Synthesis of Some New Pyrimidine and Pyrimido[4,5-d]pyrimidine Derivatives

A convenient synthesis of a series of pyrimidine carbonitrile, thiopyrimidine, and pyrimidopyrimidine derivatives, via the reactions of the versatile, readily accessible 6-aryl-4-oxo-2-thioxo-hexahydro-pyrimidine-5-carbonitrile with the appropriate reagents, is described.