2-benzylpyridazinone derivatives as met kinase inhibitors

A compound of formula I

• in which
• R1 denotes H or A,
• R2 denotes an unsaturated, saturated or aromatic 5- or 6-membered heterocycle having 1 to 4 N, O and/or S atoms, which is unsubstituted or mono-, di- or trisubstituted by Hal, A, [C(R3)2]nOR3, N═CR3N(R3)2, SR3, NO2, CN, COOR3, CON(R3)2, NR3COA, NR3SO2A, SO2N(R3)2, S(O)mA, [C(R3)2]nN(R3)2, [C(R3)2]nHet, O[C(R3)2]nN(R3)2, O[C(R3)2]nHet, S[C(R3)2]nN(R3)2, S[C(R3)2]nHet, NR3[C(R3)2]nN(R3)2, NR3[C(R3)2]nHet, NHCON(R3)2, NHCONH[C(R3)2]nN(R3)2, NHCONH[C(R3)2]nHet, [C(R3)2]nNHCO[C(R3)2]nN(R3)2, [C(R3)2]nNHCO[C(R3)2]nHet, CON(R3)2, CONR3[C(R3)2]nN(R3)2, CONR3[C(R3)2]nNR3COOA, CONR3[C(R3)2]nOR3, CONR3[C(R3)2]nHet, COHet, COA and/or ═O,
• R3 denotes H or A,
• R4, R4′ each, independently of one another, denote H, Hal, A, OR3, CN, COOR3, CON(R3)2, NR3COA, NR3SO2A, SO2N(R3)2 or S(O)mA,
• Ar denotes phenyl, naphthyl or biphenyl, which is unsubstituted or mono-, di- or trisubstituted by Hal, A, [C(R3)2]nOR3, [C(R3)2]nN(R3)2, SR3, NO2, CN, COOR3, CON(R3)2, NR3COA, NR3SO2A, SO2N(R3)2, S(O)mA, CO-Het, Het, O[C(R3)2]n—N(R3)2, O[C(R3)2]nHet, NHCOOA, NHCON(R3)2, NHCOO[C(R3)2]nN(R3)2, NHCOO[C(R3)2]nHet, NHCONH[C(R3)2]nN(R3)2, NHCONH[C(R3)2]nHet, OCONH[C(R3)2]1N(R3)2, OCONH[C(R3)2]nHet, CONR3[C(R3)2]nN(R3)2, CONR3[C(R3)2]nHet and/or COA,
• Het denotes a mono-, bi- or tricyclic saturated, unsaturated or aromatic heterocycle having 1 to 4 N, O and/or S atoms, which is unsubstituted or mono-, di- or trisubstituted by Hal, A, [C(R3)2]nOR3, [C(R3)2]nN(R3)2, SR3, NO2, CN, COORS, CON(R3)2, NR3COA, NR3SO2A, SO2N(R3)2, S(O)mA, CO-Het1, [C(R3)2]nHet1, O[C(R3)2]nN(R3)2, O[C(R3)2]nHet1, NHCOOA, NHCON(R3)2, NHCOO[C(R3)2]nN(R3)2, NHCOO[C(R3)2]nHet1, NHCONH[C(R3)2]nN(R3)2, NHCONH[C(R3)2]nHet1, OCONH[C(R3)2]nN(R3)2, OCONH[C(R3)2]nHet1, CO-Het1, CHO, COA, ═S, ═NH, ═NA and/or ═O,
• Het1 denotes a monocyclic saturated heterocycle having 1 to 2 N and/or O atoms, which is unsubstituted or mono- or disubstituted by A, OA, OH, Hal and/or ═O,
• A denotes unbranched or branched alkyl having 1-10 C atoms, in which 1-7 H atoms are optionally replaced by F and/or in which one or two non-adjacent CH2 groups are optionally replaced by O, NH, S, SO, SO2 and/or by CH═CH groups,
• or
• cyclic alkyl having 3-7 C atoms,
• Hal denotes F, Cl, Br or I,
• m denotes 0, 1 or 2, and
• n denotes 0, 1, 2, 3 or 4,
• or a pharmaceutically acceptable salt, tautomer or stereoisomer thereof.