The discovery of new highly potent and selective dopamine (DA) D(3) receptor antagonists has recently allowed the characterization of the DA D(3) receptor in a range of preclinical animal models of drug addiction. A novel series of 1,2,4-triazol-3-yl-azabicyclo[3.1.0]hexanes, members of which showed a high affinity and selectivity for the DA D(3) receptor and excellent pharmacokinetic profiles, is reported here. Members of a group of derivatives from this series showed good oral bioavailability and brain penetration and very high in vitro affinity and selectivity for the DA D(3) receptor, as well as high in vitro potency for antagonism at this receptor. Several members of this series also significantly attenuate the expression of conditioned place preference (CPP) to nicotine and cocaine.

The discovery of new highly potent and selective dopamine D3 receptor antagonists has recently permitted characterization of the role of the dopamine D3 receptor in a wide range of preclinical animal models. A novel series of 1,2,4-triazol-3-yl-thiopropyl-tetrahydrobenzazepines demonstrating a high level of D3 affinity and selectivity with an excellent pharmacokinetic profile is reported here. In particular, the pyrazolyl derivative 35 showed good oral bioavailability and brain penetration associated with high potency and selectivity in vitro. In vivo characterization of 35 confirmed that this compound blocks the expression of nicotine- and cocaine-conditioned place preference in the rat, prevents nicotine-triggered reinstatement of nicotine-seeking behavior in the rat, reduces oral operant alcohol self-administration in the mouse, increases extracellular levels of acetylcholine in the rat medial prefrontal cortex, and potentiates the amplitude of the relative cerebral blood volume response to d-amphetamine in a regionally specific manner in the rat brain.