Reactions With 2-Methylthiopyrimidines Synthesis of Some New Fused Pyrimidines

4-Chloro-2-methylthio-6-phenylpyrimidine-5-carbonitrile (II) reacts with hydrazine hydrate to yield the 2,4-dihydrazino derivative (IIId). Compound IIId reacts with nitrous acid to give ditetrazolo[1,5-a:1′,5′-c]pyrimidine (VI) and with carbon disulphide to form pyrazolo[3,4-d]-s-triazolo[3,4-b]pyrimidine (VII). The reaction of II with phenylhydrazine affords directly the pyrazolo[4,3-d]-pyrimidine derivative (IV). Also, compound II reacts with anthranilic acid to form 2-methylthio-4-phenyl-6-(o-carboxyphenylamino)pyrimidine-5-carbonitrile (IIIe) which can be cyclised into 1-methylthio-10-oxo-3-phenyl-10-pyrimido[6,1-b]quinazoline-4-carbonitrile (IX) by heating with acetic anhydride.