6-phenyl-4,5-dihydropyridazin-3(2H)-one derivatives as PDE3A and PDE3B inhibitors for treating cancer

1. A method of preparing a compound of general formula (I) having the structure:

said method comprising the step of allowing an intermediate compound of general formula (II) to react:

in which

R 1 is selected from a hydrogen atom, a halogen atom, a cyano group, a C 1 -C 3 -alkyl group, a C 1 -C 3 -haloalkyl group, and a C 1 -C 3 -haloalkoxy group;

R 2 is selected from a hydrogen atom and a halogen atom; and

X=F, Cl, Br, or I

to form the compound of general formula (I); wherein

a) if X=Cl, Br, or I, with the prerequisite that R 1 /R 2 is not Cl, Br, or I, the method comprises allowing the compound of Formula (II) to react under transmetal catalyzed coupling conditions with a boronic acid of formula (IIIa)

(R x )B(OH) 2    (IIIa)

whereby R x is

a C 1 -C 6 -alkoxy group,

a C 2 -C 6 -alkenyl group,

a C 3 -C 6 -cycloalkyl group,

a C 5 -C 6 -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 C 1 -C 3 -alkyl group, a hydroxy group, NR 4 R 5 group, a C 1 -C 3 -haloalkyl group and a C 1 -C 3 -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 C 1 -C 3 -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 C 1 -C 3 -alkyl group, a C 1 -C 3 -haloalkyl group, a C 1 -C 3 -alkoxy group, a C 1 -C 3 -haloalkoxy group, a —C(O)NR 4 R 5 group and a NR 4 R 5 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 cyano group, a C 1 -C 3 -alkyl group, a C 1 -C 3 -haloalkyl group, a C 1 -C 3 -alkoxy group, and a NR 4 R 5 group; or

a NR 6 R 7 group,

R 4 /R 5 is independently selected from a hydrogen atom, a C 1 -C 6 -alkyl group, a —C 1 -C 5 -alkylen-O—C 1 -C 5 -alkyl group, a —C 1 -C 5 -alkylen-S—C 1 -C 5 -alkyl group, C 3 -C 6 -cycloalkyl group, and a 3- to 5-membered heterocycloalkyl group;

R 6 /R 7 is independently selected from a hydrogen atom, a C 1 -C 6 -alkyl group, a —C 1 -C 5 -alkylen-O—C 1 -C 5 -alkyl group, a —C 1 -C 5 -alkylen-S—C 1 -C 5 -alkyl group, a —C 1 -C 5 -alkylen-NR 8 —C 1 -C 5 -alkyl group, a —C 1 -C 5 -hydroxyalkylen-(C 1 -C 3 -haloalkyl) group, a C 3 -C 6 -cycloalkyl group, and a 3- to 5-membered heterocycloalkyl group,

or R 6 and R 7 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 —NR 8 —,

and which is optionally substituted one, two, or three times with a substituent selected from a halogen atom, a hydroxy group, and a C 1 -C 3 -alkyl group

and if R 6 and R 7 together form a 5-, 6- or 7-membered ring, said ring can optionally contain a bridging group selected from a bond, —O—, —NR 8 —, —CH 2 —, —CH 2 —CH 2 —, —O—CH 2 —, —NR 8 —CH 2 —;

R 8 is a hydrogen atom or a C 1 -C 3 -alkyl group; or

a boronic ester of formula (IIIb)

(R x )B(OR Y ) 2    (IIIb)

wherein R x is as defined for the boronic acid above and

R y is C 1 -C 6 -alkyl, or the two residues R y together form a pinacol ester, /potassium carbonate/a palladium catalyst selected from the following list:

dichlorobis(triphenylphosphine)palladium, tetrakistriphenylphosphinepalladium(0), palladium(II) acetate/triscyclohexylphosphine, tris(dibenzylideneacetone)dipalladium, bis(diphenylphosphineferrocenyl)palladium(II) chloride, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene(1,4-naphthoquinone)palladium dimer, allyl(chloro)(1,3-dimesityl-1,3-dihydro-2H-imidazol-2-ylidene)palladium, palladium(II) acetate/dicyclohexyl(2′,4′,6′-triisopropyl-biphenyl-2-yl)phosphine, [1,1-bis(diphenylphosphino)ferrocene]palladium(II) chloride monodichloromethane adduct, [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II), chloro(2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl)[2-(2′-amino-1,1′-biphenyl)]palladium(II), or (2-Dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl)[2-(2′-amino-1,1′-biphenyl)]palladium(II), preference being given to chloro(2-dicyclohexylphosphino-2′, 4′, 6′-triisopropyl-1, 1′-biphenyl)[2-(2′-amino-1, 1′-biphenyl)]palladium(II) in order to obtain a compound of formula (I) wherein R 3 is R x

or

b) if X=F, with the prerequisite that R 1 is selected from a hydrogen atom, a halogen atom, a cyano group, and a C 1 -C 3 -haloalkyl group, and R 2 is selected from a hydrogen atom and a halogen atom,

the method comprises allowing the compound of Formula (II) to react with HNR 7 R 8 ;

optionally in the presence of a base, and optionally in the presence of an inert solvent, and optionally heat, up to the boiling point of the present solvent;

in order to obtain a compound of formula (I) wherein R 3 is NR 7 R 8 .

2. The method according to claim 1 wherein the transmetal catalyzed coupling conditions are suitable for Negishi couplings, Kumada couplings, and Stille couplings.

3. The method according to claim 1 wherein the transmetal catalyzed coupling conditions are suitable for Suzuki couplings.