Compounds for imaging tau proteins that accumulate in brain

1. A method for imaging tau proteins that accumulate in the brain, the method comprising the steps of:

(a) administering to a mammal an effective amount of a compound of the Formula (I), or a pharmaceutically acceptable salt or a solvate thereof, and

(b) imaging the brain of the mammal,

wherein the compound of Formula (I) is:

wherein:

R 1 and R 2 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, acyl, and hydroxyalkyl;

R 3 is hydrogen or halogen;

ring A is a benzene ring or a pyridine ring;

ring B is selected from the group consisting of the following formulae (i), (ii), (iii), and (iv):

in the formula (ii), R a is alkyl;

R 4 and R 5 are each independently selected from the group consisting of hydrogen, hydroxy, alkoxy, haloalkoxy, halohydroxyalkoxy, and aminoalkyl; and

 represents a double bona or a triple bond,

wherein the compound of Formula (I) is not:

2. The method of claim 1 , wherein, in the compound, one or more atoms are a radioisotope of the atom or atoms.

3. The method of claim 1 , wherein ring B is of formula (i) or (ii).

4. The method of claim 3 , wherein the compound is according to Formula

5. The method of claim 4 , wherein, in the compound,

represents the double bond.

6. The method of claim 4 , wherein, in the compound,

represents the triple bond.

7. The method of claim 3 , wherein the compound is according to Formula (III):

8. The method of claim 7 , wherein, in the compound,

represents a double bond.

9. The method of claim 7 , wherein, in the compound,

represents a triple bond.

10. The method of claim 3 , wherein the compound is according to Formula (IV):

11. The method of claim 10 , wherein, in the compound,

represents a double bond.

12. The method of claim 10 , wherein, in the compound,

represents a triple bond.

13. The method of claim 1 , wherein ring B is of formula (iii).

14. The method of claim 13 , wherein the compound is according to Formula (V):

15. The method of claim 14 , wherein, in the compound,

represents a double bond.

16. The method of claim 14 , wherein, in the compound,

represents a triple bond.

17. The method of claim 1 , wherein ring B is of formula (iv).

18. The method of claim 17 , wherein the compound is according to Formula (VI):

19. The method of claim 18 , wherein, in the compound,

represents a double bond.

20. The method of claim 18 , wherein, in the compound,

represents a triple bond.

21. The method of claim 1 , wherein the compound is selected from the following structural formulae:

Name

Structural Formula

PBB1

PBB2

PBB3

PBB4

PBB5

mPBB5

PBB2.1

PBB2.2

PBB2.3

PBB3.1

PBB3.2

PBB3.2N

Core1-4

Core1-5

Core1-11

Core1-15

Core1-20

Core2-9

Core2-10

Core2-14

F0-PBB3 analogue

F0-PBB3

F0-PBB3.2

F1-PBB3

F1-PBB3.2

F1-PBBf3

F1-PBBf3.2

PBQ3.0

PBQ3

PBQ3.1

PBQ3.2

or a radioisotopically labeled analog thereof, wherein an atom with a “*” symbol is the radioisotope of the atom, and wherein if there are two “*” symbols in the compound, then one or both are radioisotopes of the atom.

22. The method of claim 21 , wherein, in the compound, one or more atoms are a radioisotope of the atom or atoms.

23. The method of claim 21 , wherein, in the compound, a carbon atom on nitrogen bound to a benzene ring or a pyridine ring is the radioisotope 11 C.

24. The method of claim 21 , wherein, in the compound, F in the compound is the radioisotope 18 F.

25. The method of claim 21 , wherein, in the compound, a carbon atom of a methoxy group bound to a benzothiazole ring is the radioisotope 11 C.

26. The method of claim 21 , wherein the compound is the radioisotopically labeled analog thereof.