Synthesis of Functionalized Pyridazin-3(2<i>H</i>)-ones via Nucleophilic Substitution of Hydrogen (S<sub>N</sub>H)
作者:Tom Verhelst、Stefan Verbeeck、Oxana Ryabtsova、Stefaan Depraetere、Bert U. W. Maes
DOI:10.1021/ol102703w
日期:2011.1.21
Reaction of 2-benzyl-5-halopyridazin-3(2H)-ones (3) with Grignard reagents followed by quenching with electrophiles unexpectedly yielded 4,5-disubstituted pyridazin-3(2H)-ones instead of 5-substituted pyridazin-3(2H)-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