Adamantane and memantine derivatives as peripheral NMDA receptor antagonists

1. Cationic compound of formula (I):

wherein:

R 1 and R 2 represent, independently of each other, a hydrogen atom or a (C 1 -C 6 )alkyl group;

the group —(CH 2 ) n -A is linked to the cycle in position (a) or (b);

n is 0, 1, 2 or 3;

A represents a —NR 3 R 4 group or a —N + R 3 R 4 R 5 group;

R 3 , R 4 and R 5 represent, independently of each other, a hydrogen atom, a (C 1 -C 10 )alkyl group, a (C 1 -C 10 )alkoxy group, a (C 1 -C 10 )alkyl-C(═NH)(—OH) group, a (C 3 -C 8 )cycloalkane group, a 6- to 10-membered aryl group or a 5- to 12-membered heteroaryl group; said alkyl or alkoxy groups being optionally substituted with one or more —NR 6 R 7 group, —N + R 6 R 7 R 8 group, (C 3 -C 8 )cycloalkane group, 6- to 10-membered aryl group or 5- to 12-membered heteroaryl group;

with R 6 , R 7 and R 8 represent, independently of each other, a hydrogen atom or a (C 1 -C 6 )alkyl; and

the compound of formula (I) contains at least one positive charged nitrogen atom;

provided that R 1 and R 2 are not both a hydrogen atom; and

provided that when R 1 and R 2 are a methyl group, the group —(CH 2 ) n -A is linked to the cycle in position (a), and n is 0, then A is not a group —N + H 3 .

2. Cationic compound according to claim 1 , wherein R 1 and R 2 are chosen among a hydrogen atom or a methyl group.

3. Cationic compound according to claim 1 , wherein the group —(CH 2 ) n -A is linked to the cycle in position (a).

4. Cationic compound according to claim 1 , wherein n is 0 or 1.

5. Cationic compound according to claim 1 , wherein said compound is of formula (Ia):

wherein R 1 , R 2 , R 3 , R 4 , R 5 and n are as defined in claim 1 .

6. Cationic compound according to claim 1 , wherein R 3 , R 4 and R 5 represent, independently of each other, a (C 1 -C 10 )alkyl group.

7. Cationic compound according to claim 1 , wherein at least one of R 3 , R 4 and R 5 represents a methyl group.

8. Cationic compound according to claim 1 , wherein R 3 , R 4 and R 5 are simultaneously a methyl group.

9. Cationic compound according to claim 1 , wherein R 3 and R 4 are a methyl group and R 5 represent a (C 1 -C 10 )alkyl group substituted with a (C 3 -C 8 )cycloalkane group.

10. Cationic compound according to claim 1 , chosen among:

11. Medicament comprising as pharmaceutical active agent at least one compound as defined in claim 1 .

12. A pharmaceutical composition comprising at least one compound as defined in claim 1 , and at least one pharmaceutically acceptable excipient.

13. A pharmaceutical composition as claimed in claim 12 , wherein said compound is in combination with at least one other therapeutic agent.

14. Cationic compound of formula (I) according to claim 1 for use as a peripheral NMDA receptor antagonist.

15. Cationic compound according to claim 1 , for use for treating a disease or a condition chosen among pulmonary hypertension, pulmonary diseases involving inflammation, fibrosis and remodeling, non-neuronal cancers, diabetes, atherosclerosis, sickle cell disease, diseases involving thrombosis, acute infections, chronic infectious diseases, inflammatory disease, autoimmune disease, heart failure, arrhythmias, renal disorders, pain, psoriasis, atopic dermatitis, and osteoporosis.

16. Cationic compound according to claim 15 , wherein the disease is pulmonary arterial hypertension.