7-[3-(1-piperidinyl)propoxy]chromenones as potential atypical antipsychotics

Compound 1 (1-benzyl-3-methyl-4-[4-(4-fluorophenyl)-4-oxobutyl]piperazine), a synthetic intermediate identified as a potential atypical antipsychotic, was selected as the starting point for pharmacological improvement. From 1, sequential structural variations were conducted in order to improve its potency and oral bioavailability. These variations included a series of piperazine, ethanediamine, and piperidine derivatives. The piperidine series afforded some orally potent compounds in the inhibition of apomorphine-induced climbing and hyperactivity in mice, which are regarded as behavioral models predictive of antipsychotic efficacy. Further optimization of these structures led to the highly potent 7-[3-(1-piperidinyl)propoxy]chromenones. Inhibition of stereotypies and induction of catalepsy in rats at doses substantially higher than required for inhibition of climbing suggest an atypical antipsychotic profile, which is assumed to predict a reduced induction of extrapyramidal side effects in humans.