Synthesis and biological activity of some novel thieno[2,3-b]quinoline, quinolino[3',2':4,5] thieno[3,2-d]pyrimidine and pyrido[2',3':4,5] thieno[2,3-b]quinoline derivatives

Thieno [2,3-b] quinoline derivative 5 was synthesized by the cycloalkylation of compound bi 3a with chloro acetonitrile. Interaction of compound 5 with formic acid, formamide, and thioacetamide furnished the corresponding quinolino[3',2':4,5]thieno[3,2-d]pyrimidine derivatives 7, 8, and 9, respectively. Also, quinolinothienopyrimidine 11 was obtained in good yield by cyclization of compound 5 with phenyl isothiocyanate under reflux in pyridine. Triethyl orthoformate reacted with compound 5 to form the ethoxymethylene derivative 12. Refluxing of 5 with acetic anhydride for a short time afforded acetamide derivative 16, whereas when refluxed for a long time furnished the diacetyl derivative 17. Fusion of compound 5 with urea and thiourea yielded the corresponding quinolinothienopyrimidines 19 and 20, respectively. When compound 5 was reacted with urea in the presence of sodium ethoxide, the corresponding ureado derivative 18 was obtained.