The present invention relates to the compounds of formula (I): in which A is a group of formula (a) or (b) in which R represents a hydrogen or halogen atom, an —S(O)z(C1-C4)alkyl group, an —NHSO2(C1-C4)alkyl group, an —SO2NH(C1-C4)alkyl group, an —NHSO2phenyl-(C1-C4)alkyl group or an —NHSO2phenyl group, said phenyl possibly being substituted with a halogen atom, with a (C1-C4)alkyl group or with a (C1-C4)alkoxy group; R1 represents a hydrogen atom or a (C1-C4)alkyl group, a —CO(C1-C4)alkyl group, a phenyl-(C1-C4)alkyl group or a —COphenyl group, said phenyl also possibly being substituted with a halogen atom or with a (C1-C4)alkoxy group; R2 is a hydrogen atom or an —SO2(C1-C4)alkyl group, an —SO2phenyl-(C1-C4)alkyl group or an —SO2phenyl group; X completes a ring of 5 to 8 atoms, said ring being saturated or unsaturated, possibly being substituted with one or two (C1-C4)alkyl groups and bearing one or two carbonyl groups; n, m and z are, independently, 0, 1 or 2; R3 represents a hydrogen or halogen atom, a (C1-C6)alkyl group, a (C1-C4)alkoxy group, a —COO(C1-C4)alkyl group, a —CO(C1-C4)alkyl group, an —NHSO2(C1-C4)alkyl group, an —NHSO2phenyl-(C1-C4)alkyl groups, —NO2, —CN, —CONR4R5, —COOH, or a 4,5-dihydro-1,3-oxazol-2-yl or 4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl group; R4 and R5 represent, independently, a hydrogen atom, a phenyl, a (C1-C4)alkyl group or a phenyl-(C1-C4)alkyl group or R4 and R5 with the nitrogen atom to which they are attached, may form a ring of 5 to 7 atoms in total; and to the salts or solvates thereof, to the pharmaceutical compositions containing them, to a process for the preparation thereof and to intermediates in this process.