HK1162951B - Synthesis of 18f-radiolabeled styrylpyridines from tosylate precursors and stable pharmaceutical compositions thereof - Google Patents

Description

Synthesis from tosylate precursors18F-radiolabelled styrylpyridines and stable pharmaceutical compositions thereof

Background

This application claims priority from the provisions of section e, 35 of the U.S. code of U.S. code 35 of provisional patent application No. 61/141,885, filed on 31/12/2008, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present invention relates generally to¹⁸A method for the synthesis of F-radiolabelled brain imaging agents, more particularly to¹⁸Synthesis of F-radiolabelled styrylpyridines and their tosylate precursors and compositions containing them¹⁸Stable pharmaceutical compositions of F-radiolabelled brain imaging agents.

Background

Alzheimer's Disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline, irreversible memory loss, disorientation, and language impairment. AD affects 10% of the elderly over 65 years of age and at least 50% of the elderly over 85 years of age. It has been reported that AD has appeared in younger patients of 40-50 years, but the time at which it occurs in vivo is unknown because the presence of the disease is difficult to find without brain histopathological examination.

Currently, the only means to confirm AD is by examination of brain tissue, usually post mortem autopsy. During necropsy, necropsiers examined brain tissue for excess Neuritic Plaques (NPs) consisting of amyloid-beta peptide deposits and neurofibrillary tangles (NFTs) of filaments of hyperphosphorylated tau protein, as these features characterize the pathology of AD. Amyloid deposits are formed by the aggregation of amyloid peptides, followed by further combination with other aggregates and/or amyloid peptides. Fibrillar aggregates of amyloid peptides (A β 1-40 and A β 1-42) are the major peptide metabolites derived from amyloid precursor protein, which are found in NP and cerebrovascular amyloid deposits in AD patients.

Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by resting tremor, bradykinesia, myotonia, and postural instability. PD usually occurs after the age of 60, but 15% of patients are diagnosed under the age of 50. Between 5% and 10% of patients diagnosed with PD have a family history of PD, although only 1% of cases exhibit clear familial characteristics. It is estimated that there are currently 150 million PD patients in the united states.

Dementia with lewy bodies (DLB) is a progressive brain disease with symptoms that fluctuate among different degrees of presentation. These symptoms include progressive dementia, parkinsonian dyskinesia, hallucinations, and increased susceptibility to psychiatric drugs. As with AD, advanced age is generally considered the greatest risk factor for DLB, with the average age of onset generally between 50 and 85. In addition, 20% of all dementia patients are caused by DLB, while more than half of PD patients suffer from "parkinson's disease dementia" (PDD), a DLB. DLB may occur alone or with other brain abnormalities, including those in AD and PD as described above. Currently, definitive diagnosis of DLB is only possible at post mortem autopsy.

Both PD and DLB have causes of dopamine deficiency, which is associated with the death of dopaminergic neurons in the substantia nigra. The cause of dopaminergic neuron death in PD has not been determined, although intracerebral alpha-synuclein aggregation appears to be associated with striatal dopaminergic neuron loss. It is also generally accepted that in DLB, abnormal protein precipitates containing α -synuclein (hereinafter referred to as "lewy bodies") are responsible for the death of dopaminergic neurons. Lewy bodies are mostly found in the substantia nigra and locus coeruleus portions of the brainstem, as well as in the subcortical and cortical regions of the brain. Due to the special localization within the brain, lewy bodies may interfere with the production of acetylcholine, causing confusion in the perception and thinking process, as well as affecting behavior. Lewy bodies are considered a type of Neuritic Plaque (NP) because they are composed of aggregates of alpha-synuclein precipitates.

The etiology of neurodegenerative diseases may also involve mixed pathologies involving components of microvascular or perfusion defects in the brain. For example, a disease commonly referred to as "mixed dementia," which generally includes perfusion defects and amyloid plaque pathology. The term "mixed dementia" has various meanings, but this term is usually used to refer to the coexistence of AD and vascular dementia (VaD), particularly VaD caused by numerous microthrombobs in the cerebrovascular system. Although the true prevalence of dementia of mixed type is poorly understood, this neurodegenerative form is clinically important because the effect of AD in combination with VaD on the brain may be greater than each disease alone. Mixed dementia is traditionally very difficult to diagnose. Symptoms resemble AD or VaD or a combination of both.

The development of amyloid deposits in the brain may be characteristic of a number of other conditions, including, but not limited to, mediterranean fever, muckle-weidi's syndrome, idiopathic myeloma, amyloid polyneuropathy, amyloid cardiomyopathy, systemic neuritic amyloid diseases, amyloid polyneuropathy, hereditary cerebral hemorrhage with amyloidosis, down's syndrome, scrapie in sheep, creutzfeldt-jakob disease, kuru, gerstman syndrome, thyroid ductal carcinoma, isolated atrial amyloidosis, beta in dialyzed patients₂Beta in microglobulin amyloidosis, inclusion body myositis, muscular dystrophy₂Amyloid deposits and islets of Langerhans type II diabetic insulinomas.

Since the presence of Neuritic Plaques (NPs) play a role in the diagnosis of neurodegenerative diseases, there has been an effort to develop radiolabeled ligands that can bind to and image these abnormalities using existing methods. Some commonly used imaging agents include¹¹C]PIB、[¹¹C]4-N-methylamino-4' -hydroxy-stilbene (SB-13), and¹⁸F]FDDNP and [2 ]¹²³I]IMPY。

[¹⁸F]AV-45（“¹⁸F-AV-45”），((E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-NMethylaniline is a radiopharmaceutical used for Positron Emission Tomography (PET) imaging of amyloid aggregates in the brain (see, e.g., Choi, SR et al,J Nucl Med, 50(11), 1887-1894, 2009）。¹⁸F-AV-45 contains the F-18 radioisotope, which, due to its radioactive half-life of 110 minutes, can be produced in a concentrated location and transported to an imaging center in the 4 to 8 hour range for PET brain imaging.¹⁸The generation and fractionation of F-AV-45 and other F-18 radiolabeled amyloid imaging compounds requires that the radiopharmaceutical be generated on the same day that the PET scan is performed due to radioactive decay of the F-18 isotope. Thus, various requirements result in: first, radioactivity¹⁸F-AV-45 must be produced in a short time from a stable intermediate compound (shortly called "precursor"); in the second place, the first place is,¹⁸F-AV-45 radiopharmaceuticals must be produced in reasonable (e.g., greater than 10%) radiochemical yields (starting from precursors that react with F-18 fluoride); in the third place, the first place is,¹⁸F-AV-45 must be in a vehicle which provides the radiopharmaceutical and its nonradioactive counterpart: (¹⁹F-AV-45, typically present at lower concentrations due to the stability of F-19 in the manufacturing environment), and the stability to inhibit radiolysis of the compound.

Ethanol is generally considered to be a suitable adjuvant that can be used to solubilize lipophilic drugs, including radiopharmaceuticals (see, e.g., mail c. et al,J Label Compd and Radiopharm, 42, 63-75, 1999). Ascorbic acid or ascorbate has previously been used as an aid in inhibiting radiolysis of radiopharmaceuticals (see, e.g., Tofe AJ et al,J. Nucl Med17, 820-825, 1976; Knapp FF et al,Anticancer Res17, 1783-1795, 1997; Liu S et al,Bioconj Chem,14, 1052-' 1056, 2003) including F-18 radiopharmaceuticals (see, e.g., Firnaug et al,J Nucl Med, 25, 1228-1233, 1984). However, ascorbate in aqueous ethanol is used as the preferred medium to solubilize and stabilize the F-18 brain imaging systemInjectable drugs, e.g.¹⁸F-AV-45, which is the first time.

The use of tosylate containing precursors for reaction with F-18 fluoride in the preparation of F-18 containing radiopharmaceuticals has been previously described (see, e.g., Zhang W et al,Nucl Med Biol34, 89-97, 2007). However, there has not previously been an efficient synthetic method for producing larger quantities (i.e., greater than 10 grams) of tosylate precursor (hereinafter "AV-105"). Any publications mentioned herein are incorporated herein by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference in its entirety for all purposes.

Disclosure of Invention

Embodiments of the present invention relate to a radiopharmaceutical composition for Positron Emission Tomography (PET) imaging of neurodegenerative diseases of the brain comprising an effective amount of a pharmaceutically acceptable carrier¹⁸An F-radiolabelled compound, about 1.0% to about 20% (v/v) ethanol and at least about 0.1% (w/v) ascorbic acid or a salt thereof. In each of the embodiments, the first and second embodiments, ¹⁸the F-radiolabeled compound is capable of binding to a pathological target in the brain of a patient. Pathological targets may include abnormal concentrations of naturally or pathologically altered proteins, peptides or oligonucleotides, beta-amyloid, alpha-synuclein, or vesicular monoamine transporter 2 (VMAT 2).

In accordance with certain aspects of the present invention,¹⁸the F-radiolabelled compound is a styrylpyridine derivative. In one of the various aspects, the first and second electrodes,¹⁸the F-radiolabelled compound is (, ()E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline), (A), (B), (C), (¹⁸F-AV-45). In some embodiments of the present invention, the substrate is,¹⁸F-AV-45 was prepared from a tosylate precursor. In other aspects, in radiopharmaceutical compositions¹⁸The F-radiolabelled compound is (2)R,3R,11bR)-9-(3-[¹⁸F]Fluoropropoxy) -3-isopropyl-10-methoxyThe radical-11 b-methyl-2, 3,4,6,7,11 b-hexahydro-1H-pyrido [2,1-a]Isoquinolin-2-ols () "¹⁸F-AV-133 "). In other aspects of the present invention, the first and second substrates are,¹⁸the F-radiolabelled compound is a derivative of Dihydrotetrabenazine (DTBZ).

The radiopharmaceutical composition in certain embodiments comprises ethanol at a concentration in the range of about 1.0% to about 15.0% (v/v). Other embodiments include ascorbic acid or salts thereof at a concentration in the range of about 0.1% to about 1.0% (w/v). The pH of the radiopharmaceutical composition may be in the range of about 4.5 to about 8.0. In a preferred embodiment, the radiopharmaceutical composition has a purity of greater than or equal to about 90% when measured at least about 4 hours after the end of synthesis (EOS).

The radiopharmaceutical compositions are useful in the diagnosis of neurodegenerative diseases, such as dementia, cognitive impairment, Alzheimer's Disease (AD), Parkinson's Disease (PD), dementia with lewy bodies (DLB), vascular dementia (VaD), and combinations thereof.

Other embodiments of the present invention relate to a radiopharmaceutical composition for Positron Emission Tomography (PET) imaging of the brain comprising an effective amount of¹⁸An F-radiolabelled compound, at least about 1.0% (v/v) ethanol and at least about 0.1% (w/v) ascorbate, wherein¹⁸The F-radiolabeled compound decomposed less than about 10% from the end of the synthesis to about 12 hours after the end of the synthesis.

In another aspect of the present invention, there is provided a method for diagnosing a neurodegenerative disease in a patient, comprising the steps of: administering a radiopharmaceutical composition capable of binding to a target associated with a neurodegenerative disease in a patient, wherein the radiopharmaceutical composition comprises an effective amount of¹⁸An F-radiolabelled compound, at least about 1.0% (v/v) ethanol and at least about 0.1% (w/v) sodium ascorbate; imaging at least a portion of a patient's brain, the portion including a region of a target predetermined location; and detecting the target. Positron Emission Tomography (PET) imaging, PET with computed tomography can be usedThe imaging step is performed by surgical imaging (PET/CT), PET magnetic resonance imaging (PET/MRI), or a combination thereof.

In another embodiment of the present invention, there is provided a polypeptide capable of binding to amyloid beta¹⁸A method of preparing an F-radiolabelled composition comprising the steps of: synthesizing a tosylate precursor; nucleophilic processing of tosylate precursors in dimethyl sulfoxide (DMSO) solutions¹⁸F is fluorinated to provide¹⁸F a radiopharmaceutical; and in an ethanol aqueous solution containing ascorbic acid or a salt thereof¹⁸F a radiopharmaceutical; wherein at the end¹⁸The ethanol in the F-radiolabeled pharmaceutical composition is present at a minimum concentration of about 1.0% (v/v), and the minimum concentration of ascorbic acid or a salt thereof is about 0.1% (w/v).

In another embodiment, a method is provided¹⁸Tosylate precursor of F-AV-45 (CE) A process for the preparation of (E) -2- (2- (2- (5- (4- (tert-butoxycarbonyl (methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate ("AV-105"). The method comprises the following steps: (i) preparing a mono-Boc protected vinylaniline compound; (ii) converting the vinylaniline compound to a methyl, t-butyl carbamate derivative; (iii) reacting 2-halogen-5-iodopyridine with triethylene glycol; (iv) (iv) reacting the methyl, tert-butyl carbamate derivative of step (ii) with the compound obtained in step (iii) to obtainE) -tert-butyl 4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate; and (v) mixingE) -tert-butyl 4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate is reacted with p-toluenesulfonyl chloride to form AV-105.

In another aspect of the present invention, there is provided a method of preparing a radiopharmaceutical composition, which comprises the steps of: reacting AV-105 tosylate precursor with¹⁸Reacting F-fluoride ions in dimethyl sulfoxide (DMSO) solution or other high-boiling point aprotic solvent to generate ((DMSO))E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline), (A), (B), (C), (¹⁸F-AV-45); separation of¹⁸F-AV-45; and purification of¹⁸F-AV-45. The method of preparing the radiopharmaceutical composition may further comprise formulating in a solution comprising from about 1.0% to about 15% (v/v) ethanol and from about 0.1% to about 1.0% (w/v) ascorbate¹⁸F-AV-45. In a particular embodiment of the invention, the ascorbate salt is sodium ascorbate and is present in a concentration of about 0.5% (w/v).

The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention.

Drawings

For a better understanding of the present disclosure, reference should be made to the following drawings, in which:

FIG. 1 depicts the synthesis of tosylate precursor AV-105 from p-tosylate and non-radioactive according to one embodiment of the invention¹⁹Scheme F-AV-45.

FIG. 2 depicts an alternative synthesis of tosylate precursor AV-105 according to another embodiment of the invention.

FIG. 3 depicts a radiosynthesis method employing tosylate precursors for the preparation of amyloid-beta-binding radiopharmaceuticals according to one aspect of the invention¹⁸F-AV-45。

Detailed Description

The invention is not limited to the specific compositions or methods described, as such may vary. Furthermore, the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

The term "about" as used herein means plus or minus 10% of the numerical value, unless otherwise specified.

When used with a diagnostic agent, e.g., a radiopharmaceutical, it is meant that the drug is administered directly into or onto the target tissue, or that the radiopharmaceutical is administered systemically to the patient, whereby the diagnostic agent is useful for tissue imaging or imaging of pathologies associated with the targeted tissue. "administering" a composition may be accomplished by injection, infusion, or a combination of other known techniques.

The terms "comprising," including, "" having, "and" including, "and combinations thereof, as used herein, mean" including, but not necessarily limited to.

As used herein, an "effective amount" or "therapeutically effective amount" refers to an amount of positron-emitting radiopharmaceutical that is capable of producing sufficient gamma-emitting signals to image a biological target of interest in the brain of an individual suspected of having a neurodegenerative disease.

The term "end of synthesis" or "EOS" as used herein refers to the end of radiosynthesis. This is the point at which the radiosynthesis process is complete, including any purification steps required for radiopharmaceutical isolation.

The term "high boiling aprotic solvent" as used herein is defined as an aprotic solvent having a boiling point of at least about 140 ℃ at one atmosphere.

The term "pathology" or "pathology" as used herein refers to an altered biological process, which may be associated, for example, with abnormal production of proteins, peptides, RNA and other substances associated with a disease process.

The terms "patient" and "subject" as used herein refer to any organism to which a compound described herein is administered in conjunction with which brain activity is measured by performing the assay of the invention. The patient and/or subject may include, but is not limited to, any non-human mammal, primate, or human. Such patients and/or subjects may or may not exhibit signs, symptoms, or pathology of one or more particular disease states.

When the term "target" is used in conjunction with a diagnostic agent (e.g., a radiopharmaceutical of the present invention), the term refers to the tissue or other material associated with the pathology at the desired location of the radiopharmaceutical or diagnostic agent. Targets may include, but are not limited to, diseased cells, pathogens, infectious or other unwanted material of a patient, such as abnormal proteins, peptides, RNA or DNA or normally expressed receptors that are altered during disease.

In general, the term "tissue" as used herein refers to any collection of similarly specialized cells that associate during the performance of a particular function.

Embodiments of the invention provide for synthesis from tosylate precursors¹⁸Methods of F-radiolabeling imaging agents, and compositions comprising the same¹⁸Pharmaceutical compositions of stable pharmaceutical products of F-radiolabelled imaging agents.

Certain embodiments of the present invention relate to a radiopharmaceutical composition comprising an effective amount of a compound of formula (I) in a solution comprising from about 1.0% to about 30% (w/v) ethanol and at least about 0.1% (w/v) sodium ascorbate¹⁸F-radiolabelled compounds, e.g.¹⁸F-radiolabelled styrylpyridines or¹⁸F-labelled Dihydrotetrabenazine (DTBZ) derivatives. Other embodiments of the present invention relate to a radiopharmaceutical composition comprising an effective amount of an intravenous solution comprising about 1.0% to about 20% (v/v) ethanol and at least about 0.1% (w/v) sodium ascorbate at a pH of between about 4.5 and 8.0¹⁸F-a radiolabeled compound. The radiopharmaceutical composition is a clear solution, free ofAn insoluble material which remains stable at concentrations of up to 100 mCi/mL (37 to 3700 MBq/mL) or more of the F-18 radiopharmaceutical for at least 6 hours after manufacture.

Parenteral radiopharmaceutical compositions of embodiments of the invention may contain an F-18 radiolabeled compound capable of binding to a pathological target in the brain of a patient, for example, to an abnormal concentration of a natural or pathologically altered protein, peptide or oligonucleotide, beta-amyloid, alpha-synuclein, or to an endogenous target of normal expression impaired in the presence of certain degenerative diseases, such as Parkinson's Disease (PD), lewy body Dementia (DLB), or vesicular monoamine transporters in diabetes (VMAT 2).

Various embodiments of the present invention provide radiopharmaceutical compositions having the following characteristics, including: higher target affinity and selectivity, low molecular weight: (<400 g/mol), moderate lipophilicity (log P value in the range 1-3) to ensure high initial brain uptake and rapid clearance, in molecules for incorporation, for example¹¹C or¹⁸Functional groups of positron emitting radionuclides of F, high intracerebral stability and no brain uptake of peripheral metabolites of the tracer compound, and high availability of the tracer compound in the clinical centre.

With other radioactive isotopes, e.g.¹¹C（t_1/2= 20 min) compared with the above-mentioned ratio due to¹⁸F has a relatively long half-life (t)_1/2=110 min), using the invention¹⁸F-labelled imaging agents have a number of logistic advantages.¹⁸The relatively long half-life of F is advantageous in that it provides more time for clearance of non-specifically bound tracer, while reducing signal intensity loss due to radioactive decay.

In certain embodiments of the invention, in a radiopharmaceutical composition¹⁸F-radiolabelled compounds comprising compounds capable of binding to amyloid aggregates for use in Positron Emission Tomography (PET) imaging in the brain¹⁸F-radiolabellingA compound (I) is provided. In one aspect of the present invention,¹⁸the F-radiolabelled compound is (, ()E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline) (-) "¹⁸F-AV-45'). In some embodiments of the present invention, the substrate is,¹⁸F-AV-45 was prepared from a tosylate precursor. In other embodiments of the present invention, the substrate may be,¹⁸the F-radiolabelled compound is a derivative of Dihydrotetrabenazine (DTBZ). In other aspects, in radiopharmaceutical compositions¹⁸The F-radiolabelled compound is (2)R,3R,11bR)-9-(3-[¹⁸F]Fluoropropoxy) -3-isopropyl-10-methoxy-11 b-methyl-2, 3,4,6,7,11 b-hexahydro-1H-pyrido [2,1-a]Isoquinolin-2-ols () "¹⁸F-AV-133”）。

In another embodiment of the present invention, there is provided a radiopharmaceutical composition comprising an effective amount of¹⁸An F-radiolabelled compound, at least about 1.0% (w/v) ethanol and at least about 0.1% (w/v) ascorbate (sodium ascorbate), wherein the radiopharmaceutical composition retains greater than or equal to 90% of the radiochemical purity of the desired radiopharmaceutical for a period of at least 4 hours after radiosynthesis, more preferably up to 8 hours after radiosynthesis.

Certain embodiments of the radiopharmaceutical compositions include ethanol at a concentration ranging from about 1.0% to about 15.0% (v/v), and an ascorbate salt (e.g., sodium ascorbate or other ascorbate salts) at a concentration ranging from about 0.1% to about 1.0% (w/v). In certain embodiments of the invention, sodium ascorbate is used at a concentration of 0.5% (w/v). The pH of the composition may range from about 4.5 to about 8.0. In certain embodiments, the radiopharmaceutical is at least 90% pure when measured at least about 2 hours after the end of synthesis (EOS). In a preferred embodiment, the radiopharmaceutical is at least 90% pure when measured at least about 4 hours after EOS.

In another embodiment of the present invention, there is provided a method of binding amyloid beta¹⁸F-radiolabellingThe method of preparing the composition of (1), comprising the steps of: synthesizing a tosylate precursor; nucleophilic processing of tosylate precursors¹⁸F, fluorination; in aqueous solution¹⁸F a fluorinated tosylate precursor; adding ethanol to obtain a final ethanol concentration of about 1.0% (w/v)¹⁸F-radiolabeled styrylpyridine compositions; and adding sodium ascorbate to obtain a final sodium ascorbate concentration of up to about 0.1% (w/v)¹⁸F-radiolabelled styrylpyridine compositions.

In another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device¹⁸F-AV-45 tosylate precursor(s) ((R))E) A process for the preparation of (E) -2- (2- (2- (5- (4- (tert-butoxycarbonyl (methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate ("AV-105"). The method comprises the following steps: (i) preparing a mono-Boc protected vinylaniline compound; (ii) (ii) converting the vinylaniline compound of (i) to an N-methyl, t-butyl carbamate derivative (i.e., an N-methyl, N-Boc derivative); (iii) reacting 2-halo-5-iodopyridine (in some embodiments, halo is chloro or bromo) with triethylene glycol; (iv) (iv) reacting the N-methyl, N-Boc derivative in step (ii) with the compound obtained in step (iii) to obtainE) -tert-butyl-4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate; and (v)E)-Tert-butyl radical4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate is reacted with tosyl chloride to form AV-105.

In another aspect of the present invention, there is provided a method of preparing a radiopharmaceutical composition, which comprises the steps of: AV-105 tosylate precursor with¹⁸F-fluoride reacts in DMSO or other high boiling point aprotic solvents to form (((R))E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline () "¹⁸F-AV-45 "); separation of¹⁸F-AV-45; and purifying¹⁸F-AV-45. Preparation of radiopharmaceuticalsThe method of the composition may further comprise formulating the composition in a solution comprising about 1.0% to about 15% (v/v) ethanol and about 0.1% to about 1.0% or more (w/v) sodium ascorbate or other salts of ascorbic acid¹⁸F-AV-45. In a particular embodiment of the invention, the sodium ascorbate concentration is 0.5% (w/v).

In another embodiment of the present invention, there is provided a radiopharmaceutical composition comprising an effective amount of¹⁸An F-radiolabeled compound, at least about 1.0% (v/v) ethanol, and at least about 0.1% (w/v) sodium ascorbate, wherein the radiopharmaceutical composition decomposes at a rate measured in vitro which is substantially equivalent to: (a) about 0.01 to about 5% of the total decomposition, measured after about 2 hours; (b) about 0.01 to about 10% of the total decomposition, measured after about 10 hours; (c) about 0.01 to about 20% of the total decomposition, measured after about 15 hours; and (d) no more than about 25% of the total decomposition, measured after about 24 hours.

In certain embodiments, the invention relates to¹⁸A method for the synthesis of F-radiolabelled styrylpyridine tosylate precursor, AV-105 (shown in FIG. 1). The AV-105 synthesis utilizes the original (primary) tosylate as the active leaving group instead of the original mesylate. The use of tosylate precursors for radiofluorination is advantageous at least because tosylates produced during the radiofluorination reaction are readily purified by chromatographic methods¹⁸F-radiolabelled imaging products were removed. FIG. 1 depicts the initial synthesis of AV-105 and the synthesis of cold AV-45 in one embodiment of the present invention. The use of tosylate (tosylate) as the active leaving group eliminates the need for mesylate because mesylate is not the preferred choice due to the genotoxicity of methane sulfonic acid, which is a by-product formed when using mesylate. In addition, p-toluenesulfonic acid is easier to detect than methanesulfonic acid and therefore can be more conveniently purified using liquid chromatography and UV detection. As further shown in FIG. 1, AV-105 was prepared by introducing 4-Dimethylaminopyridine (DMAP) in the Boc protection steps (6-7) and tosylation step (8). Introduction of DMAP in the tosylation stepThe amount of time required to bring about complete conversion of the starting material is reduced. The presence of DMAP also suppresses decomposition due to an extended reaction time (reaction times). This synthesis can produce small quantities (e.g., g-scale) of AV-105, but it is not easy to scale up to produce 50g or larger batches of AV-105.

An alternative synthesis of AV-105 is shown in FIG. 2. This convergent synthesis method uses p-toluenesulfonyl chloride instead of the usual methanesulfonyl chloride to prepare the pseudo halide. The use of a Heck reaction as shown in figure 2 increases the synthesis's influx and thus makes the synthesis more efficient and more likely to produce high yields. However, the yields reported in FIGS. 1 and 2 are for illustration only and do not represent the maximum obtainable yield. As will be appreciated by those of ordinary skill in the art, the synthetic methods for the preparation of AV-105 described herein can be further optimized by using purification techniques on the intermediate reactants or AV-105 itself. These techniques may include, for example, recrystallization, solvent extraction or column chromatography methods capable of removing small amounts of reaction impurities or reaction byproducts. However, the methods described herein are capable of producing AV-105 in an overall yield of 40% or greater and in a purity of greater than about 95%.

FIG. 3 shows the preparation of amyloid-beta binding radiopharmaceuticals using pristine alkyl p-toluenesulfonate according to one embodiment of the present invention¹⁸Radiosynthesis of F-AV-45. Subsequent to the radiolabelling process of aspects of the invention, formulation in saline solution¹⁸F-AV-45 (as labeled in formula II in FIG. 3). In certain embodiments, the salt solution comprises at least about 1.0% (v/v) ethanol and at least about 0.1% (w/v) sodium ascorbate at a pH between 4.5 and 8.0. In other embodiments, the ethanol concentration is in the range of about 1.0% to about 10.0% (v/v), and the sodium ascorbate concentration is in the range of about 0.1% to about 1.0% (w/v). Without wishing to be bound by theory, the presence of sodium ascorbate may be minimized¹⁸The purification of crude F-AV-45 and radiolysis in the diluent of the final product to increase stability and shelf life. In one embodiment of the invention, the nominal concentration of sodium ascorbate is 0.5% (w/v).

In another aspect of the present invention, there is provided a method for detecting neurodegenerative disease in a patient, the method comprising the steps of: administering to a patient a radiopharmaceutical composition capable of binding to a target associated with a neurodegenerative disease, which composition comprises an effective amount of¹⁸F-radiolabelled amyloid imaging compounds, e.g.¹⁸F-AV-45, or alternatively an F-18 labeled amyloid-binding radiopharmaceutical, and about 1.0% to 15% (v/v) ethanol and about 0.1% to 1% (w/v) sodium ascorbate; imaging a portion of a patient including a region of the patient at which the target location is expected; and detecting the target. The patient region may include at least a portion of the brain.

The radiopharmaceutical composition may be used for the diagnosis of neurodegenerative diseases, such as dementia, cognitive impairment, Alzheimer's Disease (AD), Parkinson's Disease (PD), dementia with Lewy bodies (DLB), vascular dementia (VaD) and combinations thereof.

In the embodiments of the present invention¹⁸The F-radiolabeled pharmaceutical composition may be administered by any method known in the art. For example, in particular aspects, the radiopharmaceutical composition may be administered by injection. In particular, methods of administration may include, but are not limited to, intravascular injection, intravenous injection, intraperitoneal injection, subcutaneous injection, and intramuscular injection.¹⁸The F-radiolabeled pharmaceutical composition may also be administered in unit dosage form, for example as an intravenous injection. In certain embodiments, the radiopharmaceutical composition may be prepared in a unit dose syringe containing an appropriate amount of the radiopharmaceutical.

In the various embodiments of the invention¹⁸The F-radiolabeled drug may be imaged using any suitable technique known in the art, including Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), PET with computed tomography imaging (PET/CT), PET with magnetic resonance imaging (PET/MRI), or a combination thereof.

The embodiments of the invention¹⁸The F-radiopharmaceutical compositions have high radiochemical purity and high radiosynthesis yield.¹⁸The shelf life of F-radiolabeled drugs may vary from embodiment to embodiment and may depend on various aspects of the process. In general terms, the amount of the solvent to be used,¹⁸the shelf life of the F-radiolabeled drug is more than 8 hours after formulation in the compositions described herein. Certain embodiments of the present invention further provide a method of making a composite material¹⁸Formulations of F-labeled compounds that are not only safe for human administration, but are also stable to radiolysis or other chemical degradation during transport to hospitals or other imaging centers (e.g., up to 8-10 hours). For example, in one embodiment, comprising ethanol and sodium ascorbate¹⁸The F-AV-45 radiopharmaceutical composition remains stable (greater than 90% RCP) for up to 20 hours after formulation.

Examples

In order that the present disclosure described herein may be more effectively understood, the following examples are provided. These examples are for illustrative purposes only and are not to be construed as limiting the invention in any way.

Examples 1.0Synthesis from AV-105 tosylate precursor¹⁸F-AV-45。

FIG. 2 shows, in accordance with one embodiment of the present invention, ((s))E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline) (-) "¹⁸F-AV-45') methanesulfonate ester precursor ((II)E)-2-(2-(2-(5-(4-(Tertiary amineSynthetic route to scale-up synthesis of butoxycarbonyl (methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate (AV-105). The mono-Boc protected vinylaniline 10 was prepared by thoroughly stirring vinylaniline and di-tert-butyl dicarbonate in water at room temperature. Mono Boc protected vinyl groupAniline 10 was precipitated and filtered to give 98% yield for future use without further purification. Methylation of the intermediate was performed using sodium hydride and methyl iodide in Dimethylformamide (DMF) to give crude methyl (4-vinylphenyl) carbamic acid tert-butyl ester 11 (yield: 88%), which was also used without further purification. 2-bromo-5-iodopyridine was alkylated with triethylene glycol using potassium tert-butoxide. At least 4 equivalents of triethylene glycol of iodopyridine are used to ensure that the monoalkylated product 2- (2- (2- (5-iodopyridin-2-yloxy) ethoxy) ethanol 13 is the main product. The monoalkylated product 13 (yield: 88%) was used directly in reaction step d without purification. Heck reaction between crude 11 and monoalkylated 13 was carried out using palladium acetate, tetrabutylammonium bromide and potassium carbonate in DMF to give styrylpyridine 14 which was purified by Biotage medium pressure flash chromatography (yield: 55%). Tosylation of styrylpyridine 14 was performed using a DCM solution of tosyl chloride, triethylamine and DMAP to give AV-105, which was purified by Biotage flash chromatography. The total yield from 2-bromo-5-iodopyridine was 40% (3 steps).

Examples 1.14-Vinylphenylcarbamic acid tert-butyl ester

Vinylaniline (3.75 g, 31.4 mmol) and di-tert-butyl dicarbonate (7.55 g, 34.6 mmol) were stirred well in 23 mL of water at room temperature for 2 hours. The precipitate was filtered and the remaining filter cake was redissolved in ethyl acetate (50 mL). The organic layer was washed with 50mL water and 50mL brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give a slightly peach colored solid mono-Boc protected vinylaniline 5 (6.75 g, 98%) crude product, which was used in the next step without further purification.

Examples 1.2Methyl (4-vinylphenyl) carbamic acid tert-butyl ester

Sodium hydride (1.11 g, 46.2 mmol) was added to 80mL of anhydrous DMF under nitrogen and the suspension was cooled to 0 ℃ with an ice bath. MonoBoc protected vinylaniline 10 (6.75 g, 30.8 mmol) dissolved in 30mL dry DMF was added over 30 minutes via addition funnel. The reaction mixture was allowed to warm to room temperature and methyl iodide (8.75 g, 61.6 mmol) was added over 30 minutes using a syringe. After stirring at room temperature for a further 1.5 hours, the mixture is poured onto 200g of ice and extracted with 200mL of ethyl acetate. The organic and aqueous layers were separated, and the organic layer was washed with 100mL of water and 50mL of brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give crude 11 as a reddish oil (6.3 g, 88%).

Examples 1.32- (2- (2- (5-iodopyridin-2-yloxy) ethoxy) ethanol.

Potassium tert-butoxide (869 mg, 7.7 mmol) was added portionwise to a solution of 2-bromo-5-iodopyridine (2 g, 7.04 mmol) and triethylene glycol (4.23 g, 28.1 mmol) in tetrahydrofuran (40 mL). The reaction mixture was then refluxed for 20 hours. The reaction mixture was concentrated under reduced pressure to remove the THF solvent. The concentrate was diluted with 100mL of water and extracted 2 times with 50mL of ethyl acetate. The organic layers were combined, washed with 50mL of water and 50mL of brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the monoalkylated product 2- (2- (2- (5-iodopyridin-2-yloxy) ethoxy) ethanol 13 (2.2 g, 88%) as a pale yellow oil which solidified upon standing overnight at room temperature.

Examples 1.4(E) -4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamic acid tert-butyl ester

Coupling partners methyl (4-vinylphenyl) carbamic acid tert-butyl ester 11 (1.29 g, 5.55 mmol) and 2- (2- (2- (5-iodopyridin-2-yloxy) ethoxy) ethanol 13 (1.96 g, 5.55 mmol) with palladium acetate (62.3 mg, 0.278 mmol), tetrabutylammonium bromide (5.53 g, 16.65 mmol) and potassium carbonate (3.83 g, 27.75 mmol)mmol) was added to 80mL of anhydrous DMF. The reaction mixture is passed through N₂Degassed for 5 minutes and heated at 100 ℃ overnight. The reaction volume was reduced by 50% under vacuum and the mixture was partitioned between 200mL ethyl acetate and 400mL water. The aqueous layer was separated and extracted with another 150mL of ethyl acetate. The organic layers were combined, washed with 100mL of water and 100mL of brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by Biotage flash chromatography (45% ethyl acetate in hexane; 65% ethyl acetate in hexane) to giveE) Tert-butyl (4- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate 14 (1.4g, 55%).

Examples 1.5 (E) -2- (2- (2- (5- (4- (tert-butoxycarbonyl (methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate (AV-105)

Will (a) toE) Tert-butyl (4- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate 14 (1.3 g, 2.83 mmol) was dissolved in 50mL DCM followed by the addition of tosyl chloride (1.08 g, 5.68 mmol), triethylamine (0.86 g, 8.49 mmol) and DMAP (24 mg, 0.2 mmol). The mixture was stirred at room temperature for 6 hours. 50mL of water was added. The organic layer was separated, washed with brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by Biotage medium pressure flash column chromatography (starting from 30% ethyl acetate in hexane and going to 40% ethyl acetate in hexane) to give compound AV-105 (1.5 g, 86%) as a clear pale yellow oil that solidified after several days in vacuo.

Examples 2.0Radiosynthesis from AV-105¹⁸F-AV-45

[¹⁸F]Active fluoride species trapped on anion exchange cartridge and using K.2.2.2-K₂CO₃Aqueous solution (Potassium carbonate and Kryptofix)And CH₃CN elutes into the reactor vessel. The eluted active substance was dried under vacuum. By adding CH to the reactor vessel₃CN, further dried [, ]¹⁸F]Fluoride, heating to evaporate water-CH₃CN azeotrope. AV-105 (1.5 mg in 2.0mL DMSO) was added to the reactor vessel. The mixture in the container is heated to 110-120 ℃ so as to carry out¹⁸F-radiolabelling reaction. A 3M HCl solution was added to the vessel and the resulting mixture was heated to 120 ℃ for 5 minutes to remove the N-Boc group. After cooling, 1M NaOH solution was added for neutralization. The solution was loaded into a reverse phase cartridge. Separation of crude product on drum¹⁸F-AV-45, washed with about 4mL of water for injection (WFI) containing 5% w/v sodium ascorbate. Followed by 1.5mL of CH₃CN is to ¹⁸F-AV-45 was eluted into a reservoir of 2mL water for injection containing 5% w/v sodium ascorbate and 1mL High Performance Liquid Chromatography (HPLC) solvent. Then will be¹⁸F-AV-45 is loaded into a semi-preparative high performance liquid chromatography column for purification. Will contain purified¹⁸The HPLC fraction of F-AV-45 was collected in a reservoir containing 20mL of water for injection containing 0.5% w/v sodium ascorbate. The diluted solution passes through SEP-PAK C-18 cylinders to be captured¹⁸F-AV-45 was washed with 15mL of water for injection containing 0.5% w/v sodium ascorbate. Using 1mL EtOH (USP) will¹⁸F-AV-45 was eluted from SEP-PAK Light C-18 cartridges into 9mL of 0.9% sodium chloride injection (sterile, USP) containing 0.5% w/v sodium ascorbate (USP). This solution was then passed through a 0.22 μm sterile filter and dispensed into 10 or 30mL sterile pre-crimped septum sealed containers.¹⁸F-AV-45 drug product can be diluted with sodium chloride injection (0.9%, USP, sterile) containing NMT 10% v/v EtOH (USP) and 0.5% w/v sodium ascorbate (USP).

Examples 3.0For dissolving¹⁹F-AV-45 and stabilization¹⁸Formulations of F-AV-45

Evaluation of¹⁸Non-radioactive F-AV-45 radiopharmaceutical formulations/compositions¹⁹Solubility of F-AV-45 in¹⁸During radiosynthesis of F-AV-45, small amounts of fluids are generated by piping, valves and other sources within the radiosynthesis system¹⁹F fluoride is also formed in an amount of 1-5 mug/mL¹⁹F-AV-45. In the case of a composition without ethanol, the reason is that¹⁹The low solubility of F-AV-45 may allow the observation of particulate matter. Thus, the determination was evaluated by adding 10% ethanol to the radiopharmaceutical composition¹⁹Whether the solubility of F-AV-45 is sufficient to avoid the possibility of precipitate formation. The limit of dissolution of AV-45 in the pharmaceutical product composition (10% (v/v) EtOH and 0.5% (w/v) sodium ascorbate in 0.9% aqueous sodium chloride solution) was determined to be 17 μ g/mL at room temperature. When the concentration is more than or equal to 22 mug/mL, obvious visible precipitation can occur in the solution. The prepared sample concentration is less than or equal to 20 mug/mL, and analysis and evaluation are carried out by HPLC after centrifugation. And (4) storing the sample with the concentration less than or equal to 20 mug/mL for one week at room temperature, and then determining again. After one week of storage at room temperature, there was no change in concentration.

In the embodiments of the present invention¹⁸F-AV-45 radiopharmaceutical compositions are fairly stable to radiolysis or chemical degradation. Sodium ascorbate for minimizing¹⁸Radiolysis during purification of F-AV-45 and in the final drug product solution to increase stability and shelf life. The ethanol aqueous solution with the concentration of 1-10% (v/v) is helpful¹⁸And (3) dissolving the F-AV-45. In order to show in the final pharmaceutical product¹⁸Stability of F-AV-45, study compositions containing sodium ascorbate and no sodium ascorbate were prepared. The compositions were analyzed at the end of synthesis (EOS) using reverse phase High Performance Liquid Chromatography (HPLC) loaded with an Ultraviolet (UV) detector and a radiochemical detector. Monitoring by means of HPLC with radiometric detection¹⁸Radiochemical purity of F-AV-45 and monitoring of pharmaceutical products by HPLC UV detection by area percentage normalization¹⁹Purity of F-AV-45. Area percent values for radiochemical and uv analysis are shown in tables 1 and 2.

Prepared without sodium ascorbate at end of synthesis (EOS)¹⁸F-AV-45 compositionThe radiochemical purity was 84% and further decomposed so that at2 hours the purity was 80%. Prepared from sodium ascorbate¹⁸The purity of the F-AV-45 composition is significantly higher. At the end of the synthesis (EOS), the purity was 96%, and the decomposition at2 hours after the end of the synthesis (EOS) was negligible (purity 95%).

As shown in table 2, sodium ascorbate was used for¹⁹F-AV-45 has a similar stabilizing effect and is capable of minimizing the formation of non-radioactive impurities upon UV detection.

^*Only impurities greater than or equal to 1% are included in this table.

Table 3 shows¹⁸The stability of F-AV-45 radiopharmaceuticals was extended in approximately 10% v/v ethanol in physiological saline containing 0.5% w/v sodium ascorbate. As can be seen in the table, up to about 20 hours after preparation,¹⁸the radiochemical purity of the F compound is maintained.

Other studies were conducted to show that when stored within FLUOTEC @,¹⁸stability of F-AV-45 radiopharmaceuticals in 10% v/v ethanol in physiological saline containing 0.5% w/v sodium ascorbate. With three separate production batches¹⁸F-AV-45 to evaluate the stability of the pharmaceutical product. The vials were stored upright and inverted at room temperature and 40 ℃ and upright at 50 ℃. The drug product was sampled at specified intervals over 12 hours and evaluated for radiochemical purity andstrength. The RCP does not change over 12 hours at all temperatures tested and the drug product strength deviates by less than 5%, indicating stability of the drug substance in the drug product and minimal interaction of the drug substance with the vial cap.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description and the preferred versions contained herein.

Claims (7)

1. A radiopharmaceutical composition for positron emission tomography imaging of neurodegenerative disease of the brain comprising:

an effective amount of (a)E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline), (A), (B), (C), (¹⁸F-AV-45）；

10% (v/v) ethanol in 0.9% aqueous sodium chloride solution, wherein the aqueous sodium chloride solution comprises 0.5% w/v sodium ascorbate.

2. The radiopharmaceutical composition of claim 1, wherein (, (E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline) from a tosylate precursor.

3. Use of the radiopharmaceutical composition of claim 1 for the preparation of a medicament for the diagnosis of a neurodegenerative disease.

4. The use of claim 3, wherein the neurodegenerative disease is at least one of dementia, cognitive impairment, Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies, and vascular dementia.

5. Use of the radiopharmaceutical composition of any one of claims 1 to 2 in the preparation of a medicament for use in a method of diagnosing a neurodegenerative disease in a patient, which method comprises the steps of:

(ii) administering the radiopharmaceutical composition as described,

imaging at least a portion of a patient's brain, the portion including a region of a target predetermined location; and are

And detecting the target.

6. The use of claim 5, wherein the imaging step comprises performing positron emission tomography imaging, positron emission tomography with computed tomography imaging, positron emission tomography with magnetic resonance imaging, or a combination thereof.

7. A method of preparing the radiopharmaceutical composition of claim 1, comprising the steps of:

preparing a mono-Boc protected vinylaniline compound;

converting the vinylaniline compound to methyl, tert-butyl carbamate;

reacting 2-halogen-5-iodopyridine with triethylene glycol;

reacting the methyl, t-butyl carbamate with the resultant compound of the step of reacting 2-halo-5-iodopyridine with triethylene glycol to obtain: (E) -tert-butyl 4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate; and is

Will (a) toE) Reaction of (E) -tert-butyl 4- (2- (6- (2- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) phenyl (methyl) carbamate with p-toluenesulfonyl chloride to form: (E) -2- (2- (5- (4-tert-butyl) 2Butoxy radical Carbonyl radical(methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate;

will (a) toE) -2- (2- (2- (5- (4- (tert-butoxycarbonyl (methyl) amino) styryl) pyridin-2-yloxy) ethoxy) ethyl 4-methylbenzenesulfonate with¹⁸Reacting F-fluoride ions in dimethyl sulfoxide (DMSO) solution or other high-boiling point aprotic solvent to generate ((DMSO))E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline);

separation (, (E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline);

purification (, (E)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline); and

preparing effective amount of (A), (B), (C) and (C) in ethanol water solutionE)-4-(2-(6-(2-(2-(2-[¹⁸F]Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl-N-methylaniline) comprising 10% v/v ethanol and 90% v/v 0.9% aqueous sodium chloride solution, wherein the aqueous sodium chloride solution comprises 0.5% w/v sodium ascorbate.