1. 1. J. Beres, W. G. Bentrude, G. Kruppa, P. A. McKernan, and R. K. Robins. Synthesis and antitumor and antiviral activities of a series of 1-beta-D-ribofuranosyl-5-halocytosine (5-halocytidine) cyclic 3?,5?-monophosphates. J. Med. Chem. 28:418?422 (1985).
2. 2. N. W. Bischofberger, R. J. Jones, M. N. Arimilli, K. Y. Lin, M. S. Louie, L. R. McGee, E. J. Prisbe, W. A. Lee, and K. C. Cundy. Preparation of viricidal nucleotide analogs. PCT Int. Appl. 154 pp. (1995).
3. 3. P. D. Cook, G. Wang, T. W. Bruice, V. Rajappan, K. Sakthivel, K. D. Tucker, J. L. Brooks, J. M. Leeds, M. E. Ariza, and P. C. Fagan. Preparation of nucleotide 5?-monophosphate mimics and their prodrugs useful as antiviral, antibacterial, anticancer, and immunomodulatory agents. PCT Int. Appl. 75 pp. (2003).
4. 4. S. Warren. Targetable nucleotide-based prodrugs with cleavable ester linkages. PCT Int. Appl. 137 pp. (1999).
5. 5. K. C. Lieberman and C. Heidelberger. The metabolism of 32P-labeled ribonucleotides in tissue slices and cell suspensions. J. Biol. Chem. 316:823?830 (1955).