Synthesis and biological investigation of tetrahydropyridopyrimidinone derivatives as potential multireceptor atypical antipsychotics.

In the present study, a series of tetrahydropyridopyrimidinone derivatives, possessing potent dopamine D2, serotonin 5-HT1A and 5-HT2A receptors properties, was synthesized and evaluated as potential antipsychotics. Among them, 3-(2-(4-(benzo[b]thiophen-4-yl)piperazin-1-yl)ethyl)-9-hydroxy-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (10d) held the best pharmacological profile. It not only exhibited potent and balanced activities for D2, 5-HT1A, and 5-HT2A receptors, but was also endowed with low activities for α1A, 5-HT2C, H1 receptors and hERG channels, suggesting a low propensity for inducing orthostatic hypotension, weight gain and QT prolongation. In animal models, compound 10d reduced phencyclidine-induced hyperactivity with a high threshold for catalepsy induction. On the basis of its robust in vitro potency and in vivo efficacy in preclinical models of schizophrenia, coupled with a good pharmacokinetic profile, 10d was selected as a candidate for further development.