JP6488045B2 - Compounds suitable for detection of acetylcholine vesicle transporters - Google Patents

Description

  The present invention relates to compounds suitable for the detection of acetylcholine vesicle transporters.

  Alzheimer's dementia is a type of dementia whose main symptoms are reduced cognitive function and personality change, and is generally known as Alzheimer's disease.

  In patients with Alzheimer's disease, it is thought that degeneration occurs because neurotransmission does not function sufficiently because the presynaptic terminal of the acetylcholinergic nervous system is degenerated.

  At the presynaptic terminal, there are vesicles that store acetylcholine released by nerve stimulation, and a vesicle transporter (acetylcholine vesicle transporter) for taking acetylcholine into the vesicle exists on the membrane of the vesicle. This acetylcholine vesicle transporter is thought to be related to Alzheimer's disease. If it becomes possible to evaluate the acetylcholine vesicle transporter, it becomes possible to diagnose Alzheimer's disease, to elucidate the mechanism of Alzheimer's disease and to develop pharmaceuticals.

  As a compound which can evaluate the said acetylcholine vesicle transporter, the besamicol piperazine derivative of patent document 1 is mentioned, for example.

International Publication No. 01/07427

  However, the besamicol piperazine derivative is designed to be used as a labeling compound for single photon tomography (SPECT method) and is not suitable for positron emission tomography (PET method).

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a compound suitable for detection of an acetylcholine vesicle transporter that can also be used as a labeling compound for the PET method.

The present invention provides a compound represented by formula (I).

(In formula (I), R ¹ is CH ₃ , F, (CH ₂ ) _n —F, NH— (CH ₂ ) _n —F, O— (CH ₂ ) _n —F or S— (CH ₂ ) _n. -F (n represents an integer of 1 to 3)

  The compound represented by the formula (I) is a compound suitable for detection of an acetylcholine vesicle transporter.

In formula (I), ^{R 1} is _{^{11 CH 3, 18 F, (}} CH 2) n - 18 F, N- (CH 2) n - 18 F, O- (CH 2) n - 18 F or S- ( ^{_{CH 2) n - 18 F (}} n is preferably that an an integer of 1 to 3). In this way, the compound can release positrons. The positron emitted from the compound immediately combines with the electron and emits γ rays (annihilation radiation). By measuring this γ-ray with an apparatus used in the PET method, the distribution of the compound in the body can be quantitatively imaged over time. That is, it can also be used as a labeling compound for the PET method.

The compound is preferably represented by any one of formulas (II) to (V). By using these compounds, the PET method can be measured efficiently.

The present invention provides a compound represented by formula (VI) or formula (VII).

(In formula (VI), R ² represents an organic group containing B or Sn, OH, or SH. In formula (VII), R ^p represents an amino-protecting group.)

  By using the compound represented by formula (VI) or formula (VII), the compound represented by formula (I) can be efficiently synthesized.

  Moreover, this invention provides the acetylcholine vesicle transporter detection reagent containing the compound represented by a formula (I). It is preferable that the said compound is a compound represented by Formula (IV) and (V). According to the acetylcholine vesicle transporter detection reagent, a site where the acetylcholine vesicle transporter is present in the living body can be efficiently detected.

  The present invention provides a diagnostic agent for Alzheimer's disease comprising a compound represented by formula (I). It is preferable that the said compound is a compound represented by Formula (IV) and (V). According to the diagnostic agent for Alzheimer's disease, it is possible to diagnose Alzheimer's disease by efficiently detecting a site where the acetylcholine vesicle transporter is present in the living body.

  ADVANTAGE OF THE INVENTION According to this invention, the compound suitable for the detection of the acetylcholine vesicle transporter which can be utilized also as a labeling compound of PET method can be provided.

It is a graph which shows the binding ability of [ ¹¹ C] HAPT to the acetylcholine vesicle transporter present in the rhesus monkey brain. In the brain of rhesus ^is a graph showing the arterial plasma activity and metabolic activity of the [11 C] HAPT. Is a graph showing the localization of ^[11 C] HAPT for each part of the rhesus monkey brain. It is a figure which shows the MRI image and PET image in the rhesus monkey brain when (R, R) [< ¹¹ > C] HAPT-B is administered. In each part of the rhesus brain is a graph showing the binding ability of ^{[11 C]} HAPT when competed with Besamikoru.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  A compound suitable for detection of the acetylcholine vesicle transporter according to this embodiment is a compound represented by the formula (I) (hereinafter sometimes referred to as compound (I)).

R ¹ is CH ₃ , F, (CH ₂ ) _n —F, NH— (CH ₂ ) _n —F, O— (CH ₂ ) _n —F or S— (CH ₂ ) _n —F (n is 1 a ~ 3 represents an integer _{^{of), 11 CH 3, 18 F}} , (CH 2) n - 18 F, N- (CH 2) n - 18 F, O- (CH 2) n - 18 F or S- ^{_{(CH 2) n - 18 F}} (n is an integer of 1 to 3) is preferably. By making R ¹ an organic group containing ¹¹ CH ₃ or ¹⁸ F, compound (I) can release positrons. When R ¹ is ¹¹ CH ₃ , the half-life is as short as 20 minutes, so that it is possible to perform multiple measurements per day. R ¹ is _{^{18 F, (CH 2) n}} - 18 F, N- (CH 2) n - 18 F, O- (CH 2) n - 18 F or S- _{(CH 2)} n ^{- 18} If F Since the half-life is longer than 110 minutes and ¹¹ CH ₃ , one measurement time can be extended.

  As the compound (I), compounds represented by the formulas (II) to (V) are preferable. Hereinafter, the compounds represented by the formulas (II) to (V) are respectively represented by (S, S) HAPT-A, (R, R) HAPT-A, (S, S) HAPT-B, (R, R). ) It may be called HAPT-B. In addition, these may be collectively referred to simply as HAPT.

The compound represented by formula (VI) (hereinafter sometimes referred to as compound (VI)) is a precursor of the compound (I). In particular, it is preferably used for the synthesis of compound (I) in which R ¹ is CH ₃ .

R ² is an organic group containing B or Sn, OH, or SH. Examples of the organic group containing B or Sn include —B (OH) ₂ , —Sn (Bu) _3, and organic groups represented by the following structural formula. The organic group containing B is preferably used because it is generally less toxic and hardly burdens the environment, and the combination with a base increases the reactivity.

  As the compound (VI), compounds represented by formulas (VIII) to (XI) are preferable.

Compound (VI) in which R ² is an organic group containing B can be synthesized from a known compound. For example, the synthesis is possible through synthesis schemes (C) to (F) described in Examples described later.

Compound (VI) in which R ² is an organic group containing Sn can be synthesized from a known compound. For example, synthesis is possible via reaction formula (G).

The method for producing compound (I) from compound (VI) can be used without particular limitation as long as it is a known method. For example, compound (I) in which R ¹ is ¹¹ CH ₃ can be synthesized via reaction formula (A).

In the reaction formula (A), [ ¹¹ C] CH ₃ I can be synthesized by a known method. For example, it can be synthesized via reaction formula (B).

Compound (I) in which R ¹ is O— (CH ₂ ) _n ^-18 F can be synthesized by reaction formula (H) when n is 2, for example.

Compound (I) in which R ¹ is (CH ₂ ) _n —F can be synthesized by reaction formula (I) when n is 3, for example. In the following reaction formula (I), the deprotection of the acetyl group may be performed by a known method, for example, a method of deprotecting with an acid catalyst.

  A compound represented by the formula (VII) (hereinafter sometimes referred to as compound (VII)) is a precursor of the compound (I).

R ^p is not particularly limited as long as it is a protecting group for an amino group, and examples thereof include an acetyl group, a tert-butoxycarbonyl group (Boc group), and a 9-fluorenylmethyloxycarbonyl group (Fmoc group).

  Compound (VII) can be synthesized by, for example, the synthesis scheme (E) described in Examples described later.

Compound (I) tends to bind specifically to the acetylcholine vesicle transporter when administered to a living body. Therefore, for example, if a fluorescent dye or the like is bound to compound (I) or positron labeling is performed on compound (I), it can be used as a labeling compound for acetylcholine vesicle transporter. Particularly when compound (I) contains ¹¹ CH ₃ or ¹⁸ F as R ¹ , compound (I) can release positrons. The positron emitted from the compound (I) immediately combines with electrons and emits γ rays. By measuring this γ-ray with an apparatus used in the PET method, the distribution of the compound (I) in the body can be quantitatively imaged over time. Therefore, by using Compound (I), it is possible to detect a site where the acetylcholine vesicle transporter exists in the subject's living body and visualize the change over time.

  Compound (I) is useful as an acetylcholine vesicle transporter detection reagent. The acetylcholine vesicle transporter detection reagent according to the present embodiment contains the compound (I), and when administered to a living body, by measuring the γ-rays released from the compound (I) in the living body by the PET method, The site where the acetylcholine vesicle transporter is present can be detected efficiently.

  Compound (I) is also useful as a diagnostic agent for Alzheimer's disease. According to the diagnostic agent for Alzheimer's disease, it is possible to diagnose Alzheimer's disease by efficiently detecting a site where the acetylcholine vesicle transporter is present in the living body.

  In the reagent for detecting acetylcholine vesicle transporter and the diagnostic agent for Alzheimer's disease according to the present embodiment, compound (I) is a compound represented by formulas (IV) and (V), that is, (S, S) HAPT-B and (R, R) HAPT-B is preferred. While (S, S) HAPT-B and (R, R) HAPT-B are similar in chemical structure to each other, only (R, R) HAPT-B is specific for the acetylcholine vesicle transporter. Join. Therefore, by using (S, S) HAPT-B as a negative control and (R, R) HAPT-B as an acetylcholine vesicle transporter labeled compound, more accurate detection of acetylcholine vesicle transporter and Alzheimer's disease Diagnosis becomes possible. That is, by treating the binding of (S, S) HAPT-B as non-specific binding and subtracting it from the binding of (R, R) HAPT-B, the specific binding to the acetylcholine vesicle transporter is obtained. , More accurate detection of acetylcholine vesicle transporter and diagnosis of Alzheimer's disease become possible.

  The reagent for detecting acetylcholine vesicle transporter and the diagnostic agent for Alzheimer's disease according to this embodiment can be produced, for example, by dissolving compound (I) in an arbitrary buffer. In this case, the detection reagent and the diagnostic agent are provided as a solution and may contain other components such as a surfactant, a preservative, and a stabilizer in addition to the buffer component. The administration method is usually intravenous administration.

  Examples of the acetylcholine vesicle transporter detection reagent and the diagnostic agent for Alzheimer's disease according to this embodiment include, but are not limited to, humans, monkeys, mice, and rats. Moreover, when performing PET measurement using compound (I) which concerns on this embodiment, the measuring method in particular is not restrict | limited, It can implement according to a well-known method.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Production Example 1 Synthesis of Compound 6 (N- (2- (piperazin-1-yl) phenyl) acetamide) Compound 6 was synthesized according to the synthesis scheme of Reaction Formula (C). Details are shown below in Production Examples 1-1 to 1-4.

(Production Example 1-1) Synthesis of Compound 12 (tert-butyl-4- (2-nitrophenyl) piperazine-1-carboxylate) 2-Chloronitrobenzene (168 g, 1.07 mol) and Boc-piperazine (199 g, 1) 0.07 mol) and DMSO (1460 ml) were charged into a reaction flask, and potassium carbonate (295 g, 2.13 mol) was further added.
The resulting reaction mixture was reacted at 80 ° C. for 60 hours, then poured into 6 L of ice water and extracted with ethyl acetate. The obtained organic layer was washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure.
The concentrated residue was purified by column chromatography (stationary phase: silica gel, mobile phase: hexane / ethyl acetate = 10/1) to obtain Compound 12 (294 g, yield 89.5%).

(Production Example 1-2) Synthesis of Compound 13 (tert-butyl-4- (2-aminophenyl) piperazine-1-carboxylate) Compound 12 (299 g, 974 mmol) and ethanol were charged into a reaction flask, and 5% Palladium on carbon (30 g) was added. The resulting reaction mixture was reacted for 2.5 hours while blowing hydrogen gas.
The reaction mixture was filtered and concentrated under reduced pressure to give compound 13 (256 g, yield 94.8%).

(Production Example 1-3) Synthesis of Compound 14 (tert-butyl-4- (2-acetamidophenyl) piperazine-1-carboxylate) Compound 13 (256 g, 923 mol), 1500 ml of methylene chloride and diisopropylethylamine (179 g, 1. 39 mol) was charged to a reaction flask and cooled to 0 ° C. Acetyl chloride (87 g, 1.11 mol) was added to the obtained reaction mixture at 10 ° C. or lower, and then reacted at 5 to 10 ° C. for 1 hour.
The reaction mixture was poured into saturated aqueous sodium hydrogen carbonate and extracted with methylene chloride. The organic layers were combined, washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure.
The concentrated residue was washed with a mixed solvent of ethyl acetate / n-hexane to obtain Compound 14 (275 g, yield 95.2%).

(Production Example 1-4) Synthesis of Compound 6 (N- (2- (piperazin-1-yl) phenyl) acetamide) Compound 14 (150 g, 479 mmol) and methylene chloride (1500 ml) were charged into a reaction flask. Fluoroacetic acid (600 ml, 8.06 mol) was added over 2 hours.
The obtained reaction mixture was reacted at room temperature for 1 hour, poured into saturated aqueous sodium hydrogen carbonate, and extracted with a mixed solution of chloroform / methanol. The organic layers were combined, washed with water, dried over anhydrous sodium sulfate, and purified by column chromatography (NH silica gel, mobile phase: chloroform / methanol = 10/1) to obtain Compound 6 (103 g, yield 100%). Obtained. The ¹ H-NMR measurement result of the obtained compound 6 is shown below.
¹ H-NMR (300 MHz, CDCl ₃ ) δ 8.53 (1H, brs), 8.35 (1H, d), 7.17-7.02 (3H, m), 3.01-3.03 (4H, m), 2.85-2.82 (4H, m), 2.2 (3H, s)

Production Example 2 Synthesis of Compound 24 (2,2,2-trifluoro-N- (1a, 2,7,7a-tetrahydronaphtho [2,3-b] oxylen-3-yl) acetamide) Reaction Formula (D) According to the synthesis scheme of Compound 24, Compound 24 was synthesized. Details are shown below in Production Examples 2-1 to 2-3.

(Production Example 2-1) Synthesis of Compound 22 (5,8-dihydronaphthalen-1-amine) Ammonia gas was blown into 320 ml of diethyl ether at -63 ° C to -46 ° C until the total volume was 640 ml. 1-aminonaphthalene (85.0 g, 594 mmol), 2-methyl-2-propanol (53 ml) and sodium (31.6 g, 1.37 mol) are contained in this order at −57 ° C. to −48 ° C. Added to diethyl ether. 2-Methyl-2-propanol (53 ml) was further added to the obtained reaction mixture at −49 ° C. to −44 ° C., and the mixture was reacted at −52 ° C. to −44 ° C. for 1 hour, and then slowly heated to 25 ° C. . Under ice-cooling, ethyl alcohol (106 ml) and saturated aqueous ammonium chloride solution (425 ml) were added dropwise to the reaction mixture in this order.
The reaction mixture was extracted with ethyl acetate, washed with water and dried over anhydrous sodium sulfate.
The obtained extracted solution was concentrated under reduced pressure to obtain Compound 22 (85.1 g, yield 98.7%).

(Production Example 2-2) Synthesis of Compound 23 (N- (5,8-dihydronaphthalen-1-yl) -2,2,2-trifluoroacetamide) Compound 22 (85.1 g, 586 mmol) and toluene (296 ml) And trifluoroacetic anhydride (125 g, 593 mmol) was added dropwise under ice cooling.
The resulting reaction mixture was concentrated under reduced pressure to give compound 23 (142 g, yield 100%).

(Production Example 2-3) Synthesis of Compound 24 (2,2,2-trifluoro-N- (1a, 2,7,7a-tetrahydronaphtho [2,3-b] oxylen-3-yl) acetamide) Compound 23 (142 g, 586 mmol) and diethyl ether (426 ml) were charged into a reaction flask, and m-chloroperbenzoic acid (108 g, 432 mmol) was added under ice cooling.
The obtained reaction mixture was reacted at 22 ° C. to 25 ° C. for 4 hours, and then insoluble matters were filtered off and concentrated under reduced pressure.
The concentrated residue was recrystallized from methylene chloride to obtain Compound 24 (85.1 g, yield 56%). The ¹ H-NMR measurement result of the obtained compound 24 is shown below.
¹ H-NMR (300 MHz, DMSO-d ₆ ) δ 10.94 (1H, br s), 7.23-7.06 (3H, m), 3.46 (2H, m), 3.23 (2H , M), 3.14-2.87 (2H, m)

Production Example 3 Compound 7-B (N- (2- (4- (5-Amino-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl) piperazin-1-yl) phenyl) acetamide) According to the synthesis scheme of reaction formula (E), compound 7-B was synthesized.

Compound 6 (55 g, 251 mmol), compound 24 (71 g, 276 mmol) and 1150 ml of ethanol were charged into a reaction flask and reacted at 78 ° C. to 79 ° C. for 16 hours. The resulting reaction mixture was concentrated under reduced pressure and dissolved in methanol (275 ml).
1200 ml of 2N-sodium hydroxide aqueous solution was added to the above reaction mixture and stirred for 18 hours, followed by extraction with methylene chloride. The obtained organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure.
The concentrated residue was purified by column chromatography (stationary phase: NH silica gel, mobile phase: n-heptane / ethyl acetate = 1/2) and then recrystallized from ethanol to give compound 7-B (29.6 g, yield). Rate 30.0%). The ¹ H-NMR measurement result of the obtained compound 7-B is shown below.
¹ H-NMR (300 MHz, CDCl ₃ ) δ 8.45 (1H, brs), 8.36 (1H, d), 7.20-6.98 (4H, m), 6.59-6.55 (2H, m), 4.21 (1H, s), 3.95 (1H, m), 3.64 (2H, s), 3.16 (1H, m), 3.00-2.71 ( 11H, m), 2.24 (1H, m), 2.24 (3H, m)

Production Example 4 Compound (S, S) -10-B ((2S, 3S) -3- (4- (2-aminophenyl) piperazin-1-yl) -8- (4,4,5,5-tetra Synthesis of methyl-1,3,2-dioxaboran-2-yl) -1,2,3,4-tetrahydronaphthalen-2-ol) According to the synthesis scheme of reaction formula (F), compound (S, S) -10 -B was synthesized. Details are shown below in Production Examples 4-1 to 4-3.

(Production Example 4-1) Compound (S, S) -8-B N- (2- (4-((2S, 3S) -3-hydroxy-5-iodo-1,2,3,4-tetrahydronaphthalene) Synthesis of 2-yl) piperazin-1-yl) phenyl) acetamide Compound 7-B (23.4 g, 61.5 mmol), 312 ml of acetic acid and 156 ml of sulfuric acid were charged into a reaction flask, and sodium nitrite ( An aqueous solution (312 ml) of 4.86 g, 70.4 mmol) was added dropwise.
The resulting reaction mixture was stirred at -1 ° C to 1 ° C for 30 minutes, and then an aqueous solution (156 ml) of potassium iodide (12.6 g, 76.2 mmol) and iodine (9.28 g, 36.6 mmol) was added to the above reaction mixture. It was dripped in.
The reaction mixture was reacted at 0 ° C. to 3 ° C. for 3.5 hours and then neutralized with an aqueous sodium hydroxide solution.
The reaction mixture was extracted with a mixed solution of chloroform / methanol. The obtained organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure.
The concentrated residue was purified by column chromatography (stationary phase: NH silica gel, mobile phase: n-heptane / ethyl acetate = 1/2), and the resulting solid was washed with methanol to give compound 8-B (2. 84 g, 9.4% yield) was obtained as a racemate. Racemic 8-B was optically resolved with a semi-preparative chiral column (CHIRALPAK IA, mobile phase: chloroform / n-hexane = 1/1 flow rate: 10 mL / min), and a fraction having a long retention time was collected. Compound (S, S) -8-B (1.18 g, yield 3.9%) was obtained. Moreover, the compound (R, R) -8-B was obtained by collect | recovering fractions with short holding time.

(Production Example 4-2) Compound (S, S) -9-B (2S, 3S) -3- (4- (2-aminophenyl) piperazin-1-yl) -8-iodo-1,2,3 Synthesis of 1,4-tetrahydronaphthalen-2-ol Compound (S, S) -8-B (200 mg, 0.407 mmol) was dissolved in 6N hydrochloric acid (6 mL) and heated to reflux for 2 hours. After completion of the reaction, the reaction solution was cooled to 0 ° C. in an ice bath and neutralized with 2N aqueous sodium hydroxide solution. After extracting the reaction solution with methylene chloride, the obtained organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The concentrated residue was purified by column chromatography (stationary phase: silica gel, mobile phase: n-heptane / ethyl acetate = 4/1 to 3/2) to quantitatively obtain compound (S, S) -9-B. .

(Production Example 4-3) Compound (S, S) -10-B (2S, 3S) -3- (4- (2-aminophenyl) piperazin-1-yl) -8- (4,4,5,5) Synthesis of 5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1,2,3,4-tetrahydronaphthalen-2-ol Compound (S, S) -9-B (170 mg, 0.378 mmol) ), Bis (pinacolato) diboron (96 mg, 0.378 mmol), (dppf) PdCl ₂ · methylene chloride 1/1 complex (77 mg, 0.0945 mmol) and potassium acetate (148 mg, 1.51 mmol) in an argon atmosphere and anhydrous It was dissolved in dimethyl sulfoxide (10 mL) and stirred with heating at 80 ° C. for 2 hours. The reaction solution was cooled to room temperature, poured into water (10 mL), and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over sodium sulfate, and concentrated under reduced pressure. The concentrated residue was purified by column chromatography (stationary phase: NH silica gel, mobile phase: n-heptane / ethyl acetate = 7/3), and the resulting solid was washed well with cooled ethyl acetate and n-heptane. Compound (S, S) -10-B (86 mg, yield 50%) was obtained. The ¹ H-NMR measurement result of the obtained compound (S, S) -10-B is shown below. Compound (R, R) -10-B was obtained from compound (R, R) -8-B by the same method as in Production Examples 4-2 and 4-3.
¹ H-NMR (400 MHz, CDCl ₃ ) δ 7.65 (1H, dd, J = 1.6, 7.6 Hz), 7.11-7.18 (2H, s), 7.04 (1H, d, J = 8.0 Hz), 6.95 (1H, dt, J = 1.6, 8.0 Hz), 6.74-6.78 (2H, m), 4.24 (1H, − br s), 3.98 (2H, br s), 3.85-3.91 (1H, m), 2.70-3.01 (12H, m), 1.34, 1.33 (12H, s)

Production Example 5 Compound (R, R) [ ¹¹ C] HAPT-B ((2R, 3R) -3- (4- (2-aminophenyl) piperazin-1-yl) -8- [ ¹¹ C] methyl-1 , 2,3,4-Tetrahydronaphthalen-2-ol) and Formulation According to the synthesis scheme of reaction formula (A1), (R, R) [ ¹¹ C] HAPT-B was synthesized.

[ ¹¹ C] carbon dioxide labeled with ^llC, which is a positron emitting nuclide, was obtained by proton irradiation of nitrogen gas of 14N (p, α) ¹¹ C reaction. After a reduction reaction with lithium aluminum hydride, [ ¹¹ C] CH ₃ I was obtained by hydroiodic acid treatment and heating distillation.
A solution obtained by dissolving 4.6 mg of tris (dibenzylideneacetone) dipalladium (Pd ₂ (dba) ₃ ) and 6.2 mg of tri-o-tolylphosphine (P (o-Tol) ₃ ) in 0.3 mL of DMF and heating gently. As a result, a solution was obtained in which the color of the color changed from black to slightly yellow. [ ¹¹ C] CH ₃ I was added to the resulting solution.
K ₂ CO ₃ 1.4 mg and compound (R, R) the -10-B2.0mg dissolved in DMF0.3ML. The obtained solution was added to the solution to which [ ¹¹ C] CH ₃ I was added.
The methylation reaction of the reaction mixture was performed at 70 ° C. for 5 minutes. The obtained reaction solution was filtered through a glass filter having a diameter of 13 mm and a pore suspension of 0.7 μm, and the filtrate was introduced into HPLC and separated. The fraction of (R, R) [ ¹¹ C] HAPT-B was introduced into an evaporator, and then the separation solvent was distilled off by heating under reduced pressure. A physiological saline solution was added to the residue to prepare a preparation containing (R, R) [ ¹¹ C] HAPT-B.

Production Example 6 Compound 10-Sn (2R, 3R) -3- (4- (2-aminophenyl) piperazin-1-yl) -8- (tributylstannyl) -1,2,3,4-tetrahydronaphthalene- Synthesis of 2-ol Compound 10-Sn was synthesized according to the synthesis scheme of the following reaction formula (G1).

Compound 9-B (265 mg, 0.59 mmol) and toluene (15 mL) were charged into a reaction flask and degassed for 30 minutes while bubbling argon gas.
Under an argon gas atmosphere, 635 μL (1.27 mmol) of bis (tri-n-butyltin) and 41.1 mg (0.036 mmol) of tetrakis (triphenylphosphine) palladium (0) (Pd (PPh ₃ ) ₄ ) were added. And reacted at reflux temperature.
Tetrakis (triphenylphosphine) palladium (0) 15 mg (0.013 mmol) and toluene (5 mL) were added 19 hours, 24 hours and 38 hours after the start of reflux. At 22 hours from the start of reflux, 158 μL (0.32 mmol) of bis (tri-n-butyltin) was added. Refluxed for a total of 46 hours.
The reaction mixture was cooled to room temperature, concentrated under reduced pressure, and purified by silica gel column chromatography (silica gel, mobile phase: n-hexane → methylene chloride → methylene chloride / methanol = 100/1) to give compound 10-Sn (309 mg, yield). Rate 85.5%).
[Α] ²² = −22.0 (c = 0.138, CHCl ₃ )

Separation and purification of synthetic reaction solution and assay The synthesis reaction solution was separated under the following HPLC conditions.
Column: Megapak SIL C18-10 (JASCO) (7.6 x 250 mm)
Solvent acetonitrile / 30 mM ammonium acetate / acetic acid = 450/550/2
Flow rate: 6 ml / min
Detection wavelength: 254 nm

The obtained compound was assayed using the following HPLC system.
Column: Finepak SIL C18S (JASCO) (4.6x150mm)
Solvent: acetonitrile / 30 mM ammonium acetate / acetic acid = 500/500/2
Flow rate: 2 ml / min
Detection wavelength: 254 nm
Column: Kirobiotic V (ASTEC) (4.6 x 250 mm)
Solvent: methanol / acetic acid / triethylamine = 1000 / 0.3 / 0.1
Flow rate: 1 ml / min
Detection wavelength: 254 nm

(S, S) [ ¹¹ C] HAPT-A, (R, R) [ ¹¹ C] HAPT-A and (S, S) [ ¹¹ C] HAPT-B are also produced by the same synthesis route as in Production Example 5. did. The absolute configuration of HAPT was determined by X-ray analysis.

PET measurement A rhesus monkey weighing approximately 5 kg was fixed to a PET device (trade name, SHR7700, manufactured by Hamamatsu Photonics Co., Ltd.) without anesthesia, and after measuring a transmission for correction of absorption, [ ¹¹ C] HAPT was administered intravenously, 180 Minute dynamic measurement was performed.

A region of interest (ROI) was determined from a tomographic image obtained from the same individual using a nuclear magnetic resonance tomography apparatus (hereinafter referred to as MRI), and the change over time of the labeled compound ([ ¹¹ C] HAPT) in each ROI was determined. The results are shown in FIG. (S, S) [ ¹¹ C] HAPT-A, (R, R) [ ¹¹ C] HAPT-A and (R, R) [ ¹¹ C] HAPT-B specifically bind to the acetylcholine vesicle transporter. On the other hand, (S, S) [ ¹¹ C] HAPT-B did not bind to the acetylcholine vesicle transporter, and only nonspecific binding was confirmed. This result suggested that (S, S) [ ¹¹ C] HAPT-B can be used as a negative control, and the other three [ ¹¹ C] HAPT can be used as labeling compounds for acetylcholine vesicle transporters. In particular, (R, R) [ ¹¹ C] HAPT-B has reached an equilibrium state at about 15 minutes from the start of measurement, suggesting that it can be used for competition experiments.

Next, [ ¹¹ C] HAPT was examined for arterial plasma activity and metabolic activity. Specifically, the following method was used. The results are shown in FIG.

PET Measurement A cephalic vein or saphenous vein was secured as a route for intravenous administration of a test animal, and a femoral artery or posterior tibial artery was secured as a route for collecting arterial blood, respectively.
[ ¹¹ C] HAPT was administered intravenously over about 30 seconds from the indwelling needle placed in the test animal. Simultaneously with the start of administration, Emission measurement (10 seconds 6 frames, 30 seconds 6 frames, 1 minute 12 frames, 3 minutes 25 frames, 5 minutes 6 frames, 121 minutes, 55 frames in total) was started and monitored. In addition, the amount of radioactivity of [ ¹¹ C] HAPT actually administered was calculated by measuring the radioactivity before administration and the radioactivity remaining in the syringe after administration. At this time, the half-life of the radioactivity was corrected based on the time of administration.

[ ¹¹ C] Metabolism analysis of HAPT [ ¹¹ C] Ethanol in 100 μL of plasma obtained from arterial blood sampling 16, 40, 64 seconds after administration of HAPT, and 6, 10, 20, 30, 45, 60, 75, 90 minutes after administration 100 μL was added and stirred. The mixture of plasma and ethanol was centrifuged at 12000 rpm for 5 minutes with a centrifuge to obtain a supernatant. The obtained supernatant was developed on a thin layer chromatography using dichloromethane / diethyl ether / triethylamine = 100/40/1 as a solvent. Then, the thin layer plate which developed the upper fine was brought into close contact with the imaging plate. The radioactivity distribution on the imaging plate was measured with a fluoro image analyzer to determine the proportion of metabolites and unmetabolites.

This result suggests that there is no fat-soluble metabolite derived from [ ¹¹ C] HAPT and returning to the brain, and it was found that [ ¹¹ C] HAPT is suitable as a labeling compound.

The localization of each [ ¹¹ C] HAPT to each part of the rhesus monkey brain was examined. FIG. 3 (A) shows the results when (S, S) HAPT-A and (R, R) HAPT-A are used, and (S, S) HAPT-B and (R, R) HAPT-B are used. FIG. 3 (B) shows the result in the case of being present. Examination of cerebrum, pons, hippocampus, medullary raphe, amygdala, temporal cortex (TempCtx), hypothalamus, thalamus, occipital cortex (OccCtx), putamen, caudate nucleus, frontal cortex (FmtCtx) and cingulate gyrus , (S, S) HAPT-A, (R, R) HAPT-A and (R, R) HAPT-B were found to be most localized in the putamen (FIG. 3). On the other hand, (S, S) HAPT-B was suggested to show non-specific binding at any site.

  Inhibition experiments were performed using a vesicle transporter inhibitor (Vesamicol). Specifically, the procedure was as follows. The results are shown in FIGS.

PET Measurement A cephalic vein or saphenous vein was secured as a route for intravenous administration of a test animal, and a femoral artery or posterior tibial artery was secured as a route for collecting arterial blood, respectively.
L-(−) Besamicol administration was intravenously administered at a dose of 1 mg / kg 30 minutes before administration of [ ¹¹ C] HAPT.
The amount of radioactivity of [ ¹¹ C] HAPT before administration was measured. [ ¹¹ C] HAPT was administered intravenously over about 30 seconds from the indwelling needle placed in the test animal. Simultaneously with the start of administration, Emission measurement (10 seconds 6 frames, 30 seconds 6 frames, 1 minute 12 frames, 3 minutes 25 frames, 5 minutes 6 frames, 121 minutes, 55 frames in total) was started and monitored.

When vesamicol was administered (FIG. 4 (C), FIG. 5 (B)), (R, R) compared to the control experiment (FIG. 4 (B), FIG. 5 (A)) where vesamicol was not administered. [ ¹¹ C] HAPT-B was found to have reduced binding to the acetylcholine vesicle transporter. From this result, it was suggested that (R, R) [ ¹¹ C] HAPT-B is suitable for competition experiments.

Claims (1)

A compound represented by formula (VI).

(In formula (VI), R ² represents —B (OH) ₂ or an organic group containing B represented by the following structural formula, OH, or SH).