New policyclic pyrimidine derivatives with antiplatelet in vitro activity: synthesis and pharmacological screening

The prepn. and the pharmacol. screening of novel anti-aggregatory/antiphlogistic polycyclic pyrimidine derivs. are described. The compds. were developed starting from bioactive 2-aminobenzopyranopyrimidine derivs. in order to assess the importance of the benzopyrano[4,3-d]pyrimidine structure and the role of an amino basic moiety in position 2. Antiplatelet activity was assessed in vitro against ADP and arachidonic acid-induced aggregation in guinea-pig plasma. Anti-inflammatory/analgesic/antipyretic activities were studied in rat paw edema, mouse writhing test and E coli-induced rat fever. Ulcerogenic and gastroprotective effects were also investigated in vivo on rat gastric mucosa. Among the tested compds., 5-pyrrolidino-2-methylthiobenzopyrano[4,3-d]pyrimidine fulfils the chem. requirements to exhibit antiplatelet activity assocd. with gastroprotective effect.