This thesis investigates the synthesis of new fluorouracil prodrugs and new prodrug photosensitiser systems for medicinal applications including the design and preparation and attempted preparation of a novel patial cone calixarene porphyrin. The preparation of a new redox activated prodrug of fluorouracil is described. The biological activity of the new prodrugs was investigated against nitroreductase transfected cells (V79-NTR) and they were successfully activated to fluorouracil as determined by LC-MS. Two non-redox activated prodrugs of fluorouracil were also prepared and these gave activities of 15 and 20 µM against colon cancer cell lines . An attempt was made to prepare a series of porphyrazines that could be used as both PDT agents and carriers for the ‘dark’ therapeutic nitrous oxide. Unfortunately, purification of these new compounds proved unsuccessful and they were not further developed. Chapter three outlines the proposed design and synthesis of a new and novel thermally stable partial-cone calix[4]arene porphyrin. The strategy required the selective synthesis of a partial cone O-arylcalixarene nitrile, which was then to be converted to the aldehyde by reduction. The nitrile derivative was successfully prepared by both thermal and microwave conditions, however, the reduction of the nitrile to the aldehyde proved to be problematic. However, it was discovered that only lithium based reducing agents could reduce the nitrile, albeit in low yields. It was discovered that the reduction of the nitrile was stericly hindered due to the presence of calyx[4]arene t-butyl groups in the upper rim. As a consequence of the low yields of the reduction reaction, the condensation of the aldehyde to the target porphyrin could not be achieved.