Synthesis of novel thieno[2,3-c]pyridazines and related heterocycles

The reaction of ethyl 2,3-dihydro-5,6-diphenyl-3-thioxopyridazine-4-carboxy late with omega-bromoacetophenones, chloro-N-arylacetamides, chloroacetonit rile, ethyl chloroacetate, or chloro-acetone furnished the corresponding 4, 5-diphenyl-3-hydroxy thieno [2,3-c]pyridazines. 2-Cyano-, 2-ethoxycabonyl-, and 2-acetyl-4,5-diphenyl-3-hydroxythieno[2,3-c]pyridazines were employed as precursors in the synthesis of some novel furo [2',3':4,5]thieno[2,3-c]p yridazines, pyrano-[2',3' :4,5]thieno[2,3-c]pyridazines, and thieno[2,3-c]p yridazines. The antibacterial and antifungal activities of some of the comp ounds are reported.