Pyrimidopyridazines. 5. Summary of Cyclizations with Vicinally Functionalized Reagents and Studies of the Reductive Behavior of the Ring System

Article abstract of DOI:10.1021/jo00343a014

New syntheses of pyrimido<4,5-c>pyridazines from 6-hydrazinoisocytosines and vicinal carbonyl reagents and reduction studies with selected members of this compound series are reported.Structural features required for pyrimidopyridazine formation from reactions of 2-amino-4-hydrazinopyrimidines with vicinal difunctional reagents and selectivity with respect to product substituent orientations are summarized.