Calpain inhibitors

Abstract

The present invention provides a calpain inhibitor having an excellent calpain inhibitory ability. According to the present invention, a compound represented by general formula (I) or a salt thereof can be provided. In formula (I), R1 represents a hydrogen atom, an optionally substituted alkyl group, or the like, or may bind to R2 to form a ring, R2 and R3 each independently represent a hydrogen atom, or the like, or R2 and R3 may bind to form a ring, (where when R2 and R1 bind to form a ring containing a double bond, R3 may not exist, R4 represents a hydrogen atom, an optionally substituted alkyl group, or the like, R5 represents a hydrogen atom, an optionally substituted alkyl group, or the like, and R2 and R3 may bind to form a ring. R6 represents a halogen, an optionally substituted cycloalkyl group or the like, X represents O or S, when R1 and R2 are bonded to form a ring, R1 may represent O, S or N, R2 may represent O or S, and L represents an amide bond or the like. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a compound having calpain inhibitory ability, a calpain inhibitor and a pharmaceutical composition comprising the compound, and also to a method for preventing or treating a disease in which the calpain activity of the compound is involved. Background Art

[0002] Calpain is oxidized by Ca 2+ The cysteine ​​protease of dependent activation is a regulator molecule that regulates the function, structure, etc. of its protein by limiting the cutting of substrate protein. Calpain is related to various life phenomena. On the other hand, it has been reported that its activity or pathogenic variation of its gene is related to various diseases such as neurodegenerative diseases, heart / muscle lesions, ischemic diseases, cancer, eye diseases, etc. In addition, there are also infectious diseases that are necessary for the infection and survival of viruses, pathogens, etc. of calpain. For example, it is known that calpain is also associated with the new coronavirus infectious disease, malaria, trypanosomiasis, schistosomiasis (living in schistosomiasis) caused by SARS coronavirus 2 or its variants. Therefore, it is believed that in the treatment or prevention of diseases related to calpain, calpain inhibitors that inhibit the activity of calpain are useful.

[0003] Various calpain inhibitors have been reported so far. For example, Patent Document 1 discloses an α-ketoamide derivative, and states that the compound has calpain inhibitory ability and is excellent in tissue mobility and oral absorption.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-76989 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] Considering the applicability to the treatment or prevention of diseases associated with calpain, there is still a need for calpain inhibitors with higher calpain inhibitory ability. Therefore, one object of the present invention is to provide a calpain inhibitor with excellent calpain inhibitory ability.

[0009] Technical solutions for solving technical problems

[0010] The present inventors have found that the calpain inhibitory ability can be enhanced by using an α-ketoamide derivative of a peptide disclosed in Patent Document 1 as a basic skeleton and bonding an amide group having an α carbon to which an oxygen atom or a sulfur atom is bonded to the N-terminus of the peptide.

[0011] The present invention relates to a compound represented by the following general formula (I) or a salt thereof.

[0012]

[0013] (In formula (I),

[0014] R 1 represents a hydrogen atom; a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted, or R 2 Combine to form a ring,

[0015] R 2 and R 3 Each independently represents a hydrogen atom; a hydroxyl group; an alkoxy group which may be substituted; or a linear, branched or cyclic alkyl group which may be substituted, or, R 2 With R 3 can combine to form a ring, where R 2 With R 1 When combined to form a ring containing a double bond, R 3 It can not exist,

[0016] R 4 represents a hydrogen atom; or a straight-chain or branched alkyl group having 4 or more carbon atoms which may be substituted,

[0017] R 5 represents a hydrogen atom; a straight-chain or branched alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted,

[0018] R 6 represents a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; a heterocyclic group which may be substituted; a condensed polycyclic hydrocarbon group which may be substituted; an alkoxy group which may be substituted; or a hydrogen atom,

[0019] X represents O or S,

[0020] When R 1 and R 2 When combined to form a ring, R 1 Can represent O, S or N, R 2 Can represent O or S,

[0021] L represents an amide bond, an ester bond, -NH-, -N-(straight chain, branched chain or cyclic alkylene)- or -(straight chain or branched chain alkylene-O-) n -(n is an integer from 1 to 10), or represents a single bond. )

[0022] The present invention also relates to a calpain inhibitor, which comprises the above compound or a salt thereof.

[0023] The present invention also relates to a pharmaceutical composition for treating or preventing a disease associated with calpain activity, comprising the above compound or a salt thereof.

[0024] The present invention also relates to a method for treating or preventing a disease associated with calpain activity, comprising administering an effective amount of the above compound or a salt thereof to a subject in need of treating or preventing a disease associated with calpain activity.

[0025] Effects of the Invention

[0026] According to an embodiment of the present invention, the α-ketoamide derivative of the peptide disclosed in Patent Document 1 is used as a basic skeleton, and an amide group having an α carbon bonded to an oxygen atom or a sulfur atom is bonded to the N-terminus of the peptide, thereby enhancing the calpain inhibitory ability, and as a result, a calpain inhibitor having enhanced calpain inhibitory ability can be provided. The reason why such an effect can be obtained is not intended to limit the present invention in any way and has not yet been clarified, but it is presumed that the reactivity with calpain is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a graph showing the results of measuring calpain activity.

[0028] Figure 2 This is a graph showing the results of measuring calpain activity over time.

[0029] Figure 3 This is a graph showing the results of measuring calpain activity. DETAILED DESCRIPTION

[0030] The following specifically describes the embodiments of the present invention, but the present invention is not limited to these embodiments. In addition, as long as the effects of the present invention can be obtained, the embodiments can be appropriately combined.

[0031] <Definition of terms>

[0032] In the present specification, "alkyl" or the "alkyl" part in other groups means a straight-chain, branched or cyclic saturated hydrocarbon group. Unless otherwise specified, it is preferably a saturated hydrocarbon group having 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-methylbutyl, 2-methylbutyl, 1,2-dimethylpropyl, hexyl, 1-butyl, 2-butyl, 1,2-dimethyl ... The term "alkylene" refers to a C1-5 alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl or 2,3-dimethylpropyl. The term "alkylene" refers to a C1-3 alkyl group, such as methyl, ethyl, n-propyl and isopropyl. The term "alkylene" refers to a divalent group obtained by removing one hydrogen atom from the above alkyl group.

[0033] "Alkoxy" refers to a group ((alkyl)-O-group) in which the above-mentioned alkyl group and an oxygen atom are bonded, and the alkyl part is as defined above. For example, in the alkoxy group, the number of carbon atoms in the alkyl part can be 1 to 6. Examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy, neopentoxy, tert-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 1,2-dimethylpropoxy, hexyloxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1-ethyl-2-methylpropoxy, and 1,1,2-trimethylpropoxy. As the C1-6 alkoxy group, a C1-5 alkoxy group is preferred, and a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, an n-pentoxy group, an isopentoxy group, and a 2,3-dimethylpropoxy group are more preferred.

[0034] An "alkenyl group" is a monovalent group formed by removing one hydrogen atom from any carbon atom of a linear, branched or cyclic unsaturated hydrocarbon having one or more carbon-carbon double bonds, and the number of carbon atoms may be, for example, 2 to 10, 2 to 6 or 2 to 4. Examples of the C2-10 alkenyl group include vinyl, n-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 1-methylidenebutyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 2-methyl-3-butenyl, 2-methylidenebutyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl 1-methylidenepentyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl, 2-methyl-4-pentenyl, 2-methylidenepentyl, 3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl, 3-methylidenepentyl, 4-methyl-1-pentenyl, 4-methyl-2-pentenyl, 4-methyl-3-pentenyl, 4-methyl-4-pentenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 5-heptenyl, 6-heptenyl, octenyl, nonenyl and decenyl.

[0035] "Alkynyl" is a monovalent group formed by removing one hydrogen atom from any carbon atom of a straight-chain or branched unsaturated hydrocarbon having one or more carbon-carbon triple bonds, and the number of carbon atoms may be, for example, 2 to 6 or 2 to 4. Examples of the alkynyl group include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, pentynyl, hexynyl, and phenylethynyl.

[0036] The "aryl group" refers to a monovalent aromatic hydrocarbon group and may have, for example, 6 to 10 carbon atoms, and includes a phenyl group and a naphthyl group.

[0037] "Heterocyclic group" is a monovalent group containing at least one hetero atom selected from nitrogen atom, oxygen atom and sulfur atom, and preferably has 5 to 14 members. The heterocyclic group may be a monocyclic heterocyclic group or a condensed heterocyclic group. The number of heteroatoms contained in the 5 to 14-membered heterocyclic group may be, for example, 1 to 5, 1 to 4, 1 to 3, 1 to 2, 2, or 1. For example, there are various combinations of heterocyclic groups containing 1 nitrogen atom, 2 nitrogen atoms, 3 nitrogen atoms, 1 oxygen atom, 2 oxygen atoms, 1 oxygen atom and 1 nitrogen atom, and 1 sulfur atom. The 5 to 14-membered heterocyclic group may be aromatic (heteroaryl) or non-aromatic. The monocyclic heterocyclic group is preferably a 5 to 6-membered ring. The condensed heterocyclic group is preferably an 8 to 10-membered ring. Examples of the 5- to 14-membered heterocyclic group include piperidyl, piperazinyl, morpholinyl, quinuclidine, pyrrolidyl, azetidinyl, oxetinyl, azetidin-2-one-yl, aziridine, tropanediyl, furanyl, tetrahydrofuranyl, thienyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, dioxolanyl, oxazolyl, oxazolinyl, isoxazolyl, thiazolyl, thiazolinyl, isothiazolyl, imidazolyl, imidazolinyl, imidazolidinyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, oxadiazolyl, furazanyl, thiadiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, pyranyl, pyridinyl, piperidinyl, pyridazinyl, pyrimidinyl, pyrazinyl, piperazinyl, dioxanyl, oxazinyl, morpholinyl, thiomorpholinyl, thiazinyl, triazinyl, benzofuranyl, isobenzofuranyl , dihydrobenzofuranyl, dihydroisobenzofuranyl, benzothiophenyl, isobenzothiophenyl, dihydrobenzothiophenyl, dihydroisobenzothiophenyl, tetrahydrobenzothiophenyl, quinolyl, isoquinolyl, quinazolinyl, phthalazinyl, pteridinyl, coumaryl, chromonyl, 1,4-benzodiazepine, indolyl, isoindolyl, benzimidazoyl, benzofuryl, purinyl, acridinyl, phenoxazinyl, phenothiazinyl, benzoxazolyl, oxazolyl, benzothiazolyl, indazolyl, benzimidazolyl, benzodioxolyl, benzodioxanyl, chromenyl, chromanyl, isochromanyl, chromanonyl, cinnolinyl, quinoxaline, indolizinyl, quinolinyl, imidazopyridinyl, naphthyridinyl, dihydrobenzoxazinyl, dihydrobenzoxazolinonyl, dihydrobenzoxazinonyl, benzothioxadinyl, tetrahydrofuranyl, tetrahydropyranyl and tetrahydrothiophenyl.

[0038] In the present specification, "halogen atom" means fluorine atom, chlorine atom, bromine atom and iodine atom, preferably fluorine atom, chlorine atom and bromine atom, and more preferably fluorine atom or chlorine atom. In the present specification, "carboxyl group" means a group represented by -C(=O)-OH.

[0039] In the entire specification, examples of substituents in an alkyl group or an alkyl moiety, an alkenyl group or an alkynyl group generally include halogen atoms, hydroxyl groups, amino groups, alkylamino groups, dialkylamino groups, thiol groups, alkylthiol groups, sulfinyl groups, sulfonyl groups, sulfanyl groups, alkoxy groups, cyclic ethers, carboxyl groups, alkylcarbonyl groups, alkoxycarbonyl groups, alkoxycarbonylamino groups, alkylcarbonyloxy groups, alkylaminocarbonyl groups, alkylcarbonylamino groups, carbonylamino groups, hydrazino groups, cycloalkyl groups, and the like. When an alkyl group or an alkyl moiety, an alkenyl group or an alkynyl group is substituted, the number of such substituents may be, for example, 1 to 6, 1 to 5, 1 to 4, 1 to 3, 1 to 2, 1, 2 or 3. Examples of substituents that may be substituted with an aryl group or a heterocyclic group include halogen atoms or alkoxy groups. When an aryl group or a heterocyclic group is substituted, the number of such substituents may be, for example, 1 to 5, 1, 2 or 3.

[0040] <Compound represented by general formula (I)>

[0041] In one aspect, the present invention relates to a compound represented by the following general formula (I) (hereinafter sometimes referred to as compound (I)) or a salt thereof.

[0042]

[0043] (In formula (I),

[0044] R 1 represents a hydrogen atom; a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted, or R 2 Combine to form a ring,

[0045] R 2 and R 3 Each independently represents a hydrogen atom; a hydroxyl group; an alkoxy group which may be substituted; or a linear, branched or cyclic alkyl group which may be substituted, or, R 2 With R 3 can combine to form a ring, where R 2 With R 1 When combined to form a ring containing a double bond, R 3 It can not exist,

[0046] R 4 represents a hydrogen atom; or a straight-chain or branched alkyl group having 4 or more carbon atoms which may be substituted,

[0047] R 5 represents a hydrogen atom; a straight-chain or branched alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted,

[0048] R 6 represents a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; a heterocyclic group which may be substituted; a condensed polycyclic hydrocarbon group which may be substituted; an alkoxy group which may be substituted; or a hydrogen atom,

[0049] X represents O or S,

[0050] When R 1 and R 2 When combined to form a ring, R 1 Can represent O, S or N, R 2 Can represent O or S,

[0051] L represents an amide bond, an ester bond, -NH-, -N-(straight chain, branched chain or cyclic alkylene)- or -(straight chain or branched chain alkylene-O-) n - (n is an integer from 1 to 10), or represents a single bond. )

[0052] R 1 It is preferably a hydrogen atom or a straight-chain, branched or cyclic alkyl group which may be substituted, more preferably a hydrogen atom or a straight-chain, branched or cyclic alkyl group having 1 to 6 carbon atoms which may be substituted by one or more groups selected from hydroxyl, carboxyl, cyclic ether, alkoxy (e.g., methoxy, ethoxy), sulfonyl, halogen atom, amino, methylamino and dimethylamino, and further preferably a hydrogen atom or a straight-chain or branched alkyl group having 1 to 4 carbon atoms which may be substituted by one or more groups selected from hydroxyl, carboxyl, cyclic ether, alkoxy (e.g., methoxy, ethoxy), sulfonyl, halogen atom, amino, methylamino and dimethylamino. Alternatively, R 1 Preferably with R 2 Combined to form a 3-8 membered heterocyclic ring containing 1 or 2 oxygen atoms and / or sulfur atoms. 1 and R 2 When combined to form a ring, R 1 and R 2 can be independently O, S or N. Therefore, R 1 and R 2The heterocyclic ring formed by the combination may further contain a nitrogen atom. As for the heterocyclic ring, as in the above examples for the heterocyclic group, for example, it may be oxolanyl, oxanyl, dioxolanyl, dioxanyl, thiolanyl, thianyl, oxathiolanyl, dithiolanyl, dithianyl, oxazolidinyl, isoxazolidinyl, thiazolidinyl, isothiazolidinyl. R 1 and R 2 The heterocyclic ring formed by the combination may be substituted. Examples of the substituent include a halogen atom, an alkyl group (e.g., methyl, ethyl, n-propyl, isopropyl), an alkoxy group (e.g., methoxy, ethoxy, n-propoxy, isopropoxy), and a cyano group.

[0053] R 2 It is preferably a hydrogen atom, an alkyl group or an alkoxy group, and more preferably a hydrogen atom, a methyl group or a methoxy group.

[0054] R 3 It is preferably a hydrogen atom, an alkyl group or an alkoxy group, and more preferably a hydrogen atom, a methyl group or a methoxy group.

[0055] Or, R 2 and R 3 They preferably combine with each other to form a cycloalkyl group, and more preferably form a C3-C5 cycloalkyl group.

[0056] L is preferably -(straight or branched alkylene-O-) n - (n is an integer of 1 to 10) or a single bond. The linear or branched alkylene group may be, for example, an alkylene group having 1 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and more preferably 2 carbon atoms.

[0057] X is an oxygen atom (O) or a sulfur atom (S), and is preferably O.

[0058] For example, in the above formula (I), -XLR 1 The group shown may be a group represented by the following formula (II).

[0059]

[0060] (In formula (II), n represents an integer of 0 to 10.)

[0061] In addition, for example, in the above formula (I), -XLR 1 The group shown may be a hydroxyl group, a thiol group, or a group selected from the following.

[0062]

[0063] In addition, as described above, in the above formula (I), R 1 and R 2 can combine to form a ring. For example,

[0064]

[0065] The partial structure shown may be a structure represented by the following formula (wherein m represents an integer of 1 to 3, and q represents 0 or 1).

[0066]

[0067] R 1 and R 2 The ring formed by the combination may be a ring containing a double bond. As described above, the ring containing a double bond may be substituted by a substituent. The substituents are as described above. The ring containing a double bond is, for example, a 5-membered ring or a 6-membered ring. In the ring containing a double bond, when the alpha carbon of the carbonyl group participates in the formation of the double bond, R 3 Such a ring includes an oxazole ring, an isoxazole ring, a furan ring, a thiophene ring, a pyran ring, a thiopyran ring, a thiazole ring, an isothiazole ring, and the like. Thus, for example, in the above formula (I),

[0068]

[0069] The partial structure shown can be the following formula (R 7 The structures shown in (a) are the same or different and represent a substituent bonded to the heterocyclic ring, and P represents an integer of 0 to 3).

[0070]

[0071] As R 7 Examples of the substituent include a halogen atom, an alkyl group (e.g., methyl, ethyl, n-propyl, isopropyl), an alkoxy group (e.g., methoxy, ethoxy, n-propoxy, isopropoxy), and a cyano group.

[0072] As R 4 or R 5 The substituents which may be substituted by the alkyl group or alkyl moiety, alkenyl group or alkynyl group shown in the figure include aryl group (e.g., phenyl, tolyl, xylyl), heteroaryl group (imidazoyl, indolyl, etc.), alkoxy group (e.g., methoxy, ethoxy, n-propoxy, isopropoxy), C1-3 sulfanyl group, amino group, guanidino group, amide group, thiol group, carboxyl group, hydroxyl group, C3-6 cycloalkyl group, etc. R 5 The substituents which may substitute the aryl or heterocyclic group include halogen atoms, alkyl groups (e.g., methyl, ethyl, n-propyl, isopropyl), alkoxy groups (e.g., methoxy, ethoxy, n-propoxy, isopropoxy) and the like.

[0073] In one embodiment, R 4 and R 5Each of them may be a group corresponding to the side chain of an amino acid, for example, a group corresponding to the side chain of an amino acid selected from the group consisting of Met, Ser, Ala, Thr, Val, Tyr, Leu, Asn, Ile, Gln, Asp, Phe, Glu, Trp, Lys, Cys, Arg, His, Gly (represented by the three-letter amino acid symbols), norleucine (Nle) and methionine sulfoxide (MetO) (wherein R 4 is not a group corresponding to the side chain of Val).

[0074] R 4 Preferably, it may be an unsubstituted C4-5 branched alkyl group or a C1-2 alkyl group substituted by a C3-C5 cycloalkyl group. As the unsubstituted C4-5 branched alkyl group, isobutyl (-CH2CH(CH3)2) (side chain of Leu) or sec-butyl (-CH(CH3)CH2CH3) (side chain of Ile) is preferred, and isobutyl is more preferred. As the C1-2 alkyl group substituted by a C3-C5 cycloalkyl group, a C3-C5 cycloalkylmethyl group is preferred, and a cyclopropylmethyl group or a cyclobutylmethyl group is more preferred.

[0075] R 5 It is preferably a straight or branched alkyl group which may be substituted with a phenyl group, an imidazoyl group, an amino group, a guanidino group or a C1-3 sulfanyl group, and more preferably a C1-4 straight or branched alkyl group which may be substituted with a phenyl group, an imidazoyl group, an amino group, a guanidino group or a C1-3 sulfanyl group; or a phenyl group which may be substituted with a halogen atom, an alkyl group (e.g., a methyl group, an ethyl group, a n-propyl group, an isopropyl group) or an alkoxy group (e.g., a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group). 5 It may be, for example, benzyl (side chain of Phe), phenylethyl, 2-(methylthio)ethyl (side chain of Met), 2-(methylsulfinyl)ethyl (side chain of MetO), n-butyl (side chain of Nle), 1-hydroxyethyl (side chain of Thr), 3-guanidinopropyl (side chain of Arg), 4-aminobutyl (side chain of Lys), 1H-imidazol-4-yl-methyl (side chain of His), phenyl, n-propyl or isobutyl (side chain of Leu), and preferably may be benzyl, phenylethyl, 2-(methylthio)ethyl, 3-guanidinopropyl, 2-(methylsulfinyl)ethyl, n-butyl, phenyl, n-propyl or isobutyl.

[0076] R 6 Preferably it is a straight chain, branched or cyclic alkyl or alkoxy group, more preferably a C1-4 straight chain or branched alkyl group, a C3-6 cycloalkyl group or a C1-4 alkoxy group, and further preferably ethyl, n-propyl, isopropyl, methoxy, ethoxy, isopropoxy, cyclopropyloxy, cyclopropane or cyclobutane.

[0077] As R 6 The substituents which may be substituted by the alkyl group or alkyl moiety, alkenyl group or alkynyl group shown in the figure include halogen, alkoxy, phenoxy, alkenyl, alkynyl, amino, alkylamino, sulfanyl, sulfinyl, sulfonyl, carboxyl, nitrile, hydroxyl and the like. Among them, halogen, alkoxy and phenoxy are preferred. 6 The substituents on which the aryl, heterocyclic group or condensed polycyclic hydrocarbon group may be substituted include halogen atoms, alkyl groups (e.g., methyl, ethyl, n-propyl, isopropyl, cyclopropyl), alkoxy groups (e.g., methoxy, ethoxy, n-propoxy, isopropoxy, cyclopropyloxy), and the like.

[0078] About R 6 As the alkoxy group as a substituent, in addition to the above-mentioned alkoxy groups (for example, methoxy groups and ethoxy groups), groups in which the above-mentioned alkoxy groups are further substituted with the above-mentioned alkoxy groups can be appropriately used.

[0079] About R 6 The halogen of the substituent may be, for example, fluorine, chlorine or bromine, preferably fluorine.

[0080] As R 6 Examples of the condensed polycyclic hydrocarbon group include indanyl, indenyl, naphthyl, anthracenyl, pentalenyl, and azulenyl, among which indanyl is preferred.

[0081] Specific examples of the compounds in the embodiments of the present invention include compounds represented by the following formula (wherein R 1 , R 2 and R 3 As defined in formula (I), respectively. ).

[0082]

[0083] In addition, as specific examples of the compounds in the embodiments of the present invention, the compounds represented by the following formula (wherein, R 5 As defined in formula (I), preferably benzyl, phenylethyl, 2-(methylthio)ethyl, 2-(methylsulfinyl)ethyl, n-butyl, 1-hydroxyethyl, 3-guanidinopropyl, 4-aminobutyl, 1H-imidazol-4-yl-methyl, phenyl, n-propyl or isobutyl, and more preferably benzyl, 2-(methylthio)ethyl, phenyl or n-butyl. ).

[0084]

[0085] Compound (I) can be synthesized by any appropriate method. For example, compound (I) can be synthesized by referring to the method described in the examples of the present application, patent document 1 or the method described in Japanese Unexamined Patent Publication No. 2002-47256. The crude product of compound (I) obtained can be further refined. For example, the crude product obtained can be refined by reverse phase column chromatography.

[0086] Examples of the salt of compound (I) include base addition salts, acid addition salts, amino acid salts, etc. Examples of the base addition salt include metal salts such as lithium salts, sodium salts, potassium salts, calcium salts, and magnesium salts; organic amine salts such as ammonium salts, methylamine salts, dimethylamine salts, dicyclohexylamine salts, tris(hydroxymethyl)aminomethane salts, N,N-bis(hydroxyethyl)piperazine salts, 2-amino-2-methyl-1-propanol salts, ethanolamine salts, N-methylglucamine salts, L-glucamine salts, triethylamine salts, piperidine salts, and morpholine salts; or salts with basic amino acids such as lysine, δ-hydroxylysine, and arginine. As the acid addition salt, for example, inorganic acid salts such as hydrochloride, hydrobromide, sulfate, nitrate, phosphate, and organic acid salts such as methanesulfonate, benzenesulfonate, p-toluenesulfonate, citrate, oxalate, acetate, propionate, tartrate, fumarate, maleate, malate, succinate, benzoate, mandelate, cinnamate, lactate, glycolate, glucuronate, ascorbate, nicotinate, and salicylate can be cited. As amino acid salts, glycine salts etc. can be exemplified. However, the salt of the compound of the present invention is not limited to these.

[0087] Compound (I) sometimes has one or more asymmetric carbons depending on the type of substituents, and sometimes has stereoisomers such as optical isomers or diastereomers. Pure stereoisomers, any mixture of stereoisomers, racemates, etc. are all within the scope of the present invention. In addition, the compound represented by general formula (I) or its salt sometimes exists in the form of a hydrate or a solvate, and these substances are all within the scope of the present invention. The type of solvent forming the solvate is not particularly limited, but examples include solvents such as ethanol, acetone, isopropanol, etc. When "compound (I)" is mentioned in this specification, except for cases where it is obviously inappropriate, even if it is not explicitly stated, it also includes any mixture of isomers of compound (I) or specific stereoisomers, salts of compound (I) (representatively, pharmacologically acceptable salts), hydrates and solvates, and hydrates or solvates of salts of compound (I) (representatively, pharmacologically acceptable salts).

[0088] Compared to existing calpain inhibitors (e.g., calpain inhibitors disclosed in Patent Document 1), compound (I) may have enhanced calpain inhibitory ability. In addition, calpains include gene products having sequence regions with significant homology in the catalyst domain of human calpain-1 (μ-calpain, μCANP, μ80K, calpain I, CDP I), and include calpains-1 to 16. For example, calpain-1 is a heterodimer of CAPN1 and CAPNS1, and calpain-2 is a heterodimer of CAPN2 and CAPNS1. Compound (I) may, for example, have inhibitory activity against calpain-1.

[0089] Compound (I) may also be excellent in water solubility. The solubility (25°C) of compound (I) in water, physiological saline or buffer (e.g., 10 mM phosphate buffer (pH 7.0)) is, for example, greater than 0.1 mg / mL, preferably greater than 0.65 mg / mL, more preferably above 1.5 mg / mL, and further preferably above 5.0 mg / mL. In particular, compound (I) having excellent solubility in water is more advantageous from the perspective of being suitable for use in pharmaceutical compositions (e.g., eye drops). In one embodiment, compound (I) may have improved water solubility compared to existing calpain inhibitors (e.g., calpain inhibitors disclosed in Patent Document 1).

[0090] <Calpain inhibitor or pharmaceutical composition>

[0091] As described above, compound (I) may have an enhanced calpain inhibitory ability. Therefore, in one aspect, the present invention relates to a calpain inhibitor or a pharmaceutical composition comprising compound (I) as an active ingredient.

[0092] For example, calpain inhibitors can be used to inhibit the activity of calpain. The calpain inhibitors can be used, for example, in vitro, in vivo or ex vivo.

[0093] In addition, for example, the calpain inhibitor and the pharmaceutical composition are used for the treatment or prevention of diseases associated with calpain activity, respectively.

[0094] Diseases associated with calpain activity refer to diseases in which the expression of calpain or its activity is involved in the onset or progression of the disease. Examples of diseases associated with calpain activity include: glaucoma including normal-tension glaucoma, autosomal dominant neovascular inflammatory vitreoretinopathy, retinitis pigmentosa, age-related macular degeneration, retinal neuropathy associated with diabetes or retinal vascular occlusive disease, retinal ischemia, etc., retinal diseases or retinal neuropathy, or eye diseases such as cataracts; muscle diseases such as muscular dystrophy; diabetes; inflammatory diseases or autoimmune diseases such as acute esophagitis, multiple sclerosis, idiopathic inflammatory myopathy, and autoimmune encephalitis; neurological diseases such as spinal cord injury, Parkinson's disease, neurodegenerative diseases, anencephaly, Alzheimer's disease, and spinocerebellar lesions; myocardial ischemia-reperfusion injury, chronic heart disease, etc. Cardiovascular diseases such as heart disease, abdominal aortic aneurysm, and atherosclerosis; cancers such as melanoma, breast cancer, colorectal cancer, kidney cancer, stomach cancer, cervical cancer, and soft tissue sarcoma; brain tumors; aging syndrome; progeria; new coronavirus infectious diseases caused by SARS coronavirus 2 or its variants; malaria infectious diseases, trypanosomiasis, African sleeping sickness, schistosomiasis (schistosomiasis), leishmaniasis, sickle cell anemia and other parasitic / pathogenic microorganism infectious diseases; traumatic encephalopathy; Machado-Joseph disease; preeclampsia; pulmonary fibrosis.

[0095] The subjects to whom the calpain inhibitor or pharmaceutical composition is administered are typically humans or mammals other than humans (eg, cows, horses, dogs, cats, monkeys, pigs, sheep, rabbits, rats, mice, etc.).

[0096] The administration of the calpain inhibitor or pharmaceutical composition may be systemic or local. Systemic administration may be performed by oral administration, intravenous injection, subcutaneous injection, intramuscular injection, etc. Local administration may include administration to the skin, mucous membranes, nose, eyes, etc.

[0097] The dosage form of the calpain inhibitor or pharmaceutical composition can be an oral agent or a non-oral agent according to the administration form. Examples of oral agents include liquid preparations for internal use such as aqueous solutions, suspensions, emulsions, and syrups, and solid preparations for internal use such as tablets, pills, capsules, powders, granules, and tablets. Examples of non-oral agents include injections such as subcutaneous injections, intravenous injections, intramuscular injections, intraperitoneal injections, and intravitreal injections, eye drops, nasal drops, and external preparations (e.g., ointments such as eye ointments).

[0098] The calpain inhibitor or pharmaceutical composition may contain, in addition to Compound (I), pharmaceutically acceptable additives depending on the dosage form, etc. The calpain inhibitor or pharmaceutical composition can be produced by a known method, for example, a method described in the Japanese Pharmacopoeia.

[0099] For example, an oral liquid preparation can be prepared by dissolving, suspending or emulsifying Compound (I) in a diluent (e.g., purified water, ethanol or a mixture thereof). The liquid preparation may further contain a wetting agent, a suspending agent, an emulsifier, a sweetener, a flavoring agent, an aromatic agent, a preservative, a buffer, etc.

[0100] In addition, for example, the oral solid preparation can be prepared by mixing compound (I) with an excipient (e.g., lactose, mannitol, glucose, microcrystalline cellulose, starch), a binder (e.g., hydroxypropylcellulose, polyvinylpyrrolidone, magnesium aluminum metasilicate), a disintegrant (e.g., cellulose glycolate calcium), a lubricant (e.g., magnesium stearate), a stabilizer, a dissolution aid (e.g., glutamic acid, aspartic acid), etc., and preparing the preparation according to a conventional method. If necessary, the solid preparation can be coated with a coating agent (e.g., white sugar, gelatin, hydroxypropylcellulose, hydroxypropylmethylcellulose phthalate), and can be coated with two or more layers.

[0101] Injections, eye drops or nasal drops can be prepared, for example, by dissolving or dispersing Compound (I) in a solution containing appropriately added isotonic agents (e.g., sodium chloride, potassium chloride, glycerol, mannitol, sorbitol, boric acid, borax, glucose, propylene glycol), buffers (e.g., phosphate buffer, acetate buffer, borate buffer, carbonate buffer, citrate buffer, tris(hydroxymethyl)aminomethane (TRIS) buffer, glutamic acid buffer, ε-aminocaproic acid buffer), preservatives (e.g., methylparaben, The invention can be prepared by mixing an aqueous solution containing additives such as ethyl paraben, propyl paraben, chlorobutanol, benzyl alcohol, benzalkonium chloride, sodium dehydroacetate, sodium edetate, boric acid, borax), a thickener (e.g., hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyethylene glycol), a stabilizer (e.g., sodium bisulfite, sodium thiosulfate, sodium edetate, sodium citrate, ascorbic acid, butylated hydroxytoluene), and a pH adjuster (e.g., hydrochloric acid, sodium hydroxide, phosphoric acid, acetic acid).

[0102] The amount of additives added to injections, eye drops or nasal drops can be set to an appropriate amount according to the type of additive, purpose, etc. Isotonic agents are usually preferably added in an amount of about 0.5 w / v% to about 5.0 w / v% so that the osmotic pressure is about 229 mOsm to about 343 mOsm. The amount of buffer added is preferably about 0.01 w / v% to about 2.0 w / v%. The amount of thickener added is preferably about 0.01 w / v% to about 1.0 w / v%. The amount of stabilizer added is preferably about 0.001 w / v% to about 1.0 w / v%. The pH adjuster is usually added in a manner such that the pH is about 3 to about 9, and preferably about 4 to about 8.

[0103] The dosage of the calpain inhibitor or pharmaceutical composition can be set to any appropriate amount according to the target disease, symptoms, administration object or administration method, etc. For example, when it is made into an oral dosage form and administered to an adult, it is several times a day, and the single dose is about 1 mg to about 200 mg (the amount of compound (I) (i.e., potency)), and preferably about 10 mg to about 100 mg (potency). In addition, when it is made into an injection and administered to an adult, it is once a day, about 0.1 mg to about 50 mg (potency), and preferably about 1 mg to about 30 mg (potency). In addition, when it is topically applied to the eye, it is preferred to use an eye drop containing, for example, about 0.001 w / v% to about 1.0 w / v%, and preferably about 0.01 w / v% to about 0.5 w / v% of compound (I), in a dose of about 20 μL to about 50 μL, and drip into the eye several times a day.

[0104] <Prevention or treatment methods>

[0105] In one aspect, the present invention relates to a method for treating or preventing a disease associated with calpain activity, comprising the step of administering an effective amount of compound (I) to a subject in need of treating or preventing a disease associated with calpain activity.

[0106] Compound (I) can be administered as such, or in the form of a calpain inhibitor or a pharmaceutical composition to a subject in need of treatment or prevention of a disease associated with calpain activity.

[0107] The methods for administering the compound (I) and the diseases associated with calpain activity are as described above for the methods for administering the calpain inhibitor or pharmaceutical composition. In addition, the individual who needs to treat or prevent the disease associated with calpain activity is an individual suffering from the disease or an individual who is likely to suffer from the disease (e.g., an individual showing calpain activity above the baseline value). The individual is typically the same as the subject to be administered the calpain inhibitor or pharmaceutical composition, and is a human or a mammal other than a human.

[0108] The effective amount of compound (I) can be, for example, an amount that can achieve the therapeutic effect or preventive effect of the above-mentioned disease when compound (I) is administered, compared to when it is not administered. The specific effective amount is not set uniformly, but can be appropriately adjusted according to the administration form, administration method, purpose of use, and individual age, weight, symptoms, etc.

[0109] Example

[0110] The present invention will be described in more detail below using examples, but the scope of the present invention is not limited thereto. In addition, all documents cited in the present application are incorporated herein by reference.

[0111] [Synthesis example 1]

[0112] Compound 13 was synthesized according to the scheme shown below.

[0113]

[0114] (Synthesis of Compound 2)

[0115]

[0116] Slowly add ethyl chloroformate (5.3 mL, 55.6 mmol) to a CH2Cl2 solution (92.0 mL) of compound 1 (10.0 g, 46.4 mmol) and DIPEA (18.9 mL, 111 mmol) at 0°C, slowly warm to room temperature, and stir for 18 hours. Add distilled water and 2M hydrochloric acid, confirm that the pH is 4, extract with dichloromethane, wash the organic phase with a saturated sodium bicarbonate aqueous solution and then with saturated brine. After drying the organic phase with sodium sulfate, remove the solvent by vacuum distillation. Purify the obtained residue with a silica gel column to obtain the target compound 2 (11.5 g, 99%).

[0117] 1 H NMR (400MHz,CDCl3)

[0118] δ7.28(2H,dd,J=7.2,2.0Hz),7.24(1H,dd,J=7.2,2.0Hz),7.10(2H,dd,J=7.2,2.0Hz),5. 07(1H,d),4.63(1H,q),4.09(2H,q),4.09(2H,q),3.70(3H,s),3.09(2H,dd),1.21(3H,t)

[0119] (Synthesis of Compound 4)

[0120]

[0121] Under a nitrogen atmosphere, diisopropylamine (24.5 mL, 172 mmol) was added to n-BuMgCl (72.0 mL, 143 mmol, 2.0 M THF solution) at 40° C. over 30 minutes, and the mixture was stirred at the same temperature for 2 hours to obtain a slurry.

[0122] Under nitrogen atmosphere, the slurry was added to a toluene solution (20.8 mL) of compound 2 (9.0 g, 35.8 mmol), dibromomethane (5.1 mL, 71.6 mmol) and 1,2-dimethoxyethane (10.4 mL, 100 mmol) at -10°C over 1.5 hours and stirred for 2 hours. Distilled water and 2M hydrochloric acid were added, and after confirming that the pH was 2, toluene was used for extraction, and the organic phase was washed with distilled water and then with saturated brine. The organic phase was dried with sodium sulfate and filtered. The obtained toluene solution was used for the next reaction.

[0123] Potassium carbonate (12.4 g, 89.5 mmol) and N-bromosuccinimide (15.9 g, 89.5 mmol) were added to the toluene solution at 0°C and stirred for 2 hours at the same temperature. Distilled water was added, extracted with toluene, and the organic phase was washed with 0.2 M hydrochloric acid and then with saturated brine. After drying the organic phase with sodium sulfate, the solvent was distilled off under reduced pressure to obtain the target compound 4 (15.8 g, 94%, 2 steps).

[0124] 1 H NMR (400MHz,CDCl3)

[0125] δ7.36-7.15(5H,m),5.65(1H,q),5.13(1H,d),4.02(2H,q),3.40(1H,dd),3.03(1H,dd),1.15(3H,t)

[0126] (Synthesis of Compound 7)

[0127]

[0128] Sodium borohydride (1.27 g, 33.5 mmol) was slowly added to a MeOH solution (170 mL) of compound 4 (15.8 g, 33.5 mmol) at 0°C and stirred for 2 hours. Distilled water and 2M hydrochloric acid were added, and after confirming that the pH was 4, extraction was performed with dichloromethane, and the organic phase was washed with distilled water and then with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The obtained residue was used for the next reaction.

[0129] 4M lithium hydroxide aqueous solution (83.8 mL, 335 mmol) was added to a toluene solution (80.0 mL) of the above residue, and the mixture was stirred at 70° C. for 16 hours. After cooling to room temperature, the organic layer and the aqueous layer were separated, and the aqueous layer was used for the next reaction.

[0130] THF (100 mL) and Boc2O (14.6 g, 67.0 mmol) were added to the aqueous layer and stirred at room temperature for 18 hours. 2M hydrochloric acid was added and the pH was confirmed to be 4, then extracted with ethyl acetate and the organic phase was washed with saturated brine. The organic phase was dried over sodium sulfate and the solvent was removed by vacuum distillation to obtain the target compound 7 (3.90 g, 39%, 3 steps).

[0131] 1 H NMR (400 MHz, DMSO-d6)

[0132] δ7.34-7.15(6H,m),6.39(1H,d),4.00(1H,m),3.87(11H,m),2.75(2H,m),1.31(9H,m)

[0133] (Synthesis of Compound 8)

[0134]

[0135] HATU (5.10 g, 13.4 mmol) was added to a DMF solution (60.0 mL) of compound 7 (3.60 g, 12.2 mmol), DIPEA (4.30 mL, 24.4 mmol) and cyclopropylamine (1.02 mL, 14.6 mmol) and stirred for 4 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, extraction was performed with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The obtained residue was purified by silica gel column to obtain the target compound 8 (1.17 g, 29%).

[0136] 1 H NMR (400 MHz, DMSO-d6)

[0137] δ7.75(1H,m),7.32-7.14(5H,m),6.50(0.5H,d),6.14(0.5H,d),5.67(0.5H,d),5.50(0.5H,d),3.97(1.5H,m) ,3.77(0.5H,dd),2.78(0.5H,m),2.68-2.53(2.5H,m),1.28(4.5H,s),1.21(4.5H,s),0.58(2H,m),0.47(2H,m)

[0138] (Synthesis of Compound 9)

[0139]

[0140] 4M hydrochloric acid (6.40 mL, 25.6 mmol, dioxane solution) was added to compound 8 (429 mg, 1.28 mmol), and the mixture was stirred at room temperature for 1 hour. The solvent was evaporated under reduced pressure to obtain the target compound 9 (339 mg, 97%).

[0141] HRMS(ESI + ):calcd for[M+H] + ,235.1441; found,235.1434(-0.7mmu)

[0142] (Synthesis of Compound 10)

[0143]

[0144] HATU (77.2 mg, 0.203 mmol) was added to a DMF solution (1.0 mL) of compound 9 (50.0 mg, 0.185 mmol), DIPEA (0.095 mL, 0.56 mmol) and Fmoc-Leu-OH (71.8 mg, 0.203 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, extraction was performed with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The obtained residue was purified by silica gel column to obtain the target compound 10 (49.6 mg, 46%).

[0145] HRMS(ESI + ):calcd for[M+H] + ,570.2962; found,570.2955(-0.7mmu)

[0146] (Synthesis of Compound 11)

[0147]

[0148] Diethylamine (1.0 mL) was added to a solution of compound 10 (49.6 mg, 0.087 mmol) and CH2Cl2 (4.0 mL), and the mixture was stirred at room temperature for 2 hours. The solvent was distilled off under reduced pressure, hexane was added to the resulting residue, and the resulting solid was filtered to obtain the target compound 11 (30.3 mg, quantitative yield).

[0149] HRMS(ESI +):calcd for[M+H] + ,348.2282; found,348.2273(-0.9mmu)

[0150] (Synthesis of Compound 12)

[0151]

[0152] HATU (33.1 mg, 0.087 mmol) was added to a DMF solution (1.0 mL) of compound 11 (30.3 mg, 0.087 mmol), DIPEA (0.043 mL, 0.26 mmol) and methoxyacetic acid (0.0073 mL, 0.096 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, extraction was performed with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The obtained residue was purified by silica gel column to obtain the target compound 12 (13.4 mg, 37%).

[0153] HRMS(ESI + ):calcd for[M+H] + ,420.2493; found,420.2483(-1.0mmu)

[0154] (Synthesis of Compound 13)

[0155]

[0156] DMPI (27.1 mg, 0.064 mmol) was added to a CH2Cl2 solution (3.0 mL) of compound 12 (13.4 mg, 0.032 mmol) and sodium bicarbonate (43 mg, 0.26 mmol), and stirred for 5 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The obtained residue was purified by silica gel column to obtain the target compound 13 (6.3 mg, 47%).

[0157] HRMS(ESI + ):calcd for[M+H] + ,418.2336; found,418.2331(-0.5mmu) 1 H NMR (400 MHz, DMSO-d6)

[0158] δ8.72(1H,d),8.40(1H,d),7.53(1H,d),7.30-7.08(5H,m),5.13(1H,m),4.37(1H,m),3.75(2H,d),3.23(3H,s),3.0 8(1H,dd),2.75(1H,dd),2.69(1H,m),1.45(1H,m),1.36(2H,m),0.82(3H,d),0.79(3H,d),0.61(2H,m),0.53(2H,m)

[0159] [Synthesis example 2]

[0160] Compound 14 was synthesized according to the scheme shown below.

[0161]

[0162] HATU (21.9 mg, 0.058 mmol) was added to a DMF solution (1.2 mL) of compound 11 (20.0 mg, 0.058 mmol), DIPEA (0.029 mL, 0.17 mmol) and 2-methoxy-2-methylpropionic acid (0.0071 mL, 0.063 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 14p. It was used for the next reaction.

[0163] DMPI (49 mg, 0.12 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 14p and sodium bicarbonate (19 mg, 0.23 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The residue was purified by silica gel column to obtain the target compound 14 (11.8 mg, 46%, 2 steps). HRMS (ESI + ):calcd for[M+H] + ,446.2649; found,446.2650(-0.1mmu) 1H NMR(400MHz,DMSO-d6):1H NMR (400MHz, DMSO-d6): δ8.73(1H,d),8.28(1H,d),7.46(1H,d),7.27-7.09(5H,m),5.15(1H,m),4.30(1H,m),3.06(3H,s),3.10(1H,d d),2.72(1H,dd),2.62(1H,m),1.42(1H,m),1.32(2H,m),1.19(3H,s),1.16(3H,s),0.81(3H,d),0.78(3H,d),0.61(2H,m),0.54(2H,m)

[0164] [Synthesis example 3]

[0165] Compound 15 was synthesized according to the scheme shown below.

[0166]

[0167] HATU (21.9 mg, 0.058 mmol) was added to a DMF solution (1.2 mL) of compound 11 (20.0 mg, 0.058 mmol), DIPEA (0.029 mL, 0.17 mmol) and 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (0.0097 mL, 0.063 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 15p. It was used for the next reaction.

[0168] DMPI (49 mg, 0.12 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 15p and sodium bicarbonate (19 mg, 0.23 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The residue was purified by silica gel column to obtain the target compound 15 (8.7 mg, 30%, 2 steps). HRMS (ESI + ):calcd for[M+H] + ,506·2861; found,506.2856(-0.5mmu) 1 H NMR (400 MHz, DMSO-d6):

[0169] δ8.71(1H,d),8.42(1H,d),7.45(1H,d),7.30-7.07(5H,m),5.13(1H,m),4.37(1H,m),3.83(2H,br-s),3.56-3.45(6H,m),3.39(2H,m) ,3.19(3H,s),3.08(1H,dd),2.74(1H,dd),2.70(1H,m),1.47(1H,m),1.37(2H,m),0.83(3H,d),0.80(3H,d),0.62(2H,m),0.54(2H,m)

[0170] [Synthesis Example 4]

[0171] Compound 16 was synthesized according to the scheme shown below.

[0172]

[0173] HATU (54.7 mg, 0.14 mmol) was added to a DMF solution (1.0 mL) of compound 11 (50.0 mg, 0.14 mmol), DIPEA (0.075 mL, 0.43 mmol) and 2-(methylthio)acetic acid (0.014 mL, 0.16 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 16p.

[0174] DMPI (15 mg, 0.036 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 16p (15.6 mg, 0.036 mmol) and pyridine (0.014 mL, 0.18 mmol) and stirred for 1 hour. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The residue was purified by silica gel column to obtain the target compound 16 (6.9 mg, 44%).

[0175] HRMS(ESI + ):calcd for[M+H] + ,434.2108; found,434.2094(-1.4mmu) 1 H NMR (400 MHz, DMSO-d6):

[0176] δ8.70(1H,d),8.37(1H,d),7.97(1H,d),7.29-7.08(5H,m),5.15(1H,m),4.33(1H,m),3.07(1H,dd),3.02(2H,d),2. 76(1H,dd),2.68(1H,m),1.99(3H,s),1.52(1H,m),1.34(2H,m),0.83(3H,d),0.80(3H,d),0.61(2H,m),0.53(2H,m)

[0177] [Synthesis example 5]

[0178] Compound 17 was synthesized according to the scheme shown below.

[0179]

[0180] HATU (22.0 mg, 0.058 mmol) was added to a DMF solution (0.5 mL) of compound 11 (20.0 mg, 0.058 mmol), DIPEA (0.029 mL, 0.17 mmol) and (2R)-tetrahydro-2-furancarboxylic acid (0.006 mL, 0.063 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 17p. It was used for the next reaction.

[0181] DMPI (49 mg, 0.12 mmol) was added to a CH2Cl2 solution (0.5 mL) of compound 17p and sodium bicarbonate (19 mg, 0.23 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The residue was purified by silica gel column to obtain the target compound 17 (5.4 mg, 21%, 2 steps). HRMS (ESI + ):calcd for[M+H] + ,444.2493; found,444.2473(-2.0mmu) 1 H NMR (400 MHz, DMSO-d6):

[0182] δ8.78(1H,d),8.38(1H,d),7.48(1H,d),7.27-7.07(5H,m),5.13(1H,m),4.30(1H,m),3.80(1H,m),3.69(1H,m),3.10(1H,m),2. 73(1H,dd),2.66(1H,m),2.01(1H,m),1.71(4H,m),1.40(1H,m),1.30(2H,m),0.82(3H,d),0.78(3H,d),0.62(2H,m),0.54(2H,m)

[0183] [Synthesis example 6]

[0184] Compound 18 was synthesized according to the scheme shown below.

[0185]

[0186] HATU (22.0 mg, 0.058 mmol) was added to a DMF solution (0.5 mL) of compound 11 (20.0 mg, 0.058 mmol), DIPEA (0.029 mL, 0.17 mmol) and 2-(2-propyn-1-yloxy)acetic acid (0.0072 mL, 0.063 mmol), and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, extraction was performed with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was distilled off under reduced pressure to obtain compound 18p (7.2 mg, 28%).

[0187] DMPI (13.7 mg, 0.032 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 18p (7.2 mg, 0.016 mmol) and sodium bicarbonate (54 mg, 0.065 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The residue was purified by silica gel column to obtain the target compound 18 (5.1 mg, 71%).

[0188] HRMS(ESI + ):calcd for[M+H] + ,442.2336; found,442.2313(-2.3mmu) 1 H NMR (400 MHz, DMSO-d6):

[0189] δ8.70(1H,d),8.40(1H,d),7.59(1H,d),7.39-7.10(5H,m),5.12(1H,m),4.36(1H,m),4.16(2H,d),3.87(2H,s),3.50(1H, m),3.08(1H,dd),2.75(1H,dd),2.68(1H,m),1.46(1H,m),1.36(2H,m),0.82(3H,d),0.79(3H,d),0.61(2H,m),0.53(2H,m)

[0190] [Synthesis Example 7]

[0191] As a comparative compound, Compound 19 was synthesized according to the following scheme.

[0192]

[0193] HATU (22.0 mg, 0.058 mmol) was added to a DMF solution (0.5 mL) of compound 11 (20.0 mg, 0.058 mmol), DIPEA (0.029 mL, 0.17 mmol) and 3-methoxypropionic acid (6.6 mg, 0.063 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was distilled off under reduced pressure to obtain compound 19p (7.7 mg, 31%).

[0194] DMPI (15 mg, 0.035 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 19p (7.7 mg, 0.018 mmol) and sodium bicarbonate (6.0 mg, 0.071 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The residue was purified by silica gel column to obtain the target compound 19 (3.4 mg, 44%).

[0195] HRMS(ESI + ):calcd for[M+H] + ,432.2493; found,432.2471(-2.2mmu) 1 H NMR (400 MHz, DMSO-d6):

[0196] δ8.69(1H,d),8.25(1H,d),7.87(1H,d),7.28-7.09(5H,m),5.12(1H,m),4.30(1H,m),3.43(2H,m),3.14(3H,s),3.07(1H, dd),2.76(1H,dd),2.67(1H,m),2.27(2H,m),1.51(1H,m),1.30(2H,m),0.82(3H,d),0.77(3H,d),0.61(2H,m),0.53(2H,m)

[0197] [Synthesis example 8]

[0198] Compound 27 was synthesized according to the scheme shown below.

[0199]

[0200] HATU (30.0 mg, 0.079 mmol) was added to a DMF solution (1.0 mL) of compound 11 (25.0 mg, 0.072 mmol), DIPEA (0.037 mL, 0.22 mmol) and 2-furoic acid (8.8 mg, 0.063 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 27p.

[0201] DMPI (45.0 mg, 0.11 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 27p and sodium bicarbonate (18.0 mg, 0.21 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The obtained residue was purified by silica gel column to obtain the target compound 27 (13.0 mg, 41%, 2 steps).

[0202] HRMS(ESI + ):calcd for[M+H] + ,440.2180; found,440.2156(-2.4mmu) 1 H NMR (400MHz,CDCl3):

[0203] δ7.45(1H,m),7.14-7.09(4H,m),7.07-7.01(2H,m),6.90(1H,d),6.69(1H,d),6.53(1H,d),6.52(1H,d),5.54(1H,m),4.57(1 H,m),3.33(1H,dd),3.02(1H,dd),2.79(1H,m),1.65(1H,m),1.55(2H,m),0.91(3H,d),0.89(3H,d),0.86(2H,m),0.60(2H,m)

[0204] [Synthesis Example 9]

[0205] Compound 30 was synthesized according to the scheme shown below.

[0206]

[0207] (Synthesis of Compound 30n)

[0208]

[0209] Fmoc-β-cyclopropyl-L-alanine (200 mg, 0.57 mmol), DIPEA (0.30 mL, 1.72 mmol), 2-chlorotrityl chloride resin (244 mg, 0.38 mmol) and CH2Cl2 (4.0 mL) were added to a plastic container and thoroughly shaken for 17 hours. The reaction solution was filtered and the filtrate was washed with CH2Cl2 (5.0 mL).

[0210] The obtained filtrate was transferred to the plastic solution, and a piperidine:DMF=1:4 solution (5.0 mL) was added, and the mixture was shaken thoroughly for 1 hour. The reaction solution was filtered, and the filtrate was washed with DMF (5.0 mL) and then with CH2Cl2 (5.0 mL).

[0211] The obtained filtrate was transferred to the plastic solution, and DIPEA (0.27 mL, 1.55 mmol), methoxyacetic acid (0.058 mL, 0.76 mmol), DMF solution (5.0 mL) and HATU (0.29 g, 0.76 mmol) were added, and the mixture was shaken thoroughly for 3 hours. The reaction solution was filtered, and the filtrate was washed with DMF (5.0 mL) and then with CH2Cl2 (5.0 mL).

[0212] The obtained filtrate was transferred to a plastic solution, TFA (4.0 mL) was added, and after standing for 2 hours, the reaction solution was filtered, and the filtrate was washed with TFA (4.0 mL). The obtained filtrate was concentrated under reduced pressure to obtain the target compound 30n (76 mg, 99%, 4 steps).

[0213] (Synthesis of Compound 30)

[0214]

[0215] HATU (56 mg, 0.15 mmol) was added to a DMF solution (1.5 mL) of compound 9 (40 mg, 0.15 mmol), DIPEA (0.075 mL, 0.44 mmol) and compound 30n (30 mg, 0.15 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, extraction was performed with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was distilled off under reduced pressure to obtain compound 30p (18 mg, 29%).

[0216] DMPI (28 mg, 0.066 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 30p (18 mg, 0.043 mmol) and sodium bicarbonate (11 mg, 0.13 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The obtained residue was purified by silica gel column to obtain the target compound 30 (4.8 mg, 27%).

[0217] HRMS(ESI + ):calcd for[M+H] + ,416.2180; found,416.2153(-2.7mmu) 1 H NMR (400 MHz, DMSO-d6):

[0218] δ8.71(1H,d),8.39(1H,d),7.52(1H,d),7.30-7.09(5H,m),5.16(1H,m),4.38(1H,m),3.76(2H,d),3.25( 3H,s),3.08(1H,dd),2.75(1H,dd),2.65(1H,m),1.43(2H,m),0.66-0.47(5H,m),0.30(2H,m),0.00(2H,m)

[0219] [Synthesis Example 10]

[0220] Compound 35 was synthesized according to the scheme shown below.

[0221]

[0222] (Synthesis of Compound 35n)

[0223]

[0224] 2M sodium hydroxide aqueous solution (0.70mL) was added to β-cyclobutyl-L-alanine (0.10g, 0.70mmol) and dissolved, then methoxyacetic acid (0.083mL, 0.90mmol) was added and stirred at room temperature for 5 hours. 2M hydrochloric acid was added, and after confirming that the pH was 4, it was extracted with ethyl acetate and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. MTBE (1.0mL) and hexane (5.0mL) were added to the obtained residue, and the resulting solid was filtered to obtain compound 35n (12mg, 8%).

[0225] (Synthesis of Compound 35)

[0226]

[0227] HATU (21 mg, 0.056 mmol) was added to a DMF solution (1.0 mL) of compound 9 (20 mg, 0.073 mmol), DIPEA (0.029 mL, 0.17 mmol) and 35n (12 mg, 0.056 mmol) and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, it was extracted with MTBE, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was distilled off under reduced pressure to obtain compound 35p (12 mg, 49%).

[0228] DMPI (18 mg, 0.043 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 35p (12 mg, 0.028 mmol) and sodium bicarbonate (7.1 mg, 0.086 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by vacuum distillation. The obtained residue was purified by silica gel column to obtain the target compound 35 (3.0 mg, 25%).

[0229] HRMS(ESI + ):calcd for[M+H] + ,430.2336; found,430.2336(0.0mmu)

[0230] 1 H NMR (400 MHz, DMSO-d6):

[0231] δ8.72(1H,d),8.38(1H,d),7.42(1H,d),7.28-7.12(5H,m),5.13(1H,m),4.24(1H,m),3.74(2H,d),3.24(3H,s),3.08(1 H,dd),2.74(1H,dd),2.70(1H,m),2.15(1H,m),1.90(1H,m),1.90(1H,m),1.75-1.48(6H,m),0.62(2H,m)),0.54(2H,m)

[0232] [Synthesis Example 11]

[0233] Compound 36 was synthesized according to the scheme shown below.

[0234]

[0235] (Synthesis of Compound 36n)

[0236]

[0237] Fmoc-Leu-OH (2.5 g, 7.1 mmol), DIPEA (3.8 mL, 22 mmol), 2-chlorotrityl chloride resin (3.1 g, 4.8 mmol) and CH2Cl2 (16 mL) were added to a plastic container and thoroughly shaken for 20 hours. The reaction solution was filtered and the filtrate was washed with CH2Cl2 (15 mL).

[0238] A portion of the obtained filtrate (0.19 g, 0.20 mmol) was transferred to the plastic solution, and a piperidine:DMF=1:4 solution (0.4 mL) was added and the mixture was shaken thoroughly for 1 hour. The reaction solution was filtered and the filtrate was washed with DMF (1.0 mL) and then with CH2Cl2 (1.0 mL).

[0239] The obtained filtrate was transferred to the plastic solution, and DIPEA (0.14 mL, 0.82 mmol), 2-furoic acid (45 mg, 0.40 mmol), DMF solution (2.0 mL) and HATU (0.15 g, 0.40 mmol) were added, and the mixture was shaken thoroughly for 3 hours. The reaction solution was filtered, and the filtrate was washed with DMF (3.0 mL) and then with CH2Cl2 (3.0 mL).

[0240] The obtained filtrate was transferred to a plastic solution, TFA (2.0 mL) was added, and after standing for 2 hours, the reaction solution was filtered, and the filtrate was washed with TFA (2.0 mL). The obtained filtrate was concentrated under reduced pressure to obtain the target compound 36n (45 mg, quantitative yield, 3 steps).

[0241] (Synthesis of Compound 36)

[0242]

[0243] HATU (32 mg, 0.084 mmol) was added to a DMF solution (1.0 mL) of commercially available (ChemScene) compound 36o (20 mg, 0.084 mmol), DIPEA (0.043 mL, 0.25 mmol) and compound 36n (19 mg, 0.084 mmol), and stirred for 2 hours. 0.2 M hydrochloric acid was added, and after confirming that the pH was 4, MTBE was used for extraction, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound 36p (34 mg, 99%).

[0244] DMPI (53 mg, 0.13 mmol) was added to a CH2Cl2 solution (1.0 mL) of compound 36p (34 mg, 0.083 mmol) and sodium bicarbonate (21 mg, 0.25 mmol) and stirred for 2 hours. Saturated aqueous sodium bicarbonate solution and saturated aqueous sodium thiosulfate solution were added, extracted with CH2Cl2, and the organic phase was washed with saturated brine. After drying the organic phase with sodium sulfate, the solvent was removed by distillation under reduced pressure. The residue was purified by silica gel column to obtain the target compound 36 (31 mg, 92%).

[0245] HRMS(ESI + ):calcd for[M+H] + ,406.2336; found,406.2304(-3.2mmu) 1 H NMR (400 MHz, DMSO-d6):

[0246] δ8.68(1H,d),8.29(1H,d),8.15(1H,d),7.80(1H,s),7.15(1H,d),6.58(1H,dd),4.90(1H,m),4.50(1H,m),2.6 9(1H,m),1.70(1H,m),1.57(2H,m),1.45(2H,m),1.37-1.14(4H,m),0.92-0.75(9H,m),0.60(2H,m),0.52(2H,m)

[0247] Tables 1A to 1D show compounds 13 to 18, 27, 30, 35 and 36 synthesized in the above-mentioned Synthesis Examples 1 to 11, compounds 20, 22, 25, 26, 28, 29, 31 to 34, 37 to 43 synthesized according to these Synthesis Examples, and compounds 21, 23, 24 and 44 that can be synthesized.

[0248] [Table 1A]

[0249]

[0250] [Table 1B]

[0251]

[0252] [Table 1C]

[0253]

[0254] [Table 1D]

[0255]

[0256] 《Determination of Calpain Inhibitory Activity 1》

[0257] Calpain inhibitory activity using SensorLyte (R) 520 Calpain Activity Assay Kit (AnaSpec, AS-72149) was used for the assay. Calpain inhibitors SNJ1945 (Medkoo Biosciences, Inc. Cat#564979), Compound 13, Compound 14, Compound 18, or Compound 19 were mixed with calpain (calpain-1) contained in the kit in the assay buffer and incubated at 37°C for 3 minutes. 5-FAM / QXL was added as a calpain substrate. TM 520, and the enzyme reaction using calpain was carried out at 37°C for 25 minutes (the final concentration of each inhibitor was 0.062 μM, 5-FAM / QXL TM The final concentration of 520 is 5.0 μM. In this enzyme reaction, the enzyme substrate emits fluorescence due to being cut by calpain. The fluorescence intensity is measured by an Infinite (R) 200PRO, TECAN) (excitation wavelength 490nm, fluorescence wavelength 520nm). The fluorescence increase is shown in Figure 1 In addition, SNJ1945 is a known calpain inhibitor and has the structure shown below.

[0258]

[0259] from Figure 1 It can be seen that the enzyme activity of calpain is inhibited by SNJ1945. In compound 13, compound 14 and compound 18, stronger enzyme inhibitory activity than SNJ1945 was confirmed. On the other hand, compound 19 has the same degree of inhibitory activity as SNJ1945. From the above, it can be seen that by combining an amide group having an α carbon bonded to an oxygen atom or a sulfur atom at the N-terminus of the compound of formula I, the calpain inhibitory ability can be improved.

[0260] 《Determination of Calpain Inhibitory Activity 2》

[0261] Calpain-1 (Calpain-1 from human erythrocytes, Cat. No. 208713, Merck Millipore) and a DMSO solution of HMRG fluorescent probe for calpain activity detection were added to 50 mM TRIS buffer (pH 7.4, 5 mM CaCl2, 2 mM DTE, 2 mM EGTA) containing various concentrations of SNJ1945 or compound 13, and fluorescence measurement was performed (the final concentration of the fluorescent probe was 5 μM, and the final concentration of calpain-1 was 6.48 μg / mL). The enzyme reaction was carried out at 37°C, and the fluorescence spectrum of the reaction solution was observed over time for 30 minutes from the start of the reaction (excitation wavelength 460 nm, fluorescence wavelength 530 nm). The results are shown in Figure 2 (The concentrations shown in the figures are the final concentrations of SNJ1945 or Compound 13 in each assay.) In addition, the following compounds were used as probes for detecting calpain activity.

[0262]

[0263] IC is obtained based on the graph created using the data analysis software "KaleidaGraph" 50 , IC of compound 13 50 is 0.010 μM, and the IC 50 is 0.040μM.

[0264] 《Determination of Calpain Inhibitory Activity 3》

[0265] Calpain-1 (Calpain-1 from human erythrocytes, Cat. No. 208713, Merck Millipore) and a DMSO solution of HMRG fluorescent probe for calpain activity detection were added to 50 mM TRIS buffer (pH 7.4, 5 mM CaCl2, 2 mM DTE, 2 mM EGTA) containing compound 13, 20, 25, 26, 27, 28, 29, 30, 31, 32, 33, 36 or 37, and the fluorescence measurement method was performed (the final concentration of each compound was 0.062 μM, the final concentration of the fluorescent probe was 5 μM, and the final concentration of calpain-1 was 6.48 μg / mL). The enzyme reaction was carried out at 37°C, and the fluorescence spectrum of the reaction solution was observed over time for 30 minutes from the start of the reaction (excitation wavelength 460 nm, fluorescence wavelength 530 nm). The results are shown in Figure 3 In addition, the same compound as in the above-mentioned assay 2 was used as a probe for detecting calpain activity.

[0266] like Figure 3 As shown, all compounds showed calpain inhibitory activity equal to or greater than that of compound 13.

[0267] Industrial Applicability

[0268] The compound (I), calpain inhibitor or pharmaceutical composition of the present invention can be suitably used for the treatment or prevention of diseases associated with calpain activity.

Claims

1. A compound represented by the following general formula (I) or a salt thereof: In formula (I), R 1 represents a hydrogen atom; a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted, or R 2 Combine to form a ring, R 2 and R 3 Each independently represents a hydrogen atom; a hydroxyl group; an alkoxy group which may be substituted; or a linear, branched or cyclic alkyl group which may be substituted, or, R 2 With R 3 can combine to form a ring, in which When R 2 With R 1 When combined to form a ring containing a double bond, R 3 It can not exist, R 4 represents a hydrogen atom; or a straight-chain or branched alkyl group having 4 or more carbon atoms which may be substituted, R 5 represents a hydrogen atom; a straight-chain or branched alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; or a heterocyclic group which may be substituted, R 6 represents a straight-chain, branched or cyclic alkyl group which may be substituted; a straight-chain or branched alkenyl group which may be substituted; a straight-chain or branched alkynyl group which may be substituted; an aryl group which may be substituted; a heterocyclic group which may be substituted; a condensed polycyclic hydrocarbon group which may be substituted; an alkoxy group which may be substituted; or a hydrogen atom, X represents O or S, When R 1 and R 2 When combined to form a ring, R 1 Can represent O, S or N, R 2 Can represent O or S, L represents an amide bond, an ester bond, -NH-, -N-(straight chain, branched chain or cyclic alkylene)- or -(straight chain or branched chain alkylene-O-) n -, or represents a single bond, wherein n is an integer of 1 to 10.

2. The compound or salt thereof according to claim 1, characterized in that: In the formula (I), -XLR 1 The group shown is a group shown by the following formula (II): In the formula (II), n represents an integer of 0-10.

3. The compound or salt thereof according to claim 1, characterized in that: In the formula (I), -XLR 1 The group shown is a hydroxyl group, a thiol group or a group selected from the following:

4. The compound or salt thereof according to claim 1, characterized in that: In the formula (I), The partial structure shown is selected from the following formula: The structure shown and the formula below: The structure shown, In the formula, m represents an integer of 1 to 3, and q represents 0 or 1, R 7 are the same or different and represent a substituent bonded to the heterocyclic ring, and P represents an integer of 0-3.

5. The compound or salt thereof according to claim 1, characterized in that: R 2 and R 3 They are each independently a hydrogen atom or an alkyl group, or are combined with each other to form a cycloalkyl group.

6. The compound or salt thereof according to claim 1, characterized in that: In the formula (I), R 4 represents isobutyl, sec-butyl, cyclopropylmethyl or cyclobutylmethyl.

7. The compound or salt thereof according to claim 1, characterized in that: In the formula (I), R 5 represents benzyl, phenylethyl, 2-(methylthio)ethyl, 2-(methylsulfinyl)ethyl, n-butyl, 1-hydroxyethyl, 3-guanidinopropyl, 4-aminobutyl, 1H-imidazol-4-yl-methyl, phenyl, n-propyl or isobutyl.

8. The compound or salt thereof according to claim 1, characterized in that: Selected from the compounds represented by the following formula: In the formula, R 1 , R 2 and R 3 are respectively as defined in formula (I).

9. The compound or salt thereof according to claim 1, characterized in that: Selected from the compounds represented by the following formula: In the formula, R 5 As defined in formula (I).

10. The compound or salt thereof according to claim 9, characterized in that: R 5 represents benzyl, phenylethyl, 2-(methylthio)ethyl, 2-(methylsulfinyl)ethyl, n-butyl, 1-hydroxyethyl, 3-guanidinopropyl, 4-aminobutyl, 1H-imidazol-4-yl-methyl, phenyl, n-propyl or isobutyl.

11. A calpain inhibitor, characterized in that: The method comprises the compound or a salt thereof according to any one of claims 1 to 10.

12. A pharmaceutical composition for treating or preventing a disease associated with calpain activity, characterized in that: The method comprises the compound or a salt thereof according to any one of claims 1 to 10.

13. The pharmaceutical composition according to claim 12, wherein: The disease associated with calpain activity is an eye disease, a muscle disease, diabetes, an inflammatory disease, an autoimmune disease, a neurological disease, a heart or blood vessel disease, cancer, a brain tumor, an aging syndrome, progeria, an infectious disease, a traumatic encephalopathy, Machado-Joseph disease, preeclampsia or pulmonary fibrosis.

14. The pharmaceutical composition according to claim 13, wherein: The eye disease is glaucoma, autosomal dominant neovascular inflammatory vitreoretinopathy, retinitis pigmentosa, age-related macular degeneration, retinal neuropathy associated with diabetes or retinal vascular occlusive disease, retinal ischemia or cataract.

15. The pharmaceutical composition according to claim 14, wherein: The glaucoma is normal-tension glaucoma.

16. A method for treating or preventing a disease associated with calpain activity, characterized in that: The method comprises the step of administering an effective amount of the compound or a salt thereof according to any one of claims 1 to 10 to a subject in need of treating or preventing a disease associated with calpain activity.

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