The synthesis and preliminary biological testing of some bicyclic guanidine derivatives

Abstract

Condensation of 2-amino-2-imidazoline with α,β-unsaturated esters yields an imidazo[1,2-a]pyrimidin-7-one system whereas reaction with an acetylenic ester or β-keto esters gives the corresponding unsaturated imidazo[1,2-a]pyrimidin-5-one product. In some cases a non-cyclized product is obtained under milder reaction conditions. Cyclization of ω- (imidazolin-2-ylamino) acids yields fused bicyclic products for the acetic and propionic acid derivatives whereas the butyric acid analogue cyclizes to yield an N-substituted pyrrolidone. Representative examples of all these compounds do not show mutagenic properties in a modified Ames test and are mainly inactive when tested for central nervous system activity.