In this study, eight naphthoquinone derivatives were synthesized in yields ranging from 52 to 96% using easy, fast, and low‐cost methodologies. All naphthoquinone derivatives were screened for their in vitro anti‐proliferative activities against OVCA A2780 cancer cell lines. Amongst all analysed compounds, derivatives 3–5 presented the most prominent cytotoxic potential. Naphthoquinones 3 and 4, bearing sulfur‐containing groups, were identified as having high potential for ROS production, in particular the superoxide anion. Furthermore, 3 and 4 compounds caused a decrease in the cell population in G0/G1 and induced more than 90% of the cell population to apoptosis. Compound 5 did not act in any of these processes. Finally, compounds 3–5 were tested for their inhibitory ability against PI3K and MAPK. Compounds 3 and 4 do not inhibit the PI3K enzyme. On the other hand, the naphthoquinone‐polyphenol 5 was only able to inhibit the percentage of cells expressing pERK.