X-Ray Structure Determination and NMR Characterization of Some Fused Heterocycles with a 1,3,5-Triazine-2,4(1H,3H)-dione Ring. Reaction of 2-Amino-4(3H)-pyrimidinone with Chloroformyl Isocyanate

The reaction product a of 2-amino-4(3H)-pyrimidinone with chloroformyl isocyanate was methylated and the two resulting products were determined as 4(for the major product) and 5(for the minor one) by X-ray crystal structure analyses. In a DMSO solution of a, the 2atautomer was shown to be predominant by 13C NMR analysis.