Several derivatives containing dihydronaphtho, naphtho[2,1-b]thiophene and thieno[2,3-d]pyrimidine ring systems were prepared starting from 2-amino-4,5-dihydronaphtho[2,1-b]thiophene-1-carbonitrile (1). Structure characterization of the thioxo derivative 7 was also performed and its reaction with some chloro and bromoalkyl reagents was studied. Moreover, the prepared products were tested for antiviral activity against H5N1 virus [A/chicken/Egypt/1/2006 (H5N1)] by determination of both EC50 and LD50 and confirmed by plaque reduction assay on MDCK cells. Compounds 5, 7 and 8 showed the highest effect compared with the other tested compounds.