Pyridazines.: Part 36:: Synthesis and antiplatelet activity of 5-substituted-6-phenyl-3(2H)-pyridazinones

A convenient and efficient palladium-catalysed retro-ene-assisted method has been developed to prepare a series of 5-substituted-6-phenyl-3(2H)-pyridazinones as potential antiplatelet drugs. The most active compounds were those that contain a 3-phenyl-3-oxo-propenyl fragment or a phenylthio group at position 5 of the heterocyclic ring. (C) 2003 Elsevier Ltd. All rights reserved.