1-Phenacyl-3-phenyl-3-(piperidylethyl)piperidine derivatives, process for the preparation thereof and pharmaceutical compositions containing them

A compound of formula (I):

• in which:
• X represents a group
• Ar represents a phenyl monosubstituted or disubstituted with a halogen atom;
• or a (C1-C3)alkyl;
• R1 represents a chlorine atom, a bromine atom, a (C1-C3)alkyl or a trifluoromethyl;
• R2 represents a group —CR3R4CONR5R6;
• R3 and R4 represent the same radical chosen from a methyl, an ethyl, an n-propyl or an n-butyl;
• or R3 and R4, together with the carbon atom to which they are attached, constitute a (C3-C6)cycloalkyl;
• R5 and R6 each independently represent a hydrogen;
• a (C1-C3)alkyl;
• or R5 and R6, together with the nitrogen atom to which they are attached, constitute a heterocyclic radical chosen from 1-azetidinyl, 1-pyrrolidinyl, 1-piperidyl, 4-morpholinyl, 4-thiomorpholinyl or perhydro-1-azepinyl;
• or an acid-addition salt, solvate or hydrate thereof.