Synthesis of new s-triazolo[4,3-b]pyridazines

Abstract

The 2,3-dihydropyridazin-3-ones 9 were synthesized via functionalized pyruvic acids 7 with hydrazine hydrate. Transformation of 9 to s-triazolo[4,3-b]pyridazines 10a-c and 11a-c has been achieved through the 3-chloropyridazines 4 by treatment with semicarbazide and phenylacetylhydrazine, respectively. © 1989.