Compounds for use in imaging, diagnosing and/or treatment of diseases of the central nervous system

1. A compound of formula I:

wherein

D is deuterium;

R 1 is selected from methyl, ethyl, n-propyl, n-butyl, and iso-butyl;

R 2 is [ 18 F]fluorine; and

n and m are each selected from 0 and 1;

with the provisos that:

if n=0, m must be 1, and

if n=1, m must be 0;

including all stereoisomeric forms of said compound, including but not limited to enantiomers and diastereoisomers as well as racemic mixtures,

including salts thereof with an organic or inorganic acids.

2. The compound according to claim 1 , wherein

D is deuterium;

R 1 is methyl; and

R 2 is [ 18 F]fluorine.

3. The compound according to claim 1 , wherein said compound is of formula Ia:

wherein

D is deuterium; and

R 2 is [ 18 F]fluorine;

including enantiomers as well as racemic mixtures, and any suitable salt with an organic or inorganic acid.

4. The compound according to claim 1 , wherein said compound is selected from:

a compound of formula Ic,

wherein F= 18 F,

a compound of formula Ie,

wherein F= 18 F,

and salts thereof with organic or inorganic acids.

5. A diagnostic composition for PET imaging comprising a [ 18 F] labelled compound according to claim 1 .

6. A method of diagnostic PET imaging comprising subjecting a patient to diagnostic PET imaging of CNS diseases, wherein said patient has been administered an [ 18 F] labelled compound according to claim 1 .

7. A method of diagnostic PET imaging comprising subjecting a patient to diagnostic PET imaging of CNS diseases, wherein said patient has been administered a diagnostic composition according to claim 5 .

8. The method according to claim 6 , wherein said patient is imaged for Alzheimer's disease.

9. The method according to claim 6 , wherein said [ 18 F] labelled compound is a compound of formula Ie:

wherein F= 18 F.

10. A method for the synthesis of a compound according to claim 1 :

wherein

D is deuterium;

R 1 is selected from methyl, ethyl, n-propyl, n-butyl, and iso-butyl;

R 2 is [ 18 F]fluorine; and

n is 1 and m is 0;

said method comprising:

reacting a compound of formula I:

wherein

D is deuterium;

R 1 is selected from methyl, ethyl, n-propyl, n-butyl, and iso-butyl;

R 2 is leaving group, wherein said leaving group is selected from halogen, C 1 -C 6 -alkylsulfonyloxy, which is optionally substituted by fluorine, and arylsulfonyloxy, which is optionally substituted by hydrogen, methyl, halo and nitro;

n is 0; and

m is 1;

with a suitable F-fluorinating agent, wherein F is 18 F.

11. The method according to claim 10 for the synthesis of a compound of formula Ic:

wherein F is 18 F,

said method comprising:

reacting a compound of formula Id:

with a suitable F-fluorinating agent, wherein F is 18 F.

12. The method according to claim 10 for the synthesis of a compound of formula le:

wherein F is 18 F,

said method comprising:

reacting a compound of formula If:

with a suitable F-fluorinating agent, wherein F is 18 F.

13. A kit comprising at least one sealed container comprising a compound according to claim 1 .

14. A kit comprising at least one sealed container comprising a compound of claim 4 .

15. The kit according to claim 13 , further comprising a further sealed container comprising reagents.

16. The compound according to claim 1 , wherein n is 0 and m is 1.

17. The compound according to claim 1 , wherein n is 1 and m is 0.

18. The compound according to claim 1 , wherein said compound is a salt of a compound of formula I with an acid selected from carbonic, nitric, phosphoric, hydrochloric, perchloric, sulfuric, formic, acetic, trifluoracetic, propionic, succinic, glycolic, gluconic, lactic, malic, fumaric, pyruvic, benzoic, anthranilic, mesylic, fumaric, salicylic, phenylacetic, mandelic, embonic, methansulfonic, ethanesulfonic, benzenesulfonic, phantothenic, toluenesulfonic, trifluormethansulfonic and sulfanilic acids.

19. The compound according to claim 1 , wherein said compound is: