| Abstract: | The syntheses of two novel pentacyclic ring systems, the thieno3,2-f]1,2,4]triazolo4,3-a]1,4]diazepino-4,5-a]benzimidazole and the indazolo2,3-d]1,2,4]triazolo4,3-a]1,4]benzodiazepine are described. Attachment of a propargyl linked quinolinone resulted in compounds 6 and 16 which showed PAF-antagonist activity by the intravenous route of administration in guinea pigs. The more potent compound 16 also exhibited good oral activity with an ID50 of 0.2 mg/kg in the bronchoconstriction assay. |
