One-Step Synthesis of Polysubstituted Pyrimidines

Significance

The direct condensation of cyanic acid derivatives with N-vinyl or -aryl amides affording the corresponding densely substituted pyrimi­dines is described. A plausible mechanism is ­proposed as shown, without evidence but is ­precedented, in part, by a proposal for iminium ­triflate to ester hydrolysis (A. B. Charette, P. Chua Tetrahedron Lett. 1998, 39, 245). The substrate scope was well studied and the yields range from mediocre to excellent. Refreshingly, it is stated that the yields are an average of two experiments.