A compound of formula: or a tautomer, stereoisomer, N-oxide, or a pharmacologically acceptable salt of any of the foregoing, wherein: - R 1 is chosen from hydrogen or an alkyl(C 1-4) group, optionally substituted with one or more halogen atoms or an hydroxyl group, - R 2 and R 3 are independently chosen from hydrogen, an hydroxyl group or an alkyl(C 1-4) group optionally substituted with one or more substituents Q, independently chosen from: halogen, alkyl(C 1-4), alkenyl(C 1-4), alkynyl(C 1-4), CF 3, NH 2, NHalkyl(C 1-4), N[alkyl(C 1-4)] 2, OH, =O, O-alkyl(C 1-4), or OCF 3, or, R 1 and R 2, together with the carbon atoms marked 'a' and 'b' form a C 5-8 -cycloalkyl ring, optionally substituted with one or more halogen atoms, an hydroxyl group or an alkyl(C 1-4) group, or, R 2 and R 3, together with the carbon atom marked 'b' form a C 3-8 -cycloalkyl or a C 4-8 -heterocycloalkyl ring, optionally substituted with one or more substituents Q, as defined above, - R 4 and R 5 are independently chosen from hydrogen or an alkyl(C 1-4) group optionally substituted with one or more substituents Q, as defined above, or, R 4 and R 5 are independently chosen from a monocyclic or fused bicyclic aromatic or hetero-aromatic group, optionally substituted with one or more substituents Q, as defined above, with the proviso that Q cannot be =O (keto) on aromatic rings, or R 3 and R 4, together with the carbon atoms marked 'b' and 'c' form a C 3-8 -cycloalkyl or a C 5-8 -heterocycloalkyl ring, optionally substituted with one or more substituents Q, as defined above, - R 6 and R 7 are independently chosen from hydrogen, or an alkyl(C 1-4) group optionally substituted with one or more halogen atoms or an hydroxyl group, or a dialkyl(C 1-3)-amino-alkyl(C 1-3) group, or, R 6 and R 7 independently are chosen from a monocyclic or fused bicyclic aromatic or hetero-aromatic group optionally substituted with one or more substituents Q, as defined above, or, R 6 and R 7 independently are a C 5-8 -cycloalkyl group or a C 5-8 -heterocycloalkyl group optionally substituted with one or more substituents Q, as defined above, or, R 6 and R 7, together with the nitrogen atom to which they are attached, form a C 5-8 -heterocycloalkyl group optionally substituted with one or more substituents Q, as defined above, - R 8 is 4-aminophenyl, with the proviso that when R 1, R 3, R 4, R 5 and R 6 are hydrogen and R 2 and R 7 are ethyl the compound is not a racemic mixture but a pure enantiomer. - R 1 is chosen from hydrogen or an alkyl(C 1-4) group, optionally substituted with one or more halogen atoms or an hydroxyl group, - R 2 and R 3 are independently chosen from hydrogen, an hydroxyl group or an alkyl(C 1-4) group optionally substituted with one or more substituents Q, independently chosen from: halogen, alkyl(C 1-4), alkenyl(C 1-4), alkynyl(C 1-4), CF 3, NH 2, NHalkyl(C 1-4), N[alkyl(C 1-4)] 2, OH, =O, O-alkyl(C 1-4), or OCF 3, or, R 1 and R 2, together with the carbon atoms marked 'a' and 'b' form a C 5-8 -cycloalkyl ring, optionally substituted with one or more halogen atoms, an hydroxyl group or an alkyl(C 1-4) group, or, R 2 and R 3, together with the carbon atom marked 'b' form a C 3-8 -cycloalkyl or a C 4-8 -heterocycloalkyl ring, optionally substituted with one or more substituents Q, as defined above, - R 4 and R 5 are independently chosen from hydrogen or an alkyl(C 1-4) group optionally substituted with one or more substituents Q, as defined above, or, R 4 and R 5 are independently chosen from a monocyclic or fused bicyclic aromatic or hetero-aromatic group, optionally substituted with one or more substituents Q, as defined above, with the proviso that Q cannot be =O (keto) on aromatic rings, or R 3 and R 4, together with the carbon atoms marked 'b' and 'c' form a C 3-8 -cycloalkyl or a C 5-8 -heterocycloalkyl ring, optionally substituted with one or more substituents Q, as defined above, - R 6 and R 7 are independently chosen from hydrogen, or an alkyl(C 1-4) group optionally substituted with one or more halogen atoms or an hydroxyl group, or a dialkyl(C 1-3)-amino-alkyl(C 1-3) group, or, R 6 and R 7 independently are chosen from a monocyclic or fused bicyclic aromatic or hetero-aromatic group optionally substituted with one or more substituents Q, as defined above, or, R 6 and R 7 independently are a C 5-8 -cycloalkyl group or a C 5-8 -heterocycloalkyl group optionally substituted with one or more substituents Q, as defined above, or, R 6 and R 7, together with the nitrogen atom to which they are attached, form a C 5-8 -heterocycloalkyl group optionally substituted with one or more substituents Q, as defined above, - R 8 is 4-aminophenyl, with the proviso that when R 1, R 3, R 4, R 5 and R 6 are hydrogen and R 2 and R 7 are ethyl the compound is not a racemic mixture but a pure enantiomer.