Manganese Chelate Isomers

Abstract

The present invention relates to isomers of chelating compounds and their use as contrast agents in magnetic resonance imaging (MRI) procedures.

Description

[Technical field]

[0001] The present invention relates to isomers of chelating compounds and their use as contrast agents in magnetic resonance imaging (MRI) procedures. [Background technology]

[0002] MRI is a medical imaging technique that visualizes regions of the body with the nuclei of selected atoms, particularly hydrogen nuclei. The MRI signal depends on the environment surrounding the visualized nuclei and the longitudinal and transverse relaxation times, T1 and T2. Thus, if the visualized nuclei are protons, the MRI signal intensity will depend on factors such as proton density and the chemical environment of the protons. Contrast agents can be used in MRI to improve image contrast. Contrast agents can have T1, T2 and / or T2 * It works by causing relaxation times, thereby affecting the contrast of the image.

[0003] Paramagnetic contrast agents are T1, T2 and / or T2 * It is known that the relaxation time can be altered and this effect can be optimized by modifying the structure of the paramagnetic metal chelate. Of particular importance is the presence and residence time of water molecules bound to the paramagnetic ion and the rotational correlation time of the contrast agent. The presence and residence time of water molecules bound to the paramagnetic ion can be adjusted by the selection of the paramagnetic ion and the chelate moiety. The rotational correlation time can be adjusted by changing the size of the contrast agent.

[0004] The water solubility of paramagnetic chelates is also an important factor, since they are administered to patients in relatively large doses when used as contrast agents for MRI. Paramagnetic chelates that are more water soluble require smaller injection volumes, making them easier to administer to patients and less uncomfortable. Water soluble paramagnetic chelates, i.e., complexes of chelating agents and paramagnetic metal ions, are well known, including the commercially available gadolinium chelates Omniscan™ (GE Healthcare), Dotarem™ (Guerbet), Gadavist™ (Bayer), and Magnevist™ (Bayer). Due to their low molecular weight, they are rapidly distributed in the extracellular space (i.e., blood and interstitium) when administered into the vascular system. They are also relatively rapidly cleared from the body.

[0005] An important property of MRI chelates is that the paramagnetic ions are retained as much as possible within the chelate structure. Paramagnetic ions released from chelates in vivo can interfere with biological pathways and potentially induce toxicity. The ability of a chelate to retain paramagnetic ions (also referred to herein as stability) is also a property that can be tuned by the structural design of the cheland moiety. Of particular interest is the kinetic stability, measured as the dissociation half-life, which indicates the degree of inertia towards an altered chemical environment (i.e., endogenous ions).

[0006] As can be seen from the availability of commercial agents and the focus of the prior art, gadolinium is the most widely used paramagnetic metal ion for MRI chelation due to its favorable relaxivity properties. The concept of "relaxivity" of an MRI contrast agent is well known to those skilled in the art and refers to the ability of a magnetic compound to increase the relaxation rate of the surrounding water proton spins. Relaxivity is used to improve the contrast of MR images and to study specific regions of tissues where the contrast agent diffuses better or to perform functional MRI. The relaxivity of an MRI contrast agent depends on the molecular structure and kinetics of the complex. Relaxivity depends on the temperature, magnetic field strength, and the material in which the contrast agent is dissolved.

[0007] Stability of the paramagnetic ion within the chelate structure is desirable for gadolinium chelates when used as contrast agents.Therefore, there is a desire to identify new gadolinium chelates that have a higher level of stability, especially within physiological environments.

[0008] The manganese(II) ion is a paramagnetic species with a high spin number and long electronic relaxation time. The potential of manganese(II)-based high relaxivity contrast agents has been reported in the literature (Toth, E, Advances in Inorganic Chemistry, 2009, 61 (09), 63-129). However, certain manganese(II) chelates developed so far have proven to be less stable compared to the corresponding gadolinium chelates. For example, the manganese chelate of DOTA (MnDOTA) is several hundred times less stable compared to the corresponding gadolinium complex Gd-DOTA (Drahos, B; Inorganic Chemistry, 2012(12), 1975-1986).

[0009] WO 2011 / 073371, published June 23, 2011, by Andreas Meijer, describes molecular designs that favor high chelating stability and high relaxivity. This makes these compounds highly suitable for use as MRI contrast agents. Exemplary compounds in WO 2011 / 073371 have the following structures:

[0010] [ka]

[0011] WO 2017 / 220610 by Andreas Meijer et al., published on December 28, 2017, describes manganese chelates that are suitable for use as contrast agents and offer superior properties over other known manganese-based contrast agents. The manganese chelates of WO 2017 / 220610 comprise a compound of formula (I):

[0012] [ka] or a salt or solvate thereof, During the ceremony, Each R 1 is halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 independently selected from the group containing an aryl, an aryl, or a carbohydrate moiety; Each R 2 is C 1~20 Hydroxyalkyl, C 1~6 independently selected from the group consisting of alkyl and hydrogen; R 3 is C 1~3 Alkyl or -(CH2) m -C(=0)-NR 5 R 6 where m is an integer from 2 to 5, and R 5 and R 6 are R 1 and R 2 As defined in; R 4 is hydroxy, C 1~6 Alkyl and C 1~6 represents 0 to 3 substituents selected from the group consisting of hydroxyalkyl; and Each n is an integer from 0 to 4; Compounds of formula (I) include compounds or salts or solvates thereof which contain at least two hydroxy groups. Summary of the Invention

[0013] There remains a need to develop stable manganese contrast agents suitable for use as contrast agents.

[0014] The present invention relates to compounds of formula IA:

[0015] [ka] or a salt or solvate thereof. 1 is halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 Each R is independently selected from an aryl, an aryl, or a carbohydrate moiety. 2 is C 1~20 Hydroxyalkyl, C 1~6 R is independently selected from alkyl or hydrogen. 3 is C 1~3 Alkyl or -(CH2) m -C(=0)-NR 5 R 6 wherein m is an integer from 2 to 5, where R 5 and R 6 from hydrogen, halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 R is independently selected from an aryl, an aryl, or a carbohydrate moiety. 4 is hydroxy, C 1~6 Alkyl and C 1~6 hydroxyalkyl. Each n is an integer from 0 to 4.

[0016] In one embodiment, the invention involves a composition comprising a compound of formula IA, or a salt or solvate thereof, and a pharma- ceutically acceptable excipient. In one embodiment, the composition lacks detectable amounts of a compound of formula IB.

[0017] [ka] In the formula, each R 1 is halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 Each R is independently selected from an aryl, an aryl, or a carbohydrate moiety. 2 is C 1~20 Hydroxyalkyl, C 1~6 R is independently selected from alkyl or hydrogen. 3 is C 1~3 Alkyl or -(CH2) m -C(=0)-NR 5 R 6 where m is an integer from 2 to 5, where R 5 and R 6 from hydrogen, halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 R is independently selected from an aryl, an aryl, or a carbohydrate moiety. 4 is hydroxy, C 1~6 Alkyl and C 1~6 hydroxyalkyl. Each n is an integer from 0 to 4.

[0018] In one embodiment, the invention involves a method of imaging a patient, comprising administering an imaging agent or imaging agent composition followed by obtaining an MRI image of the patient.

[0019] In one embodiment, the present invention involves a process for producing the imaging agents described above, which may involve the enantioselective synthesis or isomerisation of a compound of formula (IB) to a compound of formula (IA). [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 shows the predicted stereoisomers of Mn-chelate-5. [Diagram 2] Figure 2 shows HPLC chromatographs of (a) Mn-chelate-5 synthesized without stereochemical control, (b) (R,S)-Mn-chelate-5, (c) (R,R)-Mn-chelate-5, (d) (S,S)-Mn-chelate-5, and (e) (S,R)-Mn-chelate-5. [Diagram 3] FIG. 3 shows the rate of dechelation of Mn-chelate-5 stereoisomers in human serum. [Figure 4] FIG. 4 shows the %Mn chelate-5 remaining as a function of time for (a) (R,R)-Mn chelate-5 (diamonds), (b) (S,S)-Mn chelate-5 (squares), (c) (S,R)-Mn chelate-5 (circles), and (d) (R,S)-Mn chelate-5 (triangles) when incubated in the presence of xs.ZnCl2 at pH 4 and 40 °C. [Diagram 5] FIG. 5 shows the %ID (injected amount) / organ 7 days after injection of a 0.62 mmol Mn-chelate-5 / kg dose containing approximately 30 μmol Mn-54 chelate-5, (a) synthesis with no stereochemical control (solid bars), (b) a 1:1 mixture of (R,R) and (S,S)-Mn-chelate-5 isomers (hashed bars), and (c) (R,S)-Mn-chelate-5 (checked bars). [Figure 6] FIG. 6 shows the structure of Mn-chelate-10. [Figure 7] FIG. 7 shows the structure of Mn chelate-15. [Figure 8]FIG. 8 shows the % Mn chelate remaining as a function of time for (R,S)-Mn chelate-5 (circles), a 1:1 mixture of (R,R and S,S)-Mn chelate-5 isomers (X), Mn chelate-10 isomer pool A (triangles), and Mn chelate-10 isomer pool B (diamonds). [Figure 9] FIG. 9 shows a synthetic route to isomerically pure chelates according to an embodiment of the present invention. [Figure 10] FIG. 10 is an example of a chromatogram showing the separation of manganese-containing proteins from intact chelates. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In order to more clearly and concisely describe and point out the subject matter of the claimed invention, definitions and exemplary embodiments are provided below for specific terms used throughout the specification and claims. Any instances of specific terms herein should be considered as non-limiting examples.

[0022] The terms "comprising" or "comprises" have their conventional meaning throughout this application, meaning that an agent or composition must have the essential features or components recited, but that other features or components may additionally be present. The term "comprising" includes, as a preferred subset, "consisting essentially of," which means that the composition has the recited components, with no other features or components present.

[0023] "Salts" according to the present invention include physiologically acceptable acid addition salts, for example, acid addition salts derived from inorganic acids such as, for example, hydrochloric acid, hydrobromic acid, phosphoric acid, metaphosphoric acid, nitric acid, and sulfuric acid, and acid addition salts derived from organic acids such as, for example, tartaric acid, trifluoroacetic acid, citric acid, malic acid, lactic acid, fumaric acid, benzoic acid, glycolic acid, gluconic acid, succinic acid, methanesulfonic acid, and para-toluenesulfonic acid.

[0024] Suitable "solvates" according to the present invention are selected from ethanol, water, saline, physiological buffers, and glycols.

[0025] The term “alkyl”, alone or in combination, refers to a group of the general formula C n H 2n+1 By "alkyl" is meant a straight or branched chain alkyl group having the formula: Examples of such groups include methyl, ethyl, and isopropyl.

[0026] The term "hydroxyl" refers to an OH group.

[0027] The term "hydroxyalkyl" refers to an alkyl group, as defined above, that contains one or more hydroxyl substituents, as defined above.

[0028] The term "aryl" refers to a functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, examples of which include phenyl and pyridyl. In one embodiment, an aryl group of the present invention is an aromatic 6-membered ring containing between 0 and 3 heteroatoms selected from O, N and S.

[0029] The term "halogen" or "halo" means a substituent selected from fluorine, chlorine, bromine, or iodine.

[0030] The term "hydroxy" refers to an OH group.

[0031] The term "chelating moiety" refers to a substituent that is a metal chelate, and the term "metal chelate" refers to a coordination complex, where a metal ion binds to a molecule or arrangement around an anion contained in the chield. A "chield" is defined herein as an organic compound that can form a coordinate bond with a paramagnetic metal ion through two or more donor atoms. A typical chield suitable for the present invention has 2-6, preferably 4-6, metal donor atoms arranged to obtain a 5- or 6-membered ring (by having a non-coordinating backbone of either carbon atoms or non-coordinating heteroatoms linking the metal donor atoms). Examples of suitable donor atom types in which the metal ion is a paramagnetic metal ion include amines, thiols, amides, oximes, and phosphines. In one embodiment, the metal ion is manganese.

[0032] In one embodiment, the present invention provides a compound of formula IA:

[0033] [ka] or a salt or solvate thereof. 1 is halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 aryl, or carbohydrate moiety; each R 2 is C 1~20 Hydroxyalkyl, C 1~6 R is independently selected from alkyl or hydrogen; 3 is C 1~3 Alkyl or -(CH2) m -C(=0)-NR 5 R 6 where m is an integer from 2 to 5, where R 5 and R 6 from hydrogen, halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 R is independently selected from an aryl, an aryl, or a carbohydrate moiety; 4 is hydroxy, C 1~6 Alkyl and C 1~6 hydroxyalkyl; and each n is an integer from 0 to 4.

[0034] The following process shows the stereoselective synthesis of the (R,R) and (S,S) isomers of Mn-chelate-5. (R,R)-Mn-chelate-5 is synthesized from the deprotected 2-arm cyclic chelate (compound III) by bis-alkylation with (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate to give the protected (R,R)-Mn 2-arm C5 chelate (compound V). The protected (R,R)-Mn 2-arm C5 chelate is then deprotected under acidic conditions, Mn is chelated, and an amino alcohol (D-glucamine) is coupled to give the (R,R)-Mn-chelate-5. (S,S)-Mn chelate-5 was synthesized from the deprotected 2-arm cyclic chelate (compound III) by bis-alkylation with (R)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate to give the protected (S,S)-Mn 2-arm C5 chelate (compound VI). The (S,S)-Mn 2-arm C5 chelate was converted to (S,S)-Mn chelate-5 using the approach described above for the synthesis of (R,R)-Mn chelate-5.

[0035] The following process describes the stereoselective synthesis of the (S,R) and (R,S) isomers of Mn-chelate-5. (S,R)-Mn-chelate-5 and (R,S)-Mn-chelate-5 were synthesized from the deprotected 2-arm cyclic chelate by mono-alkylation with (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate followed by alkylation with (R)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate to give the (R,S)-Mn 2-arm C5 chelate (compound VII). The (R,S)-Mn 2-arm C5 chelate was then deprotected under acidic conditions and Mn was chelated to give a mixture of (S,R)-Mn 2-arm C5 chelate and (R,S)-Mn 2-arm C5 chelate. The mixture of (S,R)-Mn 2-arm C5 chelate and (R,S)-Mn 2-arm C5 chelate was then coupled with amino alcohol (D-glucamine) to give a mixture of (S,R)-Mn chelate-5 and (R,S)-Mn chelate-5, which was then synthesized by C 18 The (R,S)-Mn chelate-5 chelate was also synthesized by heating a mixture of the (S,R)-Mn 2-arm C5 chelate and the (R,S)-Mn 2-arm C5 chelate at 90° C. until the (S,R)-Mn 2-arm C5 chelate was completely isomerized to the (R,S)-Mn 2-arm chelate-5, and then coupling the (R,S)-Mn 2-arm C5 chelate with an amino alcohol (D-glucamine) to obtain the (R,S)-Mn chelate-5. As will be appreciated by those skilled in the art, the approach described for the stereoselective synthesis of the isomers of Mn chelate-5 is applicable to the stereoselective synthesis of the compounds represented by formulae IA and IB.

[0036] Mn-chelate-5 was synthesized without stereochemical control at the attachment site to the macrocycle. In the absence of stereochemical control, four isomers were expected to exist, as shown in Figure 1. The (S,R) and (R,S) isomers can be interconverted via metal dechelation and rechelation. The R and S designations represent the stereochemistry at the attachment point to the macrocycle.

[0037] Figure 2a shows the results of HPLC analysis of Mn-chelate-5 synthesized without stereochemical control. Subsequently, (S,S)-Mn-chelate-5 and (R,R)-Mn-chelate-5 were enantioselectively synthesized as described in Figure 9. The results of HPLC analysis of (R,R)-Mn-chelate-5 are shown in Figure 2c and that of (S,S)-Mn-chelate-5 in Figure 2d. The enantioselective synthesis of (R,S)-Mn-chelate-5 and (S,R)-Mn-chelate-5 was carried out as described in Figure 9. The results of HPLC analysis of (R,S)-Mn-chelate-5 are shown in Figure 2b and that of (S,R)-Mn-chelate-5 in Figure 2e.

[0038] The stability of Mn-chelate-5 to transmetallation with Zn was evaluated at 2 mM Mn-chelate-5, pH=4, in the presence of 100-fold excess of Zn (200 mM ZnCl2 in 15 mM ammonium formate, pH=4, 40°C). Figure 3 shows the %Mn-chelate-5 remaining as a function of time for (R,R)-Mn-chelate-5 (diamonds), (S,S)-Mn-chelate-5 (open squares), (S,R)-Mn-chelate-5 (circles), and (R,S)-Mn-chelate-5 (triangles). Surprisingly, the data in Figure 3 show that the transmetallation rate of the (R,S)-Mn-chelate-5 isomer is significantly slower and the transmetallation rate of the (S,R)-Mn-chelate-5 isomer is significantly faster, suggesting differences in the strength of Mn chelation as a function of the stereochemistry of the chelate. The stability of Mn-chelate-5 stereoisomers in human serum was evaluated in vitro by monitoring the transfer of Mn from the chelate to blood proteins using a method combining size exclusion chromatography and on-line detection of manganese-containing species by ICP-MS. Figure 3 shows the percentage of dechelation during a total incubation time of 2 days at 37 °C. There is a significant difference between the (S,R)-Mn-chelate-5 isomer (upper curve, least stable) and the (R,S)-Mn-chelate-5 isomer (lower curve, most stable), similar to the results obtained in the study of Zn transmetallation.

[0039] Since Mn released in vivo is known to be retained in the brain, bone, and liver, the in vivo stability of the different isomer pools is unclear. 54 The biodistribution of Mn radioactive material was evaluated. The Mn chelate-5 synthesized without stereochemical control, a 1:1 mixture of (R,R)- and (S,S)-Mn chelate-5 isomers, and isomeric pool B of (R,S)-Mn chelate-5 were added to non-radiolabeled material. 54Mn-labeled materials were used to assess the amount of Mn released in vivo. A 1:1 mixture of (R,R)-Mn chelate-5 isomers and (S,S)-Mn chelate-5 isomers was chosen because the transmetallation kinetics of the two isomers were similar, predicting comparable stability. Rats were dosed with approximately 30 μCi 54 The animals were dosed with 0.62 mmol Mn-chelate-5 / kg containing Mn-chelate-5. Seven days after injection, the animals were sacrificed, and the organs of interest were harvested and the amount of Mn remaining in the organs was counted using a gamma counter. 54 Figure 4 shows that the Mn concentration of about 30 μmol 54 Figure 1 shows %ID (injected dose) / organ 7 days after injection with 0.62 mmol Mn-chelate-5 / kg dose containing Mn-chelate-5. Bars containing hashed lines represent %ID / organ below the detection limit of this study. Results of statistical comparisons of %ID for each organ are summarized as p-values ​​using either one-way ANOVA-Howell comparisons or 2-way t-tests as appropriate for each organ.

[0040] Surprisingly, the data in Figure 4 show that in brain and bone, significantly less Mn remained in vivo 7 days after injection of (R,S)-Mn chelate-5 compared to a 1:1 mixture of (S,S)-Mn chelate-5 and (R,R)-Mn chelate-5 or Mn chelate-5 synthesized without stereochemical control, consistent with less Mn release in vivo. This is consistent with the Zn transmetallation data and further supports the conclusion that the strength of Mn chelation is a function of chelate stereochemistry. This is further supported by the higher levels of Mn detected in the kidney for (R,S)-Mn chelate-5, which may be due to the passage of more intact Mn chelate-5 through the kidney.

[0041] Since Mn-chelate-5 has 10 additional stereocenters in the glucamine side chain in addition to the two stereocenters α to the macrocycle, we synthesized Mn-chelate-10 (Figure 5) without stereochemical control using racemic 3-amino-1,2-propanediol and C 18Mn-chelate-10 isomer pool A and Mn-chelate-10a isomer B were obtained by chromatography. The transmetallation of Zn was carried out for Mn-chelate-10 isomer pool A and Mn-chelate-10a isomer B under the above conditions (Figure 9). Surprisingly, Mn-chelate-10 isomer pool A, (S,S)-Mn-chelate-5, and (R,R)-Mn-chelate-5 transmetallated with Zn in the same proportions, while Mn-chelate-10 isomer pool B and (R,S)Mn-chelate-5 transmetallated with Zn in the same proportions. This data indicates that both the identity of the side arm and the stereochemistry of the side arm do not affect the strength of Mn chelation, while the stereochemistry of the α-site to the macrocycle is key in determining the stability of the Mn chelate. Based on the data presented above, it is reasonable to consider that the (R,S) and / or (S,R) stereochemistry α to the macrocycle is favorable for Mn chelate stability compared to the (R,R) and (S,S) stereochemistry α to the macrocycle.

[0042] The following Examples 1-8 describe the preparation of precursors to the present invention. Examples 9-23 describe compounds according to various embodiments of the present invention.

[0043] [Example 1] Synthesis of N,N'-((methylazanediyl)bis(ethane-2,1-diyl))bis(4-methylbenzenesulfonamide) (Compound I).

[0044] [ka]

[0045] A 1 L round bottom flask equipped with a magnetic stir bar was charged with N-tosylaziridine (49 g, 248 mmol) and AcN (450 mL). 41% aqueous methylamine (12 mL, 121 mmol) was added and stirred at ambient temperature for 36 h. A second aliquot of N-tosylaziridine (1.7 g, 8.62 mmol) was added and stirred at ambient temperature for an additional 48 h. The solvent was removed in vacuo and the crude residue was recrystallized from EtOH to give 45 g (87%) of the desired product as a white solid. 1H NMR (400 MHz, DMSO-D6, δ) 7.68 (4H, m), 7.36 (6H, m), 2.75 (4H, t), 2.38 (6H, s), 2.22 (4H, t), 1.93 (3H, s).

[0046] [Example 2] Synthesis of protected cyclic 2-arm chelates (compound II).

[0047] [ka]

[0048] A 12 L, 3-necked round bottom flask equipped with a reflux condenser and mechanical stirrer was charged with N,N'-((methylazanediyl)bis(ethane-2,1-diyl))bis(4-methylbenzenesulfonamide) (93 g, 218.5 mmol) and AcN (8.3 L). 2,6-Bis(chloromethyl)pyridine (38.5 g, 218.5 mmol) was added and the resulting solution was heated at 80° for 16 h. The reaction mixture was cooled to ambient temperature and the solvent was removed in vacuo until crystallization began. The resulting crystals were collected by vacuum filtration to give 86.9 g (75%) of the desired product as a white solid (ESI: m / z=530 (M+H)). + ).

[0049] [Example 3] Synthesis of the deprotected two-arm cyclic chelate (compound III).

[0050] [ka]

[0051] A 1 L 3-neck round bottom flask equipped with a mechanical stirrer was charged with the protected cyclic 2-arm chelate (150 g, 284 mmol) and concentrated sulfuric acid (250 mL, 4.69 mol) and heated at 100°C for 15 h. The solution was poured onto ice and the pH was adjusted to 7.4 by adding 50 wt % aqueous NaOH, resulting in the formation of a white solid. AcN (200 mL) was added and the white solid was removed by vacuum filtration. The filtrate was evaporated to dryness to give a brown foam. The foam was dissolved in water (200 mL) and purified with Amberlite A26 resin in the hydroxide form to give 61 g (98%) of the desired product as a tan solid. 1H NMR (400 MHz, AcN-D3, δ) 7.56 (1H, m), 7.03 (2H, m), 3.76 (4H, s), 2.47 (4H, m), 2.19 (3H, s), 1.95 (4H, s).

[0052] [Example 4] Synthesis of protected Mn 2-arm C5 chelate (compound IV).

[0053] [ka]

[0054] A 500 mL round bottom flask equipped with a magnetic stir bar was charged with the deprotected 2-arm cyclic chelate (20.0 g, 90.8 mmol) and AcN (160 mL). Diisopropylethylamine (38.7 mL, 217 mmol) and dimethyl 2-bromopentanedioate (47.7 g, 199.7 mmol) were added and the resulting solution was stirred at 65 °C for 20 h. Diisopropylethylamine (9.75 mL, 54.6 mmol) and dimethyl 2-bromopentanedioate (11.8 g, 49.4 mmol) were added and the resulting solution was stirred at 65 °C for an additional 19 h. The solvent was removed in vacuo leaving a red oil. The oil was then dissolved in water (300 mL) and washed with EtOAc (300 mL). The EtOAc layer was then extracted with water (2x50mL) and combined with the first aqueous layer and the water removed in vacuo to leave a red oil which was used without further purification.

[0055] [Example 5] Synthesis of protected (R,R)-Mn 2-arm C5 chelate (compound V).

[0056] [ka]

[0057] A 50 mL round bottom flask equipped with a magnetic stir bar was charged with the deprotected 2-arm cyclic chelate (1.01 g, 4.58 mmol), potassium carbonate (1.58 g, 11.5 mmol) and AcN (10 mL). (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (Levy, SG et al Org. Proc.Res. Dev. 2009, 13, 535-542) (2.60 g, 6.98 mmol) was dissolved in AcN (2 mL) and then added to the stirred suspension. The mixture was heated in an oil bath at 50 °C for 21 h. Additional amounts of (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (1.71 g, 4.59 mmol, in 2 mL of AcN) and potassium carbonate (317 mg, 2.29 mmol) were added and heating continued for an additional 47 h. The reaction was then cooled to room temperature and filtered through a 0.45 μm PTFE filter. After rinsing the solids with acetonitrile (5×5 mL), the combined filtrates were concentrated under reduced pressure to give a red oil that was used without further purification (ESI: m / z=774 (M+H)). + ). Specific optical rotation: [α] 27 D= +12.1° (c=0.00404, acetonitrile); 1H NMR (CDCl3, 500 MHz) δ 1.40-1.45 (m, 10H), 1.49 (s, 9H), 1.55-1.64 (m, 1H), 1.65-1.73 (m, 1H), 1.85-1.95 (m, 2H), 1.95-2.04 (m, 1H), 2.04-2.10 (m, 2H), 2.83-2.87 (m, 3H), 2.93-2.98 (m, 1H), 3.05-3.28 (m, 7H), 3.57 (d, J = 17.4 Hz, 1H), 3.70 (d, J = 16.9 Hz, 1H), 4.00 (d, J = 16.9 Hz, 1H), 4.03-4.14 (m, 2H), 4.25 (d, J = 17.6 Hz, 1H), 4.84-4.98 (m, 4H), 6.93 (d, J = 7.6 Hz, 1H), 6.99 (d, J = 7.6 Hz, 1H), 7.15-7.20 (m, 2H), 7.20-7.23 (m, 2H), 7.28-7.34 (m, 6H), 7.49 (t, J = 7.6 Hz, 1H), 11.45 (bs, 1H); 13 C NMR (CDCl3, 125 MHz) δ 25.5, 26.6, 28.3, 28.4, 30.4, 30.6, 33.9, 46.7, 52.9, 53.6, 54.3, 54.7, 57.7, 66.3, 66.5, 66.8, 67.9, 82.5, 82.6, 120.2, 120.6, 126.0, 128.5, 128.6, 128.7, 135.7, 135.8, 138.5, 159.8, 160.9, 170.7, 171.3, 172.1, 172.2.

[0058] [Example 6] Synthesis of protected された(S,S)-Mn 2アームC5キレート (compound VI).

[0059]

change

[0060] A 10 mL round bottom flask equipped with a magnetic stir bar was charged with the deprotected 2-arm cyclic chelate (0.210 g, 0.953 mmol), potassium carbonate (0.329 g, 2.38 mmol) and AcN (6 mL). (R)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (prepared from D-glutamic acid: Levy, SG et al Org. Proc.Res. Dev. 2009, 13, 535-542) (0.888 g, 2.38 mmol) was dissolved in AcN (2 mL) and then added to the stirred suspension. The mixture was heated in an oil bath at 50° C. for 67 hours. The reaction was then cooled to room temperature and concentrated under reduced pressure. The residue was partitioned between water and dichloromethane (20 mL each). After separation of the layers, the aqueous layer was extracted with dichloromethane (2x10 mL). The combined organics were back-extracted with water (2x20 mL) and dried over anhydrous sodium sulfate. The dried organic layer was then filtered through a 0.45 μm PTFE filter and the filtrate was concentrated under reduced pressure to give a yellow oil that was used without further purification (ESI: m / z=774 (M+H) + ).

[0061] [Example 7] Synthesis of protected (R,S)-Mn 2-arm C5 chelate (compound VII).

[0062] [ka]

[0063] A 10 mL round bottom flask equipped with a magnetic stir bar and nitrogen inlet was charged with the deprotected 2-arm cyclic chelate (278 mg, 1.26 mmol) and isopropanol (4 mL). Diisopropylethylamine (522 μL, 3.07 mmol) was added, followed by (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (prepared from L-glutamic acid. Levy, SG et al Org. Proc.Res. Dev. 2009, 13, 535-542) (407 mg, 0.87 mmol) and additional isopropanol (1 mL). The resulting solution was placed under nitrogen and heated in an oil bath at 50 °C for 48 h. Additional amounts of (S)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (222 mg, 0.596 mmol) and diisopropylethylamine (215 μL, 1.26 mmol) were added and heating was continued for an additional 21 h. The reaction was cooled to room temperature and concentrated under reduced pressure. The residue was diluted with 15 mL of dichloromethane and 30 mL of water. The layers were separated and the aqueous layer was extracted with 15 mL of dichloromethane. The combined organics were washed with 30 mL of water and then dried over sodium sulfate. The dried organics were filtered through a #1 filter and the resulting filtrate was concentrated under reduced pressure. Gradient elution (AcN / 2 mM HCl, 10:90 to 80:20) was used to obtain a 200 mL elution product. 18 The remaining material was purified by column to give 260 mg (43%) of the (R)-monoalkylated intermediate (ESI: m / z=497 (M+H) +). A 10 mL round bottom flask equipped with a magnetic stir bar and nitrogen inlet was charged with the monoalkylated intermediate (260 mg, 0.524 mmol) and acetonitrile (5 mL). Potassium carbonate (219 mg, 1.58 mmol) was added, followed by (R)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (prepared from D-glutamic acid. Levy, SG et al Org. Proc.Res. Dev. 2009, 13, 535-542) (252 mg, 0.676 mmol). The resulting solution was placed under nitrogen and heated in an oil bath at 50 °C for 48 h. An additional amount of (R)-5-benzyl 1-tert-butyl 2-(methylsulfonyloxy)pentanedioate (97 mg, 0.260 mmol) was added and heating was continued for an additional 48 h. The reaction was cooled to room temperature, diluted with acetonitrile, and filtered through a 0.45 μm filter. The yellow filtrate was concentrated under reduced pressure. The residue was dissolved in 1:1 acetonitrile:water (4 mL) and purified using gradient elution (AcN / 2 mM HCl, 10:90 to 80:20) at 37°C. 18 Column purification gave 310 mg (76%, 32%, for two steps) of the desired product (ESI: m / z=774 (M+H) + );Specific rotation:[α] 24 D= +1.9° (c=0.044, acetonitrile); 1H NMR (CDCl3, 500 MHz) δ 1.38 (s, 18H), 1.37-1.45 (m, 2H), 1.69-1.80 (m, 4H), 1.80-1.89 (m, 2H), 2.63 (bs, 3H), 2.89-3.02 (m, 4H), 3.03-3.08 (m, 2H), 3.08-3.14 (m, 2H), 3.47 (d, J = 17.5 Hz, 2H), 3.96 (bs, 2H), 4.15 (d, J = 17.5 Hz, 2H), 4.79 (s, 4H), 6.90 (d, J = 7.5 Hz, 2H), 7.03-7.08 (m, 4H), 7.14-7.19 (m, 6H), 7.41 (t, J = 7.5 Hz, 1H), 11.83 (bs, 1H); 13 C NMR (CDCl3, 125 MHz) δ 26.1, 27.8, 28.0, 30.0, 52.1, 52.7, 53,4, 66.0, 67.4, 82.0, 119.8, 128.2, 128.3, 135.3, 138.6, 160.4, 170.9, 171.8.

[0064] [Example 8] Synthesis of deprotected された(R,R)-Mn 2アームC5キレート(compound VIII).

[0065]

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[0066] A 100 mL round bottom flask equipped with a magnetic stir bar, reflux condenser and nitrogen inlet was charged with the protected (R,R)-Mn 2-arm C5 chelate (3.64 g, 4.71 mmol) and dioxane (20 mL). 1 M HCl (20 mL, 20.0 mmol) was added and the mixture was placed under a nitrogen atmosphere and heated to 50° C. After 5 days, concentrated aqueous hydrochloric acid was added (1.7 mL, 20.4 mmol) and heating was continued. After 3 days, the reaction was cooled to room temperature and the solution was extracted with ethyl acetate (2×25 mL). The pH of the resulting aqueous layer was adjusted to approximately 8 with KOH(s) and the solution was concentrated under reduced pressure. Methanol (25 mL) was added to the residue and the mixture was stirred. The resulting slurry was filtered through a 0.45 μm PTFE filter. The filtrate was concentrated under reduced pressure to give a brown foam that was used without further purification.

[0067] [Example 9] Synthesis of deprotected (S,S)-Mn-2 arm C5 chelate (compound IX).

[0068] [ka]

[0069] A 100 mL round bottom flask equipped with a magnetic stir bar, reflux condenser and nitrogen inlet was charged with the protected (S,S)-Mn 2-arm C5 chelate (0.713 g, 0.922 mmol) and dioxane (5 mL). Water (3.75 mL) was added followed by concentrated HCl (1.25 mL, 15.0 mmol) and the mixture was placed under a nitrogen atmosphere and heated to 50° C. After 30 h, the reaction was cooled to room temperature and the solution was extracted with ethyl acetate (2×10 mL). The combined organic extracts were back extracted with water (10 mL). The pH of the resulting aqueous layer was adjusted to approximately 8 with KOH pellets and the solution was concentrated under reduced pressure. Methanol (25 mL) was added to the residue and the mixture was stirred. The resulting slurry was filtered through a 0.45 μm PTFE filter. The filtrate was concentrated under reduced pressure to give the desired product which was used without further purification (ESI: m / z=481 (M+H) + ).

[0070] [Example 10] Synthesis of deprotected (R,S)-Mn 2-arm C5 chelate (compound X).

[0071] [ka]

[0072] A 10 mL round bottom flask equipped with a magnetic stir bar, reflux condenser and nitrogen inlet was charged with the protected (R,S)-Mn 2-arm C5 chelate (189 mg, 0.245 mmol) and dioxane (2.5 mL). Water (1.25 mL) was added followed by concentrated HCl (1.25 mL) and the mixture was placed under a nitrogen atmosphere and heated at 50° C. for 40 h. The reaction was cooled to room temperature and the solution was diluted with water (15 mL) and ethyl acetate (10 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (2×10 mL). The pH of the resulting aqueous layer was adjusted to approximately 7 with KOH(s) and the solution was concentrated under reduced pressure. Methanol (25 mL) was added to the residue and the mixture was stirred. The resulting slurry was filtered through a 0.45 μm PTFE filter. The filtrate was concentrated under reduced pressure to give the deprotected chelate, which was used without further purification (ESI: m / z=481 (M+H) + ).

[0073] [Example 11] Synthesis of Mn 2-arm C5 chelate (Compound XI).

[0074] [ka]

[0075] A 1 L round bottom flask equipped with a magnetic stir bar was charged with the protected Mn 2-arm C5 chelate (48.7 g, 90.8 mmol) and water (450 mL). Sodium hydroxide (29.1 g, 726 mmol) was added and stirred at ambient temperature for 2 h. The reaction mixture was washed with EtOAc (250 mL) and the layers were separated. The aqueous layer was washed again with EtOAc (2x100 mL) and the aqueous layer was collected. Manganese chloride tetrahydrate (19.6 g, 99 mmol) was added to the aqueous solution. The pH was adjusted to 7.1 with 6 M NaOH and stirred at ambient temperature for 17 h and then at 90 °C for 2.5 h. After cooling to ambient temperature, the pH was adjusted to 10.1 with 50 wt % aqueous NaOH, forming a fine brown precipitate. The precipitate was removed by centrifugation at 3000 rcf for 20 min and the supernatant was collected and evaporated to dryness in vacuo. The residue was triturated with MeOH (127 mL) at 40° C. for 1.5 h. The insoluble white solid was removed by centrifugation at 3000 rcf for 30 min. The supernatant was evaporated to dryness in vacuo to give an off-white solid, which was 18 Purification on silica gel (3% AcN in water) gave 36.8 g (75%) of the desired product as an off-white solid (ESI: m / z=534 (M+H) + ).

[0076] [Example 12] Synthesis of (R,R)-Mn 2-arm C5 chelate (compound XII).

[0077] [ka]

[0078] A 25 mL round bottom flask equipped with a magnetic stir bar was charged with the deprotected (R,R)-Mn 2-arm C5 chelate (2.98 g, 4.71 mmol) and water (12 mL). Manganese chloride tetrahydrate (1.41 g, 7.12 mmol) was added to the aqueous solution. The pH was adjusted to 6.5 with 50% aqueous KOH and stirred at ambient temperature for 5 h. The pH was adjusted to 10 with KOH(s) and the mixture was stirred overnight. The brown suspension was filtered through a 0.45 μm PTFE filter (4.9 cm2×1.8 cm) containing Celite. The pH of the filtrate was adjusted to 7.3 with cHCl (20 μL) and the material was concentrated under reduced pressure. Methanol (25 mL) was added to the remaining material and stirred. The resulting slurry was filtered through a 0.45 μm PTFE filter and the solid was rinsed several times with methanol. The filtrate was concentrated under reduced pressure to give the residual material C 18 Purification by column (AcN / water) gave 1.09 g (43%) of the desired product (ESI: m / z=534 (M+H) + ).

[0079] [Example 13] Synthesis of (S,S)-Mn 2-arm C5 chelate (compound XIII).

[0080] [ka]

[0081] Using the same procedure as its diastereomer, the (S,S)-Mn 2-arm C5 chelate (0.092 g, 0.17 mmol) gave 0.101 g (68%) of the expected product (ESI: m / z = 860 (M+H)). + ). Specific optical rotation: [α] 24 D= -3.0°(c=0.018, water).

[0082] [Example 14] Synthesis of (R,S)-Mn 2-arm C5 chelate (compound XIV).

[0083] [ka]

[0084] A 5 mL round-bottom flask equipped with a magnetic stir bar was charged with the deprotected (R,S)-Mn 2-arm C5 chelate (180 mg, 0.284 mmol) and water (4 mL). Manganese chloride tetrahydrate (115 mg, 0.581 mmol) was added to the aqueous solution. The pH of the solution was adjusted to 6.0-6.4 with 50% aqueous KOH and stirred at ambient temperature for 4 days. The pH was adjusted to 10 with KOH(s) and the mixture was stirred overnight. A 0.45 μm PTFE filter containing Celite (4.9 cm 2 The brown suspension was filtered through a 0.45 μm PTFE filter and the solids were rinsed several times with methanol. The filtrate was concentrated under reduced pressure and the remaining material was concentrated through a C 18 Column purification and elution with water gave 94 g (62%) of the desired product (ESI: m / z=534 (M+H) + ).

[0085] [Example 15] Synthesis of Mn chelate-5 (compound XV).

[0086] [ka]

[0087] A 50 mL 2-neck flask equipped with a magnetic stir bar was charged with D-glucamine (0.713 g, 3.94 mmol) and water (19.7 mL). The pH of the resulting solution was adjusted to 7.4 with 1.0 M HCl and Mn 2-arm C5 chelate (1.00 g, 1.87 mmol) was added, followed by EDCI-HCl (0.848 g, 4.42 mmol) and HOBt hydrate (0.121 g, 0.787 mmol). The pH was maintained at 6 by adding 1.0 M HCl or 1.0 M NaOH as needed with stirring at ambient temperature for 8 hours. D-glucamine (0.359 g, 1.98 mmol) and EDCI-HCl (0.433 g, 2.26 mmol) were added and the pH was maintained at 6 with stirring at ambient temperature for 16 hours. The reaction solution was evaporated to dryness in vacuo and the crude product was purified on C18 silica gel (100% water to 20% AcN in water) to give 0.782 g (48%) of the desired product as a pale yellow solid (ESI: m / z=860 (M+H) + ).

[0088] [Example 16] Synthesis of (R,R)-Mn chelate-5 (compound XVI).

[0089] [ka]

[0090] A 25 mL flask equipped with a magnetic stir bar was charged with (R,R)-Mn 2-arm C5 chelate (1.06 g, 2.04 mmol), D-glucamine (0.833 g, 4.60 mmol), HOBt hydrate (0.016 g, 0.10 mmol) and water (8.2 mL). The pH of the resulting solution was adjusted to 6.2 with concentrated HCl. EDCI-HCl (0.924 g, 4.82 mmol) was added and stirred at ambient temperature for 23 h while maintaining the pH between 6 and 6.5 by adding concentrated HCl as needed. The reaction solution was diluted with water (30 mL) and purified by passing the solution sequentially through an IR-120(Na) ion exchange column followed by an IR-400(Cl) ion exchange column. The crude product was purified using C 18Purification on silica gel (2% AcN in water to 50% AcN in water) gave 1.42 g (81%) of the desired product as a pale yellow foam (ESI: m / z=860(M+H)+). Specific rotation: [α]26D=-19.7° (c=0.0129, water).

[0091] [Example 17] Synthesis of (S,S)-Mn chelate-5 (compound XVII).

[0092] [ka]

[0093] Using the same procedure as its diastereomer, the (S,S)-Mn 2-arm C5 chelate (0.092 g, 0.17 mmol) gave 0.101 g (68%) of the expected product (ESI: m / z = 860 (M+H)). + ). Specific optical rotation: [α]24D=-3.0° (c=0.018, water).

[0094] [Example 18] Synthesis of (R,S)-Mn chelate-5 (compound XVIII).

[0095] [ka]

[0096] A 5 mL flask equipped with a magnetic stir bar was charged with (R,S)-Mn chelate-1a (60 mg, 0.112 mmol), D-glucamine (50 mg, 0.276 mmol), HOBt hydrate (4.6 mg, 0.030 mmol) and water (3 mL). The pH of the resulting solution was adjusted to 6 with concentrated HCl (40 μL). EDCI-HCl (52 mg, 0.271 mmol) was added and the mixture was stirred at ambient temperature. Additional amounts of EDCI were added after 6 h (44 mg, 0.230 mmol), 24 h (40 mg, 0.209 mmol) and 30 h (50 mg, 0.261 mmol). The reaction solution was diluted with water (3 mL) and purified by passing the solution sequentially through an IR-120(Na) followed by an IR-400(Cl) ion exchange column. Use gradient elution (AcN / water, 0:100 to 10:90) for C 18 The crude product was purified by column to give 23 mg of (S,R)-Mn chelate-5 (24%, 42%de) and 40 mg of (R,S)-Mn chelate-5 (42%, 91%de) (ESI: m / z=860 (M+H) + ).

[0097] [Example 19] Isomerization of the (S,R)-Mn 2-arm C5 chelate to (R,S)-Mn 2-arm C5. A mixture of (R,S)-Mn chelate-1a and (S,R)-Mn chelate-1a (59 mg, 0.111 mmol) was dissolved in water (1 mL). The mixture was sealed in a glass vial and heated at 90° C. for 42 h. After this heating period, HPLC showed that the two peaks had collapsed into one peak. (ESI: m / z=534 (M+H) + ).

[0098] [Example 20] Synthesis of (R,S)-Mn chelate-5 prepared from an isomerized (S,R)-Mn 2-arm C5 chelate. To an HPLC vial containing (R,S)-Mn chelate-1a (59 mg, 0.111 mmol) and water (1 mL) were added D-glucamine (49 mg, 0.270 mmol) and HOBt hydrate (5 mg, 0.032 mmol). The pH of the resulting solution was adjusted to 5.7 with concentrated HCl (35 μL). EDCI-HCl (53 mg, 0.276 mmol) was added and the mixture was stirred at ambient temperature for 22 h. More EDCI (23 mg, 0.120 mmol) was added and the reaction was stirred for an additional 42 h. The reaction solution was diluted with water (3 mL) and purified by passing the solution sequentially through an IR-120(Na) ion exchange column followed by an IR-400(Cl) ion exchange column. Gradient elution (AcN / water, 0:100 to 10:90) was used to obtain the C 18 The crude product was purified by column to give 12 mg (37%, 74% de) of the desired (R,S) isomer as an off-white solid (ESI: m / z=860 (M+H) + ).

[0099] [Example 21] Synthesis of Mn chelate-10 (compound XIX).

[0100] [ka]

[0101] rac-3-aminopropane-1,2-diol (0.190 g, 2.08 mmol) was dissolved in HO (10.4 mL) in a 25 mL two-neck round bottom flask equipped with a magnetic stir bar and pH probe. The resulting solution was adjusted to pH 7.1 with 1.0 M HCl and Mn-chelate-1a (0.603 g, 0.996 mmol) was added, followed by EDCI-HCl (0.473 g, 2.47 mmol) and HOBt hydrate (0.063 g, 0.466 mmol). The pH was maintained at 6 by adding 1.0 M HCl or 1.0 M NaOH as needed with stirring at ambient temperature for 7.5 h. rac-3-aminopropane-1,2-diol (0.095 g, 1.04 mmol) and EDCI-HCl (0.453 g, 2.36 mmol) were added and stirred at ambient temperature for 15 h while maintaining the pH at 6. The reaction solution was evaporated to dryness in vacuo and the crude product was obtained as C 18 Purification on silica gel (100% water to 20% AcN in water) afforded 0.280 g (41%) of the desired product as a pale yellow solid (ESI: m / z=680 (M+H) + ).

[0102] [Example 22] Synthesis of Mn-chelate-10 isomer pool A and isomer pool B. Mn-chelate-10 was synthesized as above, and the two isomer pools were separated and 18 It was isolated on silica gel (100% water to 20% AcN in water) as a pale yellow solid (ESI: m / z = 680 (M+H) + ).

[0103] [Example 23] Synthesis of Mn chelate-15 (compound XX).

[0104] [ka]

[0105] Ethanolamine (5.153 g, 84.4 mmol) was dissolved in HO (50 mL) in a 250 mL three-neck round bottom flask equipped with a magnetic stir bar and pH probe. Mn-chelate-1a (20.107 g, 37.7 mmol) was added followed by HOBt hydrate (0.289 g, 1.89 mmol). The pH was adjusted to 6.3 with concentrated HCl, followed by EDCI-HCl (16.966 g, 88.5 mmol). The pH was maintained between 6.0 and 6.5 with stirring at ambient temperature for 2.5 h. The reaction solution was diluted with water (280 mL) and purified by passing the solution sequentially through an IR-120(Na) ion exchange column followed by an IR-400(Cl) ion exchange column. The resulting crude material was then subjected to C 18 Purification on silica gel (5% AcN in water to 20% AcN in water) afforded 16.05 g (69%) of the desired product as a pale yellow solid (ESI: m / z=620 (M+H) + ).

[0106] [Example 24] Synthesis of Mn-chelate-15 isomer pool A and isomer pool B. Mn-chelate-15 was synthesized as above and the two isomer pools were separated and 18 It was isolated on silica gel (5% AcN in water to 20% AcN in water) as a pale yellow solid (ESI: m / z = 620 (M+H) + ).

[0107] [Example 25] General method for the measurement of r1 and r2 relaxivities. Manganese-containing chelates were dissolved in water at concentrations ranging from 5 to 0 mM Mn. T1 and T2 relaxation times were then measured at 60 MHz and 40 °C using a Bruker mq60 relaxometer. The linear fit of 1 / T1 or 1 / T2 as a function of Mn concentration (R in all cases) was 2 >0.99) to obtain values ​​of r1 or r2, respectively.

[0108] [Table 1]

[0109] Method for assessing transmetallation with Zn. Mn-chelate was dissolved in an aqueous solution containing 200 mM ZnCl2 and 15 mM ammonium formate at pH=4 to give a Mn-chelate concentration of approximately 2 mM. The resulting solution was incubated with mixing at 40°C and aliquots were periodically analyzed by HPLC. The percentage of Mn-containing chelate remaining in solution was measured by integration at 265 nm.

[0110] Method for preparation of Mn-54 labeled chelate for biodistribution studies. To a 3 mL glass vial equipped with a magnetic stir bar, add the manganese-containing chelate (1 mg) and 1.0 M ammonium formate, pH = 4 (0.5 mL). Then, add 1.0 M HCl (~500 μCi) 54 MnCl2 was added and the resulting solution was heated at 40°C for 16 h. To remove unchelated Mn, the resulting solution was purified by preparative HPLC. The radioactive fraction was collected and evaporated to dryness in vacuo. The radioactive residue was taken up in water containing non-radioactive Mn chelate (0.310 M) and formulated to give an injection volume of 2 mL / kg with an activity of approximately 30 μCi at a dose of 0.620 mmol Mn / kg.

[0111] General methods for Mn-54 biodistribution studies. Experimental procedures conformed to the Guide for the Care and Use of Laboratory Animals and were approved by the Institutional Animal Care and Use Committee. Female Sprague-Dawley rats (130–150 g) were housed in standard cages with free access to standard commercial chow and water, and maintained in a temperature- and humidity-controlled room with alternating 12-h light-dark cycles. Prior to injection of the Mn-54 labeled chelate, rats were anesthetized via inhaled 3% isoflurane (EZ Anesthesia Systems). The injection site was prepped with alcohol wipes, and a temporary 27Ga catheter was placed in the tail vein. Approximately 30 μCi of Mn-54 labeled chelate, formulated with nonradioactive Mn chelate, was dosed at 0.620 mmol of nonradioactive Mn chelate / kg in an infusion volume of 2 mL / kg and injected at a rate of 1 mL / min. After injection, animals were individually housed in wire-bottom cages lined with filter paper until the first voided urine was collected. Rats were then housed together in standard long-term cages. Seven days after injection, animals were sacrificed by CO2 immersion and organs and tissues of interest were removed and assayed for radioactivity using a Wizard 2480 gamma counter (Table 2).

[0112] [Table 2]

[0113] [Example 26] To measure the dissociation of manganese from manganese chelates in human serum, the following method was used.

[0114] To human serum obtained from clotted blood (Sigma-Aldrich, 1900 μL) was added an aqueous solution of manganese chelate (2 mM, 100 μL). The mixture was incubated at 37 °C. At specific time points, aliquots of 200 μL of test sample were mixed with saline (400 μL) and analyzed by size-exclusion chromatography (metal-free HPLC with a column with a separation range of 5000-500 000 Daltons) combined with on-line detection of manganese-containing species by ICP-SF-MS. The percentage of dechelation was measured as the area % of the high molecular weight (protein) fraction. At regular intervals, EDTA solution was flushed through the system to ensure low levels of background metal ions. Human serum was incubated with Mn(II) acetate and injected to identify the location of Mn-bound components in the high molecular weight region of the chromatogram.

[0115] FIG. 10 shows the chromatographic separation of protein-bound manganese from the intact manganese chelate in the slower eluting low molecular weight fraction.

[0116] In this assay, four different stereoisomers of Mn-chelate-5 (RR, SS, SR, and RS) were analyzed. Table 3 shows the percentage of dechelation measured by quantitative detection of protein-bound manganese at 3, 24, and 49 hours after the start of the experiment.

[0117] [Table 3] The present invention includes the following aspects. <1> Compounds of formula IA: [ka] or a salt or solvate thereof, During the ceremony, Each R 1 is halo and -C(=O)-NH-C1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 aryl, or carbohydrate moiety; Each R 2 is C 1~20 Hydroxyalkyl, C 1~6 independently selected from alkyl or hydrogen; R 3 is C 1~3 Alkyl or -(CH 2 ) m -C(=0)-NR 5 R 6 where m is an integer from 2 to 5, where R 5 and R 6 from hydrogen, halo and -C(=O)-NH-C 1~6 C optionally substituted with one or more substituents selected from hydroxyalkyl 1~20 Hydroxyalkyl, C 1~6 Alkyl or C 3~6 aryl, or carbohydrate moiety; R 4 is hydroxy, C 1~6 Alkyl and C 1~6 represents 0 to 3 substituents selected from hydroxyalkyl; and A compound, or a salt or solvate thereof, wherein each n is an integer from 0 to 4. <2> Contains at least two hydroxy groups; <1> The compound according to claim 1, <3> A compound of formula IA: <1> The compound according to claim 1, <4> A compound of formula IA, Each R 1 is C 1~20 is hydroxyalkyl; R3 is methyl; R2 and R4 are hydrogen; and n is 2, <1> The compound according to claim 1, <5> Each R 1 is C 1~20 is hydroxyalkyl, <1> The compound according to claim 1, <6> R 3 is methyl, <1> The compound according to claim 1, <7> R 2 and R 4 is hydrogen, <1> The compound according to claim 1, <8> n is 2, <1> The compound according to claim 1, <9> Each R 1 is independently C 3~9 is hydroxyalkyl, <1> The compound according to claim 1, <10> Each R 1 is independently C 3~6 is hydroxyalkyl, <1> The compound according to claim 1, <11> Compounds of formula IA:

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Claims

1. Compound of formula IA: 【Chemistry 1】 or a salt or solvate thereof, During the ceremony, Each R １ is halo and -C(=O)-NH-C １～６ C optionally substituted with one or more substituents selected from hydroxyalkyl １～２０ Hydroxyalkyl, C １～６ Alkyl or C ３～６ aryl; Each R ２ is C １～２０ Hydroxyalkyl, C １～６ is independently selected from alkyl or hydrogen; R ３ is C １～３ Alkyl or -(CH ２ ) ｍ -C(=0)-NR ５ R ６ where m is an integer from 2 to 5, where R ５ and R ６ is hydrogen, or halo and -C(=O)-NH-C １～６ C optionally substituted with one or more substituents selected from hydroxyalkyl １～２０ Hydroxyalkyl, C １～６ Alkyl or C ３～６ aryl; R ４ is hydroxy, C １～６ Alkyl and C １～６ represents 0 to 3 substituents selected from hydroxyalkyl; and A compound or a salt or solvate thereof, wherein each n is an integer from 0 to 4.

2. The compound of claim 1, wherein the compound of formula IA contains at least two hydroxy groups.

3. 2. The compound of claim 1 which is a compound of formula IA.

4. A compound of formula IA, Each R １ is C １～２０ is hydroxyalkyl; R ３ is methyl; R ２ and R ４ is hydrogen; and The compound of claim 1 , wherein n is 2.

5. Each R １ is C １～２０ The compound of claim 1 which is a hydroxyalkyl.

6. R ３ The compound of claim 1 , wherein is methyl.

7. R ２ and R ４ The compound of claim 1 , wherein is hydrogen.

8. The compound of claim 1 , wherein n is 2.

9. Each R １ is independently C ３～９ The compound of claim 1 which is a hydroxyalkyl.

10. Each R １ is independently C ３～６ The compound of claim 1 which is a hydroxyalkyl.

11. A compound of the formula: 【Chemistry 23】

12. Compound of formula IA: 【Chemistry 2】 or a salt or solvate thereof, and a pharma- ceutically acceptable excipient, During the ceremony, Each R １ is halo and -C(=O)-NH-C １～６ C optionally substituted with one or more substituents selected from hydroxyalkyl １～２０ Hydroxyalkyl, C １～６ Alkyl or C ３～６ aryl; Each R ２ is C １～２０ Hydroxyalkyl, C １～６ is independently selected from alkyl or hydrogen; R ３ is C １～３ Alkyl or -(CH ２ ) ｍ -C(=0)-NR ５ R ６ where m is an integer from 2 to 5, where R ５ and R ６ is hydrogen, or halo and -C(=O)-NH-C １～６ C optionally substituted with one or more substituents selected from hydroxyalkyl １～２０ Hydroxyalkyl, C １～６ Alkyl or C ３～６ aryl; R ４ is hydroxy, C １～６ Alkyl and C １～６ represents 0 to 3 substituents selected from hydroxyalkyl; and The composition wherein each n is an integer from 0 to 4.

13. The composition of claim 12, wherein the compound of formula IA contains at least two hydroxy groups.

14. The composition of claim 12, wherein the compound of formula IA is a compound of the following formula: 【Chemistry 23】

15. The composition contains a detectable amount of a compound of formula (IB): 【Chemistry 3】 13. The composition of claim 12, wherein the composition is devoid of any of the salts or solvates thereof.

16. The composition of claim 15, wherein the compound of formula IB is a compound of the following formula: 【Chemistry 3-2】 17. The composition of claim 1, further comprising a compound of formula I, which is a Mn chelate having (R,R) and / or (S,S) stereochemistry, or a salt or solvate thereof; In formula I, each R 1 is independently selected from C 1-20 hydroxyalkyl, C 1-6 alkyl, or C 3-6 aryl optionally substituted with one or more substituents selected from halo, and -C(=O)-NH-C 1-6 hydroxyalkyl; each R 2 is independently selected from C 1-20 hydroxyalkyl, C 1-6 alkyl, or hydrogen; R 3 is selected from C 1-3 alkyl or —(CH 2 ) m —C(═0)—NR 5 R 6 , where m is an integer from 2 to 5, where R 5 and R 6 are independently selected from hydrogen, or C 1-20 hydroxyalkyl, C 1-6 alkyl or C 3-6 aryl optionally substituted with one or more substituents selected from halo and —C(═O)—NH—C 1-6 hydroxyalkyl; R 4 represents 0-3 substituents selected from hydroxy, C 1-6 alkyl, and C 1-6 hydroxyalkyl; and The composition of claim 12, wherein each n is an integer from 0 to 4. 【Chemistry 26】

18. Each R １ is C １～２０ The composition of claim 12 which is a hydroxyalkyl.

19. R ３ The composition of claim 12 , wherein is methyl.

20. R ２ and R ４ The composition of claim 12 , wherein is hydrogen.

21. The composition of claim 12 , wherein n is 2.

22. Each R １ is independently C ３～９ The composition of claim 12 which is a hydroxyalkyl.

23. Each R １ is independently C ３～６ The composition of claim 12 which is a hydroxyalkyl.

24. 13. A method of imaging a patient, comprising the step of administering a compound of claim 1 to a patient in need thereof and then obtaining an MRI image of the patient.

25. 12. A method of imaging a patient, comprising administering to a patient in need thereof the composition of claim 11 and then obtaining an MRI image of the patient.

26. A process for the enantioselective synthesis of a compound of formula (IA) according to claim 1, comprising: (a) mono-alkylating the compound of formula (III) using the first enantiomer of 5-benzyl-1-tert-butyl-2-(methylsulfonyloxy)pentanedioate; 【Chemistry 4】 (b) subsequently alkylating the compound from step (a) using the second enantiomer of 5-benzyl-1-tert-butyl-2-(methylsulfonyloxy)pentanedioate, which is the opposite of the first enantiomer; (c) reacting the product of step (b) with Mn; (d) reacting the product of step (c) with an amino alcohol; The method includes:

27. 13. A method for the enantioselective synthesis of a composition comprising a compound of formula (IA) according to claim 12, comprising: (a) mono-alkylating the compound of formula (III) using the first enantiomer of 5-benzyl-1-tert-butyl-2-(methylsulfonyloxy)pentanedioate; 【Chemistry 5】 (b) subsequently alkylating the compound from step (a) using the second enantiomer of 5-benzyl-1-tert-butyl-2-(methylsulfonyloxy)pentanedioate, which is the opposite of the first enantiomer; (c) reacting the product of step (b) with Mn; (d) reacting the product of step (c) with an amino alcohol; The method includes:

28. 28. The method of claim 27, wherein the method results in a composition comprising a compound of formula (IA).

29. A method for producing the composition of claim 12, comprising the steps of: Compound of formula (IB): 【Chemistry 6】 or a salt or solvate thereof, wherein the heating step is carried out for a time and at a temperature sufficient to convert substantially all of the compound of formula (IB) to the compound of formula (IA).

30. 30. The method of claim 29, wherein the resulting composition lacks a detectable amount of the compound of formula (IB).

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