On the basis of high-throughput screening, fragment-based drug discovery, structure-activity relationships and building block analysis methods, herein we report the synthesis and biological evaluation of a novel series of diethyl 2,5-diaminothiophene-3,4-dicarboxylate derivatives. All of the prepared Schiff bases (with mono-, di-and poly-substituents at the aromatic portion), mono-and bis-amides of diethyl 2,5diaminothiophene- 3,4-dicarboxylate, were evaluated against various human cancer and non-cancerous (only for active compounds) cell lines, as well as influenza A (subtypes FM/1/47/H1N1, hanfang/359/95/ H3N2) and B (subtype jifang/13/97) viruses. The obtained results suggest that some selected compounds revealed promising antitumor and antiviral activities and may serve as lead compounds for further drug discovery and development.