Hmmm,
steam hammers to crack walnuts comes to mind
RTF is a particular file format with data embedded in formatting codes certain other applications will understand. PDF is another file format using other formatting codes, and there is no easy translation of which I am aware.
Conceptually you could hand craft something to surgically excise and interpret the RTF codes and reinsert PDF codes back into the data stream, but this is neither easy nor necessarily an easy task.
There are multiple helper applications about that will take a Word document and produce a PDF file, including the early versions of MS Office 2007. Since Word recognises and handles RTF files as if they were native word files, this is the path I would take.
If you use a SAS session to create an RTF file, then it seems to me it might be easier to create a PDF file at the same time by also opening a PDF destination in ODS.
Kind regards
David