N-Boc-4-oxo-L-proline was used as a reactant in the synthesis of benzidine and diaminofluorene prolinamide derivatives which are highly potent inhibitors of hepatitis C virus. Also used in the preparation of heterodimeric antagonists which diplay potent antiproliferative activities and have potential for further investigation. Molecular Formula: C10H15NO5 Molecular Weight: 229.23