Synthesis of diverse 4,5-dihydro-3(2H)-pyridazinones on Wang resin
N Gouault1, J F Cupif, S Picard
1UPRES-Synthèse et extraction de molécules à visée thérapeutique-Faculté de Pharmacie 2, Rennes, France.
Abstract:
An efficient solid-phase synthesis of structurally diverse 4,5-dihydro-3(2H)-pyridazinones is described using readily available substituted 4-oxo-butanoic acids. Polymer-supported gamma-keto-esters prepared from Wang resin reacted with several hydrazines to afford the corresponding hydrazones. A protocol developed in mild conditions without isolating the intermediate hydrazone led to pyridazinones in good yields after a cyclization cleavage approach. This successful strategy represents an attractive method for a rapid synthesis of heterocyclic libraries for biological evaluation.
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