- Design, synthesis, and biological activities of classical N-[4-[2-(2-amino-4-ethylpyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoyl]-l-glutamic acid and its 6-methyl derivative as potential dual inhibitors of thymidylate synthase and dihydrofolate reductase and as potential antitumor agents. Gangjee, A., Yu, J., Kisliuk, R.L., Haile, W.H., Sobrero, G., McGuire, J.J. J. Med. Chem. (2003)