sodium thiosulfate aqueous solution was added to the organic phase and stirred, and the aqueous phase was removed. Sodium bicarbonate aqueous solution was added to the organic phase and stirred, and the aqueous phase was removed. Saltwater was added to the organic phase and stirred, and the aqueous phase was removed. Anhydrous sodium sulfate was added to the organic phase, and after standing, the mixture was filtered, and the resulting organic phase was concentrated. The residue was purified using a silica gel column with a mixture of hexane and ethyl acetate as the developing solvent, and compound (C-12) was obtained in 52% yield. The identification data for the obtained compound (C-12) is shown below.

[0365] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.36(s,18H),3.65(s,6H),7.63(d,J=2.4Hz,2H) ,7.87(s,2H),7.93(d,J=2.4Hz,2H),8.17(d,J=8.1Hz,2H),8.31(d,J=8.1Hz,2H)

[0366] <Synthesis of compound (C-16)> Compound (C-16) was synthesized according to the reaction equation shown below.

[0367] [ka]

[0368] After creating a nitrogen atmosphere in the reaction vessel, 150.00 g (0.226 mol) of compound (C-12), 119.45 g (0.566 mmol) of 1-N-Boc-pyrrole-2-boronic acid, 5.18 g (5.66 mmol) of tris(benzylideneacetone)dipalladium, 9.30 g (22.6 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, and 210.00 g (0.989 mol) of potassium phosphate were dissolved in a mixed solvent of 7500 mL of dioxane and 750 mL of water, and the mixture was heated to 60°C and stirred for 6 hours. The reaction mixture was cooled to room temperature and filtered through a funnel packed with Celite. Distilled water and chloroform were added to the filtrate and liquid-liquidate was removed to remove the aqueous phase. Anhydrous sodium sulfate was added to the obtained organic phase, and after standing, the mixture was filtered and the resulting organic phase was concentrated. The residue was purified using a silica gel column to obtain compound (C-16) in 63% yield. The identification data for the obtained compound (C-16) is shown below.

[0369] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.34(s,18H),1.37(s,18H),3.30(s,6H),6.21(m,2H),6.27(m,2H) ),7.37(m,2H),7.41(s,2H),7.82(s,2H),8.00(s,2H),8.19(d,J=8.6Hz,2H),8.27(d,J=8.6Hz,2H)

[0370] <Synthesis of compound (C-17)> Compound (C-17) was synthesized according to the reaction equation shown below.

[0371] [ka]

[0372] After creating a nitrogen gas atmosphere in the reaction vessel, 74.0 g (88.6 mmol) of compound (C-16) was dissolved in 740 mL of anhydrous dichloromethane. While the resulting dichloromethane solution was cooled to -78°C, 740 mL of a 1.0 M dichloromethane solution of boron tribromide (740 mmol as boron tribromide) was added dropwise. After stirring for 30 minutes, the mixture was gradually heated over 2 hours to room temperature. The reaction mixture was cooled to -20°C, and 1600 mL of water was added. This was heated to room temperature, saturated sodium bicarbonate aqueous solution was added and stirred, and the aqueous phase was removed. Hydrochloric acid was added to the organic phase and stirred, and the aqueous phase was removed. Anhydrous sodium sulfate was added to the obtained organic phase and allowed to stand, then filtered, and the obtained organic phase was concentrated. The residue was purified using a silica gel column with a mixture of chloroform and hexane as the developing solvent to obtain compound (C-17) in 46% yield. The identification data for the obtained compound (C-17) is shown below.

[0373] 1 H-NMR (300MHz, CDCl3): δ(ppm)=1.40(s,18H),6.25(m,2H),6.44(m,2H),6.74(m,2H),7.84(s,2H), 7.89(s,2H),7.92(s,2H),8.35(d,J=8.4Hz,2H),8.46(d,J=8.4Hz,2H),10.61(s,2H),15.88(s,2H)

[0374] Table 1 below shows the purification method, yield, and overall yield for an example in which purification was performed by crystallization filtration via a metal complex intermediate, and a comparative example in which purification was performed by column chromatography without using a metal complex. The organic phase containing compound (C-15) was used in the next step in solution. The yield was determined by measuring the mass of the target product, dividing the mass by the theoretical yield (mass at 100% yield), and multiplying by 100%.

[0375] [Table 1]

[0376] Regarding compound (C-17), isolation was performed by crystallization filtration in Example 1 and by column chromatography in Comparative Example 1. In Example 1, deprotection was performed using dodecanethiol and sodium methoxide, and it is thought that isolation by crystallization filtration was possible due to the high reaction yield. On the other hand, in Comparative Example 1, deprotection was performed using boron tribromide, and it is thought that isolation by crystallization filtration was impossible due to the low reaction yield (i.e., high impurity ratio). However, comparing the yield up to compound (C-15) in Example 1 with the yield up to compound (C-16) in Comparative Example 1, the yields were 48% in Example 1 and 21% in Comparative Example 1. Even if deprotection was performed using the same method, the yield of compound (C-17) would be higher in Example 1 than in Comparative Example 1.

[0377] From the above, it was found that by using the manufacturing method of the present invention, purification by crystallization filtration is possible, and bipyridine derivatives can be produced in a higher yield compared to cases where a metal complex is not used as an intermediate. [Explanation of Symbols]

[0378] 1...Air battery, 11...Catalyst layer, 12...Positive electrode current collector, 13...Negative electrode active material layer, 14...Negative electrode current collector, 120...Positive electrode terminal, 140...Negative electrode terminal, 15...Electrolyte

Claims

1. A first step is to obtain a metal complex 1 represented by the following formula (2) from a compound represented by the following formula (1), The process includes a second step of obtaining a bipyridine derivative represented by the following formula (3) from the metal complex 1, The second step comprises a step of performing either a halogenation reaction and a pyrrole reaction or both on the metal complex 1 to obtain a metal complex 2, and a demetallation step of removing the metal from the metal complex 2. A method for producing a bipyridine derivative, wherein the number of halogen atoms contained in the bipyridine derivative is greater than the number of halogen atoms contained in the compound, or the number of optionally substituted pyrrolyl groups contained in the bipyridine derivative is greater than the number of optionally substituted pyrrolyl groups contained in the compound. 【Chemistry 1】 (In the above formula (1), R １ is a hydrogen atom or a phenyl group having (—OR ５ ) at the 2-position, (—R ６ ) at the 3-position, (—R ７ ) at the 4-position, (—R ８ ) at the 5-position, and (—R ９ ) at the 6-position. The R ５ to R ９ are each independently the same as R ５ to R ９ in the following formula (2). R ２ to R3 are each independently a hydrogen atom or a substituent. R ２ to R3 may be the same or different from each other. Two R １ , two R ２ , and two R ３ may be the same or different from each other. Two R ４ are bonded to each other to form a benzene ring (the benzene ring may have a substituent). R ２ to R3 may include a halogen atom or a pyrrolyl group optionally having a substituent. The substituent is a hydrocarbyl group or a monovalent group having a hetero element.). 【Chemistry 2】 (In the above formula (2), R ５ is a hydrogen atom or -OR ５ It is a protecting group that can convert the site to an -OH structure, R ６ Each of R11 is independently a hydrogen atom or a substituent, ６ ~R11 may be the same or different, and the two R ５ , 2 R ６ , 2 R ７ , 2 R ８ , 2 R ９ , 2 R １０ , 2 R １１ Each of them may be the same or different, and there are six R's. ６ ~R ８ At least one of them is a substituent, and two R ９ At least one of them is a hydrogen atom, and two R １２ They are bonded to each other to form a benzene ring (which may have substituents), R ６ ~R11 may contain a halogen atom or a pyrrolyl group which may have a substituent, the substituent being a hydrocarbyl group or a monovalent group having a heteroatom, M is a metal belonging to any group from group 4 to group 12 in the fourth period of the periodic table, X is an anionic species, a is an integer from 1 to 3, and b is 0 or greater. 【Transformation 3】 (In formula (3) above, R １３ is a hydrogen atom or -OR １３ It is a protecting group that can convert the site to an -OH structure, R １４ Each of R19 is independently a hydrogen atom or a substituent, １４ ~R19 may be the same or different, and the two R １３ , 2 R １４ , 2 R １５ , 2 R １６ , 2 R １７ , 2 R １８ , 2 R １９ Each of them may be the same or different, and there are six R's. １４ ~R １６ At least one of them is a substituent, and two R １７ At least one of them is a hydrogen atom, and two R ２０ They are bonded to each other to form a benzene ring (which may have substituents), R １７ ~R19 may contain a halogen atom or a pyrrolyl group which may have a substituent, R １４ ~R １６ At least one of these groups contains a halogen atom or a pyrrolyl group which may have a substituent, and the substituent is a monovalent group having a hydrocarbyl group or a heteroatom.

2. The method for producing a bipyridine derivative according to claim 1, wherein the demetallation step is carried out by reacting with an amine represented by the following formula (4). 【Chemistry 4】 (In formula (4) above, R ２１ ~R ２３ Each of these is independently a hydrogen atom, a methyl group, an ethyl group, a hydroxymethyl group, or a hydroxyethyl group.

3. The method for producing a bipyridine derivative according to claim 1 or 2, wherein the first step includes reacting the compound with a metal salt containing a metal represented by M and an anionic species represented by X.

4. The second step includes a deprotection step after the demetallation step, and in formula (2), R ５ ha-OR ５ A protecting group capable of converting the site to an -OH structure, in formula (3), R １３ A method for producing a bipyridine derivative according to claim 1 or 2, wherein is a hydrogen atom.

5. A method for producing a bipyridine derivative according to claim 1 or 2, comprising the step of isolating the metal complex 1, the metal complex 2, or the bipyridine derivative by crystallization.

6. A method for producing a macrocyclic compound, comprising cyclizing a bipyridine derivative having two or more pyrrolyl groups which may have substituents, produced by the method for producing a bipyridine derivative according to claim 1 or 2, to obtain a macrocyclic compound represented by the following formula (5), In the above formula (2), R ５ ha-OR ５ It is a protecting group that can convert the site to an -OH structure, R ６ This is a method for producing macrocyclic compounds, which are hydrogen atoms. 【Transformation 5】 (In formula (5) above, R ３４ ~R ４０ Each is independently a hydrogen atom or a substituent, R ３４ ~R ４０ These two Rs may be the same or different, and ３４ , 2 R ３５ , 2 R ３６ , 2 R ３７ , 2 R ３８ , 2 R ３９ , 2 R ４０ These may be the same or different, R ４２ is a hydrocarbyl group having 1 to 30 carbon atoms, which may have a hydrogen atom or substituents, and two R ４１ (The benzene ring (which may have substituents) forms a benzene ring, and the substituents are a hydrocarbyl group or a monovalent group having a heteroatom.)

7. A method for producing a metal complex containing a macrocyclic compound as a ligand, comprising reacting a metal salt containing a metal belonging to the fourth to sixth periods of the periodic table with the macrocyclic compound produced by the method for producing a macrocyclic compound described in claim 6 as a ligand.

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