Synthesis, antiarrhythmic, and antihypertensive effects of novel 1-substituted pyrrolidin-2-one and pyrrolidine derivatives with adrenolytic activity.

A series of 1-substituted pyrrolidin-2-one and pyrrolidine derivatives were synthesised and tested for electrocardiographic, antiarrhythmic, and antihypertensive activity as well as for alpha(1)- and alpha(2)-adrenoceptors binding affinities. Among the newly synthesised derivatives several compounds with 3-(4-arylpiperazin-1-yl)propyl moiety displayed strong antiarrhythmic (7a-12a) and antihypertensive (7a-11a) activities. Compound 11a, 1-[2-acetoxy-3-[4-(2-methoxyphenyl)piperazin-1-yl]propyl]pyrrolidin-2-one, was the most potent in this series. The pharmacological results and binding studies suggest that their antiarrhythmic and hypotensive effects may be related to their alpha-adrenolytic properties, and that those properties depend on the presence of the 1-phenylpiperazine moiety with a methoxy- or chloro- substituent in the ortho position in the phenyl ring.