Process for the preparation of ribonucleotide reductase inhibitors

摘要

The present invention is directed toward a novel process of preparing 2'-exocyclic vinylfluoride derivatives of cytidine analogues for use as ribonucleotide reductase inhibitors. The novel process of the present invention utilizes a cytidine derivative as the required starting material and provides the ribonucleotide reductase inhibitor in a more efficient than the reaction sequence. The process is more efficient than the process disclosed by McCarthy et al. in European Patent Application Publication No. 0 372 268 published Jun. 13, 1990, in that it requires fewer chromatographies and results in an overall yield of greater than 25% for the five steps. The present invention further provides the ribonucleotide reductase inhibitor in a four step reaction sequence and results in an overall yield of greater than 35%.