EA046355B1 - COMPOSITIONS FOR DIAGNOSTICS FOR PET VISUALIZATION, METHOD FOR OBTAINING THE COMPOSITION FOR DIAGNOSTICS AND ITS APPLICATION IN DIAGNOSTICS - Google Patents

Description

Field of technology to which the invention relates

The invention relates to a composition for diagnostics, which is suitable for obtaining images using positron emission tomography (PET). In addition, the invention relates to a method for producing a composition for diagnostics, as well as a composition for use in diagnostics.

State of the art

Alzheimer's disease (AD) is a neurological disease thought to be caused by amyloid plaques, an extracellular accumulation of abnormal deposits of amyloid-beta (AR) aggregates in the brain or eyes. Other major neuropathological features in AD are intracellular neurofibrillary tangles (NFTs), which arise from the aggregation of hyperphosphorylated Tau (tubulin-associated unit), phosphorylated Tau, or pathological Tau and its conformers. AD shares this pathology with many neurodegenerative tauopathies, particularly certain types of frontotemporal dementia (FTD). In the brains of AD patients, Tau pathology (tauopathy) develops later than amyloid pathology, but it is still controversial whether the Av protein is the causative agent of AD, which is the essence of the so-called amyloid cascade hypothesis (Hardy et al., Science 1992, 256, 184-185, and most recently Musiek et al., Nature Neurosciences 2015, 18(6), 800-806, Three dimensions of the amyloid hypothesis: time, space and 'wingmen').

Currently, the only definitive way to diagnose AD is to identify plaques and tangles in brain tissue through histological analysis of biopsies or autopsies after death. In addition to AD, Tau plays an important role in other (non-AD) neurodegenerative diseases. Such non-AD tauopathies include, for example, supranuclear palsy (PSP), Pick's disease (PiD), and corticobasal degeneration (CBD).

It has been suggested that the compound of general formula A is useful for the selective detection of disorders and anomalies associated with Tau aggregates, such as Alzheimer's disease (AD) and other tauopathies, and several methods for preparing this compound have been described in the prior art.

The pharmaceutical composition described in WO 2015/052105 and Gobbi et al. consists of [ ^18F ]-2-(6fluoropyridin-3-yl)-9H-dipyrido[2,3-b;3',4'-d] pyrrole in 1 ml ethanol and 10 ml saturated saline solution. The components are passed through a 0.22 micron sterilizing filter.

1^-radiolabeled PET imaging tracers are prepared as needed and the diagnostic composition is typically used within 10-12 hours after completion of preparation. When transporting over long distances and receiving multiple doses from a single batch, the level of radioactivity increases (for example, for batches of [1^]fluorinated pyridinyl-9H-pyrrolodipyridines >20 GBq or 50 GBq or even > 100 GBq). Radiopharmaceuticals are known to be sensitive to radiolysis, requiring the use of stabilizing agents in suitable compositions for diagnosis.

Especially for lipophilic compounds such as [1^]fluorinated pyridinyl-9Hpyrrolodipyridines, losses on sterile filters and surfaces (eg, syringes) must be minimized for effective and reliable use of the composition for diagnostics.

It is therefore an object of the present invention to provide a diagnostic composition having improved stability.

Description of the figures

Fig. 1 - diagram of the setup for the synthesis of GE Tracerlab FX; fig. 2 - diagram of the setup for IBA Synthera synthesis.

The essence of the invention

The present invention relates to the following points:

1. Composition for diagnosing a disorder associated with Tau aggregates, comprising: a) a compound of formula Ib

b) from 1 to 20% v/v. ethanol,

c) water and

d) from 2.5 to 500 µmol/ml of hydroxycarboxylic acid, hydroxycarboxylic acid salt or mixture thereof, where the hydroxycarboxylic acid, hydroxycarboxylic acid salt or mixture thereof is selected

- 1 046355 on/selected from ascorbic acid, sodium ascorbate, gentisic acid, sodium salt of gentisic acid, citric acid, sodium citrate or a mixture thereof, and

e) a buffer selected from alkali metal dihydrogen phosphates, di(alkali metal) hydrogen phosphates, tri(alkali metal) phosphates, alkali metal acetates, alkaline earth metal acetates, alkaline earth metal formates, mono/di/tri alkali metal citrate, where F in Formula Ib is ¹⁸ F or a mixture of ¹⁸ F and ¹⁹ F.

2. A diagnostic composition according to claim 1, wherein the hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof is gentisic acid.

3. A diagnostic composition according to claim 1 or 2, comprising from 2.5 to 500 µmol/ml of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid or a mixture thereof, preferably from 10 to 300 µmol/ml of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid or a mixture thereof, more preferably 25 to 300 µmol/ml hydroxycarboxylic acid, hydroxycarboxylic acid salt or mixture thereof.

4. Diagnostic composition according to any one of claims 1 to 3, where the alkali metals in the buffer are selected from sodium and potassium.

5. A method for obtaining a composition for diagnostics according to any one of paragraphs. 1-4, including stages:

a) interaction of a compound of formula IIb with a ^-fluorinating agent

(lib) where X is H or PG,

LG is a leaving group selected from the group consisting of nitro, bromine, iodine, chlorine, trialkylammonium, hydroxyl, boronic acid, iodonium, sulfonic acid ester, and

PG is an amino protecting group selected from the group consisting of carbobenzyloxy (Cbz), (p-methoxybenzyl)oxycarbonyl (Moz or MeOZ), tert-butyloxycarbonyl (BOC), 9fluorenylmethyloxycarbonyl (FMOC), benzyl (Bn), p-methoxybenzyl ( PMB), 3,4-dimethoxybenzyl (DMPM), p-methoxyphenyl (PMP), triphenylmethyl (trityl), methoxyphenyldiphenylmethyl (MMT) or dimethoxytrityl (DMT),

b) if X is PG, removal of the PG protecting group,

c) purifying the compound of formula Ib and

d) mixing the compound of formula Ib obtained in step c) with ethanol, water, a hydroxycarboxylic acid and a hydroxycarboxylic acid salt to obtain a diagnostic composition.

6. The method according to claim 5, wherein LG in formula IIb represents a leaving group that can be replaced by a nucleophilic [ ¹⁸ E]fluoride ion or an electrophilic [ ^18F ] fluorine atom, LG selected from nitro or trimethylammonium, where compounds containing trialkylammonium or iodonium may additionally contain an anion.

7. The method according to claim 5 or 6, wherein PG in formula IIb is a group selected from tert-butyloxycarbonyl (BOC), dimethoxytrityl (DMT) and triphenylmethyl (trityl), more preferably PG is tert-butyloxycarbonyl (BOC) or triphenylmethyl ( trityl).

8. Use of the composition according to any one of claims 1-4 for visualization of Tau protein aggregates.

9. Application according to claim 8, in positron emission tomography for visualization of Taubelka aggregates.

10. Use of a composition according to any one of claims 1 to 4 for the diagnosis of a disorder associated with Tau aggregates or for the diagnosis of tauopathy.

11. Application according to claim 10, where the diagnosis is carried out using positron emission tomography.

12. Use according to claim 10, where the disorder is selected from Alzheimer's disease (AD), familial AD, Creutzfeldt-Jakob disease, Boxer's dementia, Down syndrome, Gerstmann-Straussler-Scheinker disease, inclusion body myositis, cerebral amyloid angiopathy associated with protein- prion, traumatic brain injury (TBI), amyotrophic lateral sclerosis, Guam parkinsonism-dementia complex, non-Guam motor neuron disease with neurofibrillary tangles, argyrophilic grain disease, corticobasal degeneration (CBD), diffuse neurofibrillary tangles with calcification, frontotemporal dementia with parkinsonism , associated with chromosome 17, Hallervoorden-Spatz disease, multiple system atrophy, Niemann-Pick disease type C, pallidoponto-nigral degeneration, Pick disease (PiD), progressive subcortical gliosis, progressive supranuclear palsy (PSP), subacute sclerosing panencephalitis, plexus-only dementia, postencephalitic parkinsonism, myotonic dystrophy, Tau panencephalopathy, AD

- 2 046355 similar with astrocytes, selected prion diseases (GSS with Tau), mutations in LRRK2, chronic traumatic encephalopathy, familial British dementia, familial Danish dementia, frontotemporal lobar degeneration, Guadalupean parkinsonism, neurodegeneration with iron accumulation in the brain, SLC9A6-related mental illness retardation, white matter tauopathy with globular glial inclusions, post-traumatic stress syndrome, epilepsy, dementia with Lewy bodies (LBD), hereditary hemorrhagic stroke with amyloidosis (Dutch type), mild cognitive impairment (MCI), multiple sclerosis, Parkinson's disease, atypical parkinsonism, HIV-related dementia, adult-onset diabetes, age-related cardiac amyloidosis, endocrine tumors, glaucoma, ocular amyloidosis, primary retinal degeneration, macular degeneration (eg, age-related macular degeneration (AMD)), optic drusen, optic neuropathy, optic neuritis, lattice dystrophy, Huntington's disease, ischemic stroke and psychosis in AD.

13. Use according to claim 12, wherein the disorder is Alzheimer's disease (AD), Parkinson's disease, atypical parkinsonism, progressive supranuclear palsy (PSP) or Pick's disease (PiD).

14. Use of the composition according to any one of claims 1 to 4 as an analytical standard or as an in vitro screening tool.

15. A method of collecting data for diagnosing a disorder associated with Tau aggregates in a sample, comprising:

(a) bringing the sample suspected of containing the Tau aggregate into contact with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib;

(b) allowing the compound of formula Ib to bind to the Tau aggregate;

(c) detecting a compound of formula Ib bound to a Tau aggregate.

16. A method for determining the amount of Tau aggregate in a tissue and/or body fluid, comprising: (a) providing a sample representative of the tissue and/or body fluid being examined;

(b) testing a sample for the presence of a Tau aggregate with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib;

(c) determining the amount of compound of formula Ib associated with the Tau aggregate; and (d) calculating the amount of Tau aggregate in tissue and/or body fluid.

17. A method of collecting data to determine susceptibility to Tau aggregate disorder in a patient, which includes the stages of:

(a) contacting a sample suspected of containing a Tau aggregate with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib that specifically binds to the Tau aggregate;

(b) allowing a compound of formula Ib to bind to a Tau aggregate to form a compound/Tau aggregate complex and (c) detecting formation of a compound/Tau aggregate complex;

wherein the method is (i) a method comprising detecting the specific binding of a composition according to any one of claims 1 to 4, which contains a compound of formula Ib, to a Tau aggregate in the sample.

Definitions

The term alkyl refers to a saturated straight or branched carbon chain that, unless otherwise noted, contains from 1 to 6 carbon atoms.

Gal or halogen is F, Cl, Br and I. Preferably, the halogen is independently in each case selected from F, Cl and Br, more preferably from F and Cl, even more preferably F.

The term amino protecting group (PG), as used herein, means any protecting group that is suitable for protecting an amino group during the intended chemical reaction. Examples of suitable protecting groups are well known to one skilled in the art. Suitable protecting groups are described, for example, in Greene and Wuts, Protecting groups in Organic Synthesis, third edition, pages 494-653, which is incorporated herein by reference. Protecting groups can be selected from carbamates, amides, imides, N-alkylamines, Narylamines, imines, enamines, boranes, N-P protecting groups, N-sulfenyl, N-sulfonyl and N-silyl. Specific preferred examples of protecting groups (PG) include carbobenzyloxy (Cbz), (p-methoxybenzyl)oxycarbonyl (Moz or MeOZ), tert-butyloxycarbonyl (BOC), 9-fluorenylmethyloxycarbonyl (FMOC), benzyl (Bn), p-methoxybenzyl (PMB) ), 3,4-dimethoxybenzyl (DMPM), pmethoxyphenyl (PMP), triphenylmethyl (trityl), methoxyphenyldiphenylmethyl (MMT) or dimethoxytrityl (DMT). More preferred examples of the PG protecting group include tert-butyloxycarbonyl (BOC), dimethoxytrityl (DMT) and triphenylmethyl (trityl). Another preferred example of a PG protecting group is tert-butyloxycarbonyl (BOC).

The term carbamate amino protecting group refers to an amino protecting group containing a *-CO-O group, where the asterisk denotes a bond to an amine. Examples are carbobenzyloxy (Cbz), (pmethoxybenzyl)oxycarbonyl (Moz or MeOZ), tert-butyloxycarbonyl (BOC) and 9-fluorenyl

- 3 046355 methyloxycarbonyl (FMOC).

The term leaving group (LG), as used herein, means any leaving group and means that an atom or group of atoms can be replaced by another atom or group of atoms. Examples are given, for example, in Synthesis (1982), p. 85-125, table 2, Carey and Sundberg, Organische Synthese, (1995), pages 279-281, table 5.8; or Netscher, Recent Res. Dev. Org. Chem., 2003, 7, 71-83, scheme 1, 2, 10 and 15 and others). (Coenen, Fluorine-18 Labeling Methods: Features and Possibilities of Basic Reactions, (2006), in: Schubiger P.A., Friebe M., Lehmann L., (eds), PET-Chemistry - The Driving Force in Molecular Imaging. Springer, Berlin Heidelberg, pp. 15-50, explicitly: scheme 4 pp. 25, scheme 5 pp 28, table 4 pp 30, Figure 7 pp 33). Preferably, the leaving group (LG) is selected from the group consisting of nitro, bromine, iodine, chlorine, trialkylammonium, hydroxyl, boronic acid, iodonium, sulfonic acid ester. More preferably, the leaving group (LG) is nitro or trimethylammonium. It should be understood that compounds containing trialkylammonium or iodonium may additionally contain an anion. Even more preferably, the leaving group (LG) is nitro.

The term crown ether, as used herein, refers to chemical compounds that consist of a ring containing several ether groups. More specifically, the term crown ether refers preferably to monocyclic organic groups that may be substituted and contain from 8 to 16 carbon atoms and from 4 to 8 heteroatoms selected from N, O and S in the ring. Each of the one or more optional substituents may be independently selected from any organic group containing from 1 to 15 carbon atoms and optionally from 1 to 6 heteroatoms selected from N, O and S. Preferred examples of crown ether are optionally substituted monocyclic rings containing from 10 to 14 carbon atoms and from 5 to 7 heteroatoms selected from N, O and S in the ring. Examples of crown ethers are optionally substituted monocyclic rings containing 12 carbon atoms and 6 heteroatoms selected from N and O in the ring. Specific examples include 18-crown-6, dibenzo-18-crown-6, and diaza-18-crown-6.

The term cryptand, as used herein, refers to a class of polycyclic compounds belonging to crown ethers having three chains attached to two nitrogen atoms. A well-known cryptand is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (Kryptofix®).

Tau, as used herein, refers to a highly soluble microtubule-binding protein primarily found in neurons and includes the major 6 isoforms, cleaved or truncated forms, and other modified forms such as those resulting from phosphorylation, glycosylation, glycation, prolyl isomerization , nitration, acetylation, polyamination, ubiquitination, sumoylation and oxidation. Pathological Tau or Tau aggregates (neurofibrillary tangles, NFTs), as used herein, refer to insoluble aggregates of hyperphosphorylated Tau protein containing paired helical filaments and straight filaments. Their presence is a hallmark of AD and other diseases known as tauopathies.

The Tau gene contains 16 exons, with the major isoforms of the Tau protein encoded by 11 of them. Alternative splicing of exon 10 generates Tau isoforms with three (exon 10 missing) or four (exon 10 present) repeat domains known as 3R and 4R Tau, respectively (A. Andreadis et al., Biochemistry 31, (1992) 10626-10633; M. Tolnay et al., IUBMB Life, 55(6): 299-305, 2003). In Alzheimer's disease, the ratio of 3R and 4R isoforms is similar. In contrast, in some types of tauopathies, one of the two isoforms predominates. As used herein, the term 3R tauopathy refers to tauopathies (such as Pick's disease (PiD)) in which the 3R isoform is predominantly present. As used herein, the term 4R tauopathy refers to tauopathies (such as progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD)) in which the 4R isoform is predominantly present.

As used hereinafter in the specification and claims, the term pharmaceutically acceptable salt or diagnostically acceptable salt refers to non-toxic derivatives of the disclosed compounds wherein the parent compound is modified by producing inorganic and organic acid salts thereof. Inorganic acids include, but are not limited to, acids such as carboxylic, hydrochloric, nitric or sulfuric acid. Organic acids include, but are not limited to, acids such as aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic acids. The pharmaceutically acceptable salts of the present invention can be synthesized from a parent compound that contains a basic or acidic moiety by conventional chemical methods. Typically, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the corresponding base or acid in water or an organic solvent or a mixture of the two. Lists of suitable salts can be found in Remington's Pharmaceutical Sciences, 18th ed., Mack Publishing Company, Easton, PA, 1990, p. 1445, the disclosure of which is incorporated herein by reference.

- 4 046355

Pharmaceutically acceptable or diagnostically acceptable are defined as those compounds, substances, compositions and/or dosage forms that, within the bounds of sound medical judgment, are suitable for use in contact with tissues of humans and animals, without excessive toxicity, irritation, allergic reaction or other problems, or complications commensurate with a reasonable benefit/risk ratio. Preferably, each of the components of the claimed compositions is pharmaceutically and diagnostically acceptable.

The patients or subjects of the present invention are typically animals, especially mammals, more particularly humans.

Chromatography or liquid chromatography refers to a method of separating a mixture of compounds. The mixture is dissolved in liquid and transferred by moving the mobile phase through the stationary phase. Separation is based on the interaction of compounds in the mobile phase with stationary phases. These different interactions lead to differential retention at the stationary phase and thus influence the separation. Chromatography can be preparative or analytical. The purpose of preparative chromatography is to separate the components of a mixture and is thus a form of purification. Analytical chromatography is performed on a small sample of a substance and is used to measure the proportions of compounds in a mixture.

High performance liquid chromatography (HPLC) is a form of liquid chromatography for separating compounds using very small stationary phase particles (<10 µm) and applying fairly high pressures. An HPLC system typically consists of a reservoir of mobile phase(s), a pump, an injector, a separation column (containing the stationary phase), and detectors. To separate radioactive compounds, suitable HPLC systems are equipped with a radioactivity detector. If necessary, the HPLC system has additional detectors, such as, for example, UV, photodiode array, refractometric, conductivity, fluorescence, mass spectrometric.

Solid phase extraction (SPE) is a sample preparation and/or purification process with two or more distinct steps. First, the compounds are dissolved or suspended in a liquid solvent mixture and the liquid sample is passed through a stationary (solid) phase. Some compounds are retained in the stationary phase while others pass through it. In the second step, the remaining compounds are eluted with a suitable solvent. Optionally, the stationary phase is washed with another solution before the elution step. In contrast to the HPLC method, the particle size used is much larger (e.g. >25 µm compared to HPLC with a typical particle size <10 µm) and therefore the pressure applied is much lower (for HPLC the pressure is typically >50 bar).

A solid phase extraction cartridge (SPE cartridge) is a syringe or container (eg Sep Pak®) pre-filled with SPE stationary phase.

Sterilizing filtration is a method of sterilizing a solution by filtration through a microfilter. A microfilter is a filter having, for example, a pore size of about 0.25 μm or less, preferably from about 20 nm to about 0.22 μm, which is typically used to remove microorganisms. Membrane filters used in microfiltration production processes are typically made from materials such as cellulose ester blends, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) or polyethersulfone (PES).

Automated, as used herein, means carrying out the synthesis and/or purification steps with a suitable device (synthesis unit).

The term radioabsorber refers to a compound that reduces the rate of degradation due to radiolysis. Preferred radioabsorbers include ascorbic acid and its salts and gentisic acid and its salts.

Suitable synthesis setups for ¹⁸ F radiolabeling are well known to one of ordinary skill in the art, including, but not limited to, IBA Synthera, GE Fastlab, GE Tracerlab MX, GE Tracerlab FX, Trasis AllinOne, ORA Neptis Perform, ORA Neptis Mosaic, ORANeptis Plug, Scintomics GPR, Synthera, Comecer Taddeo, Raytest Synchrom, Sofie Elixys, Eckert&Ziegler Modular Lab, Sumitomo Heavy Industries F100 F200 F300, Siemens Explora.

Radiochemical purity means the proportion of the total activity of a radionuclide present in its resulting chemical form. Typically, radiochemical purity is determined using thin layer chromatography or HPLC.

The term hydroxycarboxylic acid refers to a C ₂ -C ₁₀ compound that has one or more carboxylic acid groups and one or more hydroxy groups (not including the hydroxy group(s) in the carboxylic acid group(s). The hydroxycarboxylic acid may be saturated or unsaturated (including aromatic) and be cyclic or acyclic. In a preferred embodiment, the hydroxycarboxylic acid has from one to three carboxylic acid groups. Preferably, the hydroxycarboxylic acid has one to six hydroxy groups, more preferably one to four hydroxy groups. Hydroxycarboxylic acid may be in free form

- 5 046355 noic acid or its cyclic ester (i.e. lactone). Possible hydroxycarboxylic acids include, but are not limited to, ascorbic acid, hydroxybenzoic acids (such as gentisic acid), hydroxybenzoic acid derivatives, citric acid, lactic acid, malic acid, 2-hydroxybutanoic acid, 3-hydroxybutanoic acid, mandelic acid, gluconic acid , tartaric acid and salicylic acid, preferably ascorbic acid, hydroxybenzoic acids (such as gentisic acid), hydroxybenzoic acid derivatives and citric acid.

The preferred definitions given in the Definitions section apply to all embodiments described herein unless otherwise noted.

Detailed description

In a first aspect, the invention relates to a diagnostic composition comprising:

a) compound of formula I

b) ethanol,

c) water and

d) a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof.

F in Formula I is ¹⁸ F or ¹⁹ F. Preferably F is ¹⁸ F or a mixture of ¹⁸ F and ¹⁹ F.

Preferred compounds of formula I are selected from the group consisting of

Preferably, the diagnostic composition includes from about 0.03 to about 10 GBq/ml of a compound of formula I. More preferably, the diagnostic composition includes from about 0.03 to about 5 GBq/ml of a compound of formula I. Preferably, the diagnostic composition includes at least about 1 GBq/ml of a compound of Formula I. More preferably, the diagnostic composition includes at least about 2 GBq/ml of a compound of Formula I. Even more preferably, the diagnostic composition includes at least about 3 GBq/ml of a compound of Formula I.

Preferably, the diagnostic composition includes a maximum concentration of a compound of formula I of about 10 μg/ml, more preferably a maximum concentration of a compound of formula I of about 5 μg/ml.

Preferably, the diagnostic composition includes from about 1 to about 20% v/v. ethanol, based on the total amount of ethanol and water. More preferably, the diagnostic composition includes from about 1 to about 15% v/v. ethanol, based on the total amount of ethanol and water. Even more preferably, the diagnostic composition includes from about 5 to about 10% v/v. ethanol, based on the total amount of ethanol and water.

The diagnostic composition includes a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof. Any hydroxycarboxylic acid or salt thereof may be used. However, diagnostically acceptable hydroxycarboxylic acids or salts thereof are preferred. Preferably, the diagnostic composition comprises a hydroxycarboxylic acid, a hydroxycarboxylic acid salt, or a mixture thereof, which is selected from the group consisting of ascorbic acid and ascorbic acid salts, hydroxybenzoic acids and hydroxybenzoic acid salts, hydroxybenzoic acid derivatives and hydroxybenzoic acid derivative salts, citric acid and citric salts acids and their mixtures. Preferably hydroxybenzoic acid derivatives

- 6 046355 branes from the group consisting of hydroxybenzoic acid, dihydroxybenzoic acid and trihydroxybenzoic acid. More preferably, the dihydroxybenzoic acid derivative is gentisic acid.

More preferably, the diagnostic composition includes one or more selected from ascorbic acid, sodium ascorbate, gentisic acid, sodium gentisic acid, citric acid, sodium citrate, or a mixture thereof.

In one preferred embodiment, the diagnostic composition includes from about 2.5 to about 500 μmol/ml of a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof. More preferably, the diagnostic composition includes from about 10 to about 300 μmol/ml of a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof. Even more preferably, the diagnostic composition includes from about 25 to about 300 μmol/ml of a hydroxycarboxylic acid, an organic acid salt, or a mixture thereof.

In another preferred embodiment, the diagnostic composition comprises ascorbic acid, sodium ascorbate, or a mixture thereof (as a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof). Preferably, the diagnostic composition includes from about 10 to about 500 μmol/ml ascorbic acid, sodium ascorbate, or a mixture thereof. More preferably, the diagnostic composition includes from about 50 to about 500 μmol/ml ascorbic acid, sodium ascorbate, or a mixture thereof. Even more preferably, the diagnostic composition includes from about 100 to about 500 μmol/ml ascorbic acid, sodium ascorbate, or a mixture thereof. The diagnostic composition may also include from about 50 to about 300 μmol/ml ascorbic acid, sodium ascorbate, or a mixture thereof. Even more preferably, the diagnostic composition includes from about 200 to about 300 μmol/ml ascorbic acid, sodium ascorbate, or a mixture thereof.

In a further preferred embodiment, the diagnostic composition comprises gentisic acid, a sodium salt of gentisic acid, or a mixture thereof (as a hydroxycarboxylic acid, a hydroxycarboxylic acid salt, or a mixture thereof). Preferably, the diagnostic composition includes from about 2.5 to about 100 μmol/ml gentisic acid, sodium salt of gentisic acid, or a mixture thereof. More preferably, the diagnostic composition includes from about 10 to about 100 μmol/ml gentisic acid, sodium salt of gentisic acid, or a mixture thereof. Even more preferably, the diagnostic composition includes from about 25 to about 75 μmol/ml gentisic acid, sodium salt of gentisic acid, or a mixture thereof.

Preferably, the diagnostic composition comprises citric acid, sodium citrate or a mixture thereof (as a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid or a mixture thereof). Preferably, the diagnostic composition includes from about 10 to about 500 μmol/ml citric acid, sodium citrate, or a mixture thereof. More preferably, the diagnostic composition includes from about 50 to about 500 μmol/ml citric acid, sodium citrate, or a mixture thereof. Even more preferably, the diagnostic composition includes from about 50 to about 300 μmol/ml citric acid, sodium citrate, or a mixture thereof.

The hydroxycarboxylic acid, hydroxycarboxylic acid salt, or mixture thereof acts as a scavenger to prevent radiolytic decomposition of the compound of Formula I. It is further preferred that the hydroxycarboxylic acid, hydroxycarboxylic acid salt, or mixture thereof be diagnostically acceptable.

Optionally, the diagnostic composition includes an inorganic acid, an organic acid, a base, a salt, or a mixture thereof, each of which is preferably diagnostically acceptable, wherein the organic acid, salt, or mixture thereof is other than a hydroxycarboxylic acid, a hydroxycarboxylic acid salt, or a mixture thereof. In one embodiment, an inorganic acid, organic acid, base, salt, or mixture thereof is used during the synthesis or purification of a compound of Formula I. In another embodiment, an inorganic acid, organic acid, base, salt, or mixture thereof is used to adjust the pH and/or ionic strength of the composition for diagnostics.

Examples of suitable inorganic or organic acids, bases and salts include sodium chloride, potassium chloride, monosodium phosphate, disodium phosphate, trisodium phosphate, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, hydrochloric acid, phosphoric acid, sodium hydroxide and potassium hydroxide.

In addition to the above components, the diagnostic composition includes water. The amount of water is chosen so that the total amount of the composition is 100%.

The diagnostic composition has a pH of from about 4 to about 8.5, preferably from about 4.5 to about 8.

In a preferred embodiment, the diagnostic composition is sterile.

The diagnostic compositions of the present invention are suitable for parenteral administration to mammals for PET imaging.

In a second aspect, the invention relates to a method for preparing the diagnostic composition of the present invention. In one embodiment, the method includes the steps of:

- 7 046355

a) interaction of a compound of formula II with a β-fluorinating agent

where X represents H or PG,

LG is a leaving group and

PG is an amino protecting group,

b) optionally, if X is PG, removal of the PG protecting group,

c) purifying the compound of formula I and

d) optionally mixing the compound of formula I obtained in step c) with ethanol, water and a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid or a mixture thereof to obtain a diagnostic composition.

If necessary, sterilizing filtration can also be carried out (step e).

The compound of formula II is a precursor for the synthesis of the compound of formula I.

Preferred compounds of formula II are selected from the group consisting of

More preferred compounds of formula II are selected from the group consisting of

In these connections, PG and LG have the meanings defined in the Definitions section. Even more preferred compounds of formula II are selected from the group consisting of

- 8 046355

as a counterion selected from the group consisting of halo, where X ^- is a counterion such as CF3SO3 ^- and CF3CO2 ^- .

Even more preferred compounds of formula II are selected from the group consisting of

where X ^- is a counterion, such as a counterion selected from the group consisting of halogen, CF3SO3 ^- and CF3CO2 ^- .

Stage a):

Stage a) involves the interaction of a compound of formula II with a β-fluorinating agent

Where

X represents H or PG,

LG is a leaving group and

PG is an amino protecting group.

If X is H, a compound having formula I will be obtained. If X is PG, an intermediate having formula III will be obtained.

^-fluorinating agents are well known to one skilled in the art. Any suitable ^-fluorinating agent may be used. Typical examples include H ¹⁸ F, alkali or alkaline earth ^-fluorides (eg, K ¹⁸ F, Rb ¹⁸ F, Cs ¹⁸ F, and Na ¹⁸ F). Optionally, the ^-fluorinating agent can be used in combination with a chelating agent such as a cryptand (for example: 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane - Kryptofix®) or crown ether (for example: 18-crown-6). Alternatively, the ^-fluorinating agent may be an ^18F tetraalkylammonium salt or an ^18F tetraalkylphosphonium salt; for example, tetra(C1-6alkyl)ammonium salt ^18F or tetra(C1-6alkyl)phosphonium salt ^18F . Examples thereof include tetrabutylammonium [1^]fluoride and tetrabutylphosphonium [1^]fluoride. Preferably the ^-fluorinating agent is K ¹⁸ F, H ¹⁸ F,

- 9 046355

Cs ^{B * * * * * * * * * 18} F, Na ¹⁸ F or tetrabutylammonium [ ¹⁸ P]fluoride. In an even more preferred embodiment, the γ-fluorinating agent is K ¹⁸ F. In another more preferred embodiment, the γ-fluorinating agent is tetrabutylammonium [1^]fluoride.

^-fluorination is usually carried out in a solvent, which is preferably selected from acetonitrile, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, amyl alcohol, t-butyl alcohol or a mixture thereof, preferably the solvent contains or is acetonitrile or DMSO. But other solvents that are well known to one skilled in the art can also be used. The solvent may further include water and/or other alcohols, such as C _1-10 linear, branched or cyclic alkanols, as a co-solvent. In one preferred embodiment, the γ-radiolabelling solvent contains dimethyl sulfoxide. In another preferred embodiment, the solvent for carrying out β-radiolabeling contains acetonitrile. In one preferred embodiment, the solvent for performing ¹⁸ E radiolabeling is dimethyl sulfoxide. In another preferred embodiment, the solvent for performing β-radiolabeling is acetonitrile.

^-fluorination is usually carried out for about 60 minutes. The preferred reaction time is about 30 minutes maximum. Further preferred reaction times are at most about 15 minutes.

^-fluorination is usually carried out at a temperature of from about 60 to about 200°C with conventional heating or heating using microwave radiation. In a preferred embodiment, γ-fluorination is carried out at a temperature of from about 100 to about 180°C. In a more preferred embodiment, the γ-fluorination is carried out at a temperature of from about 100 to about 160°C. Preferably, γ-fluorination is carried out under conventional heating. Conventional heating refers to any heating without the use of microwaves.

The amount of starting material is not particularly limited. For example, from about 0.5 to about 50 µmol of a compound of formula II can be used to prepare a compound of formula I in one batch. In a preferred embodiment, from about 2 to about 25 µmol of a compound of formula II is used. In a more preferred embodiment, from about 2.5 to about 15 µmol of a compound of formula II is used. In one embodiment, at least about 2 µmol of a compound of formula II is used. In a preferred embodiment, at least about 2.5 µmol of a compound of Formula II is used. In a more preferred embodiment, at least about 3 micromoles of a compound of formula II is used.

If X is PG, an intermediate having formula III will be obtained. The PG protecting group can be removed in either step a) or an optional subsequent step b).

Preferred compounds of formula III are selected from the group consisting of •N\PG

N\PG

In these connections, PG is as defined in the Definitions section.

Stage b):

Step b) is an optional step that involves removing the protecting group PG from a compound of formula III to obtain a compound of formula I. As will be apparent to one skilled in the art, this step is not applicable if step a) is carried out with a compound of formula II in which X represents is hydrogen, or if the protecting group PG has already been removed in step a).

Reaction conditions for removing a wide variety of protecting groups are well known to one skilled in the art and can be selected from, but not limited to, those described in the manual

Greene and Wuts, Protecting groups in Organic Synthesis, third edition, pages 494-653, and R. J. Kocienski, Protecting Groups, 3rd Edition 2003, both of which are incorporated herein by reference.

The conditions that are used in step b) will depend on the protecting group to be removed, and are thus not particularly limited.

- 10 046355

Possible reaction conditions include:

i) heating at about 60°C to about 160°C, ii) adding acid and heating at about 0°C to about 160°C, or iii) adding base and heating at about 0°C to about 160°C.

Preferred acids are hydrochloric acid, sulfuric acid and phosphoric acid. One preferred acid is sulfuric acid. Another preferred acid is phosphoric acid. Preferred bases are sodium hydroxide, potassium hydroxide.

The preferred reaction condition is the addition of acid and heating at a temperature of from about 25 to 160°C, preferably from 25 to 120°C.

If desired, steps a) and b) can be performed in the same or different reaction vessels. Preferably, steps a) and b) are carried out in the same reaction vessel.

If desired, the solution obtained after step b) can be used without further purification in step c). Alternatively, the solution composition can be adapted to be more suitable for HPLC performance. For example, a buffer or diluent may be added before step c).

Stage c):

Step c) involves purifying the compound of formula I.

Suitable methods for purifying a compound of formula I are HPLC, solid phase extraction (SPE), or a combination thereof.

In one preferred embodiment, the compound of formula I obtained in step a) or, if used, step b), is subjected to HPLC using a mobile phase containing ethanol and water and, optionally, acid, base, buffer, salt and/or hydroxycarboxylic acid. acid, hydroxycarboxylic acid salt or a mixture thereof.

The ratio of ethanol to water is not particularly limited, but is preferably from about 5/95 to about 80/20 v/v, more preferably from about 5/95 to about 50/50 v/v, even more preferably from about 5/95 to about 20/80 rpm

The pH of the mobile phase is not limited, but is preferably from about 0 to about 8, preferably from about 0 to about 6, more preferably from about 1 to about 5, even more preferably from about 1 to about 3.

Possible buffers may include salts which may be selected from alkali metal dihydrogen phosphates, di(alkali metal) hydrogen phosphates or tri(alkali metal) phosphates, alkali metal acetates, alkaline earth metal acetates, alkaline earth metal formates, mono/di/citrate three alkali metals, with the preferred alkali and alkaline earth metals being sodium and potassium. Preferred buffers include salts which may be selected from alkali metal dihydrogen phosphates, di(alkali metal) hydrogen phosphates, tri(alkali metal) phosphates, alkali metal acetates, mono/di/tri-alkali metal citrate, with the preferred alkali metals being sodium and potassium.

Possible bases include sodium hydroxide and/or potassium hydroxide.

If desired, the pH of the mobile phase can be adjusted using inorganic or organic acid. Examples of inorganic acids include ascorbic acid, citric acid and acetic acid. Examples of organic acids include hydrochloric acid, sulfuric acid and phosphoric acid, preferably phosphoric acid.

The preferred mobile phase includes from about 5 to about 20% v/v. ethanol, from about 95 to about 80% v/v. water, about 50 to about 150 mM buffer (eg, alkali metal dihydrogen phosphate), with a pH of about 1 to about 3, and optionally a radioabsorbent.

Stationary phases for use in HPLC methods are well known and can be selected accordingly by one skilled in the art. In a preferred embodiment, the stationary phase is a reverse phase (RP) stationary phase.

Examples of RP-HPLC stationary phases include C18, C8, phenyl, cyano (eg cyanopropyl), pentafluorophenyl, amino (eg aminopropyl), amide (eg _C10-24 -alkanoaminopropyl), phenylhexyl-functionalized resins or mixed phase resins .

In one embodiment, the particle size of the HPLC stationary phase is from about 1.6 to about 15 μm. In a preferred embodiment, the particle size of the HPLC stationary phase is from about 5 to about 10 μm. In another embodiment, the particle size of the HPLC stationary phase is about 10 μm.

Typically the HPLC column has a diameter of about 2.0 mm to about 50 mm and a length of about 50 mm to about 300 mm. In a preferred embodiment, the HPLC column has a diameter of about 4.6 mm to about 20 mm and a length of about 150 mm to about 250 mm. In a more preferred embodiment, the HPLC column has a size of 10 x 250 mm.

The flow rate used in high performance liquid chromatography is not limited and

- 11 046355 may be from about 1 to about 20 ml/min, more typically from about 2 to about 15 ml/min, even more typically from about 2 to about 7 ml/min.

The pressure used in high performance liquid chromatography is not particularly limited and may range from about 50 to about 400 bar, typically from about 50 to about 250 bar, more typically from about 50 to 200 bar.

Optional step d) involves mixing the compound of formula I obtained in step c) with one or more selected from the group consisting of ethanol, water, a hydroxycarboxylic acid and a hydroxycarboxylic acid salt, if these are not already present in the desired amount in the mixture with the compound formula I after step c) to obtain a composition for diagnostics. In addition, optionally, one or more selected from an inorganic acid, additional organic acid, base or salt may be further added in step d) if they are not already present in the desired amount in the mixture with the compound of Formula I after step c).

If the diagnostic composition is to be administered to a patient, it must be sterile. The diagnostic composition can be sterilized by any known method. One option is to perform sterilizing filtration (stage e). The sterile filter may be a standard sterile filter used for radiotracer filtration. Such sterile filters are well known in the art. Suitable sterile filters are sterile polytetrafluoroethylene (PTFE) filters (e.g. Millipore Millex-LG), sterile polyethersulfone (PES) filters (e.g. Millipore Millex-GP), sterile polyvinylidene fluoride (PVDF) filters (e.g. Millipore Millex-GV ). More preferably, the hydrophobic filter is a sterile polytetrafluoroethylene (PTFE) filter or a sterile polyvinylidene fluoride (PVDF) filter.

Step e) may be carried out after step d) or before step d), where the compound of formula I obtained after step c) is subjected to sterilizing filtration and then optionally mixed with other components of the diagnostic composition, where the other components of the pharmaceutical composition are sterile or undergo sterilizing filtration before mixing.

Preferably, step a), step b) and step c) are carried out using a synthesis plant. More preferably, step a), step b), step c) and step d) are carried out using a synthesis unit. Even more preferably, step a), step b), step c), step d) and step e) are carried out using a synthesis unit.

Examples of such suitable synthesis devices include, but are not limited to, IBA Synthera, Ge Fastlab, GE Tracerlab MX, Ge Tracerlab FX, Trasis AllinOne, ORA Neptis Perform, ORA Neptis Mosaic, ORA Neptis Plug, Scintomics GPR, Synthera, Comecer Taddeo, Raytest Synchrom, Sofie Elixys, Eckert&Ziegler Modular Lab, Sumitomo Heavy Industries F100 F200 F300, and Siemens Explora.

Preferably, step a), step b) and step c) are carried out by remote control. More preferably, step a), step b), step c) and step d) are carried out by remote control. Even more preferably, step a), step b), step c), step d) and step e) are carried out by remote control.

Preferably, stage a), stage b) and stage c) are automated. More preferably, step a), step b), step c) and step d) are automated. Even more preferably, step a), step b), step c), step d) and step e) are automated.

Diagnostic methods

The diagnostic composition of the present invention is preferably intended for use in diagnostics. In such a case, the F in the compound of formula I is preferably ¹⁸ F.

Accordingly, in a third aspect, the invention relates to a diagnostic composition, as defined in the first aspect, for use in diagnostics. The composition of the present invention is particularly suitable for imaging Tau aggregates, for example, using positron emission tomography (PET). It can be used in the diagnosis of a disorder (such as a neuropathological disorder) associated with Tau aggregates, or in the diagnosis of tauopathy, especially if the diagnosis is made using positron emission tomography. Tau aggregates can be found in the human brain.

The diagnostic compositions of the present invention have been found to be particularly suitable for visualizing Tau protein aggregates. With regard to the Tau protein, detectably labeled compounds of formula I are capable of binding to various types of Tau aggregates, such as pathologically aggregated Tau, hyperphosphorylated Tau, neurofibrillary tangles, paired helical filaments, straight filaments, neurotoxic soluble oligomers, polymers and fibrils.

Due to the above binding characteristics, detectably labeled compounds of formula I are suitable for use in the diagnosis of disorders associated with Tau aggregates. Detectably labeled compounds of Formula I are particularly suitable for positron emission tomography (PET) imaging of Tau deposits. Typically, β-labeled compounds of formula I are used as detectably labeled compounds when the compounds are to be administered to a patient.

- 12 046355

It should be understood that in the following examples, detectably labeled compounds of formula I are preferably included in the diagnostic composition of the present invention.

Thus, the diagnostic composition of the present invention can be used in a method of collecting data for diagnosing a disorder associated with Tau aggregates in a sample or patient, preferably a human, comprising:

(a) bringing a sample or a specific body part or area of the body suspected of containing a Tau aggregate into contact with a composition that includes a compound of Formula I;

(b) allowing connections to communicate with the Tau unit;

(c) detection of a compound associated with a Tau aggregate; and (d) optionally correlating the presence or absence of binding of a compound to a Tau aggregate with the presence or absence of a Tau aggregate in a sample or a particular body part or region of the body.

A specific method for detecting Tau deposits in a subject (eg, a human) may involve the steps of:

1) administering a suitable amount of the diagnostic composition to the subject,

2) if necessary, waiting for the distribution of the composition for diagnosis in the subject,

3) performing positional emission tomography (PET),

4) if necessary, reconstruction of PET imaging data and

5) interpretation of PET imaging data.

Preferably, the diagnostic composition is administered intravenously. The dosage of detectably labeled compounds of Formula I may vary depending on the exact compound to be administered, the weight of the subject, the size and type of sample, and other variables that will be apparent to one skilled in the art. Typically, the volume of the diagnostic composition to be administered to a human subject may be from about 0.1 to about 20 ml, preferably from about 0.1 to about 10 ml, more preferably from about 0.5 to about 10 ml . Preferably, about 100 to about 740 MBq of the diagnostic composition is administered, more preferably about 100 to about 400 MBq, even more preferably about 150 to about 300 MBq.

Preferably, PET imaging is acquired in about 5 to about 30 minutes, preferably from about 5 to about 20 minutes, more preferably from about 10 to about 20 minutes. Preferably, PET acquisition begins from about 30 to about 120 minutes after administration of the diagnostic composition, more preferably from about 30 to about 90 minutes after administration, even more preferably from about 45 to about 60 minutes after administration. Interpretation of PET imaging data is carried out using visual assessment or quantitative analysis.

When visualizing Tau aggregates, a detectably labeled compound of formula I is administered and the signal emanating from a compound that is specifically associated with Tau aggregates is detected. Specific binding results from the high binding affinity of the compounds of formula I to Tau aggregates.

In a preferred embodiment, a detectably labeled compound of formula I is used to diagnose the presence of tauopathy (preferably Alzheimer's disease). In this method, a detectably labeled compound of formula I is administered to a patient suspected of having tauopathy (preferably Alzheimer's disease) or to a sample obtained from such a patient, and the signal emanating from the detectable label is detected, preferably by positron emission tomography (PET) .

If no signal emanating from the detectable label is detected, then this method can be used to exclude tauopathy, which indicates the presence of a neurological disorder other than tauopathy.

In methods of diagnosing a disorder associated with Tau protein aggregates, such as Alzheimer's disease, or a predisposition thereto in a subject, the method includes:

a) administering to the mammal a diagnostically effective amount of a detectably labeled compound of formula I;

b) allowing the detectably labeled compound of Formula I to distribute into tissue of interest (such as brain tissue or body fluids such as cerebrospinal fluid (CSF)); And

c) imaging the tissue of interest, wherein an increase in binding of the detectably labeled compound of formula I to the tissue of interest compared to the normal control level of binding indicates that the subject suffers from or is at risk of developing a disorder associated with Tau protein aggregates.

Detectably labeled compounds of Formula I can be used to visualize Tau protein aggregates in any sample or specific body part or region of a patient's body that is suspected of containing a Tau protein aggregate. Detectably labeled compounds of formula I are capable of crossing the blood-brain barrier. Therefore, they are particularly suitable for imaging Tau protein aggregates in the brain as well as in body fluids such as cerebrospinal fluid (CSF).

Diagnosis of tau disorder or predisposition to Tau-associated disorder in

- 13 046355 patient can be achieved by detecting the specific binding of a detectably labeled compound of formula I to Tau protein aggregates in a sample or in situ, which includes:

(a) contacting a sample or a specific body part or region of the body suspected of containing a Tau protein aggregate with a detectably labeled compound of formula I that binds the Tau protein aggregate;

(b) allowing a detectably labeled compound of Formula I to bind to a Tau protein aggregate to form a compound/Tau protein aggregate complex (hereinafter, the compound/Tau protein aggregate complex will be abbreviated as a compound/protein aggregate complex);

(c) detecting the formation of a compound/protein aggregate complex, (d) optionally correlating the presence or absence of a compound/protein aggregate complex with the presence or absence of Tau protein aggregates in the sample or a specific body part or region, and (e) optionally comparing the amount of complex compound/protein aggregate with a normal control value, wherein an increase in the amount of a compound/protein aggregate complex compared to the normal control value may indicate that the patient has or is at risk of developing a Tau-associated disorder.

After contacting a sample or a specific body part or region of the body with a detectably labeled compound of Formula I, the compound is allowed to bind to the Tau protein aggregate. The amount of time required for binding will depend on the type of test (eg, in vitro or in vivo) and can be determined by one of ordinary skill in the art through routine experimentation.

The compound that binds to the Tau protein aggregate can subsequently be detected by any suitable method. The preferred method is positron emission tomography (PET).

The presence or absence of a compound/protein aggregate complex then optionally correlates with the presence or absence of Tau protein aggregates in the sample or a particular body part or region. Finally, the amount of the compound/protein aggregate complex can be compared to a normal control value that was determined in a sample or a specific body part or region of the body of a healthy subject, where an increase in the amount of compound/protein aggregate complex compared to the normal control value may indicate that the patient suffers from or is at risk of developing a Tau-associated disorder.

Predicting the response of a patient suffering from a disorder associated with Tau protein aggregates and receiving treatment with a drug can be achieved by (a) bringing a sample or a specific body part or region of the body suspected of containing a Tau protein aggregate into contact with a detectably labeled compound of formula I ;

(b) allowing a detectably labeled compound of Formula I to bind to a Tau protein aggregate to form a compound/protein aggregate complex;

(c) detecting formation of a compound/protein aggregate complex;

(d) optionally, correlating the presence or absence of a compound/protein aggregate complex with the presence or absence of a Tau protein aggregate in a sample or a specific body part or region; and (e) optionally, comparing the amount of compound/protein aggregate complex with a normal control value.

How steps (a) to (e) can be carried out has previously been explained above.

In a method for predicting response, the amount of compound/protein aggregate complex can optionally be compared at different time points during treatment, for example, before and after the start of treatment or at different time points after the start of treatment. A change, especially a decrease in the amount of compound/protein aggregate complex, may indicate that the patient has a high potential for response to appropriate treatment.

The diagnostic composition of the present invention has a number of significant advantages: it is chemically stable and can be stored at room temperature for at least 8 hours or even for at least 10 hours, it is stable at concentrations of the compound of formula I not exceeding 5 μg/ml , preferably not more than 10 μg/ml, sterilizing filtration of the diagnostic composition can be accomplished without significant loss of radioactivity, allows administration to the subject without significant loss of radioactivity on syringes and other materials, it has high purity and stability of the compound of formula I at high concentrations of radioactivity, e.g. >2 GBq/ml, preferably >3 GBq/ml, more preferably >5 GBq/ml for 10 hours, preferably for 12 hours, it provides high purity and stability of the compound of formula I at high levels of radioactivity per batch, for example > 20 GBq, preferably >50 GBq, more preferably >100 GBq for 10 hours, preferably for 12 hours, it can be used to detect Tau protein deposits in subjects.

The present invention is illustrated by the following examples, which should not be considered

- 14 046355 as limiting.

Examples

All reagents and solvents were obtained from commercial sources and were used without further purification. Proton (1H) spectra were recorded on a Bruker DRX400 MHz NMR spectrometer or a Bruker AV-400 MHz NMR spectrometer in deuterated solvents. Mass spectra (MS) were recorded on an Advion CMS mass spectrometer. Chromatography was carried out using silica gel (Fluka: silica gel 60, 0.063-0.2 mm) and suitable solvents as indicated in the specific examples. Flash purification was performed using a Biotage Isolera One Flash Purification System using HP-Sil (Biotage) or puriFlash (Interchim) columns and the solvent gradient specified in the specific examples. Thin layer chromatography (TLC) was performed on silica gel plates with UV detection.

Abbreviations

AD Alzheimer's disease B.S.A. bovine serum albumin Vos, VOS from/?eot-butyloxycarbonyl CBD corticobasal degeneration d.c. adjusted for decay d doublet dd double doublet ddd double doublet doublet dt double triplet DMA dimethylacetamide DMF N, A-dimethylformamide DMSO dimethyl sulfoxide DMTrt-Cl 4,4'-(chloro(phenyl)methylene)bis(methoxybenzene) dppf 1,1'-bis(diphenylphosphino)ferrocene EI electron ionization ELSD evaporative light scattering detector ESI electrospray ionization EtOH ethanol FTD frontotemporal dementia HPLC high performance liquid chromatography

- 15 046355

NS Healthy control GBk gigabecquerel K222 4,7,13,16,21,24-hexaoxa-1,10-d iazabicyclo[8.8.8]-hexacosane (Kryptofix 222) MBq megabecquerel MS mass spectrometry MeCN acetonitrile M multiplet me centered multiplet n.c.a. no media added n.d.c. unspecified decay NMR nuclear magnetic resonance spectroscopy: chemical shifts (δ) are given in ppm. PBS Phosphate-buffered saline solution PAT positron emission tomography PiD Pick's disease PSP progressive supranuclear palsy q quadruplet (quartet) Room pace. room temperature c singlet T triplet Tay Tau protein, Tau deposits, Tau aggregates TBI traumatic brain injury Trt trityl (triphenylmethyl) TLC thin layer chromatography % 06./06. Percentage by volume EOS End of synthesis GBk Giga-Becquerel MBq megabecquerel SPE solid phase extraction WFI water for injection

Synthesis of test compounds Preparation example A.

N ₂ H ₄ xH ₂ O U4 O^JnBoc

JH || _[ u Μ 1

Br N Br EtOH Br NN ² polyphosphoric acid

Stage A Stage B

A

Stage A:

Commercially available 2,6-dibromopyridine (4.12 g, 16.6 mmol) was suspended in ethanol (40 ml) and hydrazine hydrate (10 ml, 97.6 mmol) in water (-50-60%) was added. The mixture was heated in a sand bath at -115°C for 18 hours. The solvent was removed and the residue was purified by silica gel chromatography using ethyl acetate/n-heptane (60/40) to give the title compound as an off-white solid substances (3.05 g, 93%).

¹ H-NMR (400 MHz, CDCl ₃ ): δ=7.33 (t, 1H), 6.83 (d, 1H), 6.67 (d, 1H), 6.00 (brs, 1H ), 3.33-3.00 (br.s, 2H)

- 16 046355

Stage B:

The title compound from Step A above (10 g, 53.2 mmol) and commercially available l-Boc-4-piperidone (10.6 g, 53.2 mmol) were added to a 500 ml flask and stirred until the mixture was homogeneous. Polyphosphoric acid (80 g, 115% H ₃ PO ₄ base) was then added and the mixture was heated at ~160°C in a sand bath. At ~120°C, the Boc-protecting group is split off, which leads to foaming of the reaction mixture. After complete Boc cleavage, the foam collapsed and the dark reaction mixture was stirred at ~160°C for 20 hours. The reaction mixture was allowed to cool to room temperature and water (400 ml) was added. The reaction mixture was stirred/sonicated until the viscous substance dissolved. The reaction mixture was then placed in an ice bath and the pH of the solution was adjusted to pH ~12 by adding solid sodium hydroxide granules (exothermic). The precipitate was collected by filtration and washed with water (400 ml) to remove salts. The precipitate was dissolved in dichloromethane/methanol (9/1; 1500 ml) using ultrasound and washed with water (2 x 400 ml) to remove remaining salts and insoluble matter. The organic phase was dried over Na ₂ SO ₄ , filtered and the solvents were removed under reduced pressure. The dark residue was treated with dichloromethane (100 ml), sonicated for 5 min and the precipitate was collected by filtration. The residue was washed with dichloromethane (40 ml) and air dried to give the title compound as a beige solid (3.5 g, 26%).

¹ H-NMR(400 MHz, DMSO-d6): 6=11.5(brs, 1H), 7.72 (d, 1H), 7.15 (d, 1H), 3.86-3, 82 (m, 2H), 3.063.00 (m, 2H), 2.71-2.65 (m, 2H)

Stage C:

The title compound from Step B above (1.75 g, 6.94 mmol) was suspended in xylene (380 ml) and manganese(IV) oxide (6.62 g, 76.9 mmol) was added. The reaction mixture was then heated at ~160°C in a sand bath for 36 hours. The cooled reaction mixture was evaporated under reduced pressure, the residue was suspended in dichloromethane/methanol (1/1; 400 ml) and stirred at room temperature for 30 minutes. The reaction mixture was then filtered through paper filters to remove manganese(IV) oxide and the filter was washed with methanol (50 ml). The combined filtrates were evaporated under reduced pressure and the dark residue was purified by silica gel chromatography (50 g HP-SIL cartridge) using a Biotage Isolera system using an ethyl acetate/heptane gradient (5/95-100/0) to remove non-polar impurities and then dichloromethane/methanol (9/1 -> 4/1) to give the title compound as a dark yellow solid. The total yield from 2 runs was 1.77 g (51%).

1H-NMR (400 MHz, DMSO-d6): δ=12.52 (br.s, 1H), 9.42 (s, 1H), 8.61 (d, 1H), 8.53 (d, 1H ), 7.56-7.52 (m, 2H)

Example of receiving B.

Stage A:

To a suspension of the title compound of Preparation Example A (0.776 g, 0.72 mmol) in dichloromethane (65 mL) was added triethylamine (1.86 mL, 13 mmol) and trityl chloride (2.63 g, 9.39 mmol). After adding 4-(dimethylamino)pyridine (0.074 g, 0.608 mmol), the reaction mixture was stirred at room temperature for 16 hours. The reaction mixture was diluted with dichloromethane (150 ml) and water (50 ml). The organic phase was separated, dried over Na2SO4, filtered and the solvents were removed in vacuo. The residue was purified on HP-Sil SNAP cartridges (50 g) using the Biotage Isolera One purification system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0) to give the title compound B as a pale yellow solid (0.831 g, 54%). The unreacted starting material was recovered by washing the cartridge with ethyl acetate/methanol (90/10) to obtain the starting material as an off-white solid (0.195 g, 25%).

1H-NMR (400 MHz, CDCl3) δ=9.22 (s, 1H), 8.23 (d, 1H), 8.13 (d, 1H), 7.48-7.42 (m, 7H) , 7.33-7.22 (m, 12H), 6.41 (d, 1H) MS (ESI); m/z=490.03/491.96 [M+H]+

An example of obtaining S.

OSN ₃

- 17 046355

Stage A:

To a suspension of the title compound from Preparation Example A (0.482 g, 1.94 mmol) in dichloromethane (40 mL) was added triethylamine (1.15 mL, 8 mmol) and 4,4'-(chloro(phenyl)methylene)bis (methoxybenzene; DMTrt-Cl) (1.963 g, 5.8 mmol). After adding 4(dimethylamino)pyridine (0.046 g, 0.377 mmol), the reaction mixture was stirred at room temperature for 3 days. The reaction mixture was diluted with dichloromethane (100 ml) and water (40 ml). The organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were removed in vacuo. The residue was purified on HP-Sil SNAP cartridges (50 g) using the Biotage Isolera One purification system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0) to give the title compound C as a pale yellow solid (0.825 g, 72%). The unreacted starting material was recovered by washing the cartridge with ethyl acetate/methanol (90/10) to obtain the starting material as an off-white solid (0.042 g, 8.8%).

¹ H-NMR (400 MHz, CDCl ₃ ) δ=9.23 (s, 1H), 8.23 (d, 1H), 8.13 (d, 1H), 7.39-7.31 (m, 6H), 7.29-7.25 (4H), 6.80 (d, 4H), 6.41 (dd, 1H), 3.81 (s, 6H)

Example 1.

Stage A:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0.0084 g, 0.01 mmol), then the title compound of Preparation Example A (0.05 g, 0.2 mmol), (2-fluoropyridin-4-yl)boronic acid (0.035 g, 0.245 mmol) and cesium carbonate ( 0.133 g, 0.41 mmol). The reaction mixture was then heated at ~115°C in a sand bath for 6 hours. The reaction mixture was diluted with ethyl acetate (60 ml) and water (20 ml), the organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were evaporated in vacuum. The dark residue was purified by silica gel chromatography (25 g HP-SIL) using a Biotage Isolera system using a dichloromethane/methanol gradient (100/0 -> 95/5 -> 90/10 -> 80/20) to give the title compound 1 (Ib) as an off-white solid (0.033 g, 63%).

1H-NMR (400 MHz, DMSO-d6) δ=12.50 (br.s, 1H), 9.45 (s, 1H), 8.83 (d, 1H), 8.56-8.52 ( m, 1H), 8.438.39 (m, 1H), 8.19-8.14 (m, 2H), 7.92 (s, 1H), 7.54-7.50 (m, 1H) MS ( ESI): m/z=265.04 [M+H]+

Example 2.

Stage A:

To a suspension of the title compound of Preparation Example A (0.430 g, 1.73 mmol) in dichloromethane (25 mL) was added triethylamine (1.93 mL, 13.89 mmol) and di-tert-butyl dicarbonate (2.27 g, 10 .02 mmol). After adding 4-(dimethylamino)pyridine (0.042 g, 0.34 mmol), the reaction mixture was stirred at room temperature for 3 days. Solvents were removed under reduced pressure and the residue was purified on HP-Sil SNAP cartridges (25 g) using a Biotage Isolera One purification system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0), with obtaining the title compound 2 (1a) as an off-white solid (0.558 g, 92%).

1H-NMR (400 MHz, CDCl ₃ ) δ=9.28 (s, 1H), 8.73 (d, 1H), 8.22 (d, 2H), 7.59 8d, 1H), 1.80 (s, 9H)

Stage B:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0.0058 g, 0.007 mmol), then the title compound from Step A above (0.05 g, 0.143 mmol), (6-fluoropyridin-3-yl)boronic acid (0.024 g, 0.17 mmol) and cesium carbonate (0.092 g, 0.286 mmol). The reaction mixture was then heated at ~100°C in a sand bath for 4 hours. The reaction mixture was diluted with ethyl acetate (80 ml) and water (35 ml), the organic phase was separated, dried over Na ₂ SO ₄ , filter

- 18 046355 were removed and the solvents were evaporated in vacuum. The dark residue was purified by silica gel chromatography (12 g, puriFlash, Interchim) using a Biotage Isolera system using a dichloromethane/methanol gradient (100/0 -> 98/2 -> 95/5 -> 90/10 -> 80 /20), yielding the less polar Deprotected Compound (0.0255 g, 49%) and the more polar title compound 2 (Ia) as an off-white solid (0.0116 g, 31%).

More polar title compound 2 (Ia):

¹ H-NMR (400 MHz, DMSO-d ₆ ) δ=12.40 (br.s, 1H), 9.40 (s, 1H), 9.05 (s, 1H), 8.78-8, 70 (m, 2H), 8.51 (d, 1H), 8.02 (d, 1H), 7.50 (d, 1H), 7.36 (dd, 1H) MS (ESI): m/z =265.09 [M+H]+

Less polar Boc-protected compound:

¹ H-NMR (400 MHz, DMSO-d ₆ ) δ=9.48 (s, 1H), 9.13 (d, 1H), 8.84-8.78 (m, 2H), 8.68 ( d, 1H), 8.23 (d, 1H), 8.19 (d, 1H), 7.40 (dd, 1H), 1.75 8s, 9H)

Synthesis of radiolabeled precursors

Example 3-a.

Stage A 3-a (llb-2b)

Stage A:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0.0084 g, 0.01 mmol), the title compound of Preparation Example B (0.1 g, 0.2 mmol), 2nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane- 2-yl)pyridine (0.061 g, 0.245 mmol) and cesium carbonate (0.133 g, 0.41 mmol). The reaction mixture was then heated at ~115°C in a sand bath for 6 hours. The reaction mixture was diluted with ethyl acetate (60 ml) and water (20 ml), the organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were evaporated in vacuum. The dark residue was purified by silica gel chromatography (25 g pufiFlash column, Interchim) using a Biotage Isolera system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0) to give the above in the title compound 3-a as a pale yellow solid (0.082 g, 75%).

1H NMR (400 MHz, CDCl ₃ ) δ=9.32 (s, 1H); 8.56 (d, 1H), 8.48 (d, 1H), 8.33 (s, 1H); 8.30 (d, 1H), 7.85 (d, 1H), 7.69 (d, 1H), 7.58-7.54 (m, 5H), 7.32-7.25 (m, 10H), 6.48 (d, 1H) MS (ESI): m/z=534.28 [M+H] ⁺ .

Example 3-b.

Method a:

Stage A:

Trifluoroacetic acid (1.2 mL) was added to a solution of 3-a (0.0396 g, 0.074 mmol) in dichloromethane (5 mL). The reaction mixture was stirred at room temperature for 6 hours and methanol (2 ml) was added. The solvents were evaporated in vacuo and the residue was dissolved/suspended in methanol (5 ml). The solvents were evaporated in vacuo and the residue was redissolved/suspended in methanol (5 ml). The solvents were evaporated in vacuo and the residue was suspended in dichloromethane (2 ml). After adding triethylamine (1 ml, 7.2 mmol), di-tert-butyl dicarbonate (0.098 g, 0.43 mmol), and 4-(dimethylamino)pyridine (0.0018 g, 0.014 mmol), the reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was diluted with ethyl acetate (50 ml) and water (20 ml). The organic phase was separated, dried over Na2SO4, filtered and the solvents were removed in vacuo. The residue was purified on silica gel (25 g puriFlash, Interchim) using a Biotage Isolera One purification system using a gradient of ethyl acetate/n-heptane (5/95 -> 100/0 -> 100/0) to elute non-polar by-products, then ethyl acetate/ methanol (95/5) to give the title compound 3-b as a pale yellow solid (0.0184 g, 63%).

1H-NMR (400 MHz, CDCl ₃ ) δ=9.36 (s, 1H), 9.15 (s, 1H), 8.82-8.76 (m, 2H), 8.57 (d, 1H ), 8.45 (d, 1H), 8.36 (d, 1H), 8.07 (d, 1H), 1.87 (s, 9H) MS (ESI); m/z=391.82 [M+H] ⁺

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Method b:

Stage A:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0 .0042 g, 0.005 mmol), then the title compound of Preparation Example C (0.055 g, 0.1 mmol), 2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane -2-yl)pyridine (0.0305 g, 0.12255 mmol) and cesium carbonate (0.067 g, 0.205 mmol). The reaction mixture was then heated at ~115°C in a sand bath for 6 hours. The reaction mixture was diluted with ethyl acetate (20 ml), the precipitate was collected by filtration, washed with water (10 ml) and methanol (5 ml) and air-dried to give 3-c (0.0277 g, 95%).

Stage B:

To a suspension of the crude title compound from Step A above (0.0277 g, 0.095 mmol) in dichloromethane (4 ml) was added triethylamine (1 ml, 7.2 mmol), di-tert-butyl dicarbonate (0.2 g, 0 .86 mmol), and 4-(dimethylamino)pyridine (0.0036 g, 0.028 mmol). The reaction mixture was stirred at room temperature for 16 hours, diluted with ethyl acetate (50 ml) and water (20 ml). The organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were removed in vacuo. The residue was purified on silica gel (25 g puriFlash, Interchim) using a Biotage Isolera One purification system using a gradient of ethyl acetate/n-heptane (5/95 -> 100/0 -> 100/0) to elute non-polar by-products, then ethyl acetate/ methanol (95/5) to give the title compound 3-b as a pale yellow solid (0.0261 g, 70%).

¹ H-NMR (400 MHz, CDCl ₃ ) δ=9.38 (s, 1H), 9.16 (s, 1H), 8.83-8.78 (m, 2H), 8.58 (d, 1H), 8.46 (d, 1H), 8.38 (d, 1H), 8.09 (d, 1H), 1.88 (s, 9H) MS (ESI); m/z=391.85 [M+H]+; 291.74 [M+N-Vos]+

Example 3-d.

Stage A:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0 .0042 g, 0.005 mmol), then the title compound of Preparation Example C (0.055 g, 0.1 mmol), 2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane -2-yl)pyridine (0.0305 g, 0.12255 mmol) and cesium carbonate (0.067 g, 0.205 mmol). The reaction mixture was then heated at ~115°C in a sand bath for 6 hours. The reaction mixture was diluted with ethyl acetate (20 ml), the precipitate was collected by filtration, washed with water (10 ml) and methanol (5 ml) and air dried to obtain 3- s as a gray solid (0.0277 g, 95%).

Stage B:

To a suspension of the crude title compound from Step A above (0.0277 g, 0.095 mmol) in dichloromethane (4 ml) was added triethylamine (1 ml, 7.2 mmol), 4,4'(chloro(phenyl)methylene)bis (methoxybenzene) (0.081 g, 0.29 mmol), and 4-(dimethylamino)pyridine (0.0036 g, 0.028 mmol). The reaction mixture was stirred at room temperature for 18 hours, diluted with ethyl acetate (50 ml) and water (20 ml). The organic phase was separated, dried over Na2SO4, filtered and the solvents were removed in vacuo. The residue was purified on silica gel (25 g puriFlash, Interchim) using a Biotage Isolera One purification system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0) to give the title compound 3- d as a pale yellow solid (0.0261 g, 44%).

¹ H-NMR (400 MHz, CDCl3) δ=9.32 (s, 1H), 8.58 (d, 1H), 8.50 (d, 1h), 8.36 (s, 1H), 8. 30 (d, 1H), 7.85 (d, 1H), 7.74 (d, 1H), 7.52-7.42 (m, 6H), 7.27-7.23 (m, 4H) , 6.80 (d, 4H), 6.49 (d, 1H), 3.78 (s, 6H)

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Example 3.

Stage A:

Commercially available H^dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2amine (0.25 g, 1 mmol) was dissolved in dichloromethane (5 ml) . To the resulting stirred solution, methyl trifluoromethanesulfonate (0.124 mL, 1.1 mmol) was added dropwise at room temperature. The solution was stirred at room temperature for 4 hours. The reaction mixture was concentrated to remove dichloromethane and the residue was dried in vacuo to obtain a yellow foam glass, which was used directly in the next step.

Stage B:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloro-palladium(II) complexed with dichloromethane (0.034 g, 0.04 mmol), the title compound of Preparation Example B (0.4 g, 0.816 mmol), the crude title compound from Step A above (~1 mmol), and cesium carbonate (0.544 g, 1.68 mmol). The reaction mixture was heated at ~120°C in a sand bath for 6 hours. The reaction mixture was diluted with ethyl acetate (150 ml) and water (50 ml), the organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were evaporated in vacuum. The dark residue was purified by silica gel chromatography (25 g HP-Ultra) using a Biotage Isolera system using an ethyl acetate/n-heptane gradient (5/95 -> 100/0 -> 100/0) to elute unreacted starting material and non-polar by-products. The gradient was then changed to dichloromethane/methanol (100/0 -> 95/5 -> 90/10) to give the dimethylamine derivative as a pale yellow glass (0.127 g, 29%; MS (ESI): m/z=532.27 [M+H]+) and methylamine derivative as a gray solid (0.0547 g, 13%; MS (ESI): m/z=519.18 [M+H]+). The gradient was changed back to dichloromethane/methanol (90/10 -> 80/20) and maintained at (80/20) to give the title compound 3 as a brown solid (0.104 g, 18%).

1H NMR (400 MHz, DMSO-d6) δ=9.47 (s, 1H); 8.89 (d, 1H), 8.55 (d, 1H), 8-35-8.32 (m, 2H), 8.29 (d, 1H), 7.63-7.57 (m, 5H), 7.48 (d, 1H), 7.34-7.25 (m, 10H), 6.48 (d, 1H), 3.60 (s, 9H) MS (ESI): m/z =546.26 [M+H]+

Example 3-f.

Stage A:

3rd (0.199 g, 0.364 mmol) was suspended in dichloromethane (10 ml). After adding trifluoroacetic acid (10 ml), the reaction mixture was stirred at room temperature for 18 hours. The solvents were removed under reduced pressure, the residue was dissolved in methanol (10 ml) and the solvents were removed under reduced pressure. Treatment of the residue with methanol was repeated two more times. The residue was then suspended in dichloromethane (20 ml) and sonicated for ~5 min. The precipitate was collected by filtration, washed with dichloromethane (10 mL) and air dried to give the title compound 3-f as a gray solid (0.127 g, 83%).

1H NMR (400 MHz, DMSO-d6) δ=13.76 (br.s, 1H), 9.84 (s, 1H); 8.12 (d, 1H), 8.89 (d, 1H), 8.80 (d, 1H), 8.75 (s, 1H), 8.54-8.50 (m, 2H), 8 .04 (d, 1H), 3.72 (s, 9H) MS (ESI): m/z=303.91 [M+H] ⁺

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Example 4-a.

Stage A:

[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) complexed with dichloromethane (0.0058 g, 0.007 mmol), then the title compound of Example 2, Step A (0.05 g, 0.143 mmol), 2-nitro-5-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)pyridine (0.0428 g, 0.17 mmol) and cesium carbonate (0.092 g, 0.286 mmol). The reaction mixture was then heated at ~100°C in a sand bath for 4 hours. The reaction mixture was diluted with ethyl acetate (80 ml) and water (35 ml), the organic phase was separated, dried over Na ₂ SO ₄ , filtered and the solvents were evaporated in vacuum. The dark residue was purified by silica gel chromatography (12 g, puriFlash, Interchim) using a Biotage Isolera system using a dichloromethane/methanol gradient (100/0 -> 98/2 -> 95/5 -> 90/10 -> 80 /20) to give the title compound 4-a as a pale yellow solid (0.0173 g, 31%).

^1H NMR (400 MHz, CDCl ₃ /CD ₃ OD) δ=9.45 (d, 1H), 9.32 (s, 1H), 8.93 (dd, 1H), 8.68-8.64 (m, 2H), 8.46 (d, 1H), 8.35 (d, 1H), 8.14 (d, 1H), 1.82 (s, 9H) MS (ESI): m/z= 392.13 [M+H]+

Radiolabeling of ¹⁸ F precursors

A general RFID tagging method A implemented using tracerlab FX as shown in FIG. 1

Radiolabeling, deprotection, HPLC and SPE - comparative examples

1 ¹⁸ 1 ^; |fluoride was collected on a Sep-Pak Accell Plus QMA light cartridge (Waters) and eluted with K2CO3/Kryptofix® 2.2.2 solution. Water was removed using a He or N2 stream at 95°C and co-evaporated with MeCN (1 ml) to dryness. The dissolved precursor solution was then added to the dried K[ ¹⁸ F]F-Kryptofix complex. The reaction vessel was closed and heated for 15 min at 150°C. Then acid (1-2 M HCl, 0.5-1 M H2SO4 or 0.5-2 M H3PO ₄ ) was added and the mixture was heated for 10 minutes at 150°C. The reaction mixture was diluted with 1 ml of NaOH and 2.4 ml of the mobile phase of the drug. HPLC and the crude product was purified using semipreparative HPLC (eg Phenomenex, Gemini C18, 5 µm, 250 x 10 mm) at 4 ml/min. The isolated indicator was diluted with water (20 ml + 10 mg/ml sodium ascorbate), passed through a C-18 Plus cartridge (Waters), washed with water (10 ml + 10 mg/ml sodium ascorbate), eluted with ethanol (1 ml) and mixed with water (14 ml + 10 mg/ml sodium ascorbate).

General radiotagging method B implemented using tracerlab FX as shown in FIG. 1

Radiolabeling, HPLC and SPE - comparative examples

[18F]fluoride was captured on a Sep-Pak Accell Plus QMA light cartridge (Waters) and eluted with K ₂ CO ₃ /Kryptofix® 2.2.2 solution. Water was removed using a He or N2 stream at 95°C and co-evaporated with MeCN (1 ml) to dryness. The dissolved precursor solution was then added to the dried K[ ¹⁸ F]F-Kryptofix complex. The reaction vessel was closed and heated for 15 min at 150°C. The reaction mixture was diluted with 0.5-1 ml of NaOH and 2.4 ml of the mobile phase of the drug. HPLC and the crude product was purified using semipreparative HPLC (eg Phenomenex, Gemini C18, 5 µm, 250 x 10 mm) at 4 ml/min. The isolated indicator was diluted with water (20 ml + 10 mg/ml sodium ascorbate), passed through a C-18 Plus cartridge (Waters), washed with water (10 ml + 10 mg/ml sodium ascorbate), eluted with ethanol (1 ml) and mixed with water (14 ml + 10 mg/ml sodium ascorbate).

The general radiolabeling method C implemented on the IBA Synthera+Synthera HPLC, as shown in FIG. 2 (Radiolabeling, HPLC)

1 ¹⁸ 1 ^; |fluoride was collected on a Sep-Pak Accell Plus QMA light cartridge (Waters) and eluted with K2CO3/Kryptofix® 2.2.2 solution. Water was removed using a He or N2 stream at 95-110°C and co-evaporated to dryness. The dissolved precursor solution was then added to the dried K[ ¹⁸ F]F-Kryptofix complex. The reaction vessel was closed and heated for 15 min at 150°C. The reaction mixture was diluted with 0.5-1 ml of 1M H3PO ₄ and 3-3.5 ml of the aqueous component of the mobile phase of the drug. HPLC and the crude product was purified using semipreparative HPLC (eg Waters XBridge Peptide BEH C18, 130 A, 10 µm, 10 mm x 250 mm) at 3-6 ml/min. The product containing fraction (5-10 ml) was collected and diluted with dilution medium containing 0-2 ml EtOH, 10-20 ml water, and 0-4 ml phosphate buffer concentrate (Braun, 3.05 g disodium monohydrogen phosphate dodecahydrate, 0.462 g sodium dihydrogen phosphate dihydrate in 20 ml water for injection) and/or sodium ascorbate (100

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1000 mg) and/or sodium citrate (100-1000 mg) and/or gentisic acid (20-200 mg).

A general RFID tagging method D implemented using tracerlab FX as shown in FIG. 1 (Radiolabeling, HPLC)

[ ¹⁸ P|fluoride was captured on a Sep-Pak Accell Plus QMA light cartridge (Waters) and eluted with K ₂ CO ₃ /Kryptofix® 2.2.2 solution. Water was removed using a He or N ₂ stream at 95°C and co-evaporated with MeCN (1 ml) to dryness. The dissolved precursor solution was then added to the dried K[ ¹⁸ F]F-Kryptofix complex. The reaction vessel was closed and heated for 15 min at 150°C.

The reaction mixture was diluted with 0.5-1 ml of 1M H ₃ PO ₄ and 3-3.5 ml of the aqueous component of the mobile phase of the drug. HPLC and the crude product was purified using semipreparative HPLC (e.g. Waters XBridge Peptide BEH C18, 130 A, 10 µm, 10 mm x 250 mm or Gemini 5 µm C18, 250 x 10 mm, Phenomenex: 00G-4435-N0) at 3 -6 ml/min. The product containing fraction (5-10 ml) was collected and diluted with dilution medium containing 0-2 ml EtOH, 10-20 ml water, and 0-4 ml phosphate buffer concentrate (Braun) and/or sodium ascorbate (100-1000 mg) and/or sodium citrate (100-1000 mg) and/or gentisic acid (20-200 mg).

A general E radiotagging method implemented using tracerlab FX as shown in FIG. 1

Radiolabeling, deprotection, HPLC

[ ¹⁸ P|fluoride was captured on a Sep-Pak Accell Plus QMA light cartridge (Waters) and eluted with K2CO3/Kryptofix® 2.2.2 solution. Water was removed using a He or N2 stream at 95°C and co-evaporated with MeCN (1 ml) to dryness. The dissolved precursor solution was then added to the dried K[ ¹⁸ F]F-Kryptofix complex. The reaction vessel was closed and heated for 15 min at 150°C. Then, 1 ml of 0.5 M H2SO ₄ was added and the mixture was heated for 10 minutes at 100°C. The reaction mixture was diluted with 0.5-1 ml of 1M NaOH and 2-3 ml of the aqueous component of the mobile phase of the drug. HPLC and the crude product was purified using semipreparative HPLC (e.g. Waters XBridge Peptide BEH C18, 130 A, 10 µm, 10 mm x 250 mm or Gemini 5 µm C18, 250 x 10 mm, Phenomenex: 00G-4435-N0) at 3 -6 ml/min. The product containing fraction (5-10 ml) was collected and diluted with dilution medium containing 0-2 ml EtOH, 10-20 ml water, and 0-4 ml phosphate buffer concentrate (Braun) and/or sodium ascorbate (100-1000 mg) and/or sodium citrate (100-1000 mg) and/or gentisic acid (20-200 mg).

Determination of chemical and radiochemical purity

Radiochemical and chemical purity was determined by analytical HPLC, for example: column: Atlantis T3, Waters, 100 x 4.6 mm, 3 µm, 100; mobile phase A: 40 mM sodium acetate, finally adjusted to pH 5.0 with glacial acetic acid; mobile phase B: 35% methanol in acetonitrile; flow rate: 1.8 ml/min; gradient: 0-5 min 15-32% B, 5-8 min 32-80% B, 8-12 min 80% B, 12-13 min 80-15% B, 13-16 min 15% B.

Evaluation of the chemical stability of compositions for diagnostics

Mixtures were obtained according to the composition described in table. 1. The chemical purity of compound 1 (Ib) was determined by HPLC (UV detection at 310 nm) after preparation of the composition, as well as after storage at room temperature.

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Table 1. Chemical stability of compound 1 (Ib) in compositions for diagnostics

# Composition of composition for diagnostics per 1 ml Chemical purity at initial level[%] Storage time [h] Chemical purity after storage[%] 1 5 µg compound 1, 50 µl EtOH, 160 µl phosphate concentrate*, 586 µl WFI, 204 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 6.9 100 25 100 2 5 µg compound 1, 76 µl EtOH, 160 µl phosphate concentrate*, 560 µl WFI, 204 µl 100 mM _NaH2PO4 (acidified to pH _{2 with H3PO4} ) Final pH: 6.9 100 25 100 3 5 µg compound 1, 100 µl EtOH, 160 µl phosphate concentrate*, 536 µl WFI, 204 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 7.0 100 25 100 4 5 µg compound 1.88 µl EtOH, 20 mg sodium citrate dihydrate, 602 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ), 4 µl conc. HC1, 34 µl 1 M HC1 Final pH: 4.5 100 93 100

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5 5 µg compound 1.88 µl EtOH, 20 mg sodium citrate dihydrate, 640 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with n ₃ PO ₄ ) Final pH: 6.1 100 93 100 6 5 µg compound 1.88 µl EtOH, 20 mg sodium citrate dihydrate, 600 µl WFI, 272 µl 100 _{mM NaH2PO4} (acidified to pH 2 _{with H3PO4} ), 40 µl IMNaOH Final pH: 7.1 100 92 100 7 5 µg compound 1.88 µl EtOH, 20 mg sodium citrate dihydrate, 638 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ), 1.6 µl conc. NaOH, 0.4 µl 3M NaOH Final pH: 8.5 100 43 100 8 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 476.4 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ), 160 µl phosphate concentrate*, 2.8 µl H ₃ PO ₄ 85%, 0.8 µl 3 M H ₃ PO ₄ Final pH: 4.5 100 20 100 9 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 480 µl WFI, 272 µl 100 _{mM NaH2PO4} (acidified to pH 2 _{with H3PO4} ), 160 µl phosphate concentrate* Final pH: 6.6 100 22 73.3

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10 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 450 µl WFI, 272 µl 100 mM _NaH2PO4 (acidified to pH 2 with _H3PO4 ), 160 µl phosphate concentrate*, 30 µl 3 M NaOH Final pH: 8.5 40.9 19 18.6 eleven 5 µg compound 1, 88 µl EtOH, 30 mg sodium ascorbate, 640 µl WFI, 272 µl 100 mM NaH ₂ PO4 (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 5.1 100 19 91.8 12 5 µg compound 1, 88 µl EtOH, 50 mg sodium ascorbate, 640 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 5.5 100 17 96.6

*phosphate buffer concentrate: Braun, 3.05 g disodium monohydrogen phosphate dodecahydrate, 0.462 g sodium dihydrogen phosphate dihydrate in 20 ml water for injection

Table 2. Radiochemical stability of compound ¹⁸ F-1 (Ib) in compositions for diagnostics

The compositions were prepared as described in General Radiolabeling Methods

# Composition of composition for diagnostics General radiolabeling method Previous tvnik Radioactivity concentration at EOS [GBq/ml] Radiochemical purity at EOS [%] Radiochemical purity after storage[%] 1 36 GBq ¹⁸ F-1, 1 ml EtOH, 14 ml sodium ascorbate solution in water (10 mg/ml) A 3-a 3.3 97.6 < Yu(EO8+4h) 2 34 GBq ¹⁸ F-1, 1.3 ml EtOH, 7.7 ml 70 mM NaOAc (acidified to pH 2 with HC1), 1 ml phosphate buffered saline (Gibco DPBS #: 14190), 100 µl 5 M NaOH WITH 3-b 3.4 100 < 5 (EOS+2 h) 3 32GBq ¹⁸ E-1, 1.9 ml EtOH, 5.1 ml 100 mM NaH ₂ PO4 pH 2, 540 mg sodium ascorbate, 3.5 ml phosphate concentrate, 7.5 ml water WITH 3-b 1.78 100 91.2 (EOS+4 h) 88.3% (EOS+21 h) 4 85 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 750 mg sodium ascorbate, 6 mg ascorbic acid, 18 ml water WITH 3-b 3.2 99.3 81.8 (EOS+4 h)

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5 22TBk ¹⁸ F-1, 1.9 ml EtOH, 5.1 ml 100 mM NaH ₂ PO ₄ pH 2, 100 mg gentisic acid, 9.5 ml water, 3.5 ml phosphate buffer concentrate* WITH 3-b 1.1 97.7 97.0 (EOS+4 h) 6 102 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 100 mg gentisic acid, 13.5 ml water, 4.5 ml phosphate buffer concentrate* WITH 3-b 3.8 99.7 98.7 (EOS+6 h) 7 38GBq ¹⁸ B-1, 1.9 ml EtOH, 5.1 ml 100 mM NaH ₂ PO ₄ pH 2, 13 ml water, 500 mg sodium citrate WITH 3-b 1.9 99.7 96.2 (EOS+4 h) 95.4 (EOS+20 h) 8 91 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 500 mg sodium citrate, 16 ml water With 3-b 3.5 99.9 >97(EO8+10h) 9 114 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 17 ml water, 50 mg/ml sodium ascorbate With 3-b 4.4 99.8 >91 (EOS+8 h) 9 107 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 17 ml water, 70 mg/ml sodium ascorbate With 3-b 4.1 99.5 > 92 (EOS+8 h) 10 105 GBq ¹⁸ F-1, 2.2 ml EtOH, 6.8 ml 100 mM NaH ₂ PO ₄ pH 2, 17 ml water, 100 mg/ml sodium ascorbate With 3-b 4.0 99.7 > 93 (EOS+8 h)

*phosphate buffer concentrate: Braun, 3.05 g disodium monohydrogen phosphate dodecahydrate, 0.462 g sodium dihydrogen phosphate dihydrate in 20 ml water for injection

Assessing Sterile Filter Retention

Mixtures were obtained according to the composition described in table. 1. The filter retention of compound 1 (Ib) was determined by comparing the corresponding peak area in analytical HPLC (UV detection at 310 nm) before and after filtration of 10 ml of the diagnostic composition.

Table 3. Filter retention capacity

# Composition of composition for diagnostics per 1 ml % retention of compound 1 on sterile filter B. Braun, Sterifix (PES) What-man FP (Cage, acetate) MillexGV (PVDF) Millex GP (PES) Millex LG (PTFE) 1 5 µg compound 1, 50 µl EtOH, 160 µl phosphate concentrate*, 586 µl WFI, 204 µl 100 mM NaH ₂ PO4 (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 6.9 24.9 89.8 25.5 25.1 25.4 2 5 µg compound 1, 76 µl EtOH, 160 µl phosphate concentrate*, 560 µl WFI, 204 µl 100 mM NaH ₂ PO4 (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 6.9 5.7 82.6 5.4 4.3 4.0

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3 5 µg compound 1, 100 µl EtOH, 160 µl phosphate concentrate*, 536 µl WFI, 204 µl 100 mM NaE^PCE (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 7.0 5.4 74.2 3.5 1.2 4.1 4 5 µg compound 1, 88 µl EtOH, 20 mg sodium citrate dihydrate, 602 µl WFI, 272 µl 100 mM NaH ₂ PO4 (acidified to pH 2 with H ₃ PO ₄ ), 4 µl conc. HC1, 34 µl 1 M HC1 Final pH: 4.5 < 1 3.4 2.7 < 1 < 1 5 5 µg compound 1, 88 µl EtOH, 20 mg sodium citrate dihydrate, 640 µl WFI, 272 µl 100 mM _NaH2PO4 (acidified to _{pH 2} with _H3PO4 ) Final pH: 6.1 <1 31.8 1.2 < 1 <1 6 5 µg compound 1, 88 µl EtOH, 20 mg sodium citrate dihydrate, 600 µl WFI, 272 µl 100 mM _NaH2PO4 (acidified to pH ₂ with _H3PO4 ), 40 µl IM NaOH Final pH: 7.1 5.3 82.2 4.0 3.2 3.3

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7 5 µg compound 1, 88 µl EtOH, 20 mg sodium citrate dihydrate, 638 µl WFI, 272 µl 100 mM NaE^PCE (acidified to pH 2 with H3PO4), 1.6 µl CONC. NaOH, 0.4 µl 3M NaOH Final pH: 8.5 8.8 98.2 7.4 6.8 11.3 8 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 476.4 µl WFI, 272 µl 100 mM _NaH2PO4 (acidified to pH 2 with _H3PO4 ), 160 µl phosphate concentrate*, 2.8 µl H3PO4 85 %, 0.8 µl 3 M H3PO4 Final pH: 4.5 <1 6.2 I,9 - <1 9 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 480 µl WFI, 272 µl 100 mM _NaH2PO4 (acidified to pH 2 with _H3PO4 ), 160 µl phosphate concentrate* Final pH: 6.6 2.6 48.8 4.5 - 4.0

- 29 046355

10 5 µg compound 1, 88 µl EtOH, 2 mg gentisic acid, 450 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ), 160 µl phosphate concentrate*, 30 µl 3 M NaOH Final pH: 8.5 9.3 100 12 - 13.8 And 5 µg compound 1, 88 µl EtOH, 30 mg sodium ascorbate, 640 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 5.1 1.5 8.1 1.9 2.8 12 5 µg compound 1, 88 µl EtOH, 50 mg sodium ascorbate, 640 µl WFI, 272 µl 100 mM NaH ₂ PO ₄ (acidified to pH 2 with H ₃ PO ₄ ) Final pH: 5.5 <1 8.7 <1 - <1

*phosphate buffer concentrate: Braun, 3.05 g disodium monohydrogen phosphate dodecahydrate, 0.462 g sodium dihydrogen phosphate dihydrate in 20 ml water for injection

Claims (17)

1. Composition for diagnosing a disorder associated with Tau aggregates, comprising: a) a compound of formula Ib b) from 1 to 20% v/v. ethanol, c) water, d) from 2.5 to 500 µmol/ml of a hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid or a mixture thereof, where the hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid or a mixture thereof is/are selected from ascorbic acid, sodium ascorbate, gentisic acid, sodium salt of gentisic acid, citric acid, sodium citrate or a mixture thereof, and e) a buffer selected from alkali metal dihydrogen phosphates, di(alkali metal) hydrogen phosphates, tri(alkali metal) phosphates, alkali metal acetates, alkaline earth metal acetates, alkaline earth metal formates, mono/di/tri-alkali citrate, where F in formula Ib is ¹⁸ F or a mixture of ¹⁸ F and ¹⁹ F. 2. A diagnostic composition according to claim 1, wherein the hydroxycarboxylic acid, a salt of a hydroxycarboxylic acid, or a mixture thereof is gentisic acid. 3. A diagnostic composition according to claim 1 or 2, comprising from 2.5 to 500 µmol/ml of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid or a mixture thereof, preferably from 10 to 300 µmol/ml of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid or a mixture thereof, more preferably from 25 to 300 µmol/ml of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid or a mixture thereof. 4. Diagnostic composition according to any one of claims 1 to 3, where the alkali metals in the buffer are selected from sodium and potassium. 5. A method for obtaining a composition for diagnostics according to any one of claims 1-4, including the stages: a) interaction of a compound of formula IIb with a ^-fluorinating agent, - 30 046355 (lib) where X represents H or PG, LG is a leaving group selected from the group consisting of nitro, bromine, iodine, chlorine, trialkylammonium, hydroxyl, boronic acid, iodonium, sulfonic acid ester, and PG is an amino protecting group selected from the group consisting of carbobenzyloxy (Cbz), (p-methoxybenzyl)oxycarbonyl (Moz or MeOZ), tert-butyloxycarbonyl (BOC), 9fluorenylmethyloxycarbonyl (FMOC), benzyl (Bn), p-methoxybenzyl ( PMB), 3,4-dimethoxybenzyl (DMPM), p-methoxyphenyl (PMP), triphenylmethyl (trityl), methoxyphenyldiphenylmethyl (MMT) or dimethoxytrityl (DMT), b) if X is PG, removal of the protecting group from PG, c) purifying the compound of formula Ib and d) mixing the compound of formula Ib obtained in step c) with ethanol, water, a hydroxycarboxylic acid and a hydroxycarboxylic acid salt to obtain a diagnostic composition. 6. The method according to claim 5, where LG in formula IIb represents a leaving group that can be replaced by a nucleophilic [1^]fluoride ion or an electrophilic [ ^18F ] fluorine atom, LG is selected from nitro or trimethylammonium, where compounds containing trialkylammonium or iodonium may additionally contain an anion. 7. The method according to claim 5 or 6, wherein PG in formula IIb is a group selected from tert-butyloxycarbonyl (BOC), dimethoxytrityl (DMT) and triphenylmethyl (trityl), more preferably PG is tert-butyloxycarbonyl (BOC) or triphenylmethyl ( trityl). 8. Use of the composition according to any one of claims 1-4 for visualization of Tau protein aggregates. 9. Application according to claim 8 in positron emission tomography for visualization of Taubelka aggregates. 10. Use of a composition according to any one of claims 1 to 4 for the diagnosis of a disorder associated with Tau aggregates or for the diagnosis of tauopathy. 11. Application according to claim 10, where the diagnosis is carried out using positron emission tomography. 12. Use according to claim 10, where the disorder is selected from Alzheimer's disease (AD), familial AD, Creutzfeldt-Jakob disease, Boxer's dementia, Down syndrome, Gerstmann-Straussler-Scheinker disease, inclusion body myositis, cerebral amyloid angiopathy associated with protein- prion, traumatic brain injury (TBI), amyotrophic lateral sclerosis, Guam parkinsonism-dementia complex, non-Guam motor neuron disease with neurofibrillary tangles, argyrophilic grain disease, corticobasal degeneration (CBD), diffuse neurofibrillary tangles with calcification, frontotemporal dementia with parkinsonism , associated with chromosome 17, Hallervoorden-Spatz disease, multiple system atrophy, Niemann-Pick disease type C, pallidoponto-nigral degeneration, Pick disease (PiD), progressive subcortical gliosis, progressive supranuclear palsy (PSP), subacute sclerosing panencephalitis, plexus-only dementia, postencephalitic parkinsonism, myotonic dystrophy, Tau panencephalopathy, AD-like with astrocytes, selected prion diseases (GSS with Tau), mutations in LRRK2, chronic traumatic encephalopathy, familial British dementia, familial Danish dementia, frontotemporal lobar degeneration, Guadalupe parkinsonism, neurodegeneration with brain iron accumulation, SLC9A6-related mental retardation, white matter tauopathy with globular glial inclusions, post-traumatic stress syndrome, epilepsy, dementia with Lewy bodies (LBD), hereditary hemorrhagic stroke with amyloidosis (Dutch type), mild cognitive disorders (MCI), multiple sclerosis, Parkinson's disease, atypical parkinsonism, dementia due to HIV, adult-onset diabetes, age-related cardiac amyloidosis, endocrine tumors, glaucoma, ocular amyloidosis, primary retinal degeneration, macular degeneration (eg, age-related macular degeneration macules (AMD), optic drusen, optic neuropathy, optic neuritis, lattice dystrophy, Huntington's disease, ischemic stroke and AD psychosis. 13. Use according to claim 12, wherein the disorder is Alzheimer's disease (AD), Parkinson's disease, atypical parkinsonism, progressive supranuclear palsy (PSP) or Pick's disease (PiD). 14. Use of the composition according to any one of claims 1 to 4 as an analytical standard or as an in vitro screening tool. 15. A method for collecting data for diagnosing a disorder associated with Tau aggregates in a sample, - 31 046355 including: (a) bringing the sample suspected of containing the Tau aggregate into contact with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib; (b) allowing the compound of formula Ib to bind to the Tau aggregate; (c) detecting a compound of formula Ib bound to a Tau aggregate. 16. A method for determining the amount of Tau aggregate in tissue and/or body fluid, including: (a) providing a sample representative of the tissue and/or biological fluid being examined; (b) testing a sample for the presence of a Tau aggregate with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib; (c) determining the amount of compound of formula Ib associated with the Tau aggregate, and (d) calculating the amount of Tau aggregate in the tissue and/or body fluid. 17. A method of collecting data to determine susceptibility to Tau aggregate disorder in a patient, which includes the stages of: (a) contacting a sample suspected of containing a Tau aggregate with a composition according to any one of claims 1 to 4, which contains a compound of formula Ib that specifically binds to the Tau aggregate; (b) allowing a compound of formula Ib to bind to a Tau aggregate to form a compound/Tau aggregate complex and (c) detecting formation of a compound/Tau aggregate complex; wherein the method is (i) a method comprising detecting the specific binding of a composition according to any one of claims 14, which contains a compound of formula Ib, to a Tau aggregate in the sample.