Pyridazine Derivatives and Related Compounds Part 5. Pyrazolo[3,4-c]pyridazine: Synthesis and Some Reactions

Abstract

This paper describes the synthesis of three pyrimido[1',2':1,5]-pyrazolo[3,4-c]pyridazines (6,7 and 9) starting from 3-amino[3,4-c]pyridazine (1). Pyrimido[5',4':5,6]pyrimido[1',2':1,5]pyrazolo[3,4-c]pyridazine derivative (8) was obtained by condensing 7a with formamide. Reactions of 1 with acetic anhydride, benzoyl chloride, phenacyl bromide and 4-chlorophenacyl bromide gave 3-substituted amino derivatives