Pyrimidinyl-piperazines useful as D3/D2 receptor ligands

A method of treating a condition selected from the group consisting of psychoses, drug abuse, cognitive impairment accompanying schizophrenia, mild-to-moderate cognitive deficits, dementia, attention deficit disorders, hyperactivity disorders, mania, bipolar disorder, paranoid and delusional disorders, Parkinson's disease, neuroleptic-induced parkinsonism, depression and depressive states, and autism, which comprises administering to a subject in need thereof an effective amount of a compound of formula (I)

• wherein
• Q represents C1-4 alkyl, —NR3R4, phenyl, optionally substituted phenyl, 1-pyrrolidinyl, 1-piperidinyl, 4-R5-piperazin-1-yl or 4-morpholinyl group,
• R1 represents hydrogen or C1-4 alkyl group,
• R2 represents hydrogen or C1-4 alkyl group,
• R3 represents hydrogen, C1-4 alkyl group, phenyl or optionally substituted phenyl,
• R4 represents hydrogen, C1-4 alkyl group, phenyl or optionally substituted phenyl,
• R5 represents hydrogen or C1-4 alkyl group,
• and/or geometric isomers and/or stereoisomers and/or diastereomers and/or salts thereof.