Formation of N–S Bonds in Reactions of 2-[2-Oxo-1-(tosyloxyimino)-2-phenylethyl]pyrimidin-4(3 H )-one and Its 6-derivatives with Thiourea and Potassium Thiocyanate

Reaction of potassium thiocyanate with 2-[2-oxo-1-(1-tosyloxyimino)-2-phenylethyl]pyrimidin-4-(3H)-one derivatives led to the formation of a new fused heterocyclic system with a common nitrogen atom, substituted 7H-[1,2,5]thiadiazolo[2,3-a]pyrimidin-7-one.