Aromatic heterocyclic compounds with five- and six-membered rings containing heteroatoms such as sulfur (S), oxygen (O), and nitrogen (N) have been widely studied due to their promising pharmacological potential. These compounds are essential for life, and the heteroatoms in the ring structures enhance interactions with amino acids, improving properties such as lipophilicity, solubility, and absorption. These attributes play a key role in reducing transactivation, which in turn boosts the therapeutic activity of these molecules. Among these heterocyclic compounds, derivatives of 1,3,4-thiadiazole, benzimidazole, quinazoline, and pyrimidine have shown a wide range of biological effects, including anticancer, antimicrobial, anti-inflammatory, antidepressant, antioxidant, antifungal, and antibacterial activities, as well as inhibiting carbonic anhydrase and exhibiting anticonvulsant properties. These compounds are crucial in the discovery of new drugs. This review highlights FDA-approved heterocyclic compounds and their contributions to the development of new therapeutic agents. The review specifically examines synthetic derivatives of thiadiazole, benzimidazole, quinazoline, and pyrimidine, emphasizing their remarkable anticancer effects on multiple cancer cell lines.
