Piperidinone Carboxamide Derivatives as P2X7 Modulators

A compound of formula (I) or a pharmaceutically acceptable salt thereof:

• wherein:
• R1 represents C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-6 cycloalkyl, C3-6 cycloalkylmethyl-, pyridinylmethyl- or benzyl, any of which is optionally substituted with 1, 2 or 3 halogen atoms;
• or an unsubstituted phenyl;
• R2 and R3 independently represent hydrogen, C1-6 alkyl, C6-10 arylmethyl- or C3-6 cycloalkylmethyl-;
• and any of said C1-6 alkyl, C6-10 arylmethyl- or C3-6 cycloalkylmethyl- is optionally substituted with 1, 2 or 3 halogen atoms;
• R4, R5, R6, R7, and R8 independently represent hydrogen, fluorine or methyl;
• and
• R9, R10, R11, R12 and R13 independently represent hydrogen, halogen, cyano, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-6 cycloalkyl or phenyl, and any of said C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-6 cycloalkyl or phenyl is optionally substituted with 1, 2 or 3 halogen atoms;
• or R12 and R13 together with the carbon atoms to which they are attached form a benzene ring which is optionally substituted with 1, 2 or 3 halogen atoms;
• with the proviso that when R9 and R13 are both selected from hydrogen or fluorine, at least one of R10, R11 and R12 is a halogen atom.

A compound which is:

• N-[(2,4-dichlorophenyl)methyl]-1,2-dimethyl-6-oxo-2-piperidinecarboxamide;
• 1-cyclobutyl-N-[(2,4-dichlorophenyl)methyl]-2-methyl-6-oxo-2-piperidinecarboxamide;
• 1-cyclopropyl-N-[(2,4-dichlorophenyl)methyl]-6-oxo-2-piperidinecarboxamide;
• N-[(2-chloro-4-fluorophenyl)methyl]-6-oxo-1-(phenylmethyl)-2-piperidinecarboxamide;
• N-{[2-chloro-3-(trifluoromethyl)phenyl]methyl}-6-oxo-1-(phenylmethyl)-2-piperidinecarboxamide;
• N-[(2,4-dichlorophenyl)methyl]-6-oxo-1-(phenylmethyl)-2-piperidinecarboxamide;
• N-{[2-chloro-3-(trifluoromethyl)phenyl]methyl}-1-(2,2-dimethylpropyl)-6-oxo-2-piperidinecarboxamide;
• N-{[2-chloro-3-(trifluoromethyl)phenyl]methyl}-1-[(2,6-dichlorophenyl)methyl]-6-oxo-2-piperidinecarboxamide;
• 1-ethyl-6-oxo-N-[(2,3,4-trifluorophenyl)methyl]-2-piperidinecarboxamide;
• or
• N-[(2-chloro-4-fluorophenyl)methyl]-1-ethyl-6-oxo-2-piperidinecarboxamide.