Provided herein are compounds, compositions, and methods for the treatment of viral infections, for example, Flaviviridae infections, including HCV infections. In certain embodiments, compounds and compositions of nucleoside derivatives are disclosed, which can be administered either alone or in combination with other anti-viral agents. In certain embodiments, the compounds are D-amino acid phosphoramidate halogeno pyrimidine nucleoside analog compounds which display remarkable efficacy and bioavailability for the treatment of, for example, HCV infection in a human. In certain embodiments, the compounds are of Formula I: or a pharmaceutically acceptable salt, solvate, stereoisomeric form, tautomeric form, or polymorphic form thereof, wherein: PD, X, R1, R2, RA, and RB are as described herein.
