Curran, K.J., Verheijen, J.C., Kaplan, J., Richard, D.J., Toral-Barza, L., Hollander, I., Lucas, J., Ayral-Kaloustian, S., Yu, K. and Zask, A. (2010) Pyrazolopyrimidines as Highly Potent and Selective, ATP-Competitive Inhibitors of the Mammalian Target of Rapamycin (mTOR): Optimization of the 1-Substituent. Bioorganic & Medicinal Chemistry Letters, 20, 1440-1444.
https://doi.org/10.1016/j.bmcl.2009.12.086

has been cited by the following article:

• TITLE: Synthesis, Characterization and In Vitro Antitumor Evaluation of New Pyrazolo[3,4-d]Pyrimidine Derivatives

  AUTHORS: Ahmed M. El-Morsy, Mohamed S. El-Sayed, Hamada S. Abulkhair

  KEYWORDS: Pyrazolo[3, 4-d]Pyrimidine, Antitumor, Human Breast Adenocarcinoma Cell Line MCF7

  JOURNAL NAME: Open Journal of Medicinal Chemistry, Vol.7 No.1, March 31, 2017

  ABSTRACT: A new series of 3-(methylthio)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine derivatives was synthesized. The structures of the new derivatives were confirmed by the spectral data and elemental analyses. The antitumor activity of this series against human breast adenocarcinoma cell line MCF7 was evaluated. Out of twenty new derivatives, ten were revealed mild to moderate activity compared with doxorubicin as a reference antitumor. Among this new series N-(2-chlorophenyl)-2-(3-(methylthio)-4-oxo-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-5(4H)-yl)acetamide (13a) was found the most active one with IC50 equal to 23 μM.