Pyrimidin-2-one compounds and their use as dopamine D3 receptor ligands

A pyrimidin-2-one compound of the formula I, or a tautomer thereof,

• in which
• A is —(CH2)n—, in which n is 4, 5, or 6, or is trans-CH2—CH═CH—CH2—, trans-CH2—C(CH3)═CH—CH2—, —CH2—CH(CH3)—CH2—CH2—, or —CH2—CH2—CH2—CH(CH)3—,
• B is a radical of the formula:
• in which X is CH2 or N, and Y is CH2 or CH2CH2, or X—Y together may also be C═CH, C═CH—CH2 or CH—CH═CH,
• R1 is selected from OR3a, NR4R5, SR6, C3-C6-cycloalkyl, C1-C4-alkyl which is optionally substituted by OH, C1-C4-alkoxy, halogen or phenyl,
• 5- or 6-membered aromatic heterocyclyl having 1, 2 or 3 heteroatoms selected from O, S and N, which may be substituted by one or two radicals which are selected independently of one another from C1-C4-alkyl, C1-C4-alkoxy, NR4R5, CN, OH, C1-C2-fluoroalkyl or halogen, and
• phenyl which may be substituted by one or two radicals which are selected independently of one another from C1-C4-alkyl, C1-C4-alkoxy, NR4R5, OH, CN, C1-C2-fluoroalkyl or halogen
• R2 is selected from H, C1-C4-alkyl, halogen, C1-C2-fluoroalkyl and cyano,
• Ar is an aromatic radical which is selected from phenyl, pyridyl, pyrimidinyl and triazinyl, where the aromatic radical may have 1, 2 or 3 substituents which are selected independently of one another from C1-C6-alkyl which is optionally substituted by OH, C1-C4-alkoxy, halogen or phenyl, or C2-C6-alkenyl, C2-C6-alkynyl, C3-C6-cycloalkyl, C5-C10-bicycloalkyl, C6-C10-tricycloalkyl, where the last three groups mentioned may optionally be substituted by halogen or C1-C4-alkyl, or halogen, CN, OR3c, NR4R5, NO2, SR6, SO2R6, SO2NR4R5, COOR7, COR8, 5- or 6-membered heterocyclyl having 1, 2 or 3 heteroatoms selected from O, S and N, and phenyl, where phenyl and heterocyclyl optionally have one or two substituents which are selected independently of one another from C1-C4-alkyl, C1-C4-alkoxy, NR4R5, CN, C1-C2-fluoroalkyl and halogen, and where 2 substituents bonded to adjacent C atoms of the aromatic radical may together be C3- or C4-alkylene, or may together with the C atoms to which they are bonded be a fused-on, unsaturated 5 or 6-membered carbocycle or a 5- or 6-membered heterocycle having 1 or 2 nitrogen atoms as ring members,
• R3, R3a, R3b, R3c, R3d, R4, R5, R6, R7 and R8 are independently of one another H, C1-C6-alkyl which is optionally substituted by OH, C1-C4-alkoxy or phenyl, or C1-C6-haloalkyl or phenyl, where R5 may also be a group COR9 where R9 is hydrogen, C1-C4-alkyl or phenyl which is optionally substituted by one or two radicals which are selected independently of one another from C1-C4-alkyl, C1-C4-alkoxy, NR4R5, CN, C1-C2-fluoroalkyl or halogen, where
• R4 with R5 may also form together with the nitrogen atom to which they are bonded a 4-, 5- or 6-membered saturated or unsaturated heterocycle which may optionally have a further heteroatom selected from O, S and NR10 as ring member, where R10 is hydrogen or C1-C4-alkyl, and where the heterocycle may optionally carry 1, 2, 3 or 4 C1-C4-alkyl groups,
• or a physiologically tolerated salt thereof.