Synthesis of Functionalized Pyridazin-3 (2 H)-ones via Nucleophilic Substitution of Hydrogen (SNH)

…, S Verbeeck, O Ryabtsova, S Depraetere…

Index: Verhelst, Tom; Verbeeck, Stefan; Ryabtsova, Oxana; Depraetere, Stefaan; Maes, Bert U. W. Organic Letters, 2011 , vol. 13, # 2 p. 272 - 275

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Citation Number: 9

Abstract

Reaction of 2-benzyl-5-halopyridazin-3 (2 H)-ones (3) with Grignard reagents followed by quenching with electrophiles unexpectedly yielded 4, 5-disubstituted pyridazin-3 (2 H)-ones instead of 5-substituted pyridazin-3 (2 H)-ones. These reactions represent the first examples of cine substitution in which the anionic σH-adduct is quenched by electrophiles (other than a proton) before elimination takes place. Insight into the reaction mechanism led to the ...