JP2014218454A - Styrylpyridine derivative compounds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide compounds improved in the absolute accumulation amount in amyloid.SOLUTION: There are provided styrylpyridine derivative compounds represented by a prescribed general formula or salts thereof, and pharmaceutical compositions containing them.

Description

  The present invention relates to a styrylpyridine derivative compound.

  In recent years, attempts have been made to detect amyloid in the brain in vivo using a compound having high affinity for amyloid as a marker.

  As such amyloid affinity compounds, thioflavine derivatives described in Patent Document 1, stilbene derivatives described in Patent Document 2, imidazopyridine derivatives described in Patent Documents 3 to 5, DDNP described in Patent Document 6 The derivative (2- (1,1-dicyanopropen-2-yl) -6-dimethylaminonaphthalene) is known.

In addition, [ ¹⁸ F] florbetaben ([ ¹⁸ F] florabetaben) and [ ¹⁸ F] flrobetapil ([ ¹⁸ F] flovapetir) are expected to be useful as tracers of brain amyloid imaging for positron emission tomography (PET). (Non-Patent Documents 1 and 2).

JP-T-2004-506723 JP 2005-504055 Gazette JP 2005-504055 Gazette International Publication 2007/063946 Pamphlet International Publication 2010/128595 Brochure Japanese translation of PCT publication No. 2002-523383

Rowe C, et al. , The Lancet Neurology, 7 (2), 129-135, 2008. Choi, SR, et al. , J .; Nucl. Med, 50 (11), 1887-1894, 2009

  However, in order to perform quantitative evaluation of amyloid accumulation with high accuracy, it is expected to develop a compound that further increases the absolute accumulation amount in amyloid.

  In view of the above circumstances, the present inventors have newly found a compound that has improved the absolute accumulation amount in amyloid.

  According to one aspect of the present invention, a compound represented by the following general formula (1) or a salt thereof is provided.

[Wherein, n is an integer of 1 or 2, and X ₁ is a fluorine atom. ]

  Moreover, according to another aspect of this invention, the pharmaceutical composition containing said compound or its salt is provided.

  According to another aspect of the present invention, there is provided an amyloid imaging agent comprising the above compound or a salt thereof and used for imaging amyloid.

  According to another aspect of the present invention, there is provided a compound represented by the following general formula (2) or a salt thereof.

[Wherein n is an integer of 1 or 2, and R ₁ is a chlorine atom, a bromine atom, an iodine atom, an alkylsulfonic acid ester group having 10 or less carbon atoms in which hydrogen may be substituted with halogen, or An aromatic sulfonate group that may have a substituent. ]

  According to another aspect of the present invention, the compound represented by the general formula (2) or a salt thereof is reacted with a fluoride ion to obtain the compound represented by the general formula (1) or a salt thereof. A method of manufacturing is provided.

  According to the present invention, a compound having an increased absolute accumulation amount in amyloid is provided.

(E) -1- (2- (6- (2- (2-Fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole is there. It is a figure which shows the Alzheimer patient brain section. (A) is (E) -1- (2- (6- (2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3- an autoradiography of brain sections treated with triazole, (b) is an autoradiography of brain sections treated with ^[18 F] Furobetabiru ^{([18 F] florbetapir),} (c) is ^[18 F] Furorubetaben ^([18 F] florbetaben) an autoradiography of brain sections treated with a immunostaining of brain sections with anti-amyloid antibody (d).

(Styrylpyridine derivative compound)
Specific examples of the compound according to the present invention include the following compounds.
(E) -1- (2- (6- (2- (2-fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole ((E) -2 -(2- (2-fluoroethoxy) ethoxy) -9- (1H-1,2,3, -triazol-1-yl) styrylpyridine) [in the above general formula (1), X ₁ is a fluorine atom , N is an integer of 2 compounds. Hereinafter, it may be abbreviated as “ABC126”. ].
(E) -1- (2- (6- (2-fluoroethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole [in the above general formula (1), X ₁ Is a fluorine atom, and n is an integer compound of 1. ].

  These compounds according to the present invention may form a salt, and such a salt is included in the present invention in a pharmaceutically acceptable salt.

  In the present invention, “salts” include those derived from inorganic or organic acids, or inorganic or organic bases. Specifically, hydrochloride, hydrobromide, hydroiodic acid, sulfate, nitrate, perchlorate, fumarate, maleate, phosphate, glycolate, lactate, salicylate , Succinate, tartrate, acetate, citrate, methanesulfonate, ethanesulfonate, p-toluenesulfonate, aspartate, glutamate, formate, benzoate, malonate, Examples include, but are not limited to, naphthalene-2-sulfonate, trifluoroacetate, benzenesulfonate, amine salt, and ammonium salt.

  As described above, in the general formula (1), n is an integer of 1 or 2, but preferably n is an integer of 2.

  The styrylpyridine derivative compound of the present invention can be synthesized by, for example, the synthesis route shown in the following scheme 1.

2-halogenated nicotinaldehyde (Compound a) and ethylene glycol (in scheme 1, n is an integer of 1 and R ₂ represents a hydrogen atom), diethylene glycol (in scheme 1, n is an integer of ₂ , R ₂ Or a compound in which one of the hydroxy groups of these compounds is protected (in scheme 1, n is an integer of 1 or 2, and R ₂ represents a hydroxy protecting group). By mixing and heating in the presence of a base such as potassium carbonate, ethylene glycol or diethylene glycol is introduced into the 2-position of the pyridine ring of compound a to obtain compound b. Here, in Scheme 1, X _{2 of} compound a is preferably a chlorine atom, a bromine atom, or an iodine atom, but more preferably a chlorine atom or a bromine atom. Examples of the protecting group for the hydroxy group include Green's Protective Groups in Organic Synthesis, p. A suitable protecting group described in 17-245 (Wiley-Interscience; 4th edition) can be used.

  Next, a styrylpyridine skeleton is formed by a Wittig reaction in which diethyl 4-azidobenzylphosphonate is allowed to act on the aldehyde group of compound b in the presence of a base such as sodium hydride in an organic solvent such as tetrahydrofuran (compound c). Here, diethyl 4-azidobenzylphosphonate can be synthesized, for example, by diazotizing diethyl 4-aminobenzylphosphonate with hydrochloric acid and potassium nitrite in a solvent and further reacting with sodium azide.

  Next, trimethylsilylacetylene is reacted with the azide group of compound c under a copper catalyst to form a triazole ring. Thereafter, the trimethylsilyl group is removed with tetrabutylammonium fluoride.

Thereafter, when a hydroxy protecting group is introduced as R ₂ in Scheme 1, this is removed to obtain compound d, and then the hydroxy group of compound d is sulfonated to give the above general formula (2). Is obtained (in Scheme 1, compound e). As described above, R _{1 in the} general formula (2) has a chlorine atom, a bromine atom, an iodine atom, an alkylsulfonic acid ester group having 10 or less carbon atoms in which hydrogen may be substituted with a halogen, or a substituent. An aromatic sulfonic acid ester group which may be substituted, preferably an alkyl sulfonic acid ester group having 10 or less carbon atoms in which hydrogen may be substituted with a halogen, or an aromatic sulfone which may have a substituent It is an acid ester group, More preferably, it is an aromatic sulfonic acid ester group which may have a substituent.

  Examples of the “alkyl sulfonate group having 10 or less carbon atoms” include a methane sulfonate group. Examples of the “alkyl sulfonate group having 10 or less carbon atoms in which hydrogen may be substituted with halogen” include a trifluoromethane sulfonate group. Examples of the “aromatic sulfonate group” include a benzenesulfonate group, a 4-methylbenzenesulfonate group, or a 4-nitrobenzenesulfonate group. Of these, a 4-methylbenzenesulfonic acid ester group is preferable.

  Finally, a fluoride ion is reacted with compound e in the presence of a base in an aprotic solvent such as acetonitrile, and the styrylpyridine derivative compound of the present invention represented by the above general formula (1) (in scheme 1) To obtain compound f). Alternatively, the compound f according to the present invention can be synthesized by reacting the hydroxy group of the compound d with a fluorinating reagent such as N, N-diethylaminosulfur trifluoride (DAST).

(Radiofluorine-labeled styrylpyridine derivative compound)
In the general formula (1), X ₁ is a fluorine atom. In a preferred embodiment, X ₁ is a radioactive fluorine atom, and more specifically, ¹⁸ F is more preferable. By administering a compound labeled with ¹⁸ F, cerebral amyloid in a living body can be detected non-invasively by positron tomography (PET).

More specifically, the radioactive fluorine-labeled compound of the present invention is preferably a radiofluorine-labeled compound shown below.
(E) -1- (2- (6- (2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole (( E) -2- {2- [2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy] ethoxy} -9- (1H-1,2,3-triazol-1-yl) styrylpyridine) [general above In formula (1), X ₁ is ¹⁸ F, and n is an integer of 2. Hereinafter, it may be abbreviated as “[ ¹⁸ F] ABC126”. ].
(E) -1- (2- (6- (2- [ ¹⁸ F] fluoroethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole [the above general formula (1) In the formula, X ₁ is ¹⁸ F and n is an integer of 1. ].

When a radioactive compound in which X ₁ is a radioactive fluorine atom is employed as the compound according to the present invention, the compound represented by the above-described general formula (2) (compound in scheme 1) e) or a salt thereof can be used as a labeling precursor. As the salt, the salts exemplified above can be adopted. In general formula (2), as R ₁ , those described above (which can be used as R ₁ of compound e in scheme 1) can be employed. Alternatively, in general formula (2), n is preferably an integer of 2.

(Production of radioactive fluorine-labeled styrylpyridine derivative compound)
The radioactive fluorine-labeled styrylpyridine derivative compound according to the present invention can be synthesized by reacting a compound represented by the general formula (2) or a salt thereof, which is a labeling precursor thereof, with a radioactive fluoride ion. it can. As the radioactive fluoride ion, [ ¹⁸ F] fluoride ion is preferable. [ ¹⁸ F] fluoride ions can be produced by irradiating [ ¹⁸ O] water with protons accelerated by a cyclotron to generate a nuclear reaction of ¹⁸ O (p, n) ¹⁸ F. Produced ^{[18 F]} fluoride ions, by elution from ^{[18 F]} target water containing fluoride ions are adsorbed on the anion exchange resin, with an aqueous potassium carbonate solution ^{[18 F]} fluoride ion resin ^[18 F] It is preferably prepared as potassium fluoride. In addition, the radioactive fluorine labeling reaction of the compound represented by the general formula (2) or a salt thereof uses [ ¹⁸ F] potassium potassium prepared above, a phase transfer catalyst such as Cryptofix 222 (trade name), and carbonic acid carbonate. It is preferably carried out in the presence of a base such as potassium.

(Pharmaceutical composition)
In the present invention, the “pharmaceutical composition” can be defined as a formulation containing the compound represented by the above general formula (1) or a salt thereof in a form suitable for administration in vivo. This pharmaceutical composition comprises a compound according to the present invention as an active ingredient, and a pharmacologically acceptable carrier, diluent, emulsion, excipient, extender, binder, wetting agent, disintegrant, and surfactant. , Lubricants, dispersants, buffers, preservatives, solubilizers, preservatives, colorants, stabilizers and the like may be included. The pharmaceutical composition of the present invention can be used in an administration method for oral administration or parenteral administration.

In the present invention, the “radiopharmaceutical composition” is defined as the “pharmaceutical composition” defined above containing, as an active ingredient, a compound or a salt thereof in which X is ¹⁸ F in the general formula (1). can do. The dosage form of this radiopharmaceutical composition is preferably one that can be used for parenteral administration, and is intravenous, intraarterial, topical, intraperitoneal or thoracic, subcutaneous, intramuscular, sublingual An injection that can be used for administration, transdermal administration, rectal administration, and the like is more preferable. Such an injection can be prepared by dissolving the radioactive styrylpyridine derivative compound according to the present invention in water, physiological saline, Ringer's solution, or the like.

  The concentration of the radioactive styrylpyridine derivative compound in the radiopharmaceutical composition of the present invention may be any concentration that can ensure stability against radiolysis.

  A radiofluorine-labeled styrylpyridine derivative compound or a salt thereof of the present invention and a radiopharmaceutical composition containing the compound are administered to mammals such as humans, and imaged using a PET device, so that amyloid in the living body brain (Brain amyloid β protein, Aβ) can be detected noninvasively and used as an imaging agent for imaging. Since the imaging agent of the present invention contains a compound having an increased absolute accumulation amount in amyloid, it is useful for diagnosis and prevention of Alzheimer's disease.

  EXAMPLES Hereinafter, although an Example is described and this invention is demonstrated in more detail, this invention is not limited to these content. Further, in the synthesis examples of the compounds described in the following examples, each step was repeated a plurality of times as necessary, and an amount necessary for use as an intermediate or the like in another synthesis was secured.

The following apparatus was used in the examples.
NMR apparatus: JNM-ECP-500 (manufactured by JEOL Ltd.). The measurement condition of ¹ H-NMR was a resonance frequency of 500 MHz.
Bioimaging analyzer: BAS-2500, manufactured by Fuji Photo Film Co., Ltd. Single channel analyzer: SP-20, manufactured by Applied Koken Kogyo Co., Ltd.

  In addition, regarding the statistical processing of the examples, the data was expressed as an average value ± standard deviation.

Abbreviations used in the examples were defined as follows unless otherwise noted.
PBS: phosphate buffered saline BSA: bovine serum albumin [ ¹⁸ F] AV1: [ ¹⁸ F] florbetaben ([ ¹⁸ F] florbetaben, trans-4- (N-methylamino) -4 ′-(2- (2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy) ethoxy) stilbene)
[ ¹⁸ F] AV45: [ ¹⁸ F] Frobetapyr ([ ¹⁸ F] flobetapil, (E) -4- (2- (6- (2- (2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy) ethoxy) Pyridin-3-yl) vinyl) -N-methylbenzenamine)

Example 1 (E) -1- (2- (6- (2- (2-fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole , "ABC126")

  ABC126 was synthesized according to the scheme shown in FIG.

[Step 1] Synthesis of 2- [2- (2-hydroxyethoxy) ethoxy] nicotinaldehyde (Compound 1) 2-Bromonicotinaldehyde (Compound 1, 1000 mg, 5.38 mmol) to diethylene glycol (5.12 mL), potassium carbonate (2.23 g, 16.1 mmol) was added and heated to 100 ° C. After heating for 3 hours, saturated aqueous ammonium chloride and water were added, and the mixture was extracted 3 times with ethyl acetate. The combined ethyl acetate layers were washed once with water and once with saturated brine, and dried over magnesium sulfate. The residue obtained by distilling off the solvent was purified by flash silica gel column chromatography (eluent: hexane / ethyl acetate = 1/1 volume ratio) to obtain compound 1 (403 mg, 1.91 mmol, yield 35%). )

¹ H-NMR of compound 1 (solvent: deuterated chloroform): 9.96 (s, 1H), 8.61 (d, J = 2.3 Hz, 1H), 8.08 (dd, J = 2.3) 8.7 Hz, 1H), 6.89 (d, J = 8.7 Hz, 1H), 4.61 (t, J = 4.6 Hz, 2H), 3.89 (t, J = 4.6 Hz, 2H) ), 3.78-3.75 (m, 2H), 3.67 (m, 4H), 3.60 (t, J = 4.6 Hz, 2H), 2.06 (t, J = 6.2 Hz) , 1H).

[Step 2] Synthesis of (E) -4- (2- (2- (2-hydroxyethoxy) ethoxypyridin-3-yl) vinyl) phenylazide (Compound 3)

(1) Diethyl 4-aminobenzylphosphonate (1.0 g, 4.11 mmol) was dissolved in acetonitrile (12.5 mL), 6 mol / L hydrochloric acid (5 mL) was added under ice cooling, and the mixture was stirred for 5 minutes. . To the reaction solution, potassium nitrite (392 mg, 4.60 mmol) dissolved in water (10 mL) was added and stirred for 30 minutes, and then sodium azide (2.14 g, 32.9 mmol) was added. After stirring for 30 minutes, the mixture was warmed to room temperature and further stirred for 1 hour. After completion of the reaction, water (about 30 mL) was added and extracted three times with ethyl acetate. The combined ethyl acetate layers were washed once with water and once with saturated brine, and dried over magnesium sulfate. The residue obtained by distilling off the solvent was purified by flash silica gel column chromatography (eluent: hexane / ethyl acetate = 1/1 volume ratio), and diethyl 4-azidobenzylphosphonate (Compound 2) (1 0.0 g, 3.80 mmol, 92% yield).

¹ H-NMR of compound 2 (solvent: deuterated chloroform): 7.29-7.26 (m, 2H), 6.98-6.96 (m, 2H), 4.06-3.98 (m, 4H), 3.13-3.09 (m, 2H), 1.24 (t, J = 7.1 Hz, 6H).

(2) Sodium hydride (60% liquid paraffin dispersion, manufactured by Wako Pure Chemical Industries, Ltd.) (71.3 mg, 1.78 mmol) was suspended in tetrahydrofuran (4 mL), and compound 2 (160 mg, equivalent to 0.594 mmol) was cooled with ice. ) And compound 1 (125 mg, 0.594 mmol) in tetrahydrofuran (4 mL) were added dropwise. After 2 hours at room temperature under an argon gas atmosphere, a saturated aqueous ammonium chloride solution (about 10 mL) was added, and the mixture was extracted 3 times with ethyl acetate. The combined ethyl acetate layers were washed once with saturated brine and dried over magnesium sulfate. The residue obtained by distilling off the solvent was purified by flash silica gel column chromatography (eluent: hexane / ethyl acetate = 1/1 volume ratio) to obtain compound 3 (189 mg, 0.579 mmol, yield 98%). )

[Step 3] (E) -1- (2- (6- (2- (2-hydroxyethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3-triazole (compound 4 )
Compound 3 (189 mg, 0.579 mmol) was dissolved in dimethylformamide (3.0 mL), trimethylsilylacetylene (0.160 mL, 1.16 mmol) was added, and then copper sulfate pentahydrate (28.9 mg, 0.8. 116 mmol), and the mixture was heated and stirred at 80 ° C. for 3 hours. After completion of the reaction, the reaction solution was cooled to room temperature, water (5 mL) was added, and extracted with dichloromethane three times. The combined dichloromethane layers were washed once with water, dried over magnesium sulfate, and the solvent was distilled off to obtain crude crystals (271 mg). The crude crystals (271 mg) were suspended in tetrahydrofuran (5.0 mL), and a 1.0 mol / L tetrahydrofuran solution (640 μL) of tetrabutylammonium fluoride was added. After stirring for 2 hours under heating to reflux, the reaction mixture was cooled to room temperature, about 10 mL of saturated ammonium chloride solution was added, and the mixture was extracted 3 times with ethyl acetate. The combined ethyl acetate layers were washed once with water and once with saturated brine, and dried over magnesium sulfate. The residue obtained by distilling off the solvent was purified by flash silica gel column chromatography (eluent: ethyl acetate / methanol = 95/5 volume ratio), and compound 4 (136 mg, 0.357 mmol, yield 53%). )

¹ H-NMR of compound 4 (solvent: deuterated chloroform): 8.23 (d, J = 2.3 Hz, 1H), 8.00 (d, J = 1.2 Hz, 1H), 7.86 (d, J = 1.2 Hz, 1H), 7.83 (dd, J = 2.3, 8.7 Hz, 1H), 7.75 (d, J = 8.5 Hz, 2H), 7.64 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 16.5 Hz, 1H), 7.02 (d, J = 16.5 Hz, 1H), 6.84 (d, J = 8.5 Hz, 1H), 4.53 (t, J = 4.8 Hz, 2H), 3.89 (t, J = 4.8 Hz, 2H), 3.78-3.75 (m, 2H), 3.68 ( t, J = 4.6 Hz, 2H), 2.44 (t, J = 6.2 Hz, 2H).

[Step 4] (E) -1- (2- (6- (2- (2- (p-toluenesulfonyloxy) ethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2, Synthesis of 3-triazole (Compound 5) Compound 4 (136 mg, 0.357 mmol) was dissolved in dichloromethane (4.0 mL) and 1,4-diazabicyclooctane (130 mg, 1.16 mmpol), p-toluenesulfonyl chloride. (110 mg, 0.579 mmol) was added and stirred at room temperature for 16 hours. After completion of the reaction, a salt-saturated aqueous ammonium chloride solution and water were added, and extraction was performed 3 times with ethyl acetate. The combined ethyl acetate layers were washed with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The obtained residue was subjected to silica gel column chromatography (eluent: hexane / ethyl acetate = 1/1 volume ratio). The compound 5 (153 mg, 0.302 mmol, yield 78%) was obtained.

¹ H-NMR (solvent: deuterated chloroform) of Compound 5: 8.22 (d, J = 2.5 Hz, 1H), 8.01 (d, J = 1.4 Hz, 1H), 7.86 (d, J = 1.4 Hz, 1H), 7.83 (dd, J = 2.5, 8.7 Hz, 1H), 7.80 (d, J = 7.9 Hz, 2H), 7.75 (d, J = 8.7 Hz, 2H), 7.65 (d, J = 8.7 Hz, 2H), 7.31 (d, J = 7.9 Hz, 1H), 7.10 (d, J = 16.5 Hz, 1H), 7.02 (d, J = 16.5 Hz, 1H), 6.80 (d, J = 8.7 Hz, 1H), 4.40 (t, J = 4.8 Hz, 2H), 4. 20 (t, J = 4.8 Hz, 2H), 3.80 (t, J = 4.8 Hz, 2H), 3.76 (t, J = 4.8 Hz, 2H), 2.43 (s, 3H) ).

[Step 5] Synthesis of ABC126 Compound 5 (20 mg, 0.040 mmol) was dissolved in acetonitrile (1.0 mL), Cryptofix 222 (trade name, manufactured by Merck & Co.) (22.3 mg, 0.059 mmol), fluoride Potassium (2.9 mg, 0.049 mmol) and potassium carbonate (1.1 mg, 0.008 mmol) were added, and the mixture was stirred for 2 hours with heating under reflux. After completion of the reaction, the reaction solution was cooled to room temperature, the solvent was distilled off, and the resulting residue was purified by silica gel column chromatography (eluent: hexane / ethyl acetate = 1/1 volume ratio) to obtain ABC126. (5.0 mg, 0.014 mmol, yield 36%) was obtained.

¹ H-NMR of ABC126 (solvent: deuterated chloroform): 8.23 (s, 1H), 8.01 (s, 1H), 7.86 (s, 1H), 7.84 (dd, J = 2. 3, 8.7 Hz, 1 H), 7.75 (d, J = 8.7 Hz, 2 H), 7.64 (d, J = 8.7 Hz, 2 H), 7.10 (d, J = 16.5 Hz) , 1H), 7.02 (d, J = 16.5 Hz, 1H), 6.83 (d, J = 8.7 Hz, 1H), 4.60 (dt, J = 47.7, 4.1 Hz, 2H), 4.54 (t, J = 4.8 Hz, 2H), 3.91 (t, J = 4.6 Hz, 2H), 3.82 (dt, J = 29.3, 4.1 Hz, 2H) ).

Example 2 (E) -1- (2- (6- (2- (2- [ ¹⁸ F] fluoroethoxy) ethoxy) pyridin-3-yl) vinyl) -phenyl-1H-1,2,3 -Synthesis of triazole (hereinafter referred to as “[ ¹⁸ F] ABC126”) [ ¹⁸ F] fluoride ion-containing [ ¹⁸ O] water (1440 MBq, correction value at the start of synthesis), Sep-Pak Light QMA (trade name, Nippon Waters The liquid [ ¹⁸ F] fluoride ion was adsorbed and collected. Next, an aqueous solution of potassium carbonate (42.4 μmol / L, 0.3 mL) and Cryptofix 222 (trade name, manufactured by Merck) (14 mg, 37.2 μmol) in acetonitrile (0.7 mL) were passed through the column. Then, [ ¹⁸ F] fluoride ion was eluted. This was heated to 110 ° C. under a stream of argon gas to evaporate water, and then acetonitrile (0.3 mL × 2) was added and azeotroped to dryness. The acetonitrile solution (0.3 mL) which melt | dissolved the compound 5 (5 mg, 14.1 micromol) synthesize | combined in Example 1 was added here, and it heated at 110 degreeC for 10 minutes. 1 mol / L hydrochloric acid (1.0 mL) was added after completion | finish of reaction, it applied to HPLC of the following conditions, and the fraction with the same retention time as ABC126 was fractionated.
<HPLC conditions>
Column: CAPCELL PAK (trade name, manufactured by Shiseido Co., Ltd., size: 10 mmφ × 250 mm)
Mobile phase: 0.1% by volume trifluoroacetic acid / acetonitrile (volume ratio) = gradient from 20/80 to 0/100 over 20 minutes Flow rate: 3.0 mL / min Detector: UV-visible spectrophotometer (detection wave: 260nm)

A solution obtained by adding water (10 mL) to the fraction was passed through a reverse phase column (trade name: Sep-Pak C18 Light, manufactured by Waters), and [ ¹⁸ F] ABC126 was adsorbed and collected on the column. After this column was washed with water (1 mL), diethyl ether (1 mL) was passed through a vial to which 1 mL of a 1% by mass ascorbic acid aqueous solution had been added in advance to elute [ ¹⁸ F] ABC126, and then diethyl ether was added. By distilling off, a 1 mass% ascorbic acid aqueous solution of [ ¹⁸ F] ABC126 was obtained. The obtained radioactivity was 327 MBq (103 minutes after the start of synthesis). Moreover, when the TLC analysis by the following conditions was conducted, the radiochemical purity was 100%.
<TLC analysis conditions>
TLC plate: Silica Gel 60 F ₂₅₄ (product name, manufactured by Merck)
Developing phase: ethyl acetate / methanol / diethylamine = 100: 4: 1
RI detector: Rita Star, manufactured by raytest

(Example 3) was evaluated for intracerebral transferability and clearance in rats brain migration and Evaluation of Clearance ^[18 F] ABC126.
Example was synthesized in 2 ^[18 F] ABC126, and lysis was synthesized in Non-Patent Document 2 ways ^[18 F] AV45 to saline containing ascorbic acid and 10 vol% ethanol 0.5 wt% Each solution was prepared and used as a sample solution (both the radioactivity concentration was 92.5 MBq / mL). This sample solution was administered to male Wistar rats (8 weeks old) from the tail vein without anesthesia (dose: 0.2 mL, dosed radioactivity: equivalent to 18.5 MBq). At 2 minutes (n = 5) and 60 minutes (n = 3) after administration, the animals were decapitated without anesthesia, and organs were removed and organ weights and organ radioactivity levels were measured. Radioactivity measurement was performed using a single channel analyzer. The radioactivity distribution rate of each organ relative to the dose of radioactivity was calculated and determined, and the in-vivo radioactivity distribution of [ ¹⁸ F] ABC126 was determined.

  Table 1 shows the radioactivity uptake into the brain at 60 minutes 2 minutes after administration in% dose / g (% ID / g). The clearance ratio is the ratio of radioactivity uptake (% ID / g) into the brain 2 minutes after administration and radioactivity uptake (% ID / g) into the brain 60 minutes after administration (2 minutes / 60 minutes). ).

As shown in Table 1, it was confirmed that [ ¹⁸ F] ABC126 accumulated high radioactivity at 2 minutes after administration, and was excreted from the brain 60 minutes later.

(Example 4) Evaluation of compound binding to brain section of Alzheimer patient by autoradiography In order to evaluate whether the compound according to the present invention can depict amyloid in the brain of Alzheimer patient, the following experiment was conducted.
AD patient brain tissue (Frontal lobe) commercially available from Analytical Biological Services (USA) is sliced into 5 μm, and AD patient brain sections used in this experiment are prepared and stored at −20 ° C. until use. did. The brain section is returned from −20 ° C. to room temperature, dried for 10 minutes, then immersed in PBS for 15 minutes, 5 minutes, 5 minutes each, and then immersed in PBS containing 1% by mass BSA for 30 minutes for hydrophilization. went. Contains [ ¹⁸ F] ABC126 synthesized in Example 2, [ ¹⁸ F] AV1 synthesized by the method described in Non-Patent Document 1 or 1% by mass BSA containing [ ¹⁸ F] AV45 synthesized by the method described in Non-Patent Document 2 PBS (radioactivity concentration of 30 kBq / mL) was prepared, and the brain section hydrophilized was immersed for 30 minutes at room temperature. Thereafter, each brain solution containing 1% by mass of BSA in PBS, PBS, and PBS was immersed for 5 minutes to wash brain sections. The brain section after washing was sufficiently dried, then exposed on an imaging plate for 16 hours, and autoradiogram image analysis was performed using a bioimaging analyzer.
The adjacent section was used to immunostain the amyloid deposition site with anti-amyloid antibody. Anti-Human Amyloid β (N) (82E1) Mouse IgG MoAb (Immuno-Biological Laboratories) was used as the anti-amyloid antibody, and Anti-Mouse IgG (H + L) Goat IgG Fab′-HRP (Immunology Co., Ltd.) was used as the secondary antibody. Biological Research Institute) was used. The amyloid deposition site was detected by applying DAB + (3,3′-diaminobenzidine tetrahydrochloride) substrate kit (Dako) to HRP binding to the secondary antibody.

The autoradiogram of the brain section is shown in FIGS. FIG. 2 (a) uses [ ¹⁸ F] ABC126, FIG. 2 (b) uses [ ¹⁸ F] AV45, and FIG. 2 (c) uses [ ¹⁸ F] AV1. Is. FIG. 2 (d) shows the results of immunostaining of brain sections used in this experiment. As shown in FIG. 2, amyloid deposition can be confirmed by immunostaining in the gray matter portion of the brain frozen section of Alzheimer's patient used in this experiment, and the amyloid deposition site confirmed by immunostaining on any autoradiogram. Binding of the compound to was confirmed.

Table 1 shows the absolute accumulation amounts of [ ¹⁸ F] ABC126, [ ¹⁸ F] AV45, and [ ¹⁸ F] AV1 in the gray matter of the autogram shown in FIGS. Table 2 shows the average value ± standard deviation of the photoluminescent luminance (PSL) value per square millimeter by taking four regions of interest for the gray matter of each brain section.

As shown in Table 1, [ ¹⁸ F] ABC126 improved in absolute accumulation in gray matter than [ ¹⁸ F] AV1. A slight improvement in the absolute accumulation amount was also observed for [ ¹⁸ F] AV45.

Claims (6)

A compound represented by the following general formula (1) or a salt thereof.
[Wherein, n is an integer of 1 or 2, and X ₁ is a fluorine atom. ] The compound or its salt of Claim ₁ whose X1 is a radioactive fluorine atom in the said General formula (1).   A pharmaceutical composition comprising the compound according to claim 1 or 2 or a salt thereof.   An amyloid imaging agent comprising the compound or a salt thereof according to claim 1 or 2 and used for imaging amyloid. A compound represented by the following general formula (2) or a salt thereof.
[Wherein n is an integer of 1 or 2, and R ₁ is a chlorine atom, a bromine atom, an iodine atom, an alkylsulfonic acid ester group having 10 or less carbon atoms in which hydrogen may be substituted with halogen, or An aromatic sulfonate group that may have a substituent. ]   The method of manufacturing the compound or its salt of Claim 1 or 2 by making a fluoride ion react with the compound or its salt of Claim 5.