Inhibitors

1. A compound of formula (I),

wherein said compound of formula (I) is the compound:

or a pharmaceutically acceptable salt, solvate or polymorph thereof, including all tautomers and stereoisomers thereof, wherein:

R 1 represents a phenyl ring fused to a 5-membered heteroaryl ring wherein R 1 is linked to the core of formula (I) through the phenyl ring;

R 2 represents optionally substituted aryl;

R 3 represents H or —C 1-4 alkyl;

in which aforesaid aryl may optionally be substituted by one or more groups selected from C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 1-6 haloalkyl, —C 1-6 thioalkyl, —SOC 1-4 alkyl, —SO 2 C 1-4 alkyl, C 1-6 alkoxy-, C 3-6 alkenyloxy-, C 3-6 alkynyloxy-, —C(O)C 1-6 alkyl, —C(O)OC 1-6 alkyl, C 1-6 alkoxy-C 1-6 alkyl-, nitro, halogen, cyano, hydroxyl, and —C(O)OH;

X represents CR 7 R 8 ;

Z represents —N—R 4 ;

Y represents C═O;

wherein,

R 4 represents H, —C 1-8 alkyl, or —C(O)C 1-6 alkyl; and

R 7 and R 8 independently represent H or —C 1-4 alkyl.

2. The compound according to claim 1 wherein R 1 represents

3. The compound according to claim 1 wherein R 1 represents

4. The compound according to claim 1 , wherein R 2 represents phenyl substituted by one or more groups selected from C 1-6 alkyl, C 1-6 alkoxy, hydroxyl, haloC 1-6 alkyl, haloC 1-6 alkoxy, halogen, C 1-6 alkoxy-C 1-6 alkyl- and C 1-6 alkoxy-C 1-6 alkoxy-.

5. The compound according to claim 4 wherein R 2 represents phenyl substituted by one or more groups selected from methyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, isopropyloxy, hydroxyl, trifluoromethyl, tetrafluoroethyloxy, chlorine, fluorine, and —(CH 2 ) 3 —OMe, and —O—(CH 2 ) 2 —OMe.

6. The compound according to claim 4 wherein R 2 represents phenyl substituted by one or more C 1-6 alkoxy groups.

7. The compound according to claim 6 wherein R 2 represents phenyl substituted by one or more groups selected from methoxy, ethoxy, propoxy, butoxy, pentoxy or isopropyloxy.

8. The compound according to claim 7 wherein R 2 represents phenyl substituted by a propoxy group.

9. The compound according to claim 1 , wherein R 3 represents H.

10. The compound according to claim 1 , wherein R 7 and and R 8 represent H.

11. The compound according to claim 1 , wherein X represents CH 2 , Y represents C═O and Z represents NH.

12. The compound according to claim 1 selected from the group consisting of:

or a pharmaceutically acceptable salt, solvate or polymorph thereof, including all tautomers and stereoisomers.

13. A pharmaceutical composition comprising a compound of formula (I) according to claim 1 .

14. The pharmaceutical composition of claim 13 , wherein said pharmaceutical composition comprises additionally at least one compound, selected from the group consisting of neuroprotectants, antiparkinsonian drugs, amyloid protein deposition inhibitors, beta amyloid synthesis inhibitors, antidepressants, anxiolytic drugs, antipsychotic drugs and anti-multiple sclerosis drugs.

15. The pharmaceutical composition of claim 13 , wherein said pharmaceutical composition comprises additionally at least one compound, selected from the group consisting of PEP-inhibitors, LiCl, inhibitors of inhibitors of DP IV or DP IV-like enzymes, acetylcholinesterase (ACE) inhibitors, PIMT enhancers, inhibitors of beta secretases, inhibitors of gamma secretases, inhibitors of neutral endopeptidase, inhibitors of Phosphodiesterase-4 (PDE-4), TNFalpha inhibitors, muscarinic M1 receptor antagonists, NMDA receptor antagonists, sigma-1 receptor inhibitors, histamine H3 antagonists, immunomodulatory agents, immunosuppressive agents or an agent selected from the group consisting of antegren (natalizumab), Neurelan (fampridine-SR), campath (alemtuzumab), IR 208, NBI 5788/MSP 771 (tiplimotide), paclitaxel, Anergix.MS (AG 284), SH636, Differin (CD 271, adapalene), BAY 361677 (interleukin-4), matrix-metalloproteinase-inhibitors, interferon-tau (trophoblastin) and SAIK-MS.

16. The compound according to claim 1 , wherein R 4 represents H.

17. A process for preparation of a compound of formula (I) according to claim 1 comprising:

(a) preparing a compound of formula (I) from a compound of formula (II):

wherein R 2 , R 3 , X, Y, and Z are as defined in claim 1 ;

(b) preparing a compound of formula (I) wherein R 3 represents hydrogen, Y represents CO, Z represents —N—R 4 , and X represents CR 7 R 8 and R 8 represents hydrogen by hydrogenation of a compound of formula (III):

wherein R 1 , R 2 , R 4 , and R 7 are as defined in claim 1 ;

(c) preparing a compound of formula (I) wherein R 3 represents hydrogen, Y represents CO, Z represents —N—R 4 , and X represents CH 2 from a compound of formula (V):

wherein R 1 , R 2 , and R 4 are as defined in claim 1 ;

(d) preparing a compound of formula (I) wherein R 1 represents 1 H-benzo[d]imidazol-5-yl, R 3 represents hydrogen, Y represents CO, Z represents —NH, and X represents CH 2 from a compound of formula (VII):

wherein R 2 is as defined in claim 1 ;

(e) preparing a compound of formula (I) wherein R 4 represents —C 1-8 alkyl or —C(O)C 1-6 alkyl from a corresponding compound of formula (I) wherein R 4 represents H by treatment with an alkylating or alkanoylating agent;

(f) interconversion of compounds of formula (I); or

(g) deprotecting a compound of formula (I) which is protected.