Antimetabolites: A First Synthesis of a New Class of Cytosine Thioglycoside Analogs.

A first synthesis of a new class of novel cytosine thioglycoside analogs from readily available starting materials has been described. The key step of this protocol is the formation of sodium pyrimidine-4-thiolate via condensation of N'-arylidene-2-cyanoacetohydrazides with sodium cyanocarbonimidodithioate salt, followed by coupling with halo sugars to give the corresponding cytosine thioglycoside analogs. Ammonolysis of the latter compounds afforded the free thioglycosides.