Synthesis and pharmacological evaluation of novel heterotricyclic acylhydrazone derivatives, designed as PAF antagonists

This paper describes the synthesis and the antiplatelet properties of new heterotricyclic N-acylhydrazone derivatives (7a–e), structurally analogous to known hetrazepinic PAF antagonists, exploring molecular hybridization as a tool for molecular designing. The synthetic route employed to access compounds (7a–e) used, as starting material, the previously described methyl 3-hydroxy-8-methyl-6-phenyl-6H-pyrazolo[3,4-b]thieno[2,3-d]pyridine-2-carboxylate derivative. The results from inhibitory effects of these novel acylhydrazone derivatives (7a–e) upon PAF-induced platelet aggregation, indicated that all compounds present a significant antithrombotic profile.