6-phenyl-4,5-dihydropyridazin-3(2h)-one derivatives as pde3a and pde3b inhibitors for treating cancer

A compound of formula (I)

• where
• R1 is selected from a hydrogen atom, a halogen atom, a cyano group, a C1-C3-alkyl group, a C1-C3-haloalkyl group, a C1-C3-haloalkoxy group;
• R2 is selected from a hydrogen atom and a halogen atom;
• R3 is selected from,
• a C1-C6-alkoxy group,
• a C2-C6-alkenyl group,
• a C3-C6-cycloalkyl group,
• a C5-C6-cycloalkenyl group,
• a 3- to 7-membered heterocycloalkyl group, which is optionally substituted with one, two or three substituents and each substituent is independently selected from a halogen atom,
• a C1-C3-alkyl group, a hydroxy group, NR4R5 group, a C1-C3-haloalkyl group and a C1-C3-haloalkoxy group,
• a 5- to 7-membered heterocycloalkyl group which is partially unsaturated and optionally substituted with one, two or three substituents and each substituent is independently selected from an oxo group (═O), a C1-C3-alkyl group and a halogen atom,
• an aryl group which is optionally substituted with one, two, three or four substituents and each substituent is independently selected from a halogen atom, a hydroxy group, a cyano group, a C1-C3-alkyl group, a C1-C3-haloalkyl group, a C1-C3-alkoxy group, a C1-C3-haloalkoxy group, a —C(O)NR4R5 group and a NR4R5 group,
• a mono- or bicyclic heteroaryl group which is optionally substituted with one, two or three substituents and each substituent is independently selected from a halogen atom, a hydroxy group, a C1-C3-alkyl group, a cyano group, a C1-C3-haloalkyl group, a C1-C3-alkoxy group, and a NR4R5 group,
• and a NR6R7 group,
• with the proviso that R3 cannot be imidazol-1-yl if R1 and R2 are a hydrogen atoms and R3 cannot be morpholin-4-yl, if R1 is trifluoromethyl and R2 is a hydrogen atom;
• R4/R5 is independently selected from a hydrogen atom, a C1-C6-alkyl group, a —C1-C5-alkylen-O—C1-C5-alkyl group, a —C1-C5-alkylen-S—C1-C5-alkyl group, C3-C6-cycloalkyl group, and a 3- to 5-membered heterocycloalkyl group;
• R6/R7 is independently selected from a hydrogen atom, a C1-C6-alkyl group, a —C1-C5-alkylen-O—C1-C5-alkyl group, a —C1-C5-alkylen-S—C1-C5-alkyl group, a —C1-C5-alkylen-NR3—C1-C5-alkyl group, a —C1-C5-hydroxyalkylen-(C1-C3-haloalkyl) group, a C3-C6-cycloalkyl group, and a 3- to 5-membered heterocycloalkyl group,
• or R6 and R7 together form a 3-, 4-, 5-, 6- or 7-membered ring optionally containing one or two additional heteroatoms selected from the group consisting of —O—, —S— and —NR8—,
• and which is optionally substituted one, two, or three times with a substituent selected from a halogen atom, a hydroxy group, and a C1-C3-alkyl group
• and if R6 and R7 together form a 5-, 6- or 7-membered ring, said ring can optionally contain a bridging group selected from a bond, —O—, —NR8—, —CH2—, —CH2—CH2—, —O—CH2—, —NR8—CH2—;
• R3 is a hydrogen atom or a C1-C3-alkyl group;
• or a stereoisomer, a tautomer, an N-oxide, a hydrate, a solvate, or a salt thereof, or a mixture of same.