Macrocyclic compound and use thereof

Abstract

The present disclosure relates to a macrocyclic compound and a use thereof. Specifically, the present disclosure provides a compound as shown in formula (I) or a pharmaceutically acceptable salt thereof, wherein R1-R3, Z1-Z3, K1-K12, and X1-X3 are as defined in the description.

Description

Macrocyclic compound and use thereof Technical Field

[0001] The present invention relates to the field of medicine and a macrocyclic compound and its use. Background Art

[0002] Magnetic resonance imaging (MRI) is a medical imaging technique that reconstructs images using the signals generated by atomic nuclei (e.g., hydrogen nuclei) in a magnetic field. The MRI signal depends on the environment surrounding the visualized nucleus and its longitudinal and transverse relaxation times, known as T1 and T2, respectively. Therefore, if the visualized nuclei are protons, the MRI signal intensity will depend on factors such as proton density and the proton's chemical environment.

[0003] Paramagnetic metal ion contrast agents are used in MRI to improve imaging contrast, including gadolinium complex compounds, which are characterized by high stability constants that ensure resistance to the release of free metal ions (known to be highly toxic to living organisms) in vivo.

[0004] For example, WO2007042506 discloses PCTA derivatives of the following formula, wherein D represents CH or N, E represents CH or N, F1 represents CH or N, and the others are as defined in the text,

[0005] In addition, other types of paramagnetic metal ion contrast agents have also been reported, such as WO1993011800, WO2000075141, WO2003074523, EP0438206, WO2006100305, WO2018115314, WO2019122255, US5403572, EP0661279, US20200353105 and US5334371.

[0006] Summary of the Invention

[0007] The present disclosure provides a compound represented by Formula I or a pharmaceutically acceptable salt thereof

[0008] Among them, R 1 、R 2 and R 3 Each independently selected from -COOH, -P(O)(OH)2 or -P(O)(R 4 )(OH), R 4 Selected from hydrogen or C 1-4 alkyl;

[0009] X 1 、X2 、X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-6 Alkylene, Y is selected from -COOH, -CONH2, -CONR 5 R 6 or -NR 7 COR 8 ;

[0010] R 5 Selected from hydrogen, C 1-6 Alkyl or C 1-6 Hydroxyalkyl, R 6 Selected from C 1-6 Alkyl or C 1-6 Hydroxyalkyl, and R 5 and R 6 At least one C 1-6 hydroxyalkyl;

[0011] R 7 Selected from hydrogen, C 1-6 Alkyl or C 1-6 Hydroxyalkyl, R 8 Selected from C 1-6 Alkyl or C 1-6 Hydroxyalkyl, and R 7 and R 8 At least one C 1-6 hydroxyalkyl;

[0012] Z 1 Selected from CR 9 ;

[0013] Z 2 Selected from CR 10 ;

[0014] R 9 、R 10 independently selected from hydrogen, halogen, nitro, amino, cyano, C 1-6 Alkyl, C 1-6 alkyl, 3 to 6-membered cycloalkyl, 3 to 6-membered cycloalkoxy, 3 to 6-membered heterocycloalkyl, 3 to 6-membered heterocycloalkoxy, 6-membered aryl or 5-6-membered heteroaryl, wherein the alkyl, alkoxy, cycloalkyl, heterocycloalkyl, cycloalkoxy, heterocyclooxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A Each independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy, and R 9 With R 10 Not simultaneously hydrogen;

[0015] Or, R9 、R 10 Together with the adjacent carbon atoms, they form a 6-membered aryl or 5-6-membered heteroaryl group, wherein the aryl or heteroaryl group is optionally substituted by one or more R 1B Replaced by R 1B are each independently selected from halogen, hydroxy, nitro, cyano, amino, substituted or unsubstituted C 1-6 Alkyl or substituted or unsubstituted C 1-6 alkoxy;

[0016] Z 3 selected from CH or N;

[0017] K 1 To K 12 are independently selected from hydrogen, C 1-6 Alkyl or C 1-6 hydroxyalkyl;

[0018] Or, K 1 With K 2 , K 3 or K 4 With K 5 or K 6 , K 7 or K 8 With K 9 or K 10 , or K 11 With K 12 A 3- to 6-membered carbon ring is formed.

[0019] In some embodiments, K in the compound of Formula I or a pharmaceutically acceptable salt thereof is 1 With K 2 forming a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 3 or K 4 With K 5 or K 6 forming a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 7 or K 8 With K 9 or K 10 forming a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 11 With K 12 Forming a 3- to 6-membered substituted or unsubstituted carbocyclic ring.

[0020] In some embodiments, R 1 、R 2 and R 3 Selected from -COOH.

[0021] In some embodiments, R 1 、R2 and R 3 Selected from -P(O)(OH)2.

[0022] In some embodiments, R 1 、R 2 and R 3 Selected from -P(O)(R 4 )(OH), R 4 Selected from hydrogen or C 1-4 Alkyl (eg, methyl or ethyl).

[0023] In other embodiments, Z in the compound of Formula I or a pharmaceutically acceptable salt thereof 3 Selected from N.

[0024] In some embodiments, Z in the compound of Formula I or a pharmaceutically acceptable salt thereof is 1 Selected from CR 9 , R 9 Selected from halogen, C 1-6 Alkyl, C 1-6 Alkoxy, 6-membered aryl or 5-6-membered heteroaryl, the alkyl, alkoxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A As defined above.

[0025] In some embodiments, R 9 is selected from hydrogen, chlorine, fluorine, methoxy, ethoxy or phenyl.

[0026] Some embodiments provide that the compound represented by Formula I or a pharmaceutically acceptable salt thereof is a compound represented by Formula II-1 or a pharmaceutically acceptable salt thereof,

[0027] Among them, R 1 ~R 3 、Z 2 , K 1 ~K 12 , and X 1 ~X 3 As defined above.

[0028] In some embodiments, Z in the compound of Formula I or a pharmaceutically acceptable salt thereof is 2 Selected from CR 10 , R 10 Selected from hydrogen, halogen, C 1-6 Alkyl, C 1-6 Alkoxy, 6-membered aryl or 5-6-membered heteroaryl, the alkyl, alkoxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A As defined above.

[0029] In some embodiments, R 10 is selected from hydrogen, chlorine, fluorine, methoxy, ethoxy or phenyl.

[0030] In some other embodiments, R 9 、R 10 Together with the adjacent carbon atoms, a 6-membered aryl group is formed, wherein the aryl group is optionally substituted with one or more R 1B Replaced by R 1B As defined above.

[0031] In other embodiments, the compound of formula I is

[0032] Wherein, n=an integer between 0 and 4; R 1 ~R 3 , K 1 ~K 12 、X 1 ~X 3 and R 1B As defined in the compound represented by formula I.

[0033] Some embodiments provide compounds of Formula I or Formula II or pharmaceutically acceptable salts thereof wherein X 1 、X 2 、X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -COOH, -CONH2.

[0034] In some other embodiments, X in the compound of Formula I or Formula II or a pharmaceutically acceptable salt thereof is 1 、X 2 、X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -CONR 5 R 6 or -NR 7 COR 8 , where R 5 is selected from hydrogen or methyl, R 6 Selected from C 1-6 Hydroxyalkyl, R 7 is selected from hydrogen or methyl, R 8 Selected from C 1-6 Hydroxyalkyl.

[0035] In other embodiments, R 6 Selected from C 2-6Hydroxyalkyl groups include, but are not limited to, -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

[0036] In some embodiments, R 8 Selected from C 2-6 Hydroxyalkyl, including but not limited to -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

[0037] In some embodiments, X in the compound of Formula I or a pharmaceutically acceptable salt thereof is 1 、X 2 、X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -CONR 5 R 6 , R 5 Selected from hydrogen, R 6 Selected from -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

[0038] The present disclosure also provides isotopic substitutions of the aforementioned compounds or pharmaceutically acceptable salts thereof. In some embodiments, the isotopic substitutions are deuterated.

[0039] The present disclosure also provides polymers of the aforementioned compounds or pharmaceutically acceptable salts thereof. In some embodiments, the polymers are dimers or trimers. In some embodiments, the compounds of Formula I or Formula II are coupled together via a bonding group. For example, the bonding group is bonded to the compound of Formula I or Formula II at an aromatic or heteroaromatic ring.

[0040] The present disclosure also provides a vectorized compound, which comprises the aforementioned compound or isotope-substituted compound coupled to a biological vector via an optional intermediate bonding group. In some embodiments, the biological vector is targeted to a specific pathological area.

[0041] In other embodiments, the bonding group can be bonded to the compound of Formula I at the aromatic ring or heteroaromatic ring. In other embodiments, in the absence of a bonding group, the biocarrier can be bonded to the compound of Formula I at the aromatic ring or heteroaromatic ring. 1、X 2 or X 3 is bonded to the compound represented by formula I.

[0042] For example, WO2004112839 discloses a variety of biological carriers that may be used, particularly the carrier compounds exemplified on pages 135 to 137. WO2004112839 is incorporated herein by reference for the purpose of illustrating the carrier compounds of the present disclosure.

[0043] WO2005 / 049005, WO2005 / 049095, WO2005 / 042033 and WO2001 / 9188 also disclose other biological carriers, biological carriers targeting VEGF and angiopoietin receptors, polypeptides targeting fibrin, peptides targeting integrins, peptides targeting metalloproteinases, and the like.

[0044] In another aspect, the bonding groups include, but are not limited to: A) -(CH2)2-phenyl-NH, -(CH2)3-NH, -NH-(CH2)2-NH, absent or a single bond;

[0045] B) P1-L1-P2, P1 and P2 are each independently selected from O, S, NH, -CO2, -NCS, -NCO, -SO3H, -NHCO, -CONH or not present, L1 is C 1-6 Alkylene.

[0046] The present disclosure also provides a complex formed by the aforementioned compound or isotope-substituted product or polymer or carrier compound and M, wherein M is Gd 3+ 、Mn 2+ or Fe 3+ .

[0047] Typical complexes include but are not limited to:

[0048] On the other hand, the empty orbital of gadolinium accepts the lone pair of electrons provided by the nitrogen atom in the macrocycle, forming a structure similar to the following:

[0049] In some embodiments, the complex has the following structure:

[0050] It contains 6 stereocenters (marked by asterisks and open circles in the structure), with a total of 64 stereoisomers.

[0051] In some embodiments, compound 4 comprises (regardless of the chirality of isoserinol):

[0052] The present disclosure also provides a pharmaceutical composition comprising at least one therapeutically effective amount of the compound of the aforementioned formula I or a pharmaceutically acceptable salt thereof, or an isotope substituted product thereof, or a polymer thereof, or a carrier compound thereof, or a complex thereof, and a pharmaceutically acceptable excipient.

[0053] In some embodiments, a pharmaceutical composition comprising the following compound or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient

[0054] In some embodiments, a pharmaceutical composition comprising RRR / SSS isomers

[0055] and pharmaceutically acceptable excipients.

[0056] In some embodiments, a pharmaceutical composition comprising RRS / SSR isomers and pharmaceutically acceptable excipients.

[0057] In some embodiments, a pharmaceutical composition comprising RSS / SRR isomers and pharmaceutically acceptable excipients.

[0058] In some embodiments, a pharmaceutical composition comprising RSR / SRS isomers and pharmaceutically acceptable excipients.

[0059] In some embodiments, a pharmaceutical composition comprising the following compound or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient At least 50% of the compounds are RRR / SSS isomers

[0060] In some embodiments, a pharmaceutical composition comprising the following compound or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient At least 70% of the compounds are RRR / SSS isomers

[0061] In some embodiments, a pharmaceutical composition comprising the following compound or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient At least 90% of the compounds are RRR / SSS isomers

[0062] In some embodiments, the RRR / SSS isomers in the pharmaceutical composition The content is at least 90%, such as 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more (such as 100%).

[0063] The present disclosure also provides the following compounds or salts thereof

[0064] In some embodiments, the unit dose of the pharmaceutical composition is 0.001 mg-1000 mg.

[0065] In certain embodiments, the pharmaceutical composition contains 0.01-99.99% of the aforementioned compound or its pharmaceutically acceptable salt, or its isotopic substitution, or its multimer, or its carrier compound, or its complex, based on the total weight of the composition. In certain embodiments, the pharmaceutical composition contains 0.1-99.9% of the aforementioned compound or its pharmaceutically acceptable salt, or its isotopic substitution, or its multimer, or its carrier compound, or its complex. In certain embodiments, the pharmaceutical composition contains 0.5%-99.5% of the aforementioned compound or its pharmaceutically acceptable salt, or its isotopic substitution, or its multimer, or its carrier compound, or its complex. In certain embodiments, the pharmaceutical composition contains 1%-99% of the aforementioned compound or its pharmaceutically acceptable salt, or its isotopic substitution. In certain embodiments, the pharmaceutical composition contains 2%-98% of the aforementioned compound or its pharmaceutically acceptable salt, or its isotopic substitution, or its multimer, or its carrier compound, or its complex.

[0066] In certain embodiments, the pharmaceutical composition comprises 0.01% to 99.99% of a pharmaceutically acceptable excipient, based on the total weight of the composition. In certain embodiments, the pharmaceutical composition comprises 0.1% to 99.9% of a pharmaceutically acceptable excipient. In certain embodiments, the pharmaceutical composition comprises 0.5% to 99.5% of a pharmaceutically acceptable excipient. In certain embodiments, the pharmaceutical composition comprises 1% to 99% of a pharmaceutically acceptable excipient. In certain embodiments, the pharmaceutical composition comprises 2% to 98% of a pharmaceutically acceptable excipient.

[0067] The present disclosure also provides use of the compound represented by the aforementioned formula I or its pharmaceutically acceptable salt, or its isotope-substituted product, or its polymer, or its carrier compound, or its complex, or its pharmaceutical composition in the preparation of a drug for nuclear magnetic resonance imaging.

[0068] The present disclosure also provides the compound of the aforementioned formula I or its pharmaceutically acceptable salt, or its isotope-substituted product, or its multimer, or its carrier compound, or its complex, or its pharmaceutical composition for use in nuclear magnetic resonance imaging.

[0069] The present disclosure also provides a method for nuclear magnetic resonance imaging, which comprises administering to a subject a certain effective amount of the compound represented by the aforementioned formula I or a pharmaceutically acceptable salt thereof, or an isotope substituted product thereof, or a polymer thereof, or a carrier compound thereof, or a complex thereof, or a pharmaceutical composition thereof.

[0070] The pharmaceutically acceptable salts of the compounds described in the present disclosure may be selected from inorganic salts or organic salts.

[0071] On the other hand, the present disclosure also provides a method for preparing compound 4 or a salt thereof,

[0072] It includes the steps of reacting compound A with compound B to form compound 4,

[0073] In some embodiments, compound A reacts with compound B in the presence of a condensation reagent selected from, but not limited to, 1-hydroxybenzotriazole (HOBT) and 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDCI).

[0074] The present disclosure also provides Compound A or a salt thereof

[0075] Contains 3 stereo centers (represented by asterisks in the structure), with a total of 8 stereoisomers, as shown in the following table:

[0076] Isomer RRR and isomer SSS are mirror images of each other and are called enantiomers. Corresponding isomers exhibit the same physical and chemical properties, such as melting point, water solubility, and relaxivity. In addition to isomers RRR and SSS, the other six isomers are called diastereomers. In the embodiment, a preparative HPLC method is used, which separates four signal peaks from compound A obtained by non-stereoselective synthesis, corresponding to the four pairs of enantiomers formed by different optical isomers in the previous table.

[0077] Another aspect of the present disclosure relates to enrichment of the aforementioned enantiomers or mixtures thereof. "Enrichment" refers to the process of obtaining a higher content of an isomer, enantiomer, or enantiomeric pair of the present disclosure using existing techniques, such as stereoselective synthesis. The stereoselective synthesis method is described in CN112533921A and is incorporated herein by reference for illustrative purposes.

[0078] In another aspect, the enrichment comprises obtaining by preparative HPLC.

[0079] In some embodiments, The enrichment of the RRR / SSS isomer is at least 50%, such as 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or more.

[0080] In some embodiments, the enriched RRR / SSS enantiomer pair of Compound A is reacted with isoserinol to form the RRR / SSS isomer of Compound 4.

[0081] In some embodiments, the enriched RRS / SSR enantiomer pair of Compound A is reacted with isoserinol to form the RRS / SSR isomer of Compound 4.

[0082] In some embodiments, the enriched RSS / SRR enantiomer pair of Compound A is reacted with isoserinol to form the RSS / SRR isomer of Compound 4.

[0083] In some embodiments, the enriched RSR / SRS enantiomer pair of Compound A is reacted with isoserinol to form the RSR / SRS isomer of Compound 4.

[0084] In other embodiments, in the longitudinal relaxation rate r1 test experiment in human plasma (using a medium-sized nuclear magnetic resonance imaging analyzer (MesoMR23-060-I) to test the longitudinal relaxation time T1 under a 0.5T magnetic field, the relaxation rate r1 is calculated based on the relaxation time T1 of samples with different concentrations. The relaxation rate calculation formula is: ), the aforementioned RRR / SSS isomer Relaxation rate 21.8mM -1 s -1 .

[0085] The compounds of the present disclosure may exist in specific geometric or stereoisomeric forms. The present disclosure contemplates all such compounds, including cis and trans isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, and racemic mixtures and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the present disclosure. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All of these isomers and their mixtures are included within the scope of the present disclosure. The compounds of the present disclosure containing asymmetric carbon atoms can be isolated in optically pure form or in racemic form. Optically pure forms can be resolved from racemic mixtures or synthesized by using chiral starting materials or chiral reagents.

[0086] Optically active (R)- and (S)-isomers, as well as D and L isomers, can be prepared by chiral synthesis or chiral reagents or other conventional techniques. If one enantiomer of a compound of the present disclosure is desired, it can be prepared by asymmetric synthesis or derivatization with a chiral auxiliary, wherein the resulting diastereomeric mixture is separated and the auxiliary group is cleaved to provide the pure desired enantiomer. Alternatively, when the molecule contains a basic functional group (such as an amino group) or an acidic functional group (such as a carboxyl group), a diastereomeric salt is formed with an appropriate optically active acid or base, and then the diastereoisomers are separated by conventional methods known in the art, and then the pure enantiomer is recovered. In addition, the separation of enantiomers and diastereomers is typically accomplished using chromatography, which employs a chiral stationary phase and is optionally combined with a chemical derivatization method (e.g., carbamate formation from an amine).

[0087] In the chemical structures of the compounds disclosed herein, the bond Indicates that the configuration is not specified, that is, if chiral isomers exist in the chemical structure, the bond Can be or include both Two configurations.

[0088] Compounds and intermediates of the present disclosure can also exist in different tautomeric forms, and all such forms are included in the scope of the present disclosure. The term "tautomer" or "tautomeric form" refers to structural isomers of different energies that can interconvert via a low energy barrier. For example, proton tautomers (also referred to as prototransfer tautomers) include interconversions via proton migration, such as keto-enol and imine-enamine, lactam-lactim isomerization. The lactam-lactim equilibrium example is between A and B as shown below.

[0089] All compounds in this disclosure can be drawn as either Form A or Form B. All tautomeric forms are within the scope of this disclosure. The naming of the compounds does not exclude any tautomers.

[0090] The present disclosure also includes isotopically labeled compounds of the present disclosure that are identical to those described herein, but where one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into the compounds of the present disclosure include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, iodine, and chlorine, such as 2 H. 3 H. 11 C. 13 C. 14 C. 13 N. 15 N. 15 O. 17 O. 18 O. 31 P. 32 P. 35 S. 18 F. 123 I. 125 I and 36 Cl et al.

[0091] Unless otherwise stated, when a position is specifically designated as deuterium (D), the position is understood to have at least 1000 times the abundance of deuterium greater than the natural abundance of deuterium (which is 0.015%) (i.e., at least 10% deuterium incorporation). In the example, the compound has a natural abundance greater than deuterium that can be at least 1000 times the abundance of deuterium, at least 2000 times the abundance of deuterium, at least 3000 times the abundance of deuterium, at least 4000 times the abundance of deuterium, at least 5000 times the abundance of deuterium, at least 6000 times the abundance of deuterium or more abundant deuterium. The disclosure also includes various deuterated forms of formula (I) compounds. Each available hydrogen atom connected to a carbon atom can be independently replaced by a deuterium atom. Those skilled in the art can synthesize deuterated forms of formula (I) compounds with reference to relevant literature. Commercially available deuterated starting materials may be used in the preparation of deuterated forms of the compounds of formula (I), or they may be synthesized using conventional techniques using deuterated reagents, including but not limited to deuterated borane, trideuterated borane in tetrahydrofuran, deuterated lithium aluminum hydride, deuterated iodoethane, deuterated iodomethane, and the like.

[0092] "Optionally" or "optionally" means that the subsequently described event or circumstance may but need not occur, and the description includes instances where the event or circumstance occurs or does not occur. For example, "optionally substituted C 1-6The term "alkyl" means that halogen or cyano may but need not be present, and the description includes both the case where the alkyl is substituted by halogen or cyano and the case where the alkyl is not substituted by halogen and cyano.

[0093] Explanation of terms:

[0094] A "pharmaceutical composition" refers to a mixture containing one or more compounds described herein, or their physiologically acceptable salts or prodrugs, together with other chemical components, as well as other components such as physiologically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration to an organism, facilitating absorption of the active ingredients and thereby exerting their biological activity.

[0095] The "effective amount" described in the present disclosure includes an amount sufficient to allow or promote diagnosis. An effective amount can be the maximum dose or administration regimen that avoids significant side effects or toxic effects.

[0096] "Pharmaceutically acceptable excipients" include, but are not limited to, any adjuvant, carrier, glidant, sweetener, diluent, preservative, dye / colorant, flavoring agent, surfactant, wetting agent, dispersant, suspending agent, stabilizer, isotonic agent, solvent or emulsifier that has been approved by the U.S. Food and Drug Administration for use in humans or domestic animals.

[0097] "Alkyl" refers to a saturated aliphatic hydrocarbon group, including straight and branched groups of 1 to 20 carbon atoms, and alkyl groups containing 1 to 6 carbon atoms. Non-limiting examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl and various branched isomers thereof. Alkyl groups can be substituted or unsubstituted. When substituted, the substituents can be substituted at any available point of attachment, preferably one or more of the following groups, independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy.

[0098] The term "cycloalkyl" or "carbocycle" refers to a saturated or partially unsaturated monocyclic or polycyclic hydrocarbon substituent, wherein the cycloalkyl ring contains 3 to 20 carbon atoms, preferably 3 to 7 carbon atoms. Non-limiting examples of monocyclic cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, and the like; polycyclic cycloalkyls include spirocyclic, fused, and bridged cycloalkyls. Cycloalkyls can be substituted or unsubstituted.

[0099] The term "heterocycloalkyl" refers to a saturated or partially unsaturated monocyclic or polycyclic hydrocarbon substituent containing 3 to 6 ring atoms. Non-limiting examples of "heterocycloalkyl" include: etc.

[0100] Heterocycloalkyl may be optionally substituted or unsubstituted. When substituted, the substituents are preferably one or more of the following groups independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1- 6 alkoxy.

[0101] The term "heteroaryl" refers to a heteroaromatic system containing 1 to 3 heteroatoms, wherein the heteroatoms are selected from oxygen, sulfur and nitrogen. Heteroaryl is preferably 5-membered. For example. Non-limiting examples include: etc.

[0102] Heteroaryl may be optionally substituted or unsubstituted. When substituted, the substituents are preferably one or more of the following groups independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy.

[0103] The term "alkoxy" refers to -O-(alkyl), wherein alkyl is as defined above. Non-limiting examples include: methoxy, ethoxy, propoxy, butoxy. Alkoxy may be optionally substituted or unsubstituted, and when substituted, the substituents are preferably one or more of the following groups independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy.

[0104] The term "heterocycloalkoxy" refers to -O-(heterocycloalkyl), wherein heterocycloalkyl is as defined above. Similarly, "cycloalkoxy" refers to -O-(cycloalkyl), wherein cycloalkyl is as defined above.

[0105] A "monovalent group" is a compound formed by formally eliminating a monovalent atom or group. A "subunit" is a compound formed by formally eliminating two monovalent or one divalent atom or group.

[0106] The term "alkylene" refers to the portion remaining after removing two hydrogen atoms from an alkane molecule, including straight and branched chain subgroups having 1 to 20 carbon atoms. Non-limiting examples of alkylene groups having 1 to 6 carbon atoms include methylene (-CH2-) and ethylene (e.g., -CH2CH2- or -CH(CH3)-). Unless otherwise specified, alkylene groups may be substituted or unsubstituted.

[0107] The "substituted group" disclosed herein includes halogen, hydroxy, oxo, nitro, cyano, C 1-6 Alkyl, C 1-6 alkoxy, 3 to 6-membered cycloalkoxy, 3 to 6-membered heterocycloalkoxy, 6-membered aryl or 5 to 6-membered heteroaryl, the C1-6 Alkyl, C 1-6 Alkoxy, 3 to 6 membered cycloalkoxy, 3 to 6 membered heterocycloalkoxy, 6 membered aryl or 5 to 6 membered heteroaryl are optionally substituted by one or more selected from halogen, hydroxy, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy substitution.

[0108] The term "hydroxy" refers to an -OH group.

[0109] The term "halogen" refers to fluorine, chlorine, bromine or iodine.

[0110] The term "cyano" refers to -CN.

[0111] The term "amino" refers to -NH2.

[0112] The term "nitro" refers to -NO2.

[0113] The term "oxo" refers to a =0 substituent.

[0114] "Substituted" means that one or more hydrogen atoms, preferably up to 5, more preferably 1 to 3 hydrogen atoms in a group are replaced independently of one another by a corresponding number of substituents. It goes without saying that the substituents are only in their possible chemical positions, and a person skilled in the art can determine (by experiment or theory) whether substitution is possible or not without undue effort. DETAILED DESCRIPTION

[0115] The present disclosure is further described below with reference to examples, but these examples are not intended to limit the scope of the present disclosure.

[0116] Experimental methods in the examples of this disclosure that do not specify specific conditions are generally based on conventional conditions or the conditions recommended by the raw material or product manufacturers. Reagents without specific sources are conventional reagents purchased from the market.

[0117] The structures of the compounds were determined by nuclear magnetic resonance (NMR) and / or mass spectrometry (MS). -6 The unit of ppm is given. NMR measurements were performed using a Bruker AVANCE-400 NMR spectrometer. The solvents used were deuterated dimethyl sulfoxide (DMSO-d6), deuterated chloroform (CDCl3), and deuterated methanol (Methanol-d4). The internal standard was tetramethylsilane (TMS).

[0118] HPLC determination used Agilent1100 high pressure liquid chromatograph, GAS15B DAD UV detector, Water Vbridge C18 150*4.6mm 5um chromatographic column.

[0119] MS was determined using an Agilent 6120 triple quadrupole mass spectrometer, a G1315D DAD detector, and a Waters Xbridge C18 4.6*50mm, 5um column. The samples were scanned in positive / negative ion mode with a mass scan range of 80-1200.

[0120] Thin-layer chromatography silica gel plates used were Yantai Huanghai HSGF254 silica gel plates. Thin-layer chromatography (TLC) employed silica gel plates with a plate size of 0.2 mm ± 0.03 mm, and the plate size used for TLC separation and purification was 0.4 mm to 0.5 mm. Flash column purification systems used either Combiflash RF150 (TELEDYNE ISCO) or Isolara One (Biotage).

[0121] Forward column chromatography generally uses Yantai Huanghai silica gel 200-300 mesh or 300-400 mesh silica gel as the carrier, or uses Changzhou Santai pre-packed ultra-pure normal phase silica gel column (40-63μm, 60g, 24g, 40g, 120g or other specifications).

[0122] The known starting materials in the present disclosure can be synthesized by methods known in the art, or can be purchased from Shanghai Titan Technology, ABCR GmbH & Co. KG, Acros Organics, Aldrich Chemical Company, Accela ChemBio Inc, Bid Pharmaceuticals, etc.

[0123] Unless otherwise specified in the examples, all reactions were carried out under a nitrogen atmosphere.

[0124] Nitrogen atmosphere means that the reaction bottle is connected to a nitrogen balloon with a capacity of about 1L.

[0125] Hydrogen atmosphere means that the reaction bottle is connected to a hydrogen balloon with a capacity of about 1L.

[0126] Hydrogen was produced by a QPH-1L hydrogen generator from Shanghai Quanpu Scientific Instrument Co., Ltd.

[0127] The nitrogen atmosphere or hydrogen atmosphere is usually evacuated and filled with nitrogen or hydrogen, and the operation is repeated three times.

[0128] Unless otherwise specified in the examples, the solution refers to an aqueous solution.

[0129] Unless otherwise specified in the examples, the reaction temperature is room temperature, 20°C to 30°C.

[0130] The reaction progress in the examples was monitored by thin layer chromatography (TLC). The developing solvent used in the reaction, the column chromatography eluent system used to purify the compound, and the developing solvent system for thin layer chromatography, the volume ratio of the solvent were adjusted according to the polarity of the compound, and a small amount of alkaline or acidic reagents such as triethylamine and acetic acid could be added for adjustment.

[0131] Example 1

[0132] 2,2',2"-(3,6,9-triaza-1(1,3)-isoquinolinacyclophane-3,6,9-tris(5-((2,3-dihydroxypropyl)amino)-5-oxopentanoate)gadolinium(III) complex (Compound 1)

[0133] Step 1) Preparation of 1,3-dimethylisoquinoline (Compound 1b)

[0134] In a 500 mL three-necked flask, TfOAg (silver trifluoromethanesulfonate, 8.26 g, 32 mmol, 1.0 eq) and acetonitrile (64 mL) were added at 25°C. Compound 1a (3.8 g, 32 mmol, 1.0 eq) was then added to the reaction flask. The temperature was then lowered to 0°C, and an acetonitrile solution (128 mL) of iodine (8.12 g, 32 mmol, 1 eq) was added. The reaction was stirred at room temperature until nearly complete. The reaction solution was filtered. A methanol solution (100 mL) of KOH (11 g, 167 mmol, 5.2 eq) was added to the filtrate, and stirring was maintained at 40°C. The reaction solution was concentrated under reduced pressure, water was added, and the mixture was extracted with dichloromethane, dried, concentrated, and filtered to obtain 3.16 g of the product (yield: 62.9%).

[0135] MS (ESI): m / z 158.1[M+1] + .

[0136] 1 H NMR (400MHz, CDCl3) δ8.06 (d, J = 8.4Hz, 1H), 7.70 (d, J = 8.2Hz, 1H), 7.61 (t, J = 7.5Hz, 1H), 7.50 (t, J = 7.6Hz, 1H), 7.33 (s, 1H), 2.94 (s, 3H), 2.65 (s, 3H).

[0137] Step 2) Preparation of a mixture of 1-(bromomethyl)-3-(dibromomethyl)isoquinoline and 3-(bromomethyl)-1-(dibromomethyl)isoquinoline (Compound 1d)

[0138] At 25°C, solid compound 1b (5.2 g, 33.08 mmol, 1.0 eq) was added to a 500 mL single-necked flask, followed by CCl₄ (220 mL) and stirred to dissolve. NBS (30 g, 169.0 mmol, 5 eq) and BPO (480 mg, 1.32 mmol, 0.04 eq) were added and refluxed at 95°C until nearly complete. The mixture was cooled to 30°C, filtered, washed with saturated brine, dried, and concentrated to yield 14.4 g of compound 1d; the crude product was used directly in the next step.

[0139] MS (ESI): m / z 391.9 [M+H] + .

[0140] Step 3) Preparation of a mixture of 1,3-bisbromomethylisoquinoline (Compound 1e)

[0141] To a reaction flask, add the crude compound 1d mixture (14.4 g, 33.07 mmol, 1.0 eq) and dissolve it in dry tetrahydrofuran (120 mL). Cool to approximately -5°C under nitrogen. Add DIPEA (17.1 g, 132.28 mmol, 4.0 eq) and diethyl phosphite (18.27 g, 17.1 mL). Maintain the temperature at approximately 0°C and allow the reaction to proceed until nearly complete. Pour the reaction mixture into an ice-water mixture and extract with ethyl acetate. The organic phases are combined and dried. Concentrate to yield 5.2 g of the product, a 50% yield.

[0142] MS (ESI): m / z 313.9 [M+H] + .

[0143] 1 H NMR (400MHz, CDCl3) δ8.24 (d, J = 8.1Hz, 1H), 7.85 (d, J = 7.9Hz, 1H), 7.78–7.66 (m, 3H), 5.02 (s, 2H), 4.71 (s, 2H).

[0144] Step 4) Preparation of 3,6,9-trimethylbenzenesulfonyl-3,6,9-triaza-1(1,3)-isoquinolinecyclophane (Compound 1f)

[0145] At room temperature, SM-1 (9.83 g, 17.378 mmol, 1 eq), potassium carbonate (10.09 g, 72.99 mmol, 4.2 eq), and DMF (240 mL) were added to a reaction flask in sequence and stirred to dissolve. Under nitrogen, the mixture was heated to 100°C. Compound 1e (6.35 g, 20.15 mmol, 1.16 eq) was dissolved in DMF (120 mL) and added to the reaction mixture. The reaction mixture was stirred until nearly complete. The reaction mixture was cooled to 30°C, then poured into water, filtered under reduced pressure, washed with a small amount of water, and dried to obtain the product (11.4 g, 91% yield).

[0146] MS (ESI): m / z 719.2 [M+H] + .

[0147] 1 H NMR (400MHz, CDCl3) δ8.55(d,J=8.2Hz,1H),7.84(dd,J=15.8,6.2Hz,4H),7.75(dd,J=14.7,8.3Hz,4H),7.57(d,J=8.2Hz,2H),7.37(dd,J=13.7,8.0Hz ,4H),7.21(d,J=8.0Hz,2H),5.28–4.57(m,4H),4.45(s,2H),3.75(t,J=6.3 Hz, 2H), 3.39 (dd, J = 24.6, 17.3Hz, 4H), 2.47 (d, J = 6.7Hz, 6H), 2.36 (s, 3H).

[0148] Step 5) Preparation of 3,6,9-triaza-1(1,3)-isoquinoline cyclophane (Compound 1g)

[0149] In a 500 mL reaction tube, compound 1f (13.25 g, 18.4 mmol, 1.0 eq) was dispersed in 116 mL of concentrated sulfuric acid. The atmosphere was replaced with nitrogen three times, then heated to 105°C and allowed to react until nearly complete. The reaction mixture was cooled to room temperature, poured into ice water, and the pH was adjusted to approximately 12 with 40% NaOH solution. The mixture was then extracted with DCM / MeOH (20 / 1). The combined extracts were washed with saturated brine, dried, filtered, and concentrated to yield 1 g of the title compound (4.57 g, 97% yield).

[0150] MS (ESI): m / z 257.2 [M+H] + .

[0151] 1H NMR(400MHz, CDCl3)δ8.05(d,J=8.4Hz,1H),7.81–7.54(m,3H),7.39(s,1H),4.51(s,2H),4.1 5(s,2H),2.88(d,J=4.6Hz,2H),2.77(t,J=5.3Hz,2H),2.65–2.57(m,2H),2.55-2.51(m,2H).

[0152] Step 6) Preparation of hexaethyl 2,2',2"-(3,6,9-triaza-1(1,3)-isoquinolinecyclophane-3,6,9-triyl)tripentarate (Compound 1h)

[0153] In a 250 mL single-necked flask, compound 1g (4.82 g, 18.81 mmol, 1.0 eq) was dissolved in CH3CN (193 mL). K2CO3 (11.7 g, 84.64 mmol, 4.5 eq) was added and stirred at room temperature. SM-2 (20.6 g, 77.1 mmol, 4.1 eq) was dissolved in CH3CN (193 mL) and added dropwise to the above solution. After the addition, the temperature was raised to 66°C and stirred until the reaction was nearly complete. The mixture was filtered, washed with acetonitrile, and concentrated under reduced pressure to obtain the crude product. Purification afforded compound 1h (7.9 g, 51.5% yield).

[0154] MS (ESI): m / z 815.4 [M+H] + .

[0155] 1 H NMR (400MHz, CDCl3) δ8.13 (dd, J=8.6, 3.0Hz, 1H), 7.81 (d, J=8.2Hz, 1H), 7.65 (t, J= 7.6Hz,1H),7.59-7.55(m,2H),4.31–3.97(m,15H),3.93–3.84(m,1H),3.75(td,J=4. 1,2.0Hz,3H),2.88–2.73(m,3H),2.52–2.37(m,4H),2.29-2.25(m,3H),2.20–2.07( m,3H),2.06–1.95(m,2H),1.88-1.84(m,5H),1.38-1.34(m,6H),1.31–1.18(m,12H).

[0156] Step 7) Preparation of 2,2',2"-(3,6,9-triaza-1(1,3)-isoquinolin-3,6,9-triyl)triglutaric acid (Compound 1i)

[0157] In a 250 mL single-necked flask, compound 1h (3.83 g, 4.7 mmol, 1.0 eq) was added and dissolved in THF (50 mL). 1 M LiOH solution (56.4 mL) was added dropwise at 25°C. After complete addition, the mixture was stirred at room temperature for 16 hours and concentrated under reduced pressure. The pH was adjusted to 2-3 with concentrated hydrochloric acid under ice-cooling. The mixture was directly purified using a macroporous resin XAD 1600 column to obtain compound 1i (2.85 g, 93.8% yield).

[0158] MS (ESI): m / z 647.3 [M+H] + .

[0159] 1 H NMR(400MHz,D2O)δ8.14–8.00(m,1H),7.99–7.78(m,3H),7.77-7.72(m,1H),5.43–4.79(m,2H),4.69(s, 7H),4.12–3.77(m,2H),3.78–3.37(m,4H),3.25(d,J=31.7Hz,1H),2.81–2.39(m,5H),2.38–1.79(m,6H).

[0160] Step 8) Preparation of 2,2',2"-(3,6,9-triaza-1(1,3)-isoquinolin-3,6,9-triyl)triglutaric acid gadolinium (III) complex (Compound 1j)

[0161] In a 50 mL single-necked flask, compound 1i (1.57 g, 2.43 mmol, 1.0 eq) and deionized H₂O (35 mL) were added. The pH was adjusted to 10 with 2N NaOH solution, and GdCl₃·6H₂O (0.994 g, 2.67 mmol, 1.0 eq) dissolved in 35 mL of deionized water was slowly added. The pH was adjusted to approximately 6-7 with 1N HCl. The mixture was stirred at room temperature (23°C) for approximately 2 h. The reaction mixture was freeze-dried and purified by preparative liquid chromatography to afford compound 1j (1.05 g, 54% yield).

[0162] MS (ESI): m / z 802.2 [M+H] + .

[0163] Step 9) Preparation of Compound 1

[0164] In a 15 mL single-necked vial, SM-3 (33 mg, 0.364 mmol, 4.0 eq) was added and dissolved in H2O (1 mL). The pH was adjusted to 6-7 with 1N HCl. Compound 1j (73 mg, 0.091 mmol, 1.0 eq), HOBT (6 mg, 0.046 mmol, 0.5 eq), and EDCI (88 mg, 0.455 mmol, 5.0 eq) were then added. The mixture was stirred at room temperature (20°C) for 16 h. Purification was performed by preparative liquid chromatography and lyophilization to obtain the product (74 mg, 95.67% purity).

[0165] MS (ESI): m / z 1021.3 [M+H] + .

[0166] Example 2

[0167] 2,2',2'-(1 4 -phenyl-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)tris(5-((2,3-dihydroxypropyl)amino)-5-oxoglutaric acid)gadolinium(III) complex (Compound 2)

[0168] Step 1)1 4 Preparation of phenyl-3,6,9-tri-p-toluenesulfonyl-3,6,9-triaza-1(2,6)-pyridinecyclodecane (Compound 2b)

[0169] SM-1 (5.23 g, 9.2 mmol, 1.05 eq) was placed in a 500 mL single-necked bottle, DMF (157 mL) was added, stirred to dissolve, and heated to 100 ° C. Compound 2a (3.0 g, 8.8 mmol, 1.0 eq, synthesized according to Bioorganic and Medicinal Chemistry, 2020, vol. 28, # 24, no. 115816) was dissolved in 60 mL of DMF and slowly added dropwise to the above 100 ° C solution. After the addition was complete, the temperature was lowered to 90 ° C and the reaction was stirred until almost complete. The reaction system was cooled to room temperature, poured into ice water, extracted with ethyl acetate, and the organic phases were combined. Wash with water, wash with saturated NaCl aqueous solution, and dry. Filter and concentrate to obtain crude compound 2b, 5.8 g, yield: 88.5%.

[0170] MS (ESI): m / z 745.2[M+1] + .

[0171] 1H NMR (400MHz, CDCl3) δ7.74 (d, J = 8.0Hz, 4H), 7.68–7.59 (m, 6H), 7.53 –7.44(m,3H),7.35(d,J=8.0Hz,4H),7.28(m,2H),4.35(s,4H),3.36(t,J=7.4Hz,4H),2.90–2.71(m,4H),2.45(s,6H),2.39(s,3H).

[0172] Step 2) 1 4 Preparation of phenyl-3,6,9-triaza-1(2,6)-pyridinecyclodecane (Compound 2c)

[0173] Compound 2b (2.0 g, 2.7 mmol, 1.0 eq) was placed in a 100 mL flask. 20 mL of concentrated sulfuric acid was added, and the nitrogen atmosphere was replaced three times. The mixture was then heated to 100°C. Stirring was continued until the reaction was nearly complete. The reaction mixture was cooled to room temperature and poured into 100 mL of ice water. Maintaining the temperature at 0°C, the pH was adjusted to 12 with 40% aqueous NaOH. Extraction was performed with dichloromethane, and the combined extracts were dried over anhydrous sodium sulfate. Filtration and concentration were performed to obtain 390 mg of the product. Yield: 51.5%.

[0174] MS (ESI): m / z 283.2[M+1] + .

[0175] Step 3) 2, 2', 2"-(1 4 Preparation of 1-phenyl-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)triglutamate hexaethyl ester (Compound 2d)

[0176] Compound 2c (390 mg, 1.4 mmol, 1.0 eq) was placed in a 100 mL single-necked flask, acetonitrile (18 mL) was added, and the mixture was stirred to dissolve. K2CO3 (858 mg, 6.2 mmol, 4.5 eq) was then added. SM-2 (1.33 g, 5.0 mmol, 3.6 eq) was added dropwise to the reaction mixture. After addition, the mixture was heated to 66°C and stirred until the reaction was almost complete. The reaction mixture was concentrated, and the crude product was diluted with water and extracted with dichloromethane. The organic phases were combined and washed with saturated NaCl. Drying, filtration, and concentration were performed to obtain the crude product. Purification by normal phase column gave compound 2d (695 mg). Yield: 59.9%.

[0177] MS (ESI): m / z 841.4 [M+1] + .

[0178] Step 4) 2, 2', 2"-(1 4Preparation of 1-phenyl-3,6,9-triaza-1(2,6)-pyridinecyclodecane-3,6,9-triyl)triglutamic acid (Compound 2e)

[0179] Compound 2d (620 mg, 0.74 mmol, 1.0 eq) and EtOH (9 mL) were added to a 50 mL single-necked flask and stirred to dissolve. The mixture was then cooled to 0°C in an ice bath. 5M NaOH (2.4 mL, 11.8 mmol, 16.0 eq) was added dropwise to the reaction solution. After addition, the temperature was raised to 80°C and the reaction was stirred until nearly complete. The ethanol was removed by concentration under reduced pressure. The crude product was cooled to 0°C and the pH was adjusted to 3. Purification was performed on an XAD 1600 resin column to afford compound 2e, 345 mg, in a yield of 69.6%.

[0180] MS (ESI): m / z 673.3 [M+1] + .

[0181] Step 5) 2,2',2'-(1 4 Preparation of 1-phenyl-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl) tris(4-carboxybutyrate) gadolinium(III) complex (Compound 2f)

[0182] Compound 2e (280 mg, 0.42 mmol, 1.0 eq) was placed in a 50 mL single-necked flask, deionized water (8 mL) was added, and the mixture was stirred to dissolve. The pH of the reaction mixture was adjusted to 7 with 1N NaOH solution. GdCl₃·6H₂O (156 mg, 0.42 mmol, 1.0 eq) was added. Following addition, the pH of the reaction mixture was again adjusted to 7 with 1N NaOH solution. The mixture was stirred at room temperature for 16 h. Purification with XAD 1600 resin afforded 65 mg of compound 2f. Yield: 18.9%.

[0183] MS (ESI): m / z 828.2[M+1] + .

[0184] Step 6) Preparation of Compound 2

[0185] SM-3 (28.8 mg, 0.32 mmol, 4.0 eq) was placed in a 25 mL single-necked flask, deionized water (0.5 mL) was added, and the mixture was stirred to dissolve. The pH was adjusted to 7 with 1N HCl. Compound 2f (65 mg, 0.08 mmol, 1.0 eq), HOBT (5.4 mg, 0.04 mmol, 0.5 eq), and EDCI (75.7 mg, 0.4 mmol, 5.0 eq) were added to the reaction system and stirred at room temperature for 3 days. Preparative liquid phase purification afforded 64 mg of compound 2 in a 77.9% yield.

[0186] MS (ESI): m / z 1047.3 [M+1] + .

[0187] Example 3

[0188] 2,2',2'-(1 4 -fluoro-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)tris(5-((2,3-dihydroxypropyl)amino)-5-oxoglutaric acid)gadolinium(III) complex (Compound 3)

[0189] Step 1) Preparation of diisopropyl 4-chloropyridine-2,6-dicarboxylate (Compound 3b)

[0190] In a 500 mL single-necked flask, compound 3a (10 g, 43.5 mmol, 1.0 eq), isopropanol (200 mL), and concentrated sulfuric acid (5 mL) were added at room temperature (25°C). Under nitrogen, the mixture was heated to 80°C and stirred until the reaction was nearly complete. The mixture was concentrated under reduced pressure to obtain a pale yellow solid. Water was added, followed by extraction with ethyl acetate. The organic layers were combined and washed with saturated sodium bicarbonate and saturated sodium chloride. The mixture was dried, filtered, concentrated, and purified by column chromatography to obtain compound 3b, 7.87 g, in a 63.3% yield.

[0191] MS:286.1[M+H] + .

[0192] Step 2) Preparation of diisopropyl 4-fluoropyridine-2,6-dicarboxylate (Compound 3c)

[0193] Compound 3b (23.6 g, 82.6 mmol, 1.0 eq), CsF (37.66 g, 247.8 mmol, 3 eq), and 4A molecular sieves (8 g) were added to a 1 L three-necked flask. The mixture was heated to 105°C under nitrogen and stirred for 2.5 hours. The reaction mixture was cooled to 25°C, filtered under reduced pressure, and the filter cake was washed with ethyl acetate. The filtrate was collected, diluted with ethyl acetate, washed with water, and then washed with saturated sodium chloride. The mixture was dried, filtered, and concentrated under reduced pressure to obtain compound 3c, 21 g, in a 94% yield.

[0194] MS:270.1[M+H] + .

[0195] 1 H NMR (400MHz, CDCl3) δ7.95 (d, J = 8.3 Hz, 2H), 5.32 (p, J = 6.2 Hz, 2H), 1.44 (d, J = 6.2 Hz, 12H).

[0196] 19F NMR (376MHz, CDCl3) δ-98.84 (s).

[0197] Step 3) Preparation of (4-fluoropyridine-2,6-diyl)dimethanol (Compound 3d)

[0198] In a 1L single-necked flask, compound 3c (10 g, 37.8 mmol, 1.0 eq) and isopropanol (350 mL) were added, followed by the slow addition of sodium borohydride (6.6 g, 173.7 mmol, 4.6 eq) in portions at room temperature (25°C). After addition, the temperature was raised to 50°C, nitrogen atmosphere was maintained, and stirring was continued for 5 hours. The reaction mixture was cooled to 0°C and quenched by the addition of acetone. After stirring for 10 minutes, saturated sodium bicarbonate was slowly added at 0°C to further quench the reaction. The mixture was diluted with water and extracted with ethyl acetate. The organic layers were combined, washed with saturated sodium chloride, dried, filtered, and concentrated to afford compound 3d (5 g) in an 84.2% yield.

[0199] MS:158.1[M+H] + .

[0200] 1 H NMR (400MHz, DMSO-d6) δ7.13 (d, J = 10.0Hz, 2H), 5.59 (brs, 2H), 4.53 (s, 4H).

[0201] 19 F NMR (376MHz, DMSO-d6) δ-103.53.

[0202] Step 4) Preparation of 2,6-bis(bromomethyl)-4-fluoropyridine (Compound 3e)

[0203] In a 500mL single-necked flask, compound 3d (5g, 31.8mmol, 1eq) was dispersed in 120mL of chloroform. Under nitrogen, the mixture was cooled to 0°C and PBr3 (129g, 44.9mL, 477.3mmol, 15eq) was added dropwise. After the addition was complete, the temperature was raised to 60°C and the reaction was stirred until nearly complete. The reaction mixture was slowly poured into saturated sodium bicarbonate solution and the pH was adjusted to 8 with solid NaHCO3. The mixture was extracted with dichloromethane and the extracts were combined. The mixture was washed with saturated NaCl, dried, filtered, concentrated, and purified on a normal phase column to afford compound 3e, 2.52g, in a 28% yield.

[0204] MS: 281.9[M+H] + .

[0205] 1 H NMR (400MHz, CDCl3) δ7.13 (d, J=8.8Hz, 2H), 4.51 (s, 4H).

[0206] 19 F NMR (376MHz, CDCl3) δ-100.47.

[0207] Step 5) 1 4 Preparation of 3,6,9-tri-p-toluenesulfonic acid-3,6,9-triaza-1(2,6)-pyridine cyclophane (Compound 3f)

[0208] At room temperature, SM-1 (6.39 g, 11.29 mmol, 1 eq), potassium carbonate (6.55 g, 47.42 mmol, 4.2 eq), and DMF (160 mL) were added sequentially, stirring to dissolve. With stirring at room temperature, the atmosphere was replaced with nitrogen three times and the mixture was heated to 100°C. Compound 3e (3.45 g, 12.2 mmol, 1 eq) was dissolved in DMF (61 mL) and slowly added to the reaction system. After addition, the reaction was stirred until nearly complete. The reaction mixture was cooled to 30°C, poured into water with stirring, filtered, and the filter cake was washed with water and dried overnight to obtain compound 3f (6.1 g, yield: 79%).

[0209] Ms(ESI):m / z 687.2[M+H] + .

[0210] 1 H NMR (400MHz, CDCl3) δ7.69 (dd, J=12.4, 8.2Hz, 6H), 7.32 (dd, J=21.0, 8.1Hz, 6H), 7.14 (d, J=8.5Hz,2H),4.28(s,4H),3.33(t,J=7.2Hz,4H),2.89(s,4H),2.45(s,6H),2.42(s,3H).

[0211] 19 F NMR (376MHz, CDCl3) δ-98.30.

[0212] Step 6) 1 4 Preparation of 3,6,9-tri-p-toluenesulfonic acid-3,6,9-triaza-1(2,6)-pyridine cyclophane (Compound 3g)

[0213] In a 100 mL reaction tube, compound 3f (3 g, 4.37 mmol, 1.0 eq) was dispersed in 30 mL of concentrated sulfuric acid. The atmosphere was purged with nitrogen three times and then heated to 105°C for 3 h. The reaction mixture was cooled to room temperature, poured into ice water, and the pH was slowly adjusted to approximately 12 with 40% NaOH solution. The mixture was then extracted with DCM / MeOH (20 / 1). The combined extracts were washed with saturated brine, and the organic phase was dried and concentrated to yield compound 3f (1.08 g, 55.1% yield).

[0214] MS (ESI): m / z 225.2 [M+H] + .

[0215] Step 7) 2, 2', 2"-(1 4 Preparation of hexaethyl-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)triglutamate (Compound 3h)

[0216] Compound 3g (138 mg, 0.62 mmol, 1.0 eq) was placed in a 25 mL single-necked flask, acetonitrile (6 mL) was added, and the mixture was stirred to dissolve. K2CO3 (386 mg, 2.8 mmol, 4.5 eq) was then added. SM-2 (596 mg, 2.2 mmol, 3.6 eq) was added dropwise to the reaction mixture. After addition, the mixture was heated to 66°C and stirred until the reaction was almost complete. The reaction mixture was concentrated, diluted with water, and extracted with dichloromethane. The organic phases were combined and washed with saturated NaCl. Drying over anhydrous sodium sulfate, filtration, and concentration were performed to obtain the crude product. Column purification afforded compound 3h (160 mg, yield: 33.2%).

[0217] MS (ESI): m / z 783.4 [M+1] +

[0218] Step 8) 2, 2', 2"-(1 4 Preparation of 1-fluoro-3,6,9-triaza-1(2,6)-pyridinecyclodecane-3,6,9-triyl)triglutamic acid (Compound 3i)

[0219] Compound 3h (320 mg, 0.41 mmol, 1.0 eq) and THF (10 mL) were added to a 50 mL single-necked flask, stirred to dissolve, and cooled to 0°C. A 1M aqueous solution of LiOH (4.9 mL, 4.9 mmol, 12.0 eq) was added dropwise to the reaction mixture. The reaction was stirred at room temperature until nearly complete. The pH was adjusted to 6 with 1M hydrochloric acid and the mixture was concentrated under reduced pressure. Purification was performed on an XAD 1600 column to afford compound 3i, 115 mg, in a yield of 45.8%.

[0220] MS (ESI): m / z 615.2[M+1] + .

[0221] Step 9) 2,2',2'-(1 4 Preparation of 1-fluoro-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)tris(4-carboxybutyrate)gadolinium(III) complex (Compound 3j)

[0222] Compound 3i (89 mg, 0.15 mmol, 1.0 eq) was placed in a 25 mL single-necked flask, deionized water (2 mL) was added, and the mixture was stirred to dissolve. The pH of the reaction mixture was adjusted to 7 with 1N NaOH solution. GdCl₃·6H₂O (54 mg, 0.15 mmol, 1.0 eq) was added, and after addition, the pH of the reaction mixture was again adjusted to 7 with 1N NaOH solution. The mixture was stirred at room temperature for 16 h. Purification with XAD 1600 resin afforded 75 mg of compound 3j, yield: 67.4%.

[0223] MS (ESI): m / z 770.1[M+1] + .

[0224] Step 10) Preparation of Compound 3

[0225] SM-3 (36 mg, 0.39 mmol, 4.0 eq) was placed in a 25 mL single-necked flask, deionized water (0.5 mL) was added, and the mixture was stirred to dissolve. The pH was adjusted to 7 with 1N HCl. Compound 3j (75 mg, 0.1 mmol, 1.0 eq), HOBT (6.6 mg, 0.05 mmol, 0.5 eq), and EDCI (94 mg, 0.5 mmol, 5.0 eq) were added to the reaction system and stirred at room temperature for 3 days. Purification by preparative liquid chromatography afforded 65 mg of the product, compound 3, in a yield of 66.7%.

[0226] MS (ESI): m / z 989.3[M+1] + .

[0227] Example 4

[0228] 2,2',2'-(1 4 -Methoxy-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)tris(5-((2,3-dihydroxypropyl)amino)-5-oxoglutaric acid)gadolinium(III) complex (Compound 4)

[0229] Step 1)1 4 Preparation of 1-methoxy-3,6,9-tri-p-toluenesulfonyl-3,6,9-triaza-1(2,6)-pyridinecyclodecane (Compound 4b)

[0230] SM-1 (16.86 g, 29.8 mmol, 1.1 eq) was placed in a 1 L single-necked bottle, 506 mL of DMF was added, and the mixture was stirred and dissolved. Heat to 100 ° C. Compound 4a (8.0 g, 27.1 mmol, 1.0 eq, synthesized according to Bioorganic and Medicinal Chemistry, 2020, vol. 28, # 24, no. 115816) was dissolved in 160 mL of DMF and slowly added dropwise to the above 100 ° C solution. After the addition is complete, stir the reaction until it is almost complete. The reaction system was cooled to room temperature, poured into ice water, extracted with ethyl acetate, and the organic phases were combined. Wash with water, wash with saturated NaCl aqueous solution, and dry over anhydrous sodium sulfate. Filter and concentrate to obtain compound 4b, 16.8 g, yield: 88.7%.

[0231] MS (ESI): m / z 699.2[M+1] + .

[0232] 1 H-NMR (400MHz, CDCl3) δ7.71(d,J=8.4Hz,4H),7.66(d,J=8.0Hz,2H),7.34(d,J=8.0Hz,4H),7.28(d,J=8.0Hz, 2H), 6.91 (s, 2H), 4.22 (br., 4H), 3.85 (s, 3H), 3.32 (t, J = 7.2Hz, 4H), 2.79 (br., 4H), 2.45 (s, 6H), 2.42 (s, 3H).

[0233] Step 2) 1 4 Preparation of 1-methoxy-3,6,9-triaza-1(2,6)-pyridinecyclodecane (Compound 4c)

[0234] Compound 4b (8.0 g, 11.45 mmol, 1.0 eq) was placed in a 250 mL flask, and 80 mL of concentrated sulfuric acid was added. The nitrogen atmosphere was replaced three times, and the mixture was heated to 100°C and stirred until the reaction was nearly complete. The reaction solution was cooled to room temperature and poured into ice water. Maintaining the temperature at 0°C, the pH was adjusted to 12 with 40% aqueous NaOH. The solution was extracted with dichloromethane and dried over anhydrous sodium sulfate. Concentration afforded compound 4c, 2.5 g, in a 92.6% yield.

[0235] MS (ESI): m / z 237.2[M+1] + .

[0236] Step 3) 2, 2', 2"-(1 4Preparation of hexaethyl triglutamate (compound 4d) with 1-methoxy-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)

[0237] Compound 4c (2.32 g, 9.82 mmol, 1.0 eq) was placed in a 250 mL single-necked flask, acetonitrile (50 mL) was added, and the mixture was stirred to dissolve. K2CO3 (6.79 g, 49.1 mmol, 5.0 eq) was then added. SM-2 (10.49 g, 39.28 mmol, 4.0 eq) was dissolved in acetonitrile (10 mL) and added dropwise to the reaction mixture. The mixture was heated to 66°C and stirred until the reaction was essentially complete. The mixture was concentrated, the crude product was diluted with water, and extracted with dichloromethane. The organic phases were combined and washed with saturated NaCl. After drying, concentration, and purification on a normal phase column, 3.7 g of compound 4d was obtained in a 47.7% yield.

[0238] MS (ESI): m / z 795.4[M+1] + .

[0239] 1 H NMR(400MHz, CDCl3)δ6.70(s,2H),4.23-4.01(m,14H),3.98-3.76(m,5H),3.69(s,2H),3 .34(s,2H),3.11–2.74(m,5H),2.55–2.21(m,9H),2.12–1.91(m,5H),1.36–1.18(m,18H).

[0240] Step 4) 2, 2', 2"-(1 4 Preparation of 1-methoxy-3,6,9-triaza-1(2,6)-pyridinecyclodecane-3,6,9-triyl)triglutamic acid (Compound 4e)

[0241] In a 50 mL single-necked flask, add compound 4d (3.55 g, 4.47 mmol, 1.0 eq) and EtOH (12.5 mL). Stir to dissolve, then cool to 0°C in an ice bath. Add 5 M NaOH (14.3 mL, 71.52 mmol, 16.0 eq) dropwise to the reaction solution. After addition, raise the temperature to 80°C and stir until the reaction is nearly complete. Concentrate the crude product, cool it to 0°C, and adjust the pH to 3. Purify the product using an XAD 1600 resin column to obtain 2.48 g of compound 4e in an 88.6% yield.

[0242] MS (ESI): m / z 627.2[M+1] + .

[0243] 1H NMR(400MHz,D2O)δ7.19–6.91(m,2H),4.57–4.16(m,4H),3.97–3.86 (m,3H),3.84–3.82(m,3H),3.53–2.94(m,8H),2.69–2.34(m,6H),2.26–1.82(m,6H).

[0244] Step 5) 2,2',2'-(1 4 Preparation of 1-methoxy-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl) tris(4-carboxybutyrate) gadolinium(III) complex (Compound 4f)

[0245] Compound 4e (2.48 g, 3.98 mmol, 1.0 eq) was placed in a 50 mL single-necked flask, deionized water (24 mL) was added, and the mixture was stirred to dissolve. The pH of the reaction solution was adjusted to 7 with 2N NaOH solution. GdCl3·6H2O (1.48 g, 3.98 mmol, 1.0 eq) was added. After addition, the pH of the reaction solution was again adjusted to 7 with 2N NaOH solution. The mixture was stirred at room temperature for 16 h. The mixture was dried by spin drying. Acetic acid (10 mL) was added to the residue, and the reaction was heated to 100°C for 20 h. The mixture was dried by spin drying and purified with XAD 1600 resin to obtain 2.25 g of the product, compound 4f. Yield: 72.8%.

[0246] MS (ESI): m / z 782.1[M+1] + .

[0247] Step 6) Preparation of Compound 4

[0248] SM-3 (816 mg, 8.96 mmol, 4.0 eq) was placed in a 50 mL single-necked flask, deionized water (5 mL) was added, and the mixture was stirred to dissolve. The pH was adjusted to 7 with 4N HCl. Compound 4f (1.75 g, 2.24 mmol, 1.0 eq), HOBT (151 mg, 1.12 mmol, 0.5 eq), and EDCI (2.15 g, 11.2 mmol, 5.0 eq) were added to the reaction system and stirred at room temperature for 3 days. Preparative liquid phase purification afforded compound 4 (1.72 g, yield: 77.8%).

[0249] MS (ESI): m / z 1001.3 [M+1] + .

[0250] Example 5

[0251] 2,2',2'-(1 3-Methoxy-3,6,9-triaza-1(2,6)-pyridylcyclodecane-3,6,9-triyl)tris(5-((2,3-dihydroxypropyl)amino)-5-oxoglutaric acid)gadolinium(III) complex (Compound 5)

[0252] Step 1) Preparation of 2,6-bis(bromomethyl)-3-methoxypyridine (Compound 5b):

[0253] Compound 5a (3.07 g, 18.15 mmol) was completely dissolved in CHCl₃ (90 mL) in a 250 mL single-necked flask. Phosphorus tribromide (22.10 g, 81.66 mmol, 7.68 mL) was then slowly added dropwise in an ice bath. After complete addition, the mixture was refluxed at 60°C overnight. Approximately 155 mL of saturated sodium carbonate (1.6 M) was slowly added at 0°C. The pH was adjusted to 8 with saturated sodium bicarbonate and stirred for approximately 30 min. The layers were separated, and the aqueous phase was extracted with 3 portions of dichloromethane (50 mL x 3). The combined organic phases were washed with 25 mL x 2 portions of water, dried over anhydrous sodium sulfate, stirred for 30 min, and evaporated to dryness under reduced pressure to obtain 3.44 g of a pink solid (96% purity, 64.27% yield).

[0254] Step 2) Preparation of Compound 5

[0255] Referring to the method in Example 4, compound 5 (purity 97.84%) was synthesized using 2,6-bis(bromomethyl)-3-methoxypyridine (compound 5b) as the starting material.

[0256] MS (ESI): m / z 1001.3 [M+1] + .

[0257] Example 6

[0258] Compound 4f was prepared according to the method of Example 4 and prepared by preparative HPLC (XP tC18, 250 mm × 50 mm × 7 μm, detection wavelength 214 nm, flow rate 100 ml / min, mobile phase: 0.1% aqueous acetic acid (mobile phase A) / acetonitrile (mobile phase B), elution ratio 92:8 → 40:60 → 92:8). Four signal peaks corresponding to different enantiomeric pairs were obtained.

[0259] The retention times were 33.48 min, 33.98 min, 34.75 min and 39.55 min, respectively. The retention time at 39.55 min was for the RRR / SSS enantiomer pair.

[0260] Step 1)

[0261] Referring to step 4 of Example 4), the enriched RRR / SSS isomer pair was used to replace compound 4f and reacted with isoserinol (3-amino-1,2-propanediol) to obtain RRR / SSS isomers.

[0262] MS (ESI): m / z 782.14 [M+H] + .

[0263] Test Example 1: Relaxation rate of compounds in water

[0264] 1. Test samples

[0265] Gadobutrol, RC1 (Gadopiclenol, prepared according to the method of Example 2 of WO2020030618A1), Compound 4 and Compound 5.

[0266] 2. Experimental instruments

[0267] Suzhou Newmai MRI Contrast Agent Relaxation Rate Analyzer—0.5T Magnetic Field

[0268] Bruker Small Animal MRI System (BioSpec 70 / 20USR)—7T Magnetic Field

[0269] 3. Experimental methods

[0270] Gadobutrol, RC1, compounds 4, and 5 were accurately weighed and prepared into 0.5 mM, 1 mM, 2 mM, and 4 mM solutions using deionized water. One mL of the test sample was placed in a 1.5 mL EP (eppendorf) tube and the longitudinal relaxation time T1 and transverse relaxation time T2 were measured at different magnetic fields using a Suzhou Newmai MRI contrast agent relaxivity analyzer in a 0.5 T magnetic field. A 0.2 mL sample tube was filled with the test sample and the longitudinal relaxation time T1 and transverse relaxation time T2 were measured at different magnetic fields using a Bruker small animal MRI system (BioSpec 70 / 20USR) in a 7 T magnetic field.

[0271] According to the relaxation times T1 and T2 of samples with different concentrations, the relaxation rates r1 and r2 are calculated respectively. The relaxation rate calculation formula is as follows:

[0272] r: relaxation rate; T: relaxation time (s); C: contrast agent concentration (mM).

[0273] 4. Experimental results

[0274] Table 1

[0275] Test Example 2: Kinetic stability of compounds in acidic medium

[0276] 1. Test samples

[0277] Gadobutrol, RC1 (Gadopiclenol, prepared according to the method of Example 2 of WO2020030618A1), Compound 4 and Compound 5.

[0278] 2. Experimental instruments

[0279] SpectraMax M2 / M2e microplate reader.

[0280] 3. Experimental methods

[0281] (1) Using hydrochloric acid at pH 1.2 as solvent, prepare the following solutions with a concentration of 8×10 -6 M of RC1, compound 4, compound 5 and gadobutrol solution for later use.

[0282] (2) Standard curve drawing: Accurately weigh an appropriate amount of GdCl3·6H2O in a vial and prepare it with deionized water to concentrations of 0 and 1×10 -6 M, 2×10 -6 M, 4×10 -6 M, 6×10 -6 M, 8×10 -6 M and 10×10 -6 M contains free Gd 3+ 1 mL of each solution (GdCl3·6H2O, Shanghai Dingxian Biotechnology Co., Ltd.) was mixed with 40 μL of 5.3×10 -4 M of arsenazo III solution (developer, Shanghai MacLean Biochemical Technology Co., Ltd.) was thoroughly vortexed and incubated in the dark at room temperature for 15 min. 150 μL / well was taken, and two replicates were placed in a 96-well plate. The absorbance was measured at a wavelength of 655 nm to prepare Gd 3+ Standard curve of concentration and absorbance.

[0283] (3) Compound test: The prepared concentration of 8×10 -6 500 ml of each test substance of M was divided equally into 3 bottles, each bottle of 150 ml. Place at 37 ° C, take 25 ml from each bottle after 0 h, 24 h, 48 h, 96 h and 168 h, add NaOH to adjust the pH to neutral (use pH test paper to determine the color), then add 1 ml of 5.3 × 10 -4 M of arsenazo III solution was thoroughly vortexed and incubated at room temperature in the dark for 15 min. Then 150 μL / well was taken, and two replicates were placed in a 96-well plate to measure the sample absorbance at a wavelength of 655 nm.

[0284] (4) Calculate the free Gd of each test substance at different time points according to the formula fitted by the standard curve 3+ concentration and dissociation rate.

[0285] 4. Experimental results

[0286] Table 2 Note: BLQ was below the limit of quantification, a: compared with RC1, P < 0.0001, b: compared with gadobutrol, P < 0.0001.

[0287] Test Example 3: Relaxation rate detection of compounds in human plasma

[0288] 1. Test samples

[0289] Gadobutrol (Elucirem), Elucirem TM (Gadopiclenol, commercially available), compound 4.

[0290] 2. Experimental instruments

[0291] Medium-sized MRI analyzer (Model MesoMR23-060-I)—0.5T magnetic field

[0292] 3. Experimental methods

[0293] Using human plasma containing sodium heparin as the matrix, compound 4 (0.5 M), gadobutrol injection (1 M), and gadopiclenol injection (0.5 M) were diluted to prepare test solutions with concentrations of 4, 2, 1, 0.5, and 0.25 mM, respectively. 1 mL of the test sample was placed in a 1.5 mL centrifuge tube, and the longitudinal relaxation time T1 and transverse relaxation time T2 were measured under a 0.5 T magnetic field using a medium-sized nuclear magnetic resonance imaging analyzer (MesoMR23-060-I).

[0294] According to the relaxation times T1 and T2 of samples with different concentrations, the relaxation rates r1 and r2 are calculated respectively. The relaxation rate calculation formula is as follows:

[0295] r: relaxation rate; T: relaxation time (s); C: contrast agent concentration (mM).

[0296] 4. Experimental results

[0297] Table 3

[0298] Test Example 4: Metal transfer stability test of compounds in the presence of zinc ions

[0299] 1. Experimental plan

[0300] 2. Test samples: Compound 4, gadodiamide, and gadobutrol.

[0301] 3. Experimental instrument: VTMR20-010V-I nuclear magnetic resonance cross-link density imaging analyzer

[0302] 4. Experimental methods

[0303] Prepare a 2.5mM contrast agent solution and a 2.5mM zinc chloride solution using phosphate buffer (0.026mol / L KH2PO4 and 0.041mol / L Na2HPO4). Add an equal volume of 2.5mM ZnCl2 solution to the 2.5mM gadolinium contrast agent solution and mix thoroughly. The mixing point is marked as zero. Immediately, take 0.5mL and measure the relaxation time T1 at 37°C and 0.5T magnetic field. (0) The mixed solution was incubated at 37°C. 0.5 mL of the solution was taken at 5 min, 180 min, 1440 min, and 5760 min, and T1 at different time points was measured. (t) Calculate the ratio of the relaxation rate at different time points to the initial relaxation rate at 0, that is, R 1(t) / R 1(0) .

[0304] 5. Test results

[0305] Table 4

[0306] Test Example 5: In vitro dog plasma protein binding rate of the compound

[0307] 1. Test sample: Elucirem TM (Gadopiclenol, commercially available, batch number P233A), compound 4

[0308] 2. Test method:

[0309] Elucirem was diluted with canine blank plasma. TM and compound 4 to prepare a plasma sample with a concentration of 1 mM. The binding rate of gadopiclenol and compound 4 to canine plasma proteins was determined by ultracentrifugation. After the plasma sample was prepared, 0.5 mL of plasma sample was transferred into an ultracentrifuge tube, 3 samples for each concentration, incubated at 37°C in a CO2 incubator for 0.5 h, and then ultracentrifuged at 627,000 g for 3 hours at 37°C. After centrifugation, 100 μL of sample was taken from the central layer of the ultracentrifuge tube and mixed with 100 μL of blank plasma. The samples were stored at -70°C for testing. LC-MS / MS was used to quantitatively analyze the concentrations of gadopiclenol and compound 4 in the samples.

[0310] The plasma protein binding rate of the analyte at different concentration levels was calculated using the following formula: Free rate % = (concentration C in the central layer of the ultracentrifuge tube)u / Unextracted samples were incubated for 0.5h at a concentration of C 0.5h )*100%, binding rate %=100%-free rate %.

[0311] 3. Test results:

[0312] The binding rates of gadopiclenol and compound 4 to dog plasma proteins are shown in Table 5. Gadopiclenol does not bind to plasma proteins, and the plasma protein binding rate of compound 4 is an average of 19.6%, suggesting a potential effect on improving plasma relaxivity.

[0313] Table 5 Note: Due to detection error, the binding rate was lower than 0, and the average value was recorded as 0%.

[0314] Test Example 6: General observation test of intravenous administration of compounds in rats

[0315] 1. Test sample: Elucirem TM (Gadopiclenol, commercially available, batch number P233A), compound 4

[0316] 2. Test method:

[0317] SD rats were given a single intravenous injection of 6 mmol / kg of Elucirem TM or compound 4, with 8 animals per group, half male and half female. All animals underwent detailed clinical observations during the trial, including the administration site, skin, fur, face, eyes, ears, nose, mouth, chest, abdomen, urogenital area, limbs, as well as changes in respiration, locomotion, urination, defecation, and behavior.

[0318] 3. Test results

[0319] Elucirem TM Immediately after administration, all 8 animals showed reddening of their paws / ears, with 5 animals also showing swelling of their front paws / four paws. Immediately after administration of compound 4, 5 of the 8 animals showed reddening of their paws / ears, with 4 of them also showing swelling of their front paws / four paws; 3 animals showed no abnormalities.

Claims

1. The compound represented by formula I or its pharmaceutically acceptable salt in, R 1 , R 2 and R 3 Each independently selected from -COOH, -P(O)(OH)2 or -P(O)(R 4 )(OH), R 4 Selected from hydrogen or C 1-4 alkyl; X 1 , X 2 , X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-6 Alkylene, Y is selected from -COOH, -CONH2, -CONR 5 R 6 or -NR 7 COR 8 ; R 5 Selected from hydrogen, C 1-6 Alkyl or C 1-6 Hydroxyalkyl, R 6 Selected from C 1-6 Alkyl or C 1-6 Hydroxyalkyl, and R 5 and R 6 At least one C 1-6 Hydroxyalkyl; R 7 Selected from hydrogen, C 1-6 Alkyl or C 1-6 Hydroxyalkyl, R 8 Selected from C 1-6 Alkyl or C 1-6 Hydroxyalkyl, and R 7 and R 8 At least one C 1-6 Hydroxyalkyl; Z 1 Selected from CR 9 ; Z 2 Selected from CR 10 ; R 9 , R 10 are independently selected from hydrogen, halogen, nitro, amino, cyano, C 1-6 Alkyl, C 1-6 alkoxy, 3 to 6 membered cycloalkyl, 3 to 6 membered cycloalkyloxy, 3 to 6 membered heterocycloalkyl, 3 to 6 membered heterocycloalkoxy, 6 membered aryl or 5-6 membered heteroaryl, wherein the alkyl, alkoxy, cycloalkyl, heterocycloalkyl, cycloalkoxy, heterocyclooxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A Each is independently selected from halogen, hydroxy, oxo, nitro, cyano, amino, C 1-6 Alkyl or C 1-6 Alkoxy, and R 9 With R 10 Different from hydrogen, Or, R 9 , R 10 Together with the adjacent carbon atoms, a 6-membered aryl or 5-6-membered heteroaryl group is formed, wherein the aryl or heteroaryl group is optionally substituted by one or more R 1B Replaced by R 1B are each independently selected from halogen, hydroxy, nitro, cyano, amino, substituted or unsubstituted C 1-6 Alkyl or substituted or unsubstituted C 1-6 Alkoxy; Z 3 is selected from CH or N; K 1 To K 12 are independently selected from hydrogen, C 1-6 Alkyl or C 1-6 Hydroxyalkyl; Or, K 1 With K 2 to form a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 3 or K 4 With K 5 or K 6 to form a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 7 or K 8 With K 9 or K 10 to form a 3- to 6-membered substituted or unsubstituted carbocyclic ring, or, K 11 With K 12 A 3- to 6-membered substituted or unsubstituted carbocyclic ring is formed.

2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, wherein R 1 , R 2 and R 3 Selected from -COOH.

3. The compound according to claim 1 or 2 or a pharmaceutically acceptable salt thereof, wherein Z 3 Selected from N.

4. The compound according to any one of claims 1 to 3 or a pharmaceutically acceptable salt thereof, wherein Z 1 Selected from CR 9 , R 9 Selected from halogen, C 1-6 Alkyl, C 1-6 Alkoxy, 6-membered aryl or 5-6-membered heteroaryl, wherein the alkyl, alkoxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A As defined in claim 1; further, R 9 Preferred are chlorine, fluorine, methoxy, ethoxy or phenyl.

5. The compound according to claim 1 or 4 or a pharmaceutically acceptable salt thereof, wherein the compound represented by formula I is in, R 1 ~R 3 , Z 2 , K 1 ~K 12 , and X 1 ~X 3 As defined in claim 1.

6. The compound according to any one of claims 1 to 5 or a pharmaceutically acceptable salt thereof, wherein Z 2 Selected from CR 10 , R 10 Selected from hydrogen, halogen, C 1-6 Alkyl, C 1-6 Alkoxy, 6-membered aryl or 5-6-membered heteroaryl, wherein the alkyl, alkoxy, aryl or heteroaryl is optionally substituted by one or more R 1A Replaced by R 1A As defined in claim 1; further, R 10 Preferred are hydrogen, chlorine, fluorine, methoxy, ethoxy or phenyl.

7. The compound according to any one of claims 1 to 3 or a pharmaceutically acceptable salt thereof, wherein R 9 , R 10 Together with the adjacent carbon atoms, a 6-membered aromatic group is formed, wherein the aromatic group is optionally substituted with one or more R 1B Replaced by R 1B As defined in claim 1.

8. The compound according to claim 1 or 7 or a pharmaceutically acceptable salt thereof, wherein the compound represented by formula I is in, n=an integer between 0 and 4; R 1 ~R 3 , K 1 ~K 12 , X 1 ~X 3 and R 1B As defined in claim 1.

9. The compound according to any one of claims 1 to 8 or a pharmaceutically acceptable salt thereof, wherein X 1 , X 2 , X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -COOH, -CONH2.

10. The compound according to any one of claims 1 to 9 or a pharmaceutically acceptable salt thereof, wherein X 1 , X 2 , X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -CONR 5 R 6 or -NR 7 COR 8 , where R 5 is selected from hydrogen or methyl, R 6 Selected from C 1-6 Hydroxyalkyl, R 7 is selected from hydrogen or methyl, R 8 Selected from C 1-6 Hydroxyalkyl.

11. The compound according to claim 1 or 10 or a pharmaceutically acceptable salt thereof, wherein R 6 Selected from C 2-6 Hydroxyalkyl, preferably -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

12. The compound according to claim 1 or 10, or a pharmaceutically acceptable salt thereof, wherein R 8 Selected from C 2-6 Hydroxyalkyl, preferably -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

13. The compound according to claim 1 or 10, or a pharmaceutically acceptable salt thereof, wherein X 1 , X 2 , X 3 Each is independently selected from LY, wherein L is selected from substituted or unsubstituted C 1-3 Alkylene, Y is selected from -CONR 5 R 6 , R 5 Selected from hydrogen, R 6 Selected from -CH2CH2OH, -CH(OH)CH2OH, -CH(CH2OH)2, -CH2(CHOH) p CH2OH or -C(CH2OH)3, p is an integer between 1 and 4.

14. The isotope substitution of the compound according to any one of claims 1 to 13, preferably, the isotope substitution is a deuterated substance.

15. A multimer, preferably a dimer or trimer, of the compound according to any one of claims 1 to 13.

16. The compound according to any one of claims 1 to 13, or the deuterated compound according to claim 14, or the complex of the polymer according to claim 15 and M, wherein M is Gd 3+ , Mn 2+ or Fe 3+ .

17. The complex according to claim 16, which is selected from:

18. A pharmaceutical composition comprising the compound according to any one of claims 1 to 13, or the deuterated compound according to claim 14, or the multimer according to claim 15, or the complex according to claim 16 or 17.

19. Use of the compound according to any one of claims 1 to 13, or the deuterated compound according to claim 14, or the multimer according to claim 15, the complex according to claim 16 or 17, or the composition according to claim 18 in the preparation of a medicament for nuclear magnetic resonance imaging.

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