G. Heinisch et al., PYRIDAZINES .78. ON THE REACTIVITY OF 4-METHOXY-[(4-PYRIDAZINYL)METHYLIDENE]ANILINE IN ESTER ENOLATE-IMINE CONDENSATION-REACTIONS, Journal of heterocyclic chemistry, 33(6), 1996, pp. 1731-1735
Reactions of the pyridazine derived aldimine 1 with lithium enolates o
f various a-substituted acetates were investigated. An unprecedented f
ormation of the pyrido[3,4-d]pyridazine system due to nucleophilic att
ack of a carbanion species at the beta-position of the pyridazine ring
was observed.