Synthesis and Antibacterial Activity of some New Thieno[2,3-C] Pyridazines and Related Heterocycles

Abstract

 4-Cyano-6-phenylpyridazine-3(2H)-thione 4 was  obtained by the  reaction   of   3-chloro-4 cyano-6-phenylpyridazine   3  with thiourea   in   ethanol    under  reflux. Cycloalkylation of   compound   4   with   ethyl chloroacetate  in    the   presence     of    sodium ethoxide  afforded  the novel   thieno[2,3-c]pyridazine  derivative 6.    Hydrazinolysis of    compound   6 yielded  the   corresponding carbohydrazide 9 which on treatment  with  acetylacetone   and  ethyl acetoacetate  gave the  novel  thieno [2,3-c]pyridazines  10  and 11.  The structures   of these   new  compounds were confirmed by elementary analyses and spectral data. The antibacterial activities of the  new  compounds   were   also  evaluated.