Phthalazine as a medically versatile polyheterocyclic core with underexplored anticancer potential

Phthalazine derivatives are nitrogen-containing heterocyclic compounds that have gained considerable attention in medicinal chemistry due to their pharmacological potential. This review briefly outlines the biological properties and clinical application of five- and six-membered heterocycles. The main focus is placed on the recent advances in the development and biological evaluation of the phthalazine derivatives. A particular emphasis is put on their PARP and VEGFR inhibitory activity, which has been investigated in clinical trials for cancer treatment, ultimately leading to the market launch of some of these compounds. Furthermore, the recent studies on numerous phthalazine derivatives that demonstrate promising anticancer activity in vitro are presented. Finally, this review combines the previously developed synthesis strategies and possible improvements that could be implemented in the future with clinically oriented summary focused on the application of these compounds in oncology, thereby complementing current literature.