Triazolophthalazines

1. A compound of formula I

in which

R1 is -U-A, in which

U is a direct bond, or methylene (—CH 2 —),

A is phenyl, pyridinyl, thiophenyl, or R11- and/or R111-substituted phenyl, in which

R11 is 1-4C-alkyl, halogen, trifluoromethyl, hydroxyl, 1-4C-alkoxy, phenoxy, 1-4C-alkoxycarbonyl, morpholino, di-1-4C-alkylamino, or completely or predominantly fluorine-substituted 1-4C-alkoxy,

R111 is 1-4C-alkoxy, halogen, hydroxyl, or 1-4C-alkyl,

R2 is amino, carboxyl, 1-4C-alkoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is 1-4C-alkyl, 2-4C-alkenyl, 3-7C-cycloalkyl, trifluoromethyl, phenyl, R31- and/or R311-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-4C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is 1-4C-alkoxy, halogen, nitro, 1-4C-alkyl, trifluoromethyl, hydroxyl, 1-4C-alkoxycarbonyl, 3-7C-cyloalkylmethoxy, morpholino, or mono- or di-1-4C-alkylamino,

R311 is 1-4C-alkoxy, halogen, 1-4C-alkyl, hydroxyl, or 3-7C-cyloalkylmethoxy,

or R31 and R311 together are a 1-2C-alkylenedioxy group,

R32 is hydroxyl, phenyl-1-4C-alkoxy, 1-4C-alkoxy, phenyl, R321- and/or R3211-substituted phenyl, mono- or di-1-4C-alkylamino, morpholino, or 4N-(R322)-piperazin-1-yl, in which

R321 is 1-4C-alkoxy, halogen, nitro, 1-4C-alkyl, trifluoromethyl, hydroxyl, 1-4C-alkoxycarbonyl, 3-7C-cyloalkylmethoxy, or mono- or di-1-4C-alkylamino,

R3211 is 1-4C-alkoxy, halogen, 1-4C-alkyl, hydroxyl, or 3-7C-cyloalkylmethoxy,

or R321 and R3211 together are a 1-2C-alkylenedioxy group,

R322 is 1-4C-alkyl,

R33 is hydrogen, 1-4C-alkyl, or 1-4C-alkylcarbonyl,

R4 is hydrogen, 1-4C-alkyl, R41-substituted 2-4C-alkyl, phenyl, R42- and/or R421-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, 1-4C-alkoxy, mono- or di-1-4C-alkylamino, or morpholino,

R42 is 1-4C-alkoxy, halogen, nitro, 1-4C-alkyl, trifluoromethyl, hydroxyl, 1-4C-alkoxycarbonyl, 3-7C-cyloalkylmethoxy, or mono- or di-1-4C-alkylamino,

R421 is 1-4C-alkoxy, halogen, 1-4C-alkyl, hydroxyl, or 3-7C-cyloalkylmethoxy,

or R42 and R421 together are a 1-2C-alkylenedioxy group,

R5 is hydrogen, or 1-4C-alkyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, or 4N-(1-4C-alkyl)-piperazin-1-yl, or a salt thereof.

2. A compound of formula I according to claim 1 , in which

R1 is -U-A, in which

U is a direct bond, or methylene (—CH 2 —),

A is phenyl, pyridinyl, thiophenyl, di-(1-4C-alkoxy)-phenyl, or R11-substituted phenyl, in which

R11 is 1-4C-alkyl, halogen, trifluoromethyl, hydroxyl, 1-4C-alkoxy, phenoxy, 1-4C-alkoxycarbonyl, morpholino, di-1-4C-alkylamino, or completely or predominantly fluorine-substituted 1-4C-alkoxy,

R2 is amino, carboxyl, 1-4C-alkoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is 1-4C-alkyl, 2-4C-alkenyl, 3-7C-cycloalkyl, trifluoromethyl, phenyl, R31-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-4C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is 1-4C-alkoxy, morpholino, or di-1-4C-alkylamino,

R32 is hydroxyl, phenyl-1-4C-alkoxy, 1-4C-alkoxy, phenyl, R321-substituted phenyl, di-1-4C-alkylamino, morpholino, or 4N-(R322)-piperazin-1-yl, in which

R321 is 1-4C-alkoxy,

R322 is 1-4C-alkyl,

R33 is hydrogen, 1-4C-alkyl, or 1-4C-alkylcarbonyl,

R4 is hydrogen, 1-4C-alkyl, R41-substituted 2-4C-alkyl, phenyl, R42-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, 1-4C-alkoxy, di-1-4C-alkylamino, or morpholino,

R42 is 1-4C-alkoxy, or di-1-4C-alkylamino,

R5 is hydrogen, or 1-4C-alkyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, or 4N-(1-4C-alkyl)-piperazin-1-yl,

or a salt thereof.

3. A compound of formula I according to claim 1 , in which

R1 is -U-A, in which

U is a direct bond, or methylene (—CH 2 —),

A is phenyl, pyridinyl, thiophenyl, dimethoxyphenyl, or R11-substituted phenyl, in which

R11 is methyl, tertbutyl, chlorine, fluorine, bromine, trifluoromethyl, hydroxyl, methoxy, ethoxy, trifluoromethoxy, phenoxy, methoxycarbonyl, morpholino, or dimethylamino,

R2 is amino, carboxyl, 1-4C-alkoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is 1-4C-alkyl, 2-4C-alkenyl, 3-7C-cycloalkyl, trifluoromethyl, phenyl, R31-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-4C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is 1-4C-alkoxy, morpholino, or di-1-4C-alkylamino,

R32 is hydroxyl, phenyl-1-4C-alkoxy, 1-4C-alkoxy, phenyl, R321-substituted phenyl, di-1-4C-alkylamino, morpholino, or 4N-(R322)-piperazin-1-yl, in which

R321 is 1-4C-alkoxy,

R322 is 1-4C-alkyl,

R33 is hydrogen, 1-4C-alkyl, or 1-4C-alkylcarbonyl,

R4 is hydrogen, 1-4C-alkyl, R41-substituted 2-4C-alkyl, phenyl, R42-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, 1-4C-alkoxy, di-1-4C-alkylamino, or morpholino,

R42 is 1-4C-alkoxy, or di-1-4C-alkylamino,

R5 is hydrogen, or 1-4C-alkyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, or 4N-(1-4C-alkyl)-piperazin-1-yl,

or a salt thereof.

4. A compound of formula I according to claim 1 , in which

R1 is -U-A, in which

U is a direct bond, or methylene (—CH 2 —),

A is phenyl, or R11-substituted phenyl, in which

R11 is methyl, chlorine, fluorine, bromine, trifluoromethyl, hydroxyl, methoxy, phenoxy, methoxycarbonyl, or dimethylamino,

R2 is amino, carboxyl, methoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is methyl, vinyl, cyclopropyl, cyclohexyl, trifluoromethyl, phenyl, R31-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-2C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is methoxy, morpholino, or dimethylamino,

R32 is hydroxyl, benzyloxy, methoxy, phenyl, R321-substituted phenyl, dimethylamino, morpholino, or 4N-methyl-piperazin-1-yl, in which

R321 is methoxy,

R33 is hydrogen, methyl, or acetyl,

R4 is hydrogen, methyl, 2-(R41)-ethyl, phenyl, R42-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, methoxy, dimethylamino, or morpholino,

R42 is methoxy, or dimethylamino,

R5 is hydrogen, or methyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, or 4N-methyl-piperazin-1-yl,

or a salt thereof.

5. A compound of formula I according to claim 1 , in which

R1 is -U-A, in which

U is a direct bond,

A is phenyl, or R11-substituted phenyl, in which

R11 is fluorine, bromine, trifluoromethyl, or methoxy,

R2 is attached in the meta or para position with respect to the binding position in which the phenyl ring is bonded to the amino group of the triazolophthalazine scaffold, and is amino, carboxyl, methoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is methyl, vinyl, cyclopropyl, cyclohexyl, trifluoromethyl, phenyl, R31-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-2C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is methoxy, morpholino, or dimethylamino,

R32 is hydroxyl, benzyloxy, methoxy, phenyl, R321-substituted phenyl, dimethylamino, morpholino, or 4N-methyl-piperazin-1-yl, in which

R321 is methoxy,

R33 is hydrogen, methyl, or acetyl,

R4 is hydrogen, methyl, 2-(R41)-ethyl, phenyl, R42-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, methoxy, dimethylamino, or morpholino,

R42 is methoxy, or dimethylamino,

R5 is hydrogen, or methyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, or 4N-methyl-piperazin-1-yl,

or a salt thereof.

6. A compound of formula I according to claim 1 , in which

R1 is -U-A, in which

U is a direct bond,

A is phenyl, or R11-substituted phenyl, in which

R11 is fluorine, bromine, chlorine, trifluoromethyl, methyl or methoxy,

R2 is attached in the meta or para position with respect to the binding position in which the phenyl ring is bonded to the amino group of the triazolophthalazine scaffold, and is amino, carboxyl, methoxycarbonyl, —N(H)—C(O)R3, or —C(O)—N(R4)R5, in which

R3 is methyl, vinyl, cyclopropyl, cyclohexyl, trifluoromethyl, phenyl, R31-substituted phenyl, furanyl, imidazol-4-yl, pyridinyl, R32-substituted 1-2C-alkyl, or 1N-(R33)-piperidinyl, in which

R31 is methoxy, morpholino, or dimethylamino,

R32 is hydroxyl, benzyloxy, methoxy, phenyl, R321-substituted phenyl, dimethylamino, morpholino, or 4N-methyl-piperazin-1-yl, in which

R321 is methoxy,

R33 is hydrogen, methyl, or acetyl,

R4 is hydrogen, methyl, 2-(R41)-ethyl, phenyl, R42-substituted phenyl, or pyridinyl, in which

R41 is hydroxyl, methoxy, dimethylamino or morpholino,

R42 is methoxy, or dimethylamino,

R5 is hydrogen, or methyl,

or R4 and R5 together and with inclusion of the nitrogen atom, to which they are bonded, form a heterocyclic ring radical Het, in which

Het is morpholino, 4N-methyl-piperazin-1-yl, or 4N-ethyl-piperazin-1-yl,

or a salt thereof.

7. A compound of formula I according to claim 1 , in which

R1 is 4-methoxy-phenyl, 2-methoxy-phenyl, 2-bromo-phenyl, 2-fluoro-phenyl, 2-(trifluoromethyl)-phenyl, 2-chloro-phenyl, 4-bromo-phenyl or 2-methyl-phenyl,

or a salt thereof.

8. A compound of formula I selected from the group consisting of

Cyclopropanecarboxylic acid {-4-[3-(4-methoxy-phenyl)-[1,2,4]triazolo[3,4-a]phthalazin-6-ylamino]-phenyl}-amide,

Cyclopropanecarboxylic acid {3-[3-(4-methoxy-phenyl)-[1,2,4]triazolo[3,4-a]phthalazin-6-ylamino]-phenyl}-amide, and

1-{4-[3-(4-Methoxy-phenyl)-[1,2,4]triazolo[3,4-a]phthalazin-6-ylamino]-phenyl}-1-(4-methyl-piperazin-1-yl)-methanone.

9. A pharmaceutical composition comprising a therapeutically effective amount of one or more compounds of formula I according to claim 1 or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable excipient and/or auxiliary.