Design, Synthesis, and Antitumor Evaluation of Novel Pyrazolo[3,4-d]pyrimidine Derivatives

Abstract
A new series of pyrazolo[3,4-d]pyrimidines has been synthesized. The new compounds were tested for their antitumor activity on 60 different cell lines, and some of the compounds were found to have potent antitumor activity. In particular, 2-hydroxybenzaldehyde [1-(4-chlorophenyl)-3-methyl-1H-pyrazolo-[3,4-d]pyrimidin-4-yl]hydrazone (VIIa) was found to be the most effective among the other derivatives, showing IC50 values of 0.326 to 4.31 μM on 57 different cell lines.