A naphthalene compound was chosen as lead compound to develop a new series of fibrinogen receptor antagonists. Eight new compounds with different condensed heterocyclic parts were prepared and their in vitro activities were evaluated. 5-Amidinobenzofuran compound 2, 6-amidinobenzothiophene 7, and 5-amidinofuro[2,3-b]pyridine 8 were more active than lead compound 1. Molecular orbital calculation studies suggested the presence of a preferred spatial orientation between the amidine and the carboxylic acid.

A novel series of platelet receptor glycoprotein (Gp) IIb/IIIa antagonists with condensed heterocycles as their basic core was synthesized. In an in vitro assay, trans-4-(5-amidinobenzofuran-2-carboxamido)cyclohexyloxyacetic+ ++ acid 17e and trans-3-[4-(5-amidinobenzofuran-2- carboxamido)cyclohexyl]propionic acid 17f produced marked inhibitions with IC50 values of 0.018 and 0.006 microM, respectively in a human platelet adenosin-5'-diphospate (ADP)-induced aggregation assay; they also exhibited a wide spectrum of inhibition toward major aggregation agonists (ADP, collagen, thrombin, PMA (tumor promoter) and arachidonic acid). These compounds were > 2-3 orders of magnitude more effective in inhibiting platelet aggregation than human umbilical vein endothelial cell (HUVEC) binding. The oral administration of 10 mg/kg of either 17e and 17f to guinea pig, resulted in a 60% inhibition of ex vivo platelet aggregation after 5 h. Oral administration of ethyl trans-4-(5-amidinoben-zofuran-2- carboxamido)cyclohexyloxyacetate 18e (10 mg/kg) resulted in 80% inhibition of platelet aggregation in dogs for 6 h after oral administration with a return to baseline by 24 h. Ethyl trans-3-[4-(5-amidinobenzofuran-2-carboxamido)cyclohexyl]propionat e 18f (AR0598) produced 80% inhibition for 5 h after oral administration. Prodrug 18e showed a good profile in dogs with a long duration of action. 18e (AR0510) was selected as suitable clinical candidate for development as an orally active antithrombotic agent.

Nouveau compose d'acide carboxylique a noyau fusionne represente par la formule generale (I) (dans laquelle chaque symbole est tel que defini dans la specification) ou sel de ce compose acceptable en pharmacologie; composition medicinale contenant ce compose, et son utilisation en medecine. Ce compose et ce sel presentent un excellent antagonisme GPIIb/IIIa contre les mammiferes, y compris l'homme, peuvent etre administres oralement, presentent une longue duree de vie dans le sang et une faible toxicite, ainsi que des effets secondaires limites. Ils peuvent etre utilises avantageusement dans la prevention ou le traitement des maladies thrombotiques.