Pyridazine derivatives and related compounds. Part 13: Synthesis and antimicrobial activity of some pyridazino [3′, 4′: 3, 4] pyrazolo [5, 1-c]-1, 2, 4-triazines
A general method for the preparation of substituted pyridazinopyrazolotriazines is reported. 3-Aminopyrazolo [3, 4-d] pyridazine was diazotized and coupled with active methylene reagents to afford the tricyclic pyridazino [3′, 4′: 3, 4] pyrazolo [5, 1-c]-1, 2, 4-triazines with substituents such as methyl, phenyl, ethoxycarbonyl, acetyl or benzoyl, depending on the methylene reagent used. In addition several condensation reactions with hydrazines gave ...