Because of its biological stability, hybridization and duplex invading properties, peptide nucleic acid (PNA) has been used for the construction of a variety of bioconjugates with novel biological and biotechnological applications.  Many bioconjugates of PNA have been made by conjugating molecules to the ends of PNA, but there are a number of applications that could benefit from the attachment to internal positions of the PNA.  We will describe a facile synthesis of an orthogonally protected PNA building block for solid phase Fmoc synthesis that can be used to attach groups to the C5 of U via an amino group.  The building block can be conveniently prepared from hydroxymethyl uracil in 6 steps.  We will also report on the synthesis of other derivatives of U.