SYNTHESIS AND REACTIONS OF SOME NEW 5-CARBONYL(4-AMINO-3-CYANO-2-SUBSTITUTED THIOPHENE-5-YL)-8-HYDROXY QUINOLINE AS POSSIBLE ANTIMICROBIAL AGENTS (PART I)

Abstract

Abstract S-Alkylation of 5-carbonyl-(4-amino-3-cyanothiophene-2-thio-5-yl)-8-hydroxyquinoline (4) with several halogen- containing compounds afforded the alkylthio derivatives (5a-f). Treatment of 4 with chloramine gave isothiazolothiophene (7), which was allowed to react with diethylmalonate and/or ethylacetoacetate to give the corresponding pyrimidinoisothiazolothiophenes (8) and (9). Ring closure of 5d-f with ethanolic sodium ethoxide gave thieno[2,3-b]thiophene derivatives (6a-c). Acetic anhydride, ammonium acetate, phenylisothiocyanate, nitrous acid, acetylacetone, phosphorus oxychloride, phosphorus pentachloride, hydrazine hydrate and benzoyl chloride gave further cyclization to construct an additional ring. The structure of the compounds has been established by elemental analysis, IR, NMR and mass spectra. The compounds thus synthesized were screened for their antimicrobial activity.