Comparative molecular field analysis of some pyridazinone-containing alpha1-antagonists.

Diverse series of piperazines linked at N1 to 4, 5, or 6 positions of 3-(2H)-pyridazinone ring and at N4, by a suitable alkyl spacer, to some classical alpha1-adrenoceptor pharmacophore moieties, were tested in vitro for their alpha1-adrenoceptor antagonist activity. The modeling of their biological activity (pKb) by comparative molecular field analysis led to the development of a statistically significant partial least squares (PLS) model able to detect at 3-D level the main physicochemical interactions responsible for alpha1-adrenoceptor antagonist activity.