Studies with Condensed Aminothiophenes: Microwave Assisted Cycloaddition Reactions of Thieno[3,4-d]pyridazinone and Thieno[3,4-c]quinolinone

Abstract

The arylformazane (2) was produced via coupling the α-oxoarylhydrazones (1) with aromatic diazonium salts. These formazane condensed readily with ethyl cyanoacetate to yield arylazopyridazinones (4) that reacted with sulphur in the presence of piperidine to yield the aminoazothienopyridazinone (5), the latter was reacted with electron poor olefins and acetylenes to yield aminoazophthalazines (8). Compound (8) was reacted with dimethylformamide dimethylacetal to yield amidine (9). Similarly aminothienoquinolinone (17) was reacted with electron poor olefins and acetylenes to yield aminophthalazines (20, 22a,b).