X-Ray Structure Determination and NMR Characterization of Some Fused Heterocycles with a 1,3,5-Triazine-2,4(1<i>H</i>,3<i>H</i>)-dione Ring. Reaction of 2-Amino-4(3<i>H</i>)-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 2a tautomer was shown to be predominant by 13C NMR analysis.