Synthesis,Antimicrobial, and Anticancer Activities of a New Series of Thieno[2,3‐d] Pyrimidine Derivatives

A new series from thieno[2,3‐d] pyrimidine derivatives have been synthesized based on 2‐(ethylmercapto)‐4‐mercapto‐6‐phenyl‐5‐pyrimidine carbonitrile, these compounds used in the synthesis of many pyrimidothienopyrimidine derivatives and triazolo[1″,5″:1″,6″]pyrimido[4′,5′:4,5]thieno[2,3‐d] pyrimidine derivatives. The chemical composition of these compounds was confirmed by ¹H NMR, ¹³C NMR, and MS techniques. Some of the synthesized compounds were screened for their antimicrobial and anticancer agent. Compound ( 9b ) showed strong effect on Aspergillus Fumigatus (RCMB 2568), Candida albicans (RCMB 05036), Saphylococcus aureus (RCMB 010010), Bacillis subtilis (RCMB 010067), Salmonella sp. (RCMB 010043), and Escherichia coli (RCMB 010052). Compounds ( 2 ) and ( 5a – k ) were evaluated for their IC₅₀ values against two cancer cell lines (MCF‐7 and HeLa cells) in the presence of Paclitaxel as reference material. Compound ( 5g ) showed the highest cytotoxicity against MCF‐7 (IC₅₀ values about 18.87 ± 0.2 μg/mL) cells compared with Paclitaxel (IC₅₀ values about 40.37 ± 1.7 μg/mL). Also, compound ( 5d ) showed the highest cytotoxicity against HeLa (IC₅₀ values about 40.74 ± 1.7 μg/mL) cells compared with Paclitaxel (IC₅₀ values about 45.78 ± 0.8 μg/mL).