The present invention refers to compounds of the following formula (I) or a pharmaceutically acceptable salt thereof, to pharmaceutical compositions containing them and to a process for the preparation of said compounds: Formula (I), wherein: R1 is independently selected from hydrogen atom, amine group, monocyclic or bicyclic aliphatic, aromatic, heteroaliphatic or heteroaromatic ring, optionally substituted by one or more substituents selected from C1-C4 alkyl optionally substituted by one or more halogen atom(s), halogen, C1-C4 alkoxy or phenyl group, optionally substituted by C1-C4 alkyl； R2 is independently selected from monocyclic or bicylic aliphatic, heteroaliphatic, aromatic or heteroaromatic ring, C1-C6 alkyl, alkenyl or alkynyl chain, optionally substituted by one or more substituents selected from C1-C4 alkyl optionally substituted by one or more halogen atom(s), halogen, C1-C4 alkoxy, cyano, C1-C4 alkylthio, SO-C1-C4 alkyl, SO2-C1-C4 alkyl, N(C1-C4 alkyl)2； n is 1 or 2； preferably n is 1； m is 0, 1 or 2； preferably m is 0； R3 and R4 can be, independently, -H, -F, C1-C4 alkyl, -OH, -OC1-C4 alkyl； preferably they are both -H； X is O or S； R5 is -H or -CH3 optionally substituted by one or more fluorine atoms； preferably R5 is hydrogen. The compounds of the invention can be used in the treatment of conditions or diseases mediated by P2X7 receptor.La présente invention concerne des composés de formule (I) suivante ou un sel pharmaceutiquement acceptable de ceux-ci, des compositions pharmaceutiques les contenant et un procédé de préparation desdits composés : formule (I), dans laquelle : R1 est indépendamment choisi parmi un atome d'hydrogène, un groupe amine, un cycle aliphatique, aromatique, hétéroaliphatique ou hétéroaromatique, monocyclique ou bicyclique, éventuellement substitué par un ou plusieurs substituants choisis parmi un alkyle en C1-C4 éventuellement substitué par un ou plusieurs atomes d'halogène, halogène, groupe alcoxy en C1-C4 ou groupe phényl
