Arylpiperazuine derivatives as selective ligand for the dopamine D3 receptor

Arylpiperazine compounds (I) and their stereoisomers, tautomeric forms, hydrates, solvates, salts or esters are new. Arylpiperazine compounds of formula (I) and their stereoisomers, tautomeric forms, hydrates, solvates, salts or esters are new. R1 : heteroaryl with 5-6 chain links (optionally containing heteroatoms of 2-pyridyl, 2-pyrimidinyl, 2-pyridazinyl, 2-pyrazinyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, 3-isoxazolyl, 3-isothiazolyl, 1,2,4-triazol- 2-yl, 1,3,4-oxadiazol-2-yl or 1,3,4-thiadiazol-2-yl) (all optionally substituted by halo or OH), alkyl, monofluoroalkyl, polyfluoroalkyl, alkoxy, polyfluoroalkoxy, alkylsulfanyl or polyfluoroalkylsulfanyl group); Ar : (hetero)aryl (optionally fused with R1 and optionally substituted by halo or OH), alkyl, monofluoroalkyl, polyfluoroalkyl, alkoxy, polyfluoroalkoxy, alkylsulfanyl, polyfluoroalkylsulfanyl, CN, carbamoyl, dialkylcarbamoyl, alkyl-C(=O)-, alkyl-O-C(=O)-, HO-C(=O)-, (HO)alkyl group or fused with optionally saturated or aromatic hydrocarbon cycle or heterocycle; a : 2-4; b, c : 1-2; either R2-R6 : H, halo, OH, alkyl, monofluoroalkyl, polyfluoroalkyl, alkoxy, polyfluoroalkoxy, alkylsulfanyl, polyfluoroalkylsulfanyl, CN, -NRR-a, COOR, COR or CONRR-a group; R2+R3+R4+R5+R6 : hydrocarbon cycle or optionally saturated heterocycle (both are fused to the phenyl nucleus to which they are attached); and R, R-a : H or alkyl. Provided that compounds for which R1 is 2-oxazolyl, 2-imidazolyl or 2-thiazolyl fused to the Ar group (optionally substituted phenyl), and compounds for which R1 is 2-pyridyl group, fused to the Ar group phenyl (optionally substituted by CH3 in position 4 of the resultant quinoline cycle, a is 2, b, c are 1, R2 is H, OCH3 and R3-R6 is H or R2, R3 are Me and R4-R6 is H; R1 is 2-pyrimidinyl group, fused to the Ar group is phenyl substituted by OCH3 in positions 6 and 7 and -OH in position 4 or 6 of the resultant quinazolinyl cycle, a is 2, b, c are 1, R2-R5 are H and R6 is OCH3. Independent claims are also included for the preparations of (I). [Image] ACTIVITY : Neuroleptic; Antiaddictive; Endocrine-Gen.; Vasotropic; CNS-Gen.; Muscular-Gen.; Antiparkinsonian; Antidepressant. MECHANISM OF ACTION : Dopamine D3 receptor ligand. (I) were tested for dopamine D3 receptor ligand activity in HEK 293 cells. The inhibitory constant value of 2-{4-[4-(2,3-dichlorophenyl)piperazin-1-y l]butyl}amino-4-phenylpyridine was 0.55 nM.